Abstract: OBJECTIVE: To clarify the pathogenesis of diabetes associated with mutations of the hemochromatosis (HFE) gene, 17 carriers, 9 normal glucose tolerant (NGT) and 8 diabetic, were evaluated in an interventional trial. RESEARCH DESIGN AND METHODS: At enrollment and after a 2-year bloodletting period, euglycemic-hyperinsulinemic clamp, oral glucose tolerance test (OGTT), liver histology (nonalcoholic fatty liver disease activity score [NAS]), and liver iron content (LIC) were assessed. RESULTS: NGT subjects had significantly higher baseline insulin sensitivity (P <or= 0.001), secretion, and insulinogenic index (calculated from the OGTT) (P <or= 0.0001 for both) and lower LIC (P = 0.004) and NAS (P = 0.02) than diabetic patients. Baseline LIC correlated negatively with insulin secretion (NGT r(0) = -0.676, P <or= 0.0001; diabetes r(0) = -0.589, P = 0.02) and insulin sensitivity (M value) (NGT r(0) = -0.597, P = 0.009; diabetes r(0) = -0.535, P = 0.03) and positively with NAS (diabetes r(0) = 0.649, P = 0.007) and triglycerides (NGT r(0) = 0.563, P = 0.015). At month 24, circulating iron was reduced by 179 +/- 26% in NGT and 284 +/- 54% in diabetic subjects. Insulin secretion (NGT 20 +/- 4%; diabetes 33 +/- 7%) and insulin sensitivity (NGT 25 +/- 5%; diabetes 18 +/- 3%) increased. LIC decreased in both groups (NGT 126 +/- 42%; diabetes 61 +/- 13%), and NAS ameliorated (NGT 65.1 +/- 6.5 vs. 38.1 +/- 6.83; P <or= 0.0001; diabetes 2.1 +/- 10.7 vs. 69.9 +/- 10; P <or= 0.0001). CONCLUSIONS: Iron depletion ameliorates insulin secretion and sensitivity in NGT and diabetic carriers of HFE gene mutations. This amelioration occurs in parallel with decreased LIC and improved NAS. These results justify glucose tolerance testing and prophylactic iron depletion in asymptomatic carriers as well.

Abstract: Recent evidence has disclosed previously unrecognized links among insulin resistance, obesity, circulating immune markers, immunogenetic susceptibility, macrophage function and chronic infection. Genetic variations leading to altered production or function of circulating innate immune proteins, cellular pattern-recognition receptors and inflammatory cytokines have been linked with insulin resistance, type 2 diabetes, obesity and atherosclerosis. Cellular innate immune associations with obesity and insulin resistance include increased white blood cell count and adipose tissue macrophage numbers. The innate immune response is modulated possibly by both predisposition (genetic or fetal programming), perhaps owing to evolutionary pressures caused by acute infections at the population level (pandemics), and chronic low exposure to environmental products or infectious agents. The common characteristics shared among innate immunity activation, obesity and insulin resistance are summarized.

Abstract: OBJECTIVES: Alpha-defensins are natural antibiotics made by neutrophils that have been reported to modulate cholesterol metabolism and vascular function; however, their role in vivo remains largely unknown. We hypothesized that alpha-defensins 1 to 3 (DEFA1-3) are associated with serum lipids and vascular reactivity in humans. METHODS AND RESULTS: One hundred thirteen apparently-healthy White men, participants in a prospective study of cardiovascular risk factors, were assessed for a lipid profile, insulin sensitivity (S(I), frequently-sampled intravenous glucose tolerance test), and non-stressed circulating DEFA1-3 (ELISA). In a subset of 52 subjects, vascular reactivity (high-resolution ultrasound of the brachial artery) was also assessed. Subjects in the highest quartile for plasma DEFA1-3 were found to be leaner and more insulin sensitive, and to have significantly reduced total and LDL-cholesterol, compared with subjects in the lowest quartile for circulating DEFA1-3 (P<0.0001 to P=0.002 for linear trend ANOVA). The associations with serum lipids persisted after adjustment for age, body mass index, insulin sensitivity, and smoking (which was associated with reduced plasma DEFA1-3 concentrations). Finally, endothelium-independent vasodilation increased with increasing circulating DEFA1-3 (P=0.003) and this association was not explained by age, body mass index, serum cholesterol, insulin sensitivity, or smoking. CONCLUSIONS: Circulating DEFA1-3 are associated with serum cholesterol and vascular reactivity in humans. Alpha-defensins may have clinical implications in patients with either hypercholesterolemia or vascular dysfunction.

Abstract: Tumor necrosis factor-alpha and insulin resistance play central roles in the pathogenesis of abnormal hepatocellular function. We evaluate the relationship between a novel serum DS-TNFR2 (an alternatively spliced soluble TNF-alpha receptor 2) isoform and parameters of liver health. Serum ALT, AST and GGT, insulin resistance, adiponectin and DS-TNFR2 isoform concentrations were measured in 492 subjects from two different Caucasian Spanish populations. We found a significant negative association between serum ALT and DS-TNFR2 levels in both populations (r=-0.269; p=0.002 and r=-0.152; p=0.01, respectively). DS-TNFR2 levels also correlated negatively with serum AST (r=-0.142; p=0.042) and GGT (r=-0.206; p=0.003) in population 1 and with AST (r=-0.127; p=0.038) in population 2. In multiple regression analysis models, serum DS-TNFR2 was shown to be an independent modulator of serum ALT activity after adjusting for sex, age, BMI, HOMA and adiponectin in both populations. These results suggest potential anti-inflammatory properties of this TNF-alpha receptor 2 isoform at the hepatic level.

Abstract: OBJECTIVE: Visfatin is a novel adipokine that is predominantly secreted by visceral adipose tissue. Accumulation of visceral adipose tissue is also associated with iron metabolism. Despite the coincidence of visfatin expression in iron-rich tissues, no study has investigated the possible interaction of visfatin with parameters of iron metabolism. RESEARCH DESIGN AND METHODS: We evaluated insulin sensitivity and parameters of iron metabolism in 95 men with normal glucose tolerance (NGT) and 43 men with altered glucose tolerance. RESULTS: Men with newly diagnosed type 2 diabetes had significantly increased serum visfatin in parallel with increased serum prohepcidin and serum ferritin compared with the other groups. In all subjects as a whole, circulating visfatin was not found to be significantly linked to insulin sensitivity (r = 0.07, P = 0.4) but was significantly associated with serum prohepcidin concentration (r = 0.40, P < 0.0001). Obesity status and glucose tolerance status influenced the relationships among visfatin, insulin sensitivity, and parameters of iron metabolism. Among men with altered glucose tolerance, serum visfatin was strongly associated with serum prohepcidin (r = 0.61, P < 0.0001) and serum soluble transferrin receptor (sTfR) (r = -0.51, P < 0.0001). In nonobese subjects, sTfR (P = 0.02) and prohepcidin (P = 0.04) contributed independently to visfatin variance after controlling for age and BMI. When insulin sensitivity was added to the model, only the latter (P = 0.006) contributed to 17% of visfatin variance. In obese men, however, only sTfR (P = 0.04) contributed independently to visfatin variance in this latter model. CONCLUSIONS: Serum visfatin concentration is significantly associated with parameters of iron metabolism, especially in subjects with altered glucose tolerance.

Abstract: Insulin resistance and erythrocyte sedimentation rate (ESR, a non-specific marker of inflammation) are known risk factors for cardiovascular disease. Although obesity is associated with increased ESR, it is unclear whether insulin resistance is associated with ESR in humans. The relationship between insulin resistance and ESR was studied in a cross-sectional, health-area based study of 140 (89 men and 51 women) apparently healthy Caucasians subjects. ESR, additional inflammatory markers [soluble tumor necrosis alpha receptors 1 and 2 (sTNFR1 and sTNFR2); C-reactive protein (CRP)], and insulin sensitivity (SI, frequently sampled intravenous glucose tolerance test with minimal model analysis) were assessed in all subjects. An interaction with sex was documented in the relationship between ESR and both insulin resistance and obesity (p < 0.05), as log ESR correlated with log SI in men (r=-0.29, p=0.009), but not in women (r=-0.14, p=0.33), and correlated with body mass index (BMI) in women (r=0.49, p=<0.0001), but not in men (r=0.15, p=0.16). On multivariate analyses, these associations proved to be independent of known covariates, such as age, hematocrit, smoking and additional inflammatory markers in both men and women. In a replication study, variables independently associated with ESR were also insulin resistance (homeostasis model assessment) in men and obesity markers (either BMI or fat mass) in women. In conclusion, ESR is independently associated with either insulin resistance or obesity in a sex-specific manner. These findings contribute to explain the known relationship of this inflammatory marker with cardiovascular disease.

Abstract: OBJECTIVE: Our aim was to study the effect of exposure to four infections on fat mass. RESEARCH METHODS AND PROCEDURES: This was a cross-sectional study of healthy middle-aged men from the general population (n = 74). Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)-1, HSV-2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme-linked immunosorbent assays (ELISAs). A total pathogen burden score based on these seropositivities [Quantitative Seropositivity Index (QSI)] was constructed. Fat mass was measured by bioelectrical impedance. RESULTS: We observed significant relationships between the HSV-1 titer and fat mass and percentage fat mass. The associations were stronger when considering the infection burden. The QSI was significantly associated with fat mass (r = 0.30, p = 0.009) and percentage fat mass (r = 0.27, p = 0.01). Those subjects in the highest tertile of fat mass showed significantly higher QSI (259.5 +/- 74.1 vs. 206.9 +/- 78.2, p = 0.007). In subjects that were seropositive for Enteroviruses, the relationship between the QSI and fat mass was strengthened (r = 0.51, p = 0.02). In a multivariate regression analysis, the QSI, independently of age and C-reactive protein, contributed to 9% of fat mass variance. DISCUSSION: Pathogen burden showed an association with fat mass. Subjects with increased fat mass could be more susceptible to developing multiple infections resulting in a chronic low-grade inflammation. We can not exclude the possibility that exposure to multiple infections leads to increased fat mass.

Abstract: BACKGROUND: Lactoferrin, an innate immune protein with antiinflammatory properties, shows considerable antiatherosclerosis activity in animal studies. We investigated the relationship between circulating lactoferrin, lactoferrin gene (LTF, lactotransferrin) polymorphisms, dyslipidemia, and vascular reactivity in the context of glucose-tolerance status in men. METHODS: We evaluated 2 nonsynonymous LTF polymorphisms (rs1126477 and rs1126478) and measured circulating lactoferrin concentrations by ELISA under nonstressed conditions in healthy Caucasian men (n = 188) and male patients with an altered glucose tolerance (n = 202). We also studied the association of lactoferrin concentration with vascular reactivity via high-resolution ultrasound analysis of the brachial artery in a subsample of study participants. RESULTS: Circulating lactoferrin concentration was inversely associated with fasting triglyceride concentration (r = -0.24; P = 0.001), body mass index (BMI) (r = -0.20; P = 0.007), waist-to-hip ratio (r = -0.35; P <0.001), and fasting glucose concentration (r = -0.18; P = 0.01), and directly correlated with HDL cholesterol concentration (r = 0.21; P = 0.004). Control AG heterozygotes for rs1126477 had significantly decreased fasting triglyceride concentrations (P = 0.001). Similarly, control individuals who were G carriers for rs1126478 had significantly lower fasting triglyceride concentrations (P = 0.044) and significantly higher HDL cholesterol concentrations (P = 0.028) than AA homozygotes. These associations remained significant after controlling for age, BMI, waist-to-hip ratio, fasting glucose concentration, smoking status, and alcohol intake. Circulating lactoferrin concentration was not significantly associated with endothelium-dependent vasodilatation (EDVD) in the individuals studied (n = 95); however, lactoferrin was positively associated with EDVD in obese participants with an altered glucose tolerance (r = 0.54; P = 0.04). CONCLUSIONS: We have identified associations among LTF polymorphisms, circulating lactoferrin concentration, fasting triglyceride concentration, and vascular reactivity in humans.

Abstract: CONTEXT: Obesity may be regarded as a low-grade inflammatory state. OBJECTIVE: The aim of this study was to evaluate changes in pro-inflammatory adipocytokines and the innate immune system, cardiovascular risk, and insulin sensitivity after massive weight loss. DESIGN: This was a longitudinal study. Setting: The study was conducted at Catholic University, Rome. SUBJECTS AND METHODS: There were 10 normoglucose-tolerant obese women evaluated before and 36 months after bilio-pancreatic diversion (BPD). Glucose sensitivity (M value) was estimated using the euglycemic-hyperinsulinemic clamp. Mannan-binding lectin (MBL), bactericidal/permeability increasing protein (BPI), alpha-defensins, soluble CD14 receptor (sCD14), C-reactive protein, adiponectin, leptin, visfatin, IL-6, and TNF-alpha were assayed. RESULTS: After massive weight loss (53% of excess body weight), leptin (P <or= 0.0001), IL-6 (P <or= 0.0001), alpha-defensins (P <or= 0.001), and C-reactive protein (P <or= 0.0001) decreased significantly. Adiponectin increased significantly (P <or= 0.001). Of the nine subjects who lost more than 20% of body mass index, sCD14 (2.87 +/- 0.5 to 2.55 +/- 0.5; P = 0.016) and visfatin levels (12.20 +/- 0.93 to 10.63 +/- 1.93 ng/ml; P = 0.045) decreased significantly. No significant changes were observed in TNF-alpha, BPI, or MBL. Insulin sensitivity more than doubled after BPD (P <or= 0.0001). sCD14 changes were significantly associated with body mass index (r0 = 0.80; P = 0.003) and M changes (r0 = -0.59; P = 0.03). MBL correlated with insulin sensitivity in obese (r0 = 0.93; P = 0.0001) and post-BPD women (r(0) = 0.66; P = 0.038). Adiponectin correlated negatively with cardiovascular risk (r0 = -0.709; P = 0.02) and IL-6 (r0 = -0.634; P = 0.05). Multiple linear regression analysis showed that changes in sCD14 were also significantly related to changes in insulin sensitivity. CONCLUSIONS: Surgically induced weight loss is capable of reversing low-grade inflammation, at least partially. The relationships between sCD14, MBL, BPI, and glucose sensitivity, and the role of TNF-alpha in obesity warrant further investigation.

Abstract:

Abstract: Increased plasma concentrations of tumor necrosis factor alpha (TNFalpha) system components appear in type 2 diabetes patients with poor glycemic control. We have analyzed the expression of TNFalpha, TNFR1 and TNFR2 when monocytes and lymphocytes isolated from a group of recent onset type 2 diabetic patients, with fasting glucose levels below 7.0mM and glycated haemoglobin (Hb1Ac) in the normal range, were stimulated with high glucose or LPS endotoxin. We report, that cultured monocytes from these type 2 diabetic patients, in comparison to monocytes from non-diabetic individuals, had an enhanced response to LPS but did not respond to an acute glucose challenge (p<0.05). No differences were observed in the cultured lymphocyte fractions. These results indicate the existence of differences, elicited by LPS or high glucose related stimulus, between monocytes isolated from non-diabetic subjects or from type 2 diabetes patients.

Abstract: OBJECTIVE: The relationships between iron metabolism and type 2 diabetes are bidirectional: iron affects glucose metabolism and glucose metabolism impinges on several iron metabolic pathways. The mechanisms of these interactions depend on poorly known factors. We aimed to study the contribution of the serum soluble transferrin receptor (sTfR). RESEARCH DESIGN AND METHODS: Circulating sTfR was evaluated in 221 men (97 with normal glucose tolerance [NGT], 36 with impaired glucose tolerance, and 88 with type 2 diabetes). In a subset of these subjects, glucose tolerance (oral glucose tolerance test [OGTT]), minimal model-derived insulin sensitivity, and sTfR during the OGTT were also evaluated. RESULTS: Men with altered glucose tolerance showed significantly increased sTfR (9.4 +/- 4.4 vs. 8.2 +/- 2.6 microg/ml, P = 0.02) and higher serum ferritin than men with NGT. Serum sTfR was negatively associated with serum ferritin (r = -0.16, P = 0.02). sTfR correlated with several clinical and metabolic variables such as systolic blood pressure, glycated hemoglobin, and glucose and insulin values during OGTT. Insulin sensitivity was also negatively associated with sTfR in NGT and nonobese subjects. BMI (P = 0.01), serum ferritin (P = 0.025), and insulin sensitivity (P < 0.0001) contributed independently to 21% of sTfR variance. Serum sTfR concentration did not significantly change during the OGTT. CONCLUSIONS: Both insulin sensitivity and glucose tolerance status are significantly associated with serum sTfR concentrations, although insulin sensitivity predicts independently circulating sTfR, mainly in subjects with NGT. The implications of the interrelationships between iron and glucose metabolism should be investigated further.

Abstract: CONTEXT: Aquaporin-7 is required for efflux of glycerol from adipocytes and influences whole-body glucose homeostasis in animal studies. OBJECTIVE: Our objective was to test the hypothesis that AQP7 gene expression levels may be affected by presence of obesity and type 2 diabetes in humans. DESIGN: The obesity study cohort consisted of 12 lean, 22 nonseverely obese, and 13 severely obese subjects. The type 2 diabetes study cohort consisted of 17 lean and 39 obese type 2 diabetic patients. Circulating levels of plasma soluble proteins monocyte chemoattractant protein-1, TNF receptors 1 and 2, and IL-6 and glycerol were measured. The sc adipose tissue gene expression of AQP7, MCP-1, IL-6, TNFalpha, PPARgamma, and SREBP1c genes was measured by real-time PCR. AQP7 gene mutation analysis was performed. RESULTS: Severely obese women showed lower AQP7 expression levels compared with lean and nonseverely obese (P < 0.001). Moreover, circulating glycerol concentration was lower in severely obese subjects, but no correlation with AQP7 adipose tissue expression was observed. AQP7 expression was negatively related with proinflammatory genes (for monocyte chemoattractant protein-1, r = -0.203 and P = 0.044; for TNFalpha, r = -0.209 and P = 0.036). Concerning adipogenic factors, AQP7 expression levels were found to be positively determined by PPARgamma mRNA expression levels (r = 0.265; P = 0.012). AQP7 expression did not show differences regarding the presence of type 2 diabetes. CONCLUSION: Expression of AQP7 is down-regulated in women with severe obesity. The expression of this glycerol channel is not affected by type 2 diabetes.

Abstract: OBJECTIVE: Our goal was to test any association between human plasma circulating levels of monocyte chemoattractant protein-1 (cMCP-1) and insulin resistance and to compare monocyte chemoattractant protein-1 (MCP-1) adipose tissue gene expression and cMCP-1 in relation with inflammatory markers. RESEARCH METHODS AND PROCEDURES: cMCP-1 was measured in n = 116 consecutive control male subjects to whom an insulin sensitivity (S(i)) test was performed. Circulating levels of soluble CD14, soluble tumor necrosis factor receptor type 2 (sTNFR2), soluble interleukin-6 (sIL-6), and adiponectin also were measured. Subcutaneous adipose tissue samples were obtained from n = 107 non-diabetic and type 2 diabetic subjects with different degrees of obesity. Real-time polymerase chain reaction was used to measure gene expression of MCP-1, CD68, tumor necrosis factor-alpha (TNF-alpha), and its receptor TNFR2. RESULTS: In the S(i) study, no independent effect of cMCP-1 levels on insulin sensitivity was observed. In the expression study, in non-diabetic subjects, MCP-1 mRNA had a positive correlation with BMI (r = 0.407, p = 0.003), TNF-alpha mRNA (r = 0.419, p = 0.002), and TNFR2 mRNA (r = 0.410, p = 0.003). In these subjects, cMCP-1 was found to correlate with waist-to-hip ratio (r = 0.322, p = 0.048). In patients with type 2 diabetes, MCP-1 mRNA was up-regulated compared with non-diabetic subjects. TNF-alpha mRNA was found to independently contribute to MCP-1 mRNA expression. In this group, CD68 mRNA was found to correlate with BMI (r = 0.455, p = 0.001). DISCUSSION: cMCP-1 is not associated with insulin sensitivity in apparently healthy men. TNF-alpha is the inflammatory cytokine associated with MCP-1 expression in subcutaneous adipose tissue.

Abstract: An interdisciplinary panel of specialists met in Mallorca in the first European Symposium on Morbid Obesity entitled; "Morbid Obesity, an Interdisciplinary Approach". During the two and half days of the meeting, the participants discussed several aspects related to pathogenesis, evaluation, and treatment of morbid obesity. The expert panel included basic research scientists, dietitians and nutritionists, exercise physiologists, endocrinologists, psychiatrists, cardiologists, pneumonologists, anesthesiologists, and bariatric surgeons with expertise in the different weight loss surgeries. The symposium was sponsored by the Balearic Islands Health Department; however, this statement is an independent report of the panel and is not a policy statement of any of the sponsors or endorsers of the Symposium. The prevalence of morbid obesity, the most severe state of the disease, has become epidemic. The current recommendations for the therapy of the morbidly obese comes as a result of a National Institutes of Health (NIH) Consensus Conference held in 1991 and subsequently reviewed in 2004 by the American Society for Bariatric Surgery. This document reviews the work-up evaluation of the morbidly obese patient, the current status of the indications for bariatric surgery and which type of procedure should be recommended; it also brings up for discussion some important real-life clinical practice issues, which should be taken into consideration when evaluating and treating morbidly obese patients. Finally, it also goes through current scientific evidence supporting the potential effectiveness of medical therapy as treatment of patients with morbid obesity.

Abstract: OBJECTIVE: Obesity, insulin resistance, and weight loss have been associated with changes in hypothalamic-pituitary-adrenal (HPA) axis. So far, no conclusive data relating to this association are available. In this study, we aim to investigate the effects of massive weight loss on cortisol suppressibility, cortisol-binding globulin (CBG), and free cortisol index (FCI) in formerly obese women. RESEARCH DESIGN AND METHODS: Ten glucose-normotolerant, fertile, obese women (BMI >40 kg/m2, aged 38.66 +/- 13.35 years) were studied before and 2 years after biliopancreatic diversion (BPD) when stable weight was achieved and were compared with age-matched healthy volunteers. Cortisol suppression was evaluated by a 4-mg intravenous dexamethasone suppression test (DEX-ST). FCI was calculated as the cortisol-to-CBG ratio. Insulin sensitivity was measured by an euglycemic-hyperinsulinemic clamp, and insulin secretion was measured by a C-peptide deconvolution method. RESULTS: No difference was found in cortisol suppression after DEX-ST before or after weight loss. A decrease in ACTH was significantly greater in control subjects than in obese (P = 0.05) and postobese women (P < or = 0.01) as was the decrease in dehydroepiandrosterone (P < or = 0.05 and P < or = 0.01, respectively). CBG decreased from 51.50 +/- 12.76 to 34.33 +/- 7.24 mg/l (P < or = 0.01) following BPD. FCI increased from 11.15 +/- 2.85 to 18.16 +/- 6.82 (P < or = 0.05). Insulin secretion decreased (52.04 +/- 16.71 vs. 30.62 +/- 16.32 nmol/m(-2); P < or = 0.05), and insulin sensitivity increased by 163% (P < or = 0.0001). Serum CBG was related to BMI (r(0) = 0.708; P = 0.0001), body weight (r(0) = 0.643; P = 0.0001), body fat percent (r(0) = 0.462; P = 0.001), C-reactive protein (r(0) = 0.619; P = 0.004), and leptin (r(0) = 0.579; P = 0.007) and negatively to M value (r(0) = -0.603; P = 0.005). CONCLUSIONS: After massive weight loss in morbidly obese subjects, an increase of free cortisol was associated with a simultaneous decrease in CBG levels, which might be an adaptive phenomenon relating to environmental changes. This topic, not addressed before, adds new insight into the complex mechanisms linking HPA activity to obesity.

Abstract: The aim of this study was to analyze LPIN1 adipose tissue gene expression levels in 3 clinical insulin-resistant conditions-obesity, type 2 diabetes mellitus, and human immunodeficiency virus (HIV)-associated lipodystrophy-and its relationship with adipogenic and inflammatory markers. Subcutaneous adipose tissue samples were obtained from 2 cohorts: 98 subjects with different degrees of adiposity and with or without the presence of type 2 diabetes mellitus and 37 HIV-infected patients. Real-time polymerase chain reaction was used to measure gene expression of LPIN1 and adipogenic (PPARgamma, SREBP1c) and inflammatory markers (IL6, TNFalpha, TNFR1, and TNFR2). LPIN1 messenger RNA expression levels were significantly lower in the obese group (P = .002), were similar in type 2 diabetes mellitus patients and control subjects (P = .211), and were significantly higher in HIV-infected patients (P < .001). LPIN1 messenger RNA levels positively correlated with insulin sensitivity in all subjects. Moreover, an inverse correlation with proinflammatory cytokines was observed.

Abstract: OBJECTIVE: Interleukin (IL)-6 is a proinflammatory cytokine that is implicated in the pathogenesis of atherosclerosis and insulin resistance. Both endothelial dysfunction and insulin resistance are among the earliest abnormalities that can be detected in people at risk for cardiovascular events. We aimed to evaluate whether increased serum IL-6 concentrations associated with endothelial dysfunction are independent of insulin sensitivity in apparently healthy men. RESEARCH DESIGN AND METHODS: Association studies were performed in well-characterized nondiabetic Caucasian men (n = 99) recruited for energy balance studies. Insulin sensitivity (minimal model) and brachial vascular reactivity (high-resolution external ultrasound) were assessed. Circulating IL-6 concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: Serum IL-6 was an independent contributor to the variance of endothelium-dependent vasodilatation after adjusting for age, BMI, smoking status, LDL cholesterol, systolic blood pressure, diastolic blood pressure, and insulin sensitivity (P = 0.001). In fact, circulating IL-6 was negatively associated with endothelium-dependent vasodilatation (r = -0.247, P = 0.014) and insulin sensitivity (r = -0.262, P = 0.011) and correlated positively with age (r = 0.241, P = 0.016), BMI (r = 0.240, P = 0.017), systolic blood pressure (r = 0.299, P = 0.003), diastolic blood pressure (r = 0.295, P = 0.003), and triglycerides (r = 0.212, P = 0.035). No significant associations were observed between endothelium-independent vasodilatation and serum IL-6 concentrations. CONCLUSIONS: Circulating IL-6 is linked to endothelial dysfunction independently of insulin sensitivity in apparently healthy men.

Abstract: OBJECTIVE: Recent investigations disclosed an upregulation of retinol-binding protein-4 (RBP4) in the adipose tissue of several insulin-resistant mouse models and increased serum RBP4 concentration in subjects with obesity and type 2 diabetes in association with insulin resistance. There is some experimental evidence that RBP4 also could been linked to insulin secretion. RESEARCH DESIGN AND METHODS: We aimed to evaluate insulin secretion, insulin sensitivity, insulin disposition index (minimal model analysis), and circulating RBP4 (enzyme-linked immunosorbent assay) in nondiabetic men with a wide range of obesity (n = 107). RESULTS: Serum RBP4 concentration was nonsignificantly different among lean, overweight, and obese subjects. Circulating RBP4 was not associated with age, BMI, waist-to-hip ratio, or metabolic parameters, including insulin sensitivity (r = -0.03, P = 0.6). On the contrary, circulating RBP4 was negatively associated with insulin secretion, especially in obese subjects (r = -0.48, P = 0.007), in whom RBP4 also was linked to insulin disposition index (r = -0.44, P = 0.01). On multiple regression analyses to predict insulin secretion (acute insulin response [AIR(g)]), insulin sensitivity was the only factor that contributed to 17% of AIR(g) variance in nonobese subjects. In obese subjects, however, RBP4 emerged as an independent factor that contributed independently to AIR(g) variance (23%). CONCLUSIONS: Our results suggest that oversecretion of RBP4 may negatively affect beta-cell function directly or by preventing the binding of transthyretin to its receptor. These mechanisms could be behind the association between increased circulating RBP4 and type 2 diabetes. RBP4 could be one signal from insulin-resistant tissues that impacts on beta-cell secretion.

Abstract: A diagnosis of bilateral pheochromocytoma warrants exclusion of hereditary pheochromocytoma. OBJECTIVE: To describe the first case of a bilateral pheochromocytoma associated with V804M mutation in the RET proto-oncogene. PATIENTS: The index case was a 54-year-old man with bilateral adrenal masses discovered during a CT scan performed for other reasons. MEASUREMENTS: Genetic analysis included exons 8-11 and 13-17 in the RET proto-oncogene, all four exons and flanking intronic regions in the SDHD gene, all eight exons and flanking intronic regions in the SDHB, and all three exons in the VHL gene. RESULTS: Investigations revealed elevated urinary metanephrines (32.3 micromol/day), and laparoscopic bilateral adrenalectomy confirmed bilateral pheochromocytomas. A heterozygous V804M mutation in exon 14 of the RET was found in the index case and in four relatives. Total thyroidectomy, performed in four of five affected members in this kindred, disclosed a medullary thyroid carcinoma in the index case and in a 50-year-old woman, and nodular C-cell hyperplasia in the other two subjects. CONCLUSIONS: This clinical case suggests that individuals carrying the germline V804M mutation should be screened annually for the presence of pheochromocytoma.

Abstract: OBJECTIVE: We hypothesized that burden of infection could be associated with chronic low-grade inflammation, resulting in insulin resistance. We aimed to study the effect of exposure to four infections on insulin sensitivity in apparently healthy middle-aged men (n = 124). RESEARCH DESIGN AND METHODS: By inclusion criteria, all subjects were hepatitis C virus antibody seronegative. Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)-1, HSV-2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme-linked immunosorbent assays. Insulin sensitivity was evaluated using minimal model analysis. RESULTS: The HSV-2 titer was negatively associated with insulin sensitivity even after controlling for BMI, age, and C-reactive protein (CRP). The associations were stronger when considering the infection burden. In particular, in those subjects who were seropositive for C. pneumoniae, the relationship between the quantitative seropositivity index (a measure of the exposure to various pathogens) and insulin sensitivity was strengthened (r = -0.50, P < 0.0001). We also observed decreasing mean insulin sensitivity index with increasing seropositivity score in subjects positive for enteroviruses. In the latter, the relationship between insulin sensitivity and seropositivity was especially significant (r = -0.71, P < 0.0001). In a multivariate regression analysis, both BMI and quantitative seropositivity index (7%) independently predicted insulin sensitivity variance in subjects with C. pneumoniae seropositivity. When controlling for CRP, this association was no longer significant. CONCLUSIONS: Pathogen burden showed the strongest association with insulin resistance, especially with enteroviruses and C. pneumoniae seropositivity. We hypothesize that exposure to multiple pathogens could cause a chronic low-grade inflammation, resulting in insulin resistance.

Abstract:

Abstract: TWEAK, a cytokine of the TNF family, has been found to be expressed under different inflammatory conditions but no data is available concerning the expression of this cytokine and its receptor (Fn14) in human obesity. In the present work we have evaluated the expression of many pro-inflammatory TNF system cytokines (TNF-alpha, TWEAK and their respective receptors, TNFR1, TNFR2 and Fn14) in human adipose tissue of 84 subjects some with different degree of obesity and type 2 diabetes, and its relation with inflammation by also measuring the expression of macrophage marker CD68. We detected expression of TWEAK and Fn14 in isolated mature adipocytes and in the stromovascular fraction. Additionally, we found that LPS upregulates the expression of both genes on THP-1 human monocytic cell line. TWEAK was expressed in adipose tissue of all studied subjects with no differences between obesity group, and was associated with Fn14 expression in morbid obese, mainly in women with type 2 diabetes. The data obtained here also showed that TNF-alpha and TNFR2 mRNAs were significantly more expressed in subcutaneous adipose tissue of subjects with morbid obesity compared to obese and non-obese subjects. In contrast, TNFR1 gene expression was negatively associated with BMI. Our results suggest that the expression of TNF-derived pro-inflammatory cytokines are increased in severe obesity, where macrophage infiltrate could modulate the inflammatory environment through activation of its receptors.

Abstract: OBJECTIVE: Serum concentrations of soluble tumor necrosis factor-alpha (TNF-alpha) receptor 2 (sTNFR2) are associated with insulin resistance. In a recent study, we provided evidence for the existence of a biologically active form of sTNFR2 produced by alternative splicing (DS-TNFR2). We aimed to evaluate whether this circulating DS-TNFR2 is associated with insulin action in humans. DESIGN AND METHODS: Real time PCR (light cycler technology) evaluated DS-TNFR2 expression in monocytes. DS-TNFR2 was measured using a monoclonal antibody against an epitope present in TNFR2 (first 14 residues of the juxtamembrane region) but predicted to be absent in soluble proteolytic cleavage-produced TNFR2. Insulin sensitivity was measured using euglycemic hyperinsulinemic clamp (n = 76) and homeostatic model of assessment (HOMA) value in a replication study of 223 subjects. RESULTS: Real time PCR confirmed gene expression of DS-TNFR2 in monocytes from healthy subjects. A significant and positive association was found between serum DS-TNFR2 concentration and insulin sensitivity (P = 0.032, n = 76). This association was most significant in subjects with normal glucose tolerance (r = 0.44, P = 0.002). The subjects in whom DS-TNFR2 was detectable were more insulin sensitive than those with undetectable DS-TNFR2 (42.12+/-22.08 vs 31.71+/- 16.95 micromol x kg(-1) x min(-1), P = 0.039). DS-TNFR2 was inversely associated with body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, fasting serum glucose, serum triglycerides and serum uric acid concentration and with the HOMA value (P = 0.03) in the replication study. Circulating DS-TNFR2 declined with increased number of components of the metabolic syndrome. CONCLUSION: Native sTNFR2 and DS-TNFR2 show opposite associations with insulin action. DS-TNFR2 might play a role as a counterpart of the proinflammatory environment associated with insulin resistance.

Abstract: OBJECTIVE: Variation in the tumour necrosis factor gene, (TNF) has been associated with insulin resistance traits. We questioned whether the TNF-308G/A polymorphism is associated with birthweight and insulin resistance in children born small for gestational age (SGA), a patient population known to be at risk for insulin resistance. DESIGN: A cross-sectional, hospital-based study assessing insulin sensitivity in SGA children. PATIENTS: One hundred and ninety-eight school-age children born either SGA (n=90, age 7.4+/- 4.5 years) or appropriate for gestational age (AGA, n=108, age 8.7+/- 4.0 years). MEASUREMENTS: All children were genotyped for the TNF-308G/A polymorphism; a biochemical profile was also performed in prepubertal SGA (n=58) and AGA (n=57) subjects. RESULTS: Genotype frequencies for the TNF-308G/A single nucleotide polymorphisms (SNPs) (GG and GA/AA) differed between SGA and AGA children (86%vs. 72% and 14%vs. 28%, respectively; P=0.025). The GG genotype was associated with lower birthweight and birth length (2747.0+/- 23.3 g vs. 2851.0+/- 45.7 g, P=0.045, and 47.0+/- 0.2 cm vs. 48.2+/- 0.4 cm, P=0.011, respectively) and, in AGA but not in SGA children, with higher systolic blood pressure [103.3 (95% confidence interval (CI) 96.4-110.2) mmHg vs. 92.8 (84.9-100.7) mmHg; P=0.028], higher blood glucose [4.8 (4.7-5.0) mmol/l vs. 4.5 (4.3-4.8) mmol/l; P=0.042] and higher homeostasis model assessment for insulin resistance (HOMA-IR) index [1.4 (1.1-1.7) vs. 0.9 (0.4-1.3); P=0.005]. In multivariate analysis, the TNF-308GG genotype was an independent predictor of HOMA-IR during childhood, explaining 8% of its variance. CONCLUSION: SGA children show increased frequency of the TNF-308G allele, an allele that is associated with prenatal growth and with postnatal insulin resistance. The TNF-308G/A polymorphism may have implications in the growth and metabolic abnormalities that characterise SGA children.

Abstract:

Abstract: The innate immune system can immediately respond to microorganism intrusion by helping to prevent further invasion. Bactericidal/permeability-increasing protein (BPI) is a major constituent of neutrophils that possesses anti-inflammatory properties. Inflammation is increasingly recognized as a component of the metabolic syndrome. We hypothesized that the production of BPI could be linked to insulin sensitivity and glucose tolerance. We studied circulating BPI across categories of glucose tolerance. We also studied whether these cross-sectional associations were of functional importance. For this reason, we investigated circulating bioactive lipopolysaccharide and the effects of changing insulin action-after treatment with an insulin sensitizer (metformin)-on circulating BPI in subjects with glucose intolerance. Finally, we tested whether a 3'-untranslated region (UTR) BPI polymorphism led to differences in BPI and insulin action among nondiabetic subjects. Age- and BMI-adjusted circulating BPI was significantly lower among patients with type 2 diabetes. Circulating BPI correlated negatively with fasting and postload glucose and insulin concentrations. In subjects with glucose intolerance, BPI was also linked to BMI, waist-to-hip ratio, and age- and BMI-adjusted insulin sensitivity. Bioactive lipopolysaccharide was negatively correlated with circulating BPI (r = -0.57, P < 0.0001) and positively with plasma lipopolysaccharide-binding protein (r = 0.54, P = 0.002). In parallel to improved insulin sensitivity, plasma BPI significantly increased in the metformin group but not in the placebo group. A 3'-UTR BPI polymorphism was simultaneously associated with plasma BPI concentration, waist-to-hip ratio, fasting and postload insulin concentration, fasting plasma triglycerides, and insulin sensitivity. These findings suggest that this component of the innate immune system is associated with metabolic pathways.

Abstract: Insulin resistance and cardiovascular disease share common pathophysiological mechanisms, as the chronic activation of the innate immune system. This system constitutes the first line of body's defense and is constituted by different barriers (e.g., epithelia, adipose tissue) and different blood and tissue components (e.g., macrophages, neutrophils). This system generates the acute-phase response in which different acute-phase proteins and cytokines are produced in response to different aggressions as infections and traumatisms. The aim of this response is to eradicate these agents, to repair the harmed tissues, and, through increased insulin resistance, to optimize the energetic substrates, which will be drained to vital tissues and organs (i.e., brain and the immune system). Evolutionary pressures have led to survival of the fittest individuals, those with the genetics that allows the best defense against infection and periods of famine. Evidence is reported according to which gene polymorphisms in the molecules regulating the inflammatory cascade are associated with body composition, insulin action, and characteristics of the metabolic syndrome. The evolutive advantages of increased inflammatory responses, hypersecretion of proinflammatory cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-18], or decreased anti-inflammatory molecules (adiponectin, certain TNF-alpha isoforms, soluble CD14, etc.), would lead in westernized countries to chronic inflammation conditions, such as obesity and type 2 diabetes, resulting in cardiovascular disease.

Abstract: Visfatin has shown to be increased in type 2 diabetes but to be unrelated to insulin sensitivity. We hypothesized that visfatin is associated with insulin secretion in humans. To this aim, a cross-sectional study was conducted in 118 nondiabetic men and 64 (35 men and 29 women) type 2 diabetic patients. Type 1 diabetic patients with long-standing disease (n = 58; 31 men and 27 women) were also studied. In nondiabetic subjects, circulating visfatin (enzyme immunoassay) was independently associated with insulin secretion (acute insulin response to glucose [AIRg] from intravenous glucose tolerance tests) but not with insulin sensitivity (Si) or other metabolic or anthropometric parameters, and AIRg alone explained 8% of visfatin variance (beta = -0.29, P = 0.001). Circulating visfatin was increased in type 2 diabetes (mean 18 [95% CI 16-21] vs. 15 ng/ml [13-17] for type 2 diabetic and nondiabetic subjects, respectively; P = 0.017, adjusted for sex, age, and BMI), although this association was largely attenuated after accounting for HbA1c (A1C). Finally, circulating visfatin was found to be increased in patients with long-standing type 1 diabetes, even after adjusting for A1C values (37 ng/ml [34-40]; P < 0.0001, adjusted for sex, age, BMI, and A1C compared with either type 2 diabetic or nondiabetic subjects). In summary, circulating visfatin is increased with progressive beta-cell deterioration. The study of the regulation and role of visfatin in diabetes merits further consideration.

Abstract: CONTEXT: Levels of TSH respond to fluctuations in serum free T(4) (fT(4)) but remain in a very narrow individual range. There exists current controversy regarding the upper limit of normal serum TSH values above which treatment should be indicated. OBJECTIVE: We aimed to study whether the individually determined fT(4)-TSH relationship was associated with plasma lipids, insulin sensitivity, and endothelial dysfunction in healthy subjects with strictly normal thyroid function according to recent recommendations (0.3-3.0 mU/liter). DESIGN: This was a cross-sectional study. SETTING: The study consisted of a cohort of healthy men from the general population (n = 221). MAIN OUTCOME MEASURES: Oral glucose tolerance, insulin sensitivity (S(I), minimal model), endothelium-dependent vasodilation (high-resolution ultrasound), and plasma lipids were measured in relation to thyroid function tests. RESULTS: Both serum TSH and fT(4).TSH product were positively associated with fasting and postload insulin concentration and negatively with S(I). After body mass index stratification, these associations were especially significant among lean subjects. Serum TSH and fT(4).TSH product also correlated positively with fasting triglycerides and negatively with high-density lipoprotein cholesterol. In a multiple linear regression analysis, age (P = 0.007) and S(I) (P = 0.02) but not body mass index, fasting triglycerides, or serum high-density lipoprotein concentration contributed independently to 3.7 and 3.3%, respectively, of the variance in fT(4).TSH. Those subjects over the median of fT(4).TSH showed reduced endothelium-dependent vasodilation. CONCLUSIONS: Thyroid function tests are intrinsically linked to variables of insulin resistance and endothelial function. It is possible that underlying factors lead simultaneously to increased serum TSH, insulin resistance, ensuing dyslipidemia, and altered endothelial function even within current normal TSH levels.

Abstract: Several lines of evidence indicate a causal role of the cytokine interleukin (IL)-6 in the development of type 2 diabetes in humans. Two common polymorphisms in the promoter of the IL-6 encoding gene IL6, -174G>C (rs1800795) and -573G>C (rs1800796), have been investigated for association with type 2 diabetes in numerous studies but with results that have been largely equivocal. To clarify the relationship between the two IL6 variants and type 2 diabetes, we analyzed individual data on >20,000 participants from 21 published and unpublished studies. Collected data represent eight different countries, making this the largest association analysis for type 2 diabetes reported to date. The GC and CC genotypes of IL6 -174G>C were associated with a decreased risk of type 2 diabetes (odds ratio 0.91, P = 0.037), corresponding to a risk modification of nearly 9%. No evidence for association was found between IL6 -573G>C and type 2 diabetes. The observed association of the IL6 -174 C-allele with a reduced risk of type 2 diabetes provides further evidence for the hypothesis that immune mediators are causally related to type 2 diabetes; however, because the association is borderline significant, additional data are still needed to confirm this finding.

Abstract: In a previous study, we identified a biologically active form of tumor necrosis factor-alpha receptor 2 (sTNFR2) produced by differential splicing (DS-TNFR2) which antagonized TNF-alpha biological activity. Obesity, insulin resistance and type 2 diabetes are linked to increased TNF-alpha action. We hypothesized that subjects with detectable DS-TNFR2 would be protected from developing obesity and related metabolic disorders. Thus, we investigated if circulating DS-TNFR2 concentration was associated with components of the so-called metabolic syndrome among 269 consecutive subjects from the general population. DS-TNFR2 was measured using a monoclonal antibody against an epitope present in TNFR2 (first 14 residues of the juxtamembrane region) but predicted to be absent in soluble proteolytic cleavage-produced TNFR2. Plasma DS-TNFR2 concentration was significantly decreased among patients with glucose intolerance or type 2 diabetes mellitus (p=0.026). DS-TNFR2 tended to be associated with fasting and post-load glucose (both r=-0.11, p=0.054), and with diastolic blood pressure in men (r=-0.16, p=0.07). Serum DS-TNFR2 concentration was significantly associated with LDL cholesterol (r=-0.28, p=0.002), uric acid (r=-0.13, p=0.04) and with blood glycated hemoglobin (r=-0.13, p=0.04). DS-TNFR2 declined with increased number of components of the metabolic syndrome (p=0.03). Those subjects with 2 or more components had significantly decreased circulating DS-TNFR2 levels (0.96+/-2.2 versus 1.7+/-3.2, p=0.033). In summary, the circulating concentration of DS-TNFR2 seems to be inversely linked to metabolic disorders, hinting at a possible anti-inflammatory role.

Abstract: AIMS/HYPOTHESIS: Decreased sensing of the innate immune system may lead to chronic activation of the inflammatory cascade. We hypothesised that mannan-binding lectin (MBL) deficiency may confer risk of obesity and insulin resistance. MATERIALS AND METHODS: We performed a cross-sectional study of MBL protein concentration (n=434) and MBL2 gene mutations (exon 1) (n=759) in association with obesity, markers of inflammation and insulin action (euglycaemic clamp, n=113), and a longitudinal study of MBL protein before and after weight loss in obese patients (n=10). We also studied the effects of MBL in vitro in muscle cells and circulating MBL-A (mouse equivalent of human MBL) in a mouse model. RESULTS: Among 434 consecutive non-diabetic men, the age-adjusted serum MBL concentration was lower in obese subjects than in lean subjects (median: 959 microg/ml [interquartile range: 116.8-2,044 microg/ml] vs 1,365 [467-2,513] microg/ml; p=0.01) and was accompanied by increased serum inflammatory markers. Insulin action correlated significantly with serum MBL (r=0.49, p<0.0001). Serum MBL concentration increased by a median of 110.2% after weight loss. The change in serum concentration of MBL was positively associated with the increase in insulin sensitivity (r=0.713, p=0.021). At least one MBL2 gene mutation was present in 48.2% of obese vs 39.3% of non-obese subjects (p=0.037). The plasma concentration of MBL-A was lower in insulin-resistant obese ob/ob mice, as was the glucose/insulin ratio. Incubation of rat soleus muscle with human MBL markedly increased fatty acid oxidation. CONCLUSIONS/INTERPRETATION: These findings suggest that MBL, previously thought only to be involved in inflammation and immune system function, affects metabolic pathways.

Abstract: OBJECTIVE: Low-grade inflammation has been related to obesity, insulin resistance and the metabolic syndrome. The Asp358Ala variant and the CA-repeat polymorphism in the interleukin-6 receptor (IL-6R) gene have been reported to be associated with obesity in Pima Indians and Spanish women, respectively. The aim of this study was to investigate the association between these polymorphisms and obesity in a Mediterranean-Caucasian population, and to determine whether this polymorphism was related to the metabolic syndrome as defined by the National Cholesterol Education Program - Adult Treatment Panel III (NCEP/ATP-III) criteria. DESIGN: Cross-sectional. PATIENTS: Three hundred and ninety subjects from the general population. METHODS: The Asp358Ala and CA-repeat polymorphisms were analysed by polymerase chain reaction (PCR) amplification, followed by restriction fragment length polymorphism or capillary electrophoresis, respectively. RESULTS: Both polymorphisms were in strong linkage disequilibrium, Asp358 alleles being associated with 149 CA-repeat alleles (chi2 = 76.275, P < 0.0001). Therefore, only the association of the Asp358Ala variant with obesity and the metabolic syndrome was assessed in the whole series of subjects. Subjects homozygous for Asp358 alleles had statistically higher body mass index (BMI) compared with Ala358 carriers (27.7 +/- 5.41 vs. 26.6 +/- 4.96 kg/m2; P < 0.05). Moreover, the prevalence of the metabolic syndrome was significantly higher in carriers of the Asp358 allele compared with Ala358 homozygotes (12.7%vs. 0.0%; P = 0.01). This relationship remained significant after adjusting for age, insulin resistance, sex and BMI. CONCLUSIONS: The Asp358Ala and CA-repeat polymorphisms in the IL-6R gene are associated with obesity and characteristics of the metabolic syndrome in our population of Mediterranean subjects.

Abstract: OBJECTIVE: The IGF-II receptor gene (IGFIIR) is located at chromosome 6q26, a region that harbors a genetic marker linked to insulin-resistant traits in Mexican-Americans. In the present study conducted in Spaniards, we tested a common polymorphism in IGFIIR for association with type 2 diabetes and insulin-resistant traits. DESIGN: Case-control association study. METHODS: One hundred and forty-five type 2 diabetic patients and 217 non-diabetic controls were genotyped for the ACAA-insertion/deletion polymorphism at the 3' UTR of IGFIIR. Phenotyping included anthropometrics and a metabolic profile, including serum lipid levels and surrogate indexes of insulin resistance whenever possible. RESULTS: Diabetic patients were more frequently homozygous for the wild type 144 bp allele of IGFIIR compared with controls (diabetic patients 77.2%, controls 51.6%, P<0.001) suggesting a potential protective role against type 2 diabetes for the IGFIIR 140 bp variant. Carrying 140 bp alleles was associated with an odds ratio of having diabetes of 0.290 (95% confidence interval 0.109-0.770), and controls homozygous for the wild type 144 bp allele presented with lower insulin and triglyceride levels, which are proxies for insulin resistance. CONCLUSIONS: The ACAA-insertion/deletion polymorphism at the 3' UTR of IGFIIR is associated with type 2 diabetes and influences surrogate markers of insulin resistance in non-diabetic subjects.

Abstract: IGF-binding protein (IGFBP)-related protein 1 (IGFBP-rP1) has been shown to bind both IGFs and insulin, albeit with low affinity, and to inhibit insulin signaling. We hypothesized that IGFBP-rP1 is associated with insulin resistance and components of the IGF system in humans. To this aim, a cross-sectional study was conducted in 113 nondiabetic and 43 type 2 diabetic men. Insulin sensitivity (insulin sensitivity index [S(i)] from intravenous glucose tolerance tests in nondiabetic subjects, or the rate constant for disappearance of glucose [K(ITT)] from insulin tolerance tests in type 2 diabetic subjects), circulating IGFBP-rP1 (from enzyme-linked immunosorbent assay), adiponectin (from radioimmunoassay), C-reactive protein (CRP; from immunoturbidimetry), soluble tumor necrosis factor receptor 2 (sTNFR2; from enzyme-amplified sensitivity immunoassay), and IGF system parameters (IGF-I, free IGF-I, and IGFBP-1 from immunoradiometric assay) were assessed in all subjects. Among nondiabetic men, those in the highest quartile for circulating IGFBP-rP1 exhibited decreased S(i) and adiponectin (both P < 0.01) as well as increased CRP and sTNFR2 (both P < 0.05). Circulating IGFBP-rP1 was also found to be increased in previously undiagnosed type 2 diabetic patients (P = 0.01) but not in known type 2 diabetic patients receiving pharmacological therapy. Although no changes in IGF system components were evident by IGFBP-rP1 quartiles in nondiabetic subjects, independent positive associations of IGFBP-rP1 with circulating fasting IGFBP-1 were evident after adjustment for insulin resistance parameters in both nondiabetic and type 2 diabetic subjects, with IGFBP-rP1 explaining 2 and 11% of IGFBP-1 variance, respectively. In additional multivariate analyses, S(i), sTNFR2, and age stood as independent predictive variables of IGFBP-rP1 (together explaining 18% of its variance) in nondiabetic subjects, and BMI became the only independent predictive variable of IGFBP-rP1 (explaining 26% of its variance) in type 2 diabetic men. These findings show for the first time that circulating IGFBP-rP1 is increased with insulin resistance, and they also suggest novel interactions between IGFBP-rP1 and the IGF system in humans.

Abstract: BACKGROUND: Tumor necrosis factor alpha has a key role in insulin resistance. We study the effects of metformin on glucose tolerance, insulin resistance, beta cell function, and soluble tumor necrosis factor receptor (sTNFR) levels. METHODS: We performed a double-blind, randomized metformin-placebo study. Twenty-three subjects with impaired glucose tolerance or impaired fasting glucose were studied. Oral glucose tolerance, homeostasis model assessment, and continuous infusion of glucose with model assessment tests were used to evaluate glucose tolerance, insulin sensitivity, and beta cell function, respectively. Soluble tumor necrosis factor receptor levels were measured before and after therapy. Repeated measures analysis of variance was used for statistical analysis. RESULTS: After 12-week treatment, fasting glucose (110.1 +/- 9.9 to 98.9 +/- 15.7 mg/dl, P < .001), fasting insulin (11.6 +/- 5.4 to 8.8 +/- 3.5 mU/L, P = .05), fasting C-peptide (2.5 +/- 0.7 to 1.8 +/- 0.5 ng/mL, P < .05), and achieved C-peptide (5.2 +/- 1.2 to 4.2 +/- 1 ng/mL, P < .05) levels decreased in the metformin group. In addition, there was an improvement in insulin sensitivity (37.4% +/- 15.2% to 50.4% +/- 23.2%, P < .05) with unchanged sTNFR1 (2.0 +/- 0.8 to 2.3 +/- 1.2 microg/L, P = NS) and sTNFR2 (4.8 +/- 1.7 to 4.4 +/- 1.2 microg/L, P = NS) levels. CONCLUSIONS: Metformin is able to reverse insulin resistance and hyperglycemia in high-risk subjects for type 2 diabetes mellitus independently of the effects on tumor necrosis factor alpha system activity.

Abstract: PURPOSE: To determine of the prevalence of diabetic retinopathy in the general diabetic population in the Girona region and epidemiologic study of the related factors. METHODS: A population-based cross-sectional study of a randomised sample taken of 401 diabetics in the Girona region. Descriptive statistical analysis of the ocular lesions in relation to diabetic retinopathy and analysis of logistic regression in order to determine the related factors. RESULTS: 30.6% (IC 95%: 26.5-35.5) of the sample presented some degree of diabetic retinopathy, 19.4% (IC 95%: 15.4-24.0) at the initial stage, 8.4% (IC 95%: 5.8-1.9) pre-proliferative and 2.6% (IC 95%: 1.3-5.1) at a proliferative stage. Regarding the type of diabetes, 53% of the patients with type 1 diabetes and 34.2% of those with type 2 diabetes had retinopathy. Retinopathy was observed in 15.7% of diabetics with less than 10 years of diabetes evolution, 51.3% in those between 10 and 20 years and 62.8% in those with more than 20 years. The concentration of HbA1C was significantly associated with the degree of retinopathy. Of those patients with retinopathy, 60.3% were insulin-treated, 30.6% with oral hypoglucemiants and 10.3% on diet only. Patients with family antecedents of retinopathy presented a prevalence three times greater than those without. CONCLUSIONS: Approximately one in three diabetic patients exhibited some degree of retinopathy in this study dealing with a population-based cohort of diabetic patients in Spain. The prevalence was greater among type I diabetic patients. As expected, years of evolution of the disease, type of treatment and diabetic metabolic control were the most significant factors influencing the presence of retinopathy.

Abstract: Inflammation leads to changes in lipid metabolism aimed at decreasing the toxicity of a variety of harmful agents and tissue repair by redistributing nutrients to cells involved in host defence. Acute phase response, mediated by cytokines, preserves the host from acute injury. When this inflammation becomes chronic, it might lead to chronic disorders as atherosclerosis and the metabolic syndrome. The activation of the inflammatory cascade will induce a decrease in HDL-cholesterol (HDL-C), with impairment in reverse cholesterol transport, and parallel changes in apolipoproteins, enzymes, anti-oxidant capacity and ATP binding cassette A1-dependent efflux. This decrease in HDL-C and phospholipids could stimulate compensatory changes, as synthesis and accumulation of phospholipid-rich VLDL which binds bacterial products and other toxic substances, resulting in hypertriglyceridemia. The final consequence is an increased accumulation of cholesterol in cells. When the compensatory response (inflammation) is not able to repair injury, it turns into a harmful reaction, and the lipid changes will become chronic, either by repeated or overwhelming stimulus, enhancing the formation of atherosclerotic lesions. Thus, the classical lipid changes associated with the metabolic syndrome (increased triglycerides and decreased HDL-C) may be envisioned as a highly conserved evolutionary response aimed at tissue repair. Under this assumption, the problem is not the response but the persistence of the stimulus.

Abstract: Interleukin-6 (IL-6), the major proinflammatory cytokine, has been described to be associated with the hypertensive and atherosclerotic states. We aimed to explore whether the concentration of circulating IL-6 and adhesion molecules could be modified by decreasing blood pressure in hypertensive subjects. A total of 30 subjects (18 men), aged 34-48 years, were enrolled in this study, 17 hypertensive never-treated patients (HTA) and 13 normotensive subjects (C). HTA subjects were treated with irbesartan, 150-300 mg/day for 3 months, and serum IL-6, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, sP-selectin, sE-selectin and monocyte chemoattractant protein-1 were measured at 0 and 12 weeks. The two study groups were similar in age, body mass index (BMI) and gender. At baseline, circulating IL-6 levels, but not adhesion molecules, were significantly associated with systolic blood pressure (r=0.41; P=0.03) and BMI (r=0.53; P=0.005). Systolic and diastolic blood pressure decreased significantly (P<0.01) in parallel to serum IL-6 levels (from 3.72+/-0.82 to 3.23+/-0.19 pg/ml, P=0.02) reaching a similar concentration to normotensive patients (3.33+/-0.3 pg/ml) after treatment with irbesartan. No significant changes were observed in any other of the tested parameters. In conclusion, the treatment of high blood pressure lowers circulating IL-6 in young hypertensive patients.

Abstract: Most studies describe the association between one particular inflammatory marker and insulin resistance (IR), features of the metabolic syndrome, or progression to type 2 diabetes. We aimed to build an Inflammation Score as a tool to measure IR-associated inflammatory activity and to evaluate the ability of different surrogate indexes of IR to reflect the inflammatory state.We studied 81 subjects, aged 47.7 +/- 12 yr with a body mass index of 28.3 +/- 4 kg/m(2). The Inflammation Score was composed of: white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and soluble fraction of TNF-alpha receptors 1 and 2. All the subjects underwent a frequently sampled iv glucose tolerance test, an oral glucose tolerance test, and surrogate indexes of IR were calculated.Each increase in the Inflammation Score was associated with a progressive increase in IR. We found significant differences across categories (0-1, 2, 3, and 4-5 points in the score) in age (P = 0.048), waist circumference (P = 0.015), body mass index (P = 0.013), blood pressure (P = 0.005), and uric acid (P = 0.031). The Inflammation Score was significantly associated with all but three of the surrogate IR indexes [2-h insulin glucose ratio, Gutt's insulin sensitivity (SI) index, and Avignon's 2-h SI index]. Surrogate indexes obtained from basal values showed a similar correlation with the Inflammation Score than the SI from frequently sampled iv glucose tolerance test.In summary, the Inflammation Score is a useful tool in the evaluation of IR-associated inflammatory activity. The surrogate indexes obtained using fasting glucose and insulin appear to better reflect this inflammatory state. Basal rather than stimulated indexes should be used in the evaluation of therapeutic measures aimed at modifying IR-associated inflammatory activity.

Abstract: BACKGROUND: The amount and type of fat in the diet influence the development of obesity and related inflammatory activity. Knowledge of the possible influence of dietary habits on circulating adiponectin, a molecule with putative antiinflammatory properties, may be helpful in preventing atherosclerosis and type 2 diabetes. METHODS: The association between dietary fat, as inferred from plasma fatty acid composition (gas-liquid chromatography), and circulating adiponectin (RIA) was evaluated in 116 healthy individuals. RESULTS: The proportion of saturated fatty acids in plasma was significantly associated with circulating adiponectin concentration (r = -0.24; P = 0.01). Specifically, percentage of palmitic acid (C16:0) was significantly associated with lower adiponectin concentration (r = -0.28; P = 0.002), particularly among women (r = -0.37; P = 0.02) and nonsmokers (r = -0.30; P = 0.007). Percentage of myristic acid (C14:0) was also significantly associated with lower adiponectin among nonsmokers (r = -0.26; P = 0.02) and women (r = -0.39; P = 0.01). The other fatty acids were not significantly associated with adiponectin except for eicosanoic acid (C20:1 omega-9), which was significantly and positively associated with adiponectin in all individuals (r = 0.23; P = 0.01). This latter association was most significant in smokers (r = 0.43; P = 0.007). In a multivariate regression analysis to predict circulating adiponectin, after controlling for age, body mass index, waist-to-hip ratio, and the individual remaining fatty acids, the percentages of palmitic (P = 0.005) and eicosanoic acid (P = 0.03) contributed independently (6% and 3%, respectively) to adiponectin variance. Among nonsmokers, the percentages of palmitic acid (P = 0.01) and omega-3 fatty acids contributed 8% and 7%, respectively, to adiponectin variance. Among smokers, the percentage of eicosanoic acid (P = 0.03) contributed to 10% of adiponectin variance, independently of body mass index, age, waist-to hip ratio, and the remaining individual fatty acids. CONCLUSIONS: Saturated and omega-3 fatty acids of dietary origin (as inferred from plasma fatty acid concentration) are associated with circulating adiponectin concentrations in healthy humans. The proportion of eicosanoic acid also appears to be positively associated with circulating adiponectin. The knowledge of how these interactions occur may be helpful in the planning of dietary measures aimed at the modulation of inflammatory activity.

Abstract: The gene encoding the human TNF alpha receptor (TNFR) 2 contains polymorphisms in the 3' untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been studied to date. To examine the role played by different haplotypes in the control of TNFR2 expression (haplotypes A1-A5, referring to nucleotides 1663 G/A, 1668 T/G, and 1690 T/C), we introduced these sequences into the 3'-UTR of a heterologous reporter gene and expressed the corresponding constructs in a human T-cell line. We demonstrate that a 485-nt fragment of the TNFR2 3'-UTR that contains a U-rich region decreases reporter expression and that haplotypes A1-A4 exert a stronger effect than A5. Furthermore, time-course assays of mRNA stability using actinomycin D revealed that haplotypes A1-A4 destabilize the mRNA. The proximal TNFR2 3'-UTR, independently of haplotype differences, responded to T-cell activation by increasing mRNA decay. Electromobility shift analysis demonstrated that protein(s) found in T-cell extracts bind to the 485-nt fragment. We suggest that an increased rate of TNFR2 mRNA decay protects cells from unrestrained TNF alpha effects and that this protection is weakened in A5 subjects. These findings may explain the association of this haplotype with obesity and increased leptin levels.

Abstract: AIMS/HYPOTHESIS: Knowledge of the factors which simultaneously contribute to insulin-resistance-related inflammation may contribute to early therapeutic targeting. IL-18 has recently been described as one of the factors which, in addition to insulin resistance, may also contribute to atherosclerosis. However, the source of IL-18 is not well characterised. MATERIALS AND METHODS: We aimed to study body composition (bioelectric impedance), glucose tolerance (OGTT) and insulin sensitivity (minimal model method) in relation to serum IL-18 (ELISA) concentration in 144 otherwise healthy men aged 51.9+/-12.5 years. RESULTS: In contrast to previous observations in women, circulating IL-18 was not significantly associated with BMI (r=0.12, p=0.1) or WHR (r=0.08, p=0.3). IL-18 was also not associated with absolute or percent fat mass (bioelectric impedance, p>0.20) but, interestingly, it was significantly linked to fat-free mass (p=0.03). Serum IL-18 increased with each quartile of fat-free mass, corresponding to values of < or = 64.2; >64.2 to < or = 71.6; >71.6 to < or = 80.9; and > or = 80.9 kg (ANOVA, p<0.0001). IL-18 was more closely associated with postload glucose during an OGTT (p=0.04) rather than with fasting glucose (p=0.1). HbA1c (p=0.03), HDL-cholesterol (p=0.04) and serum triglycerides (p=0.03) and parameters of systemic inflammation (C-reactive protein, p=0.02) were also significantly associated with circulating IL-18. Insulin sensitivity (minimal model analysis) was linked to circulating IL-18 (p=0.01). In a multiple linear regression analysis this relationship remained significant after controlling for BMI, age and glucose tolerance status. In another model, both fat-free mass and insulin sensitivity contributed to 10% of IL-18 variance. CONCLUSIONS/INTERPRETATION: Fat mass does not seem to influence circulating IL-18, as initially proposed. In contrast, the fat-free mass compartment (a well-known confounder in the evaluation of insulin sensitivity) may significantly contribute to the relationship between IL-18 and insulin action.

Abstract: AIMS: We have studied the relationships between soluble fractions of tumour necrosis factor receptors (sTNFR1 and sTNFR2) in Type 2 diabetes (DM2) and its chronic microvascular complications. Likewise, we have analysed the genetic susceptibility of 196T > G exon6/CA-repeat intron 4 mutations in the TNFR2 gene in this population. METHODS: A case-control study was conducted to examine the role of sTNFRs in 345 DM2 patients and 173 healthy subjects. The mutations were studied in all healthy subjects and in a subset of 232 patients. RESULTS: sTNFRs levels were similar in healthy and DM2 patients. A positive correlation between age and both sTNFRs was observed in healthy subjects. In DM2 patients, sTNFR1 showed a positive correlation with age, systolic blood pressure and leptin levels (r = 0.53, P < 0.0001; r = 0.28, P = 0.005; r = 0.46, P < 0.0001, respectively) and sTNFR2 was positively correlated with age, triglycerides and leptin levels (r = 0.34, P < 0.0001; r = 0.21, P < 0.0001; r = 0.28, P = 0.002, respectively). Patients with micro- or macroalbuminuria showed higher plasma levels of sTNFR1 and sTNFR2 than normoalbuminuric patients, after adjusting for confounding variables (B = 0.85, P = 0.022, 95% CI: 0.12-1.58 for sTNFR1 and B = 1.50, P < 0.001, 95% CI: 0.67-2.33 for sTNFR2). In DM2 patients, TT-exon 6 homozygous showed lower levels of sTNFR1 [2,4 (1.1) vs. 3.4 (1.2) ng/ml], and the CA273-allele tracked with elevated plasma HDL-cholesterol [1.8 (0.7), 1.4 (0.3) and 1.3 (0.3) mm, for CA273/273, CA273/- and CA-/-, respectively]. No association was seen with other analysed variables. CONCLUSIONS: Our findings suggest that chronic TNF activation may have some pathogenic role in diabetic nephropathy in DM2 patients. Genetic variations in exon 6/intron 4 of the TNFR2 gene do not predispose to a major risk for DM2 or its microvascular complications.

Abstract: Recent prospective studies indicate endothelial dysfunction and increased risk for cardiovascular events in patients with serological evidence of multiple infections. Soluble CD14 (sCD 14) plays a key role in the neutralization of lipopolysaccharide (LPS), a well-established bacterial product inducing endothelial dysfunction. Insulin resistance was recently identified as a significant factor influencing circulating sCD 14 concentration. Thus, we investigated the association of circulating sCD14 and endothelial dysfunction in subjects with well-established insulin resistance (patients with type 2 diabetes, n = 40) compared to control non-diabetic subjects (n = 100). To further explore the underlying mechanisms, we also analysed C-reactive protein and circulating NO2-/NO3- and cyclic GMP in the diabetic group. Serum sCD 14 concentration (ELISA) was found to be differently associated with endothelium-dependent vasodilatation (EDVD, high-resolution ultrasound) in diabetic and non-diabetic subjects. In nondiabetic subjects, serum sCD14 and C-reactive protein correlated negatively with EDVD (r = -0.21, p = 0.03, and r = -0.21, p = 0.03, respectively). In a partial correlation analysis, these associations remained significant after controlling for age and weight (sCD 14 and EDVD, r = -0.23, p = 0.023; C-reactive protein and EDVD, r = -0.21, p = 0.03; sCD14 and C-reactive protein, r = 0.30, p = 0.002). In contrast, sCD 14 was positively associated with EDVD in type 2 diabetic patients (r = 0.37, p = 0.019,). Interestingly, sCD14 was also associated with NO2-/NO3- in this group (r = 0.62, p = 0.001, n = 22). EDVD also correlated with cyclic GMP (r = 0.47, p = 0.03, n = 22). In summary, circulating sCD 14 is associated with endothelial function. While in non-diabetic subjects sCD14 behaves as an acute phase reactant, its role in type 2 diabetic patients should be further clarified. These findings need to be confirmed in further studies with larger number of patients.

Abstract: AIMS/HYPOTHESIS: We evaluated diabetes-related pregnancy outcomes in a cohort of Spanish women in relation to their glucose tolerance status, prepregnancy BMI and other predictive variables. METHODS: The present paper is part of a prospective study to evaluate the impact of American Diabetes Association (2000) criteria in the Spanish population. A total of 9,270 pregnant women were studied and categorised as follows according to prepregnancy BMI quartiles and glucose tolerance status: (1) negative screenees; (2) false-positive screenees; (3) gestational diabetes mellitus (GDM) according to American Diabetes Association criteria only; and (4) GDM according to National Diabetes Data Group criteria (NDDG). We evaluated fetal macrosomia, Caesarean section and seven secondary outcomes as diabetes-related pregnancy outcomes. The population-attributable and population-prevented fractions of predictor variables were calculated after binary logistic regression analysis with multiple predictors. RESULTS: Both prepregnancy BMI and abnormal glucose tolerance categories were independent predictors of pregnancy outcomes. The upper quartile of BMI accounted for 23% of macrosomia, 9.4% of Caesarean section, 50% of pregnancy-induced hypertension and 17.6% of large-for-gestational-age newborns. In contrast, NDDG GDM accounted for 3.8% of macrosomia, 9.1% of pregnancy-induced hypertension and 3.4% of preterm births. CONCLUSIONS/INTERPRETATION: In terms of population impact, prepregnancy maternal BMI exhibits a much stronger influence than abnormal blood glucose tolerance on macrosomia, Caesarean section, pregnancy-induced hypertension and large-for-gestational-age newborns.

Abstract: OBJECTIVE: Interleukin (IL)-18 has been associated with obesity and insulin resistance, both risk factors for the development of liver disease, but the role of IL-18 in liver disease associated with insulin resistance is presently unknown. We hypothesized that circulating IL-18 would be related to serum concentrations of liver chemistry tests (LCTs) in apparently healthy subjects and wished to study whether this correlation was dependent on insulin sensitivity (S(I)). RESEARCH METHODS AND PROCEDURES: One hundred six apparently healthy white men consecutively enrolled in a cross-sectional, population-based study dealing with S(I) in men were studied, and S(I) (minimal model analysis), LCTs (colorimetry), and IL-18 serum concentrations (immunoassay) were assessed. RESULTS: Compared with subjects in the lowest quartile for serum IL-18, subjects in the highest quartile exhibited increased serum triglycerides and decreased S(I), in addition to higher serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (all p < 0.05). The direct association between both ALT and AST and IL-18 was further confirmed by examining the distribution of serum IL-18 by quartiles of ALT and AST. Subjects in the highest quartile for serum ALT and AST had higher IL-18 concentrations compared with subjects in the lowest quartile for these LCTs (both p = 0.01). In multiple regression analysis, IL-18, but not S(I), was an independent predictor of serum concentrations of ALT and AST, explaining 7% and 4% of their variance, respectively. DISCUSSION: In summary, IL-18 serum concentrations are associated in apparently healthy humans with plasma concentrations of various LCTs. IL-18 could contribute to the development of liver disease associated with insulin resistance.

Abstract: BACKGROUND: Epidemiologists have observed that blood donation is associated with decreased risk of type 2 diabetes and cardiovascular disease. METHODS: We investigated the relationship between iron stores and insulin sensitivity, after controlling for known confounding factors, and compared insulin sensitivity between blood donors and individuals who had never donated blood (nondonors). In 181 men, insulin sensitivity and insulin secretion were evaluated through frequently sampled intravenous glucose tolerance tests with minimal model analysis. Men who donated blood between 6 months and 5 years before inclusion (n = 21) were carefully matched with nondonors (n = 66) for age, body mass index, waist-to-hip ratio, and cardiovascular risk profile, including blood lipids, blood pressure, and smoking status. RESULTS: Frequent blood donors (2-10 donations) had increased insulin sensitivity [3.42 (1.03) vs 2.45 (1.2) x 10(-4) x min(-1) x mIU/L; P = 0.04], decreased insulin secretion [186 (82) vs 401.7 (254) mIU/L x min; P <0.0001], and significantly lower iron stores [serum ferritin, 101.5 (74) vs 162 (100) microg/L; P = 0.017] than nondonors, but the 2 groups had similar blood hematocrits and blood hemoglobin concentrations. CONCLUSIONS: Blood donation is simultaneously associated with increased insulin sensitivity and decreased iron stores. Stored iron seems to impact negatively on insulin action even in healthy people, and not just in classic pathologic conditions associated with iron overload (hemochromatosis and hemosiderosis). According to these observations, it is imperative that a definition of excessive iron stores in healthy people be formulated.

Abstract: AIMS/HYPOTHESIS: This study was carried out to determine the impact of American Diabetes Association (ADA) 2000 criteria for the diagnosis of gestational diabetes mellitus (GDM) in the Spanish population. METHODS: Pregnant women were assigned to one of four categories: negative screenees, false-positive screenees, ADA-only-GDM (untreated) and GDM according to National Diabetes Data Group (NDDG) criteria (treated). Fetal macrosomia and Caesarean section were defined as primary outcomes, with seven additional secondary outcomes. RESULTS: Of 9,270 pregnant women screened for GDM, 819 (8.8%) met NDDG criteria. If the threshold for defining GDM had been lowered to ADA criteria, an additional 2.8% of women would have been defined as having the condition (relative increase of 31.8%). Maternal characteristics of women with ADA-only-GDM were between those of false-positive screenees and women with NDDG-GDM. The risk of diabetes-associated complications was slightly elevated in the individuals who would have been classified as abnormal only after the adoption of ADA criteria. In addition, the ADA-only-GDM contribution to morbidity was lower than that of other variables, especially BMI. CONCLUSIONS/INTERPRETATION: Use of the ADA criteria to identify GDM would result in a 31.8% increase in prevalence compared with NDDG criteria. However, as the contribution of these additionally diagnosed cases to adverse GDM outcomes is not substantial, a change in diagnostic criteria is not warranted in our setting.

Abstract: Inflammatory pathways are increasingly recognized to be tightly associated with insulin resistance in humans. The promoter region of the adiponectin gene--Apm1--encompasses consensus sequences for glucocorticosteroid receptor responsive element. Dexamethasone induced downregulation of adiponectin secretion in vitro, whereas prednisolone administration increased circulating adiponectin concentrations. As previous studies have demonstrated an inverse relationship between corticosteroid-binding globulin (CBG), body mass index, and insulin resistance, we studied whether CBG could explain cortisol-to-adiponectin relationship. One hundred twenty-two healthy subjects were enrolled in a cross-sectional study. Plasma CBG and serum cortisol concentration were measured by radioimmunoassay. The cortisol-to-CBG ratio was used to calculate free cortisol. An RIA kit (Linco Research, St Louis, MO) was used to measure adiponectin levels. Insulin resistance was calculated using the homeostatis model of assessment (HOMA) value. Circulating adiponectin was associated with serum CBG ( r = 0.38, P < .00001), both in men ( r = 0.26, P = .03, n = 79) and women ( r = 0.48, P = .003, n = 43), and with insulin resistance (HOMA index) ( r = -0.30, P < .0001) in both. Free cortisol correlated negatively with adiponectin only in women ( r = -0.32, P = .04), but not in men ( r = 0.01, P = .89). Serum CBG concentration was significantly lower among men in the lowest quartile of adiponectin when compared with the remaining subjects (37.3 +/- 5.7 vs 40.6 +/- 5.1, P = .016), whereas men in the highest quartile of adiponectin showed significantly increased free cortisol index (14.2 +/- 3.3 vs 12.2 +/- 3.1, P = .039). Women in the lowest quartile of adiponectin also displayed significantly lower CBG concentration than that present in the remaining subjects (38.6 +/- 6.9 vs 44.4 +/- 5.5, P = .016), whereas free cortisol index was not significantly different across adiponectin quartiles ( P = .1). In a stepwise regression analysis, body mass index ( P = .0011), CBG ( P = .0047), and sex ( P = .04) contributed to 15%, 8%, and 3%, respectively, of adiponectin variance. Using CBG as dependent variable, both adiponectin ( P = .0002) and fasting cortisol ( P = .019) contributed to 14% and 4%, respectively, of CBG variance. In summary, circulating adiponectin, CBG concentration, and fasting cortisol were significantly interrelated in healthy subjects. A significant sexual dimorphism exists in this association.

Abstract: BACKGROUND: In humans, adiponectin has been demonstrated to circulate in inverse proportion to the degree of insulin resistance. OBJECTIVE: To investigate the association between adiponectin and glycosylated haemoglobin (HbA1c) in a population-based study. DESIGN AND METHODS: Two hundred and ninety-seven individuals aged 30-75 years were enrolled in a cross-sectional study. They included patients with type 2 (non-insulin-dependent) diabetes mellitus and stable, good metabolic control (n=32) and individuals with glucose intolerance (n=54). Adiponectin was measured using a sandwich enzyme-linked immunosorbent assay (intra-assay and interassay coefficients of variation 3.3 and 7.4% respectively). RESULTS: Adiponectin correlated with age (r=0.161; P=0.006), body mass index (r=-0.197; P=0.001), diastolic blood pressure (r=-0.181; P=0.005), fasting glucose and HbA1c (r=-0.251 and r=-0.22 respectively; P<0.0001), high-density lipoprotein cholesterol (r=0.442; P<0.001) and serum triglycerides (r=-362; P<0.001). In multiple regression analysis, sex, age, fasting and post-load glucose, and adiponectin independently contributed to 40% of the variance in HbA1c. Among individuals with normal glucose tolerance, fasting glucose (P=0.0033), post-load glucose (P=0.0015), age (P=0.001) and adiponectin (P=0.0083) independently contributed to 21% of the variance in HbA1c. CONCLUSION: Adiponectin is significantly associated with altered glucose metabolism and independently contributes to the variance of HbA1c in a population-based manner.

Abstract: OBJECTIVE: Insulin resistance plays a major aetiological role in the development of fatty liver disease. Because adiponectin is a hepatic insulin sensitizer and also an inhibitor of tumour necrosis factor, a cytokine known to induce insulin resistance and liver damage, we wished to study whether low circulating adiponectin would be associated with higher serum concentrations of liver enzymes in healthy subjects. DESIGN: Cross-sectional, population-based study dealing with diabetes prevalence in northern Spain. PATIENTS: Two hundred and fifty-seven apparently healthy Caucasian subjects consecutively enrolled in the study. MEASUREMENTS: Adiponectin serum levels were measured by enzyme-linked immunosorbent assay (ELISA), liver function tests (LFTs) by colourimetry and insulin resistance by the homeostasis model of assessment (HOMA value). RESULTS: Adiponectin levels were negatively correlated with alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT), before and after adjustment for sex, age, body mass index (BMI) and insulin resistance (ALT; r = -0.32, P < 0.001; adjusted: r = -0.13, P = 0.033; GGT; r = -0.31, P < 0.001; adjusted: r = -0.16, P = 0.011). Additionally, adiponectin correlated with alkaline phosphate (ALKP) only after adjusting for the same confounding variables (r =-0.10, P = 0.098; adjusted: r = -0.14, P = 0.031). A general linear model, adjusting for age, sex and BMI, was constructed to predict the decrease in circulating adiponectin for each LFT value (i.e. ALT, GGT and ALKP) above the median. Beyond one LFT value above the median, serum adiponectin decreased by -0.97 mg/l (95% CI -1.46 to -0.48). In multiple regression analysis, sex, BMI and adiponectin, but not insulin resistance, predicted serum concentrations of both ALT and GGT, explaining 19% and 14% of their variance, respectively. Age, BMI and adiponectin, but not sex or insulin resistance, explained 20% of ALKP variance. CONCLUSIONS: Adiponectin levels are associated in healthy humans with plasma concentrations of various liver function tests. The contributions of adiponectin to maintaining liver integrity through the regulation of both insulin sensitivity and/or the inflammatory response merit further studies.

Abstract: Tumor necrosis factor (TNF)-alpha is a pleiotropic cytokine involved in a broad spectrum of inflammatory and immune responses including proliferation, differentiation and cell death induction in several cell types. The biological effects of TNF-alpha are mediated via the cell-surface TNF receptors TNFR1 and TNFR2. Soluble forms of these two receptors, which contain the extracellular ectodomains, are proteolytically cleaved from the membrane. High levels of soluble (s) TNFR2 in serum have been documented in multiple inflammatory pathologies. We describe here a new differential spliced isoform of human TNFR2 missing exons 7 and 8, DS-TNFR2(Delta7,8). This novel isoform lacks the transmembrane and cytoplasmic domains. Expression studies with DS-TNFR2(Delta7,8) cDNA transiently transfected COS cells showed that it encodes a sTNFR2 receptor of approximately 42 kDa. Soluble DS-TNFR2(Delta7,8) blocked TNF-alpha-induced apoptosis, which suggests that it regulates TNF-alpha function by antagonizing its biological activity. An ELISA was developed that quantifies sTNFR2 generated by alternative splicing. Our data show that sTNFR2 generated by alternative splicing can be found in sera of healthy individuals, at increased levels in patients with sepsis and at high concentrations in rheumatoid arthritis patients.

Abstract: OBJECTIVE: Adiponectin has been proposed to play important roles in the regulation of energy homeostasis and insulin sensitivity. In experimental studies, adiponectin has also been found to inhibit vascular smooth muscle cell proliferation. Decreased adiponectin levels have been described in patients with coronary artery disease, and circulating adiponectin predicts cardiovascular death in patients with renal failure. Because adiponectin appears to influence both insulin sensitivity and vessel wall physiology, we examined insulin sensitivity and vascular function in relation with circulating adiponectin. RESEARCH DESIGN AND METHODS: We studied brachial artery vascular reactivity (high-resolution external ultrasound) and insulin sensitivity (minimal model) in 68 healthy subjects. Brachial artery vascular reactivity was also determined in 52 patients with altered glucose tolerance: 30 subjects with impaired fasting glucose (IFG) or glucose intolerance (GIT) and 22 patients with type 2 diabetes. RESULTS: Circulating adiponectin concentration was significantly associated with insulin sensitivity (r=0.29, P=0.02) and with fasting serum triglycerides (r=-0.29, P=0.02) in healthy subjects. In the latter, adiponectin levels were positively associated with arterial vasodilation in response to nitroglycerin (endothelium-independent vasodilation [EIVD], r=0.41, P=0.002) but not with flux-induced, endothelium-dependent vasodilation (EDVD) (r=0.007, P=NS). In contrast, EIVD was not significantly associated with adiponectin in subjects with IFG, GIT, or type 2 diabetes (r < or =0.10, P=NS). In a multiple linear regression analysis to predict EIVD in healthy subjects, age (P=0.012), sex (P=0.042), and adiponectin concentration (P=0.045), but not BMI, insulin sensitivity, or fasting triglycerides, contributed to 39% of EIVD variance. CONCLUSIONS: Serum adiponectin concentration appears to be significantly associated with vascular function in apparently healthy humans. This association seems to be independent of its link with insulin sensitivity.

Abstract: OBJECTIVE: Insulin resistance has been linked to intrauterine growth restriction; adiponectin is a strong determinant of insulin sensitivity. We aimed at studying the contributions of birthweight and insulin sensitivity to circulating adiponectin in children born small for gestational age (SGA). DESIGN: Cross-sectional, hospital-based study dealing with insulin sensitivity in SGA children. PATIENTS: Thirty-two prepubertal children born SGA (age 5.4 +/- 2.9 years) and 37 prepubertal children born appropriate for gestational age (AGA, age 5.9 +/- 3.0 years). MEASUREMENTS: Serum levels of fasting glucose, serum lipids, insulin (immunometric assay) and adiponectin concentrations (ELISA) were assessed, and insulin resistance (IR) and insulin secretion (beta-cell) were calculated by the homeostasis model of assessment (HOMA). RESULTS: SGA children had similar HOMA-IR, HOMA-beta-cell and adiponectin concentrations than AGA children. However, in a separate analysis of subjects older than 3 years of age, SGA children showed higher HOMA-IR after adjusting for sex, age and body mass index (BMI) standard deviation score (SDS). Circulating adiponectin was higher in SGA children [adjusted means: 14.5 mg/l (95% CI 12.9-16.1) and 18.7 mg/l (95% CI 17.0-20.3) for AGA and SGA children, respectively; P < 0.0001]. Further analysis revealed that the group of overweight SGA (arbitrarily defined as being in the higher quartile for the BMI SDS distribution in the sample) had decreased serum concentrations of adiponectin, compared to lean SGA children [adjusted means: 12.9 mg/l (95% CI 9.3-16.5) vs. 19.0 (95% CI 16.8-21.3), respectively; P = 0.001]. In a multiple regression model, HOMA-IR and SGA status explained 35% and 15% of adiponectin variance, respectively. CONCLUSIONS: Prenatal growth restriction is associated with insulin resistance but relatively increased adiponectin concentrations, provided overweight does not ensue. The contributions of circulating adiponectin to the increased risks for developing insulin resistance and type-2 diabetes in formerly SGA subjects merit further studies.

Abstract:

Abstract: Insulin resistance is a feature of gestational diabetes mellitus (GDM). Inverse correlations between indexes of insulin sensitivity and serum markers of inflammation have been observed and, particularly, TNF-alpha has been shown to be associated with the appearance of insulin resistance in pregnancy. Mannose-binding lectin (MBL) is a protein member of the collectin family. Its deficiency is genetically determined and predisposes to recurrent infections and chronic inflammatory diseases. To test the hypothesis that a genetic predisposition to a proinflammatory state could favor the appearance of GDM during pregnancy, we studied R52C and G54D polymorphisms of MBL2 gene and plasma MBL levels from 105 consecutive GDM women and 173 healthy pregnant women. An association was found between G54D and GDM [odds ratio, 2.03 (1.18-3.49); P < 0.01], and this association remained significant when the presence of both mutated alleles was considered [odds ratio, 1.76 (1.04-2.96); P < 0.05] but not for the R52C. GDM patients who carried the G54D mutation required insulin therapy more frequently (56.4 vs. 30.4%, chi(2) =5.83; P = 0.027) and had heavier infants (3326.4 +/- 546.9 vs. 3087.5 +/- 395.5 g; P < 0.05) than GDM women homozygous for the wild-type allele. An inverse correlation in GDM patients between neonatal weight and plasma MBL levels (r = -0.320; P = 0.002) was found, remaining significant after adjustment for confounding variables. In conclusion, pregnant women bearing the G54D MBL allele have a greater risk for developing GDM and having heavier infants.

Abstract: OBJECTIVE: Tumour necrosis factor alpha (TNF-alpha) and adiponectin are strongly related to insulin sensitivity; insulin resistance of pregnancy is a major determinant of infant's birthweight. We aimed to study the contributions of maternal serum concentrations of soluble TNF-alpha receptors (sTNFR1 and sTNFR2) and adiponectin to infant's birthweight. DESIGN: Cross-sectional, hospital-based study of insulin sensitivity during gestation. PATIENTS: Fifty-one healthy women with uncomplicated pregnancy and delivery (except for elective Caesarian section) and their healthy newborn infants. measurements Maternal blood levels of glucose, insulin, glycosylated haemaglobin (HbA1c), sTNFR1, sTNFR2 and adiponectin at delivery; cord-blood levels of sTNFR1, sTNFR2 and adiponectin. RESULTS: At delivery, maternal sTNFR2 correlated with systolic blood pressure (SBP; r = 0.38, P = 0.005). In multiple regression analyses, SBP and HbA1c were independent predictors of sTNFR2, explaining 18 and 7% of its variance, respectively; insulin resistance index (HOMA-IR), body mass index at delivery and SBP were independent predictors of adiponectin, explaining 15, 8 and 7% of its variance, respectively. Both maternal sTNFR2 and SBP were negatively correlated with infant's birthweight (r = -0.28, P = 0.04 and r = -0.36, P = 0.01 respectively, adjusted for sex and gestational age). In multivariate regression analyses, infant's sex and either maternal sTNFR2 or adiponectin were independent predictors of infant's birthweight, each explaining between 6 and 9% of birthweight variance. Further addition of maternal SBP to these models revealed that this variable was the main predictor of infant's birthweight, explaining 13% of its variance. CONCLUSIONS: Maternal sTNFR2 and adiponectin are independently related to both maternal blood pressure and infant's birthweight in uncomplicated pregnancy. The contributions of the TNF-alpha system and adiponectin to hypertensive disorders of pregnancy and fetal growth merit further studies.

Abstract: The adipose tissue produces a vast number of molecules called adipokines such as leptin, tumoral necrosis factor (TNFalpha), interleukins and adiponectin. Many of the metabolic disturbances associated with obesity and the metabolic syndrome may be due to citokine production by adipocytes. The adipose tissue increases the soluble fractions of TNFalpha leading to a rise in its biological activity. The activation of TNFalpha system causes insulin resistance through different mechanisms such as defects in receptor fosforilation and reduction in insulin-sensitive glucose transporters. TNFalpha is also involved in the pathophysiology of hypertension and dyslipidaemia associated with obesity and insulin resistance. More than one third of interleukin-6 (IL-6) concentrations come from the adipocytes. It has been demonstrated a role for IL-6 in the development of hyperlipidemia, diabetes and hypertension. In contrast to the rest of adipokines, adiponectin is reduced in obesity, diabetes or cardiovascular disease. Adiponectin improves insulin resistance, dyslipidaemia and adhesion to endothelial cells protecting from atherosclerosis development. Thus, adipokines have an important role in the pathophysiology of metabolic syndrome by different mechanisms involving metabolic and vascular effects.

Abstract: Soluble CD14 (sCD14), detectable at high concentrations constitutively present in the circulation, plays a key role in the neutralization of lipopolysaccharide, one of the most potent biologic response modifiers currently recognized and involved in the regulation of the inflammatory cascade. We tested whether circulating sCD14 was linked to inflammatory parameters and to insulin resistance in apparently healthy subjects. Serum sCD14 concentration did not significantly correlate with body mass index (BMI), waist to hip ratio, systolic or diastolic blood pressure, serum glucose, fasting insulin, fasting insulin resistance index [homeostasis model assessment (HOMA)], or serum uric acid among 123 subjects. The association between sCD14 and fasting insulin (r = -0.19, P = 0.08) and between sCD14 and HOMA (r = -0.21, P = 0.06) tended toward statistical significance among men. Unexpectedly, sCD14 correlated positively with fasting triglycerides (TG) in all the subjects (r = 0.22, P = 0.014), and this association was most significant in men (r = 0.34, P = 0.002). After controlling for TG, the relationships between sCD14 levels and fasting insulin (r = -0.25, P = 0.029), HOMA (r = -0.28, P = 0.014), and uric acid (r = -0.30, P = 0.006) were significant in men. Among nonsmoking men (n = 44), sCD14 significantly correlated with waist diameter (r = -0.30, P = 0.03), diastolic blood pressure (r = -0.34, P = 0.022), and HOMA (r = -0.30, P = 0.03). In a multiple linear regression analysis, BMI (P < 0.00001), TG (P = 0.003), and sCD14 (P = 0.04) (but not age, sex, waist, or smoking status) independently contributed to 26% of HOMA variance. A polymorphism of the CD14 gene, a C-to-T transition at bp -159 from the major transcription start site, seems to play a significant role in regulating serum sCD14 levels. In a subsample of 33 healthy subjects, carriers of the T allele were similar (in age, sex, BMI, fat mass, waist to hip ratio, blood pressure, and fasting glucose and insulin levels) to C/C homozygotes. In the former, integrated area under the curve for serum glucose concentrations after an oral glucose tolerance test was significantly lower (P = 0.02), and insulin sensitivity (SI) index (minimal model analysis) significantly higher (P = 0.036), than in C/C homozygotes. Among 32 type 2 diabetic subjects, carriers of the T allele also showed a significantly higher SI index (P = 0.03) and had significantly lower C-reactive protein (P = 0.03) and lower circulating soluble intercellular adhesion molecule-1 concentrations (P = 0.01) than did C/C homozygotes. To our knowledge, this is the first study to suggest an effect of a genetic polymorphism on both SI (healthy subjects and type 2 diabetic patients) and endothelial dysfunction (sICAM-1 levels) in type 2 diabetes mellitus.

Abstract: OBJECTIVE: Fatty acids (FAs) have been involved in the development of chronic inflammatory conditions such as insulin resistance and obesity. However, the relation among insulin resistance, obesity, inflammatory activity (circulating interleukin [IL]-6) and dietary FAs has been scarcely studied in otherwise healthy subjects. RESEARCH DESIGN AND METHODS: We aimed to study these interactions in 123 overweight (BMI 26.9 +/- 2.4 kg/m(2) [means +/- SD]) subjects and 109 lean (BMI 21.7 +/- 1.7 kg/m(2), P < 0.000001) subjects. IL-6 was measured by immunoassay and FA by gas liquid cromatography. RESULTS: The percentage of saturated FAs (r = 0.30, P = 0.01) and omega-6 FAs (r = -0.32, P = 0.001) were significantly associated with circulating IL-6, whereas the percentage of omega-3 FAs correlated negatively with C-reactive protein in overweight subjects (P = 0.04). Saturated-to-omega-3 and saturated-to-omega-6 FA ratios were significantly and positively associated with C-reactive protein (P < 0.0001) and IL-6 (P < 0.001), respectively. In contrast, none of these associations reached statistical significance in lean subjects. Those subjects in the most insulin-sensitive quintile (homeostasis model assessment value) showed a significantly higher percentage of linoleic acid (C18:2 varpi6) (P = 0.03) and a significantly lower level of araquidic (C20:0) (P = 0.04), behenic (C22:0) (P = 0.009), lignoceric (C24:0) (P = 0.02), and nervonic (C24:1 varpi9) (P = 0.001) FAs than the remaining subjects. In parallel, the most insulin-sensitive subjects showed significantly decreased C-reactive protein (P = 0.03). Serum C-reactive protein was significantly associated with percent linoleic acid and eicosapentaenoic acid in nonsmoking men (P = 0.03 and P = 0.04, respectively) and with docosahexaenoic acid in nonsmoking women (r = -0.46, P < 0.0001). We constructed a multivariant regression analysis to predict circulating IL-6. Age, BMI, waist-to-hip ratio (WHR), smoking status, and the relation of saturated to omega-6 or saturated to omega-3 FAs were considered as independent variables separately in men and women. In overweight men, the ratio of saturated to omega-3 FAs (P = 0.01), but not age, sex, BMI, WHR, or smoking status, independently contributed to 17% of IL-6 variance. In lean men, smoking status (P = 0.02), but not the remaining variables, contributed to 8% of IL-6 variance. CONCLUSIONS: Dietary FAs (as inferred from plasma FA concentration) seem to be linked to inflammatory activity in overweight subjects and in subjects with insulin resistance. Being overweight modulates the relation of FAs to inflammatory markers.

Abstract: BACKGROUND AND OBJECTIVE: Despite the number of plans leading to lose weight among individuals in the developed countries, the prevalence of obesity has increased since 1980. The knowledge of ponderal evolution in a given population is very important because the adverse effects of obesity vary greatly among individuals and populations. The objective of the present paper was to determine the modifications in the different degrees of body adiposity in a population in Catalunya. PATIENTS AND METHODS: A measurement was made of weight and height of 24554 users aged over 14 years (10595 males and 13959 females) attended at four basic health areas (BHA): Girona 1, Girona 4, Salt and Camprodon, and a Primary Health Center (PHC) in the Girona province, for a five-year period, 1995-1999. The prevalence of the different degrees of obesity was compared with that obtained in a previous study with 6373 individuals during the 1986-1989 period (4,579 males and 1794 females). RESULTS: The prevalence of women with overweight (defined as a body mass index [BMI] > 25 kg/m2) increased from 7.3% (1986-1989, study 0) to 17.6% (1995-1999, study 1) for women aged 15 to 24 years ( p < 0.001), from 17.9 % to 28.1% for women aged 25 to 34 years (p < 0.001), and from 37.5% to 44.7 % for women aged 35 to 44 years (p < 0.001). In the latter age group, the proportion of women with obesity (BMI > 30 kg/m2) increased from 6.9% to 12.9%. Similar trends were observed among men, and the change in the 35-44 year age group (from 10.5 % of obese men to 16% [p < 0.001]), and 55 to 65 years (from 16.6% of obese men to 22.7% [p < 0.001] was particularly significant. And lastly, it is also noteworthy the proportion of individuals with low weight (BMI < 18.5 kg/m2) which increased from 7.3% to 11.6% for women aged 15 to 24 years, and from 0.3% to 2.2% for women aged 35 to 44 years. This trend was also observed for men aged 15 to 24 years (11% to 17.2%). CONCLUSIONS: The relative increase in the prevalence of overweight and obesity runs in parallel to that found in other surrounding countries. Also, it is worth mentioning that among women aged 15 to 24 years the increase in the prevalence of low weight and obesity is almost identical, which invalidates the mean and median values as a means to assess the ponderal evolution in this population. The current compartmentalization between the extreme BMIs, particularly among the youngest portion of population should be addressed from a multidisciplinary perspective.

Abstract: Chronic low-grade activation of the immune system may play a role in the pathogenesis of type-2 diabetes mellitus (T2DM). Interleukin-6 (IL6), a powerful inducer of hepatic acute phase response, has been implicated in the etiology of insulin resistance and T2DM. Recently, an IL6 promoter polymorphism (G/C) at position -174 was found to be associated with measures of insulin sensitivity. Because we have previously found an association between high IL6 levels and insulin resistance in both Pima Indians - a population with high rates of insulin resistance and T2DM - and Caucasians, we aimed to assess whether the IL6 promoter polymorphism is associated with T2DM in these populations. We genotyped the IL6 (-174) G/C polymorphism using pyrosequencing in 463 Native Americans and by PCR-RFLP in 329 Spanish Caucasians. Among the Spanish Caucasian subjects, there was a significant difference in genotypic distribution between diabetic and non-diabetic subjects (P=0.028); the GG genotype was more common in diabetic (0.40) than in non-diabetic (0.29) subjects. The G allele was much more frequent in the Native American sample, and among a sample of 143 cases and 145 controls, the GG genotype was significantly more common in diabetic subjects (P=0.019). When this sample population was stratified according to ethnic heritage, all 211 subjects who were of full Pima Indian heritage had the GG genotype, whereas in the 77 American Indian subjects with non-Pima admixture, T2DM was associated with IL6 genotype (P=0.001). These findings are consistent with a role for genetic determinants of inflammation in the development of T2DM in both Native Americans and Caucasians.

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Abstract: A common polymorphism (825 C/T) in exon 10 of the GNB3 gene, that encodes for the beta-3 subunit, has been associated with different degrees of activation of heterotrimeric guanine nucleotide binding proteins (G proteins). Many hormones and neurotransmitters use specific receptors that interact noncovalently with G proteins in the transmembrane signaling process. Among them, insulin uses an inhibitory G protein-sensitive mechanism that is involved in metabolic and vascular events, leading to enhanced glucose transport and vasodilation. We hypothesized differences in peripheral and vascular insulin sensitivity according to GNB3 gene polymorphism in type 2 diabetic patients. To address this issue, we used an intervention-optimization protocol to examine whether diabetic patients with the variant show a different response in terms of insulin-sensitivity. Interindividual differences in baseline insulin sensitivity and vascular dysfunction (vasodilatory response to glyceryl trinitrate) were not attributable to this polymorphism of the GNB3 gene. However, in contrast to normal homozygotes, insulin sensitivity (S(I)) significantly improved (P=0.01) in carriers of the 825T variant. Parallel to these findings, stimulated C-peptide tended to decrease, and the response to glyceryl trinitrate significantly improved (P=0.004) among 825T carriers. Body mass index, systolic and diastolic blood pressure, heart rate, or serum lipid levels did not significantly change in either group. Our findings suggest an effect of GNB3 gene polymorphism on important phenotypic variations in type 2 diabetes mellitus. The GNB3 gene polymorphism might be an example of pharmacogenetics, with the underlying etiological genetic defect altering the response to treatment.

Abstract: OBJECTIVE: Obesity may be associated with increased markers of inflammation that could be triggered by metabolic, physical, infectious or environmental processes. As smoking significantly increases cytokine production, we aimed to study how smoking influences the relationship between fat mass and soluble tumor necrosis factor-alpha (TNF-alpha) receptors 1 and 2 (sTNFR1 and sTNFR2). DESIGN: Cross-sectional, clinical observational study. SUBJECTS: A total of 133 healthy men (age: 27-53 y, body mass index (BMI): 24-30.2 kg/m(2)), 80 of whom were never-smokers and 53 smokers, matched for age, BMI and waist-to-hip ratio. MEASUREMENTS: Circulating soluble fractions of the TNF-alpha receptors sTNFR1 and sTNFR2 were measured to study their relationship with fat mass (bioelectric impedance). RESULTS: Smokers had significantly lower fat mass, lower fasting glucose, insulin and leptin concentrations than nonsmokers. Despite lower fat mass and insulin, smokers showed significantly increased circulating sTNFR2 levels (3.7+/-0.8 vs 3.4+/-0.7 ng/ml, P=0.03). The slopes of the relationships between sTNFR1 and fat mass, and between sTNFR2 and fat mass, were significantly steeper in smokers than in nonsmokers. In a stepwise multiple linear regression analysis, both fat mass (P<0.00001) and smoking (P=0.025) independently contributed to 13% of sTNFR1 variance and to 4% of sTNFR2 variance (P=0.03). CONCLUSION: Both fat mass and smoking are related to increased activity of the TNF-alpha axis.

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Abstract: BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is a key cytokine in the inflammation process of atherosclerosis. Through its effects on lipid metabolism, insulin resistance and endothelial function, it might be involved in coronary heart disease (CHD). A biallelic polymorphism within the promoter of TNF-alpha locus at the position -308 has been reported to be associated with TNF production. We have studied the association of this polymorphism with CHD in a Mediterranean non-diabetic and type 2 diabetic population. METHODS: Three hundred and forty one CHD patients (106 with type 2 diabetes), 207 healthy matched control subjects and 135 type 2 diabetic patients without CHD were evaluated. A single nucleotide polymorphism at the promoter TNF-alpha (-308) was analyzed by RFLP-PCR. RESULTS: TNF-alpha (-308) genotype and allele frequencies for A carriers were higher in CHD patients than those observed in the control group (32.3 vs. 23.2%, P=0.03; and 18.8 vs. 12.1%, P=0.0047; respectively) independently of other risk factors. Genotypic analysis revealed that CHD patients with type 2 DM displayed a greater prevalence of the -308 TNF-alpha A allele (40.6%) than controls (23.2%) or CHD patients without type 2 DM (28.5%) (P=0.0056). The odds ratio for CHD in type 2 diabetic patients in presence of -308 TNF-alpha A allele was 2.86 (CI 95%: 1.55-5.32). This difference was observed mainly in diabetic women for the A allele carriers (OR: 4.29; CI 95%: 1.6-11.76). CONCLUSIONS: These results suggest that -308 TNF-alpha gene polymorphism may contribute to CHD risk in patients with type 2 diabetes and it could constitute an useful predictive marker for CHD in type 2 diabetic women.

Abstract: Allelic variants of the tumor necrosis factor-alpha (TNF-alpha) gene seem to contribute to insulin resistance increasing the transcription rate of TNF-alpha. The TNF-alpha -863A allele is associated with a lower expression of TNF-alpha gene and less secretion of the cytokine. To investigate whether an abnormal TNF-alpha system regulation may contribute to early impairment of insulin action in first-degree relatives of patients with type 2 diabetes mellitus (DM), we studied the TNF-alpha -863C/A polymorphism and the soluble fraction of TNF-alpha receptor-2 (sTNFR2) concentration in these subjects in comparison to a control group. A total of 52% of subjects in the relatives' group showed an abnormal oral glucose tolerance (either as impaired glucose tolerance [IGT] or diabetes) and had more features of the insulin resistance syndrome, despite showing similar body composition as controls. The plasma concentration of the sTNFR2 was higher and insulin sensitivity (%S) was lower in the relatives' group than in the controls. Likewise, the TNF-alpha -863A allele was more commonly detected in the control group (10 of 41) than in the relative's group (2 of 36, P =.029). In a multivariate linear regression analysis, neither TNF-alpha -863A allele nor sTNFR2 independently determined %S. Only body mass index (BMI) and the presence of a positive family history of DM were independent determinants of insulin resistance. In summary, our study showed a lower rate of TNF-alpha -863A allele and higher concentrations of sTNFR2 in first-degree relatives of DM subjects. These findings could be included among the genetic, metabolic, and clinical heterogeneity that characterizes the pathophysiology of DM. The presence of abnormalities in the TNF-alpha pathway could predispose to the development of DM in subjects at risk for the disease.

Abstract: Several markers of chronic immune activation have been found in association with obesity and insulin resistance. We aimed to study the interaction of adiponectin with chronic inflammation and known components of the insulin resistance syndrome. Insulin sensitivity (minimal model analysis) and plasma soluble fractions of TNF-alpha receptor 1 (sTNFR1) and 2 (sTNFR2), adrenal and thyroid function, and adiponectin were evaluated in 68 apparently healthy subjects. An additional group of type 2 diabetic patients (n = 19) similarly studied, except for insulin sensitivity, were also included in the analysis. As reported by others, serum adiponectin concentrations were higher in women than in men (13.55 +/- 9.79 vs. 8.64 +/- 7.83 mg/liter; P = 0.018). They were also higher in healthy subjects compared with diabetic patients (10.35 +/- 8.48 vs. 7.41 +/- 8.31 mg/liter; P = 0.021). As expected also, circulating adiponectin was significantly associated with waist to hip ratio (r = -0.28; P = 0.013), diastolic blood pressure (r = -0.25; P = 0.027), fasting plasma high-density lipoprotein cholesterol (r = 0.35; P = 0.001), triglycerides (r = -0.37; P = 0.001), and insulin sensitivity (r = 0.30; P = 0.011). Additionally, subjects in the higher quartile of circulating adiponectin had lower sTNFR2 concentrations (3.05 vs. 4.37 microg/liter; P = 0.012), a trend to lower sTNFR1 concentrations (1.76 vs. 2.20 microg/liter; P = 0.055), higher concentration of serum morning cortisol (16.86 vs. 13.52 microg/dl; P = 0.027), and higher serum free T(4) levels (1.31 vs. 1.20 ng/dl; P = 0.038). Multiple regression analysis models were constructed to predict adiponectin concentrations. Predictive variables in these models included insulin sensitivity, waist to hip ratio and free T(4), contributing to 17%, 10%, and 8% of adiponectin variance, respectively, These findings suggest that circulating adiponectin differentially modulates insulin action and that thyroid-axis, inflammatory cytokines, and the adrenal cortex might intervene in this modulation.

Abstract: Insulin resistance is increasingly recognized as a chronic, low-level, inflammatory state. Hyperinsulinemia and insulin action were initially proposed as the common preceding factors of hypertension, low high-density lipoprotein cholesterol, hypertriglyceridemia, abdominal obesity, and altered glucose tolerance, linking all these abnormalities to the development of coronary heart disease. The similarities of insulin resistance with another inflammatory state, atherosclerosis, have been described only in the last few decades. Atherosclerosis and insulin resistance share similar pathophysiological mechanisms, mainly due to the actions of the two major proinflammatory cytokines, TNF-alpha and IL-6. Genetic predisposition to increased transcription rates of these cytokines is associated with metabolic derangement and simultaneously with coronary heart disease. Dysregulation of the inflammatory axis predicts the development of insulin resistance and type 2 diabetes mellitus. The knowledge of how interactions between metabolic and inflammatory pathways occur will be useful in future therapeutic strategies. The effective administration of antiinflammatory agents in the treatment of insulin resistance and atherosclerosis is only the beginning of a promising approach in the management of these syndromes.

Abstract: Iron-related insulin-resistance is improved by iron depletion or treatment with iron chelators. The aim of this study was to evaluate insulin sensitivity and insulin secretion after blood letting in patients who had high-ferritin type 2 diabetes and were randomized to blood letting (three phlebotomies [500 ml of blood] at 2-week intervals, group 1) or to observation (group 2). Insulin secretion and sensitivity were tested at baseline and 4 and 12 months thereafter. The two groups were matched for age, BMI, pharmacologic treatment, and chronic diabetic complications. All patients were negative for C282Y mutation of hereditary hemochromatosis. Baseline glycated hemoglobin (6.27 +/- 0.9% vs. 6.39 +/- 1.2%), insulin sensitivity (2.75 +/- 1.8 vs. 3.2 +/- 2.1 mg.dl(-1).min(-1)), and area under the curve for C-peptide (AUC(C-peptide); 38.7 +/- 11.6 vs. 37.6 +/- 14.1 ng.ml(-1).min(-1)) were not significantly different between the two groups of patients. Body weight, blood pressure, blood hematocrit levels, and drug treatment remained essentially unchanged during the study period. As expected, serum ferritin, transferrin saturation index, and blood hemoglobin decreased significantly at 4 months only in patients who received blood letting. In parallel to this changes, blood HbA(1c) decreased significantly only in group 1 subjects (mean differences, -0.61; 95% CI, -0.17 to -1.048; P = 0.01). AUC(C-peptide) decreased by -10.2 +/- 6.3% after blood letting. In contrast, a 10.4 +/- 6.4% increase in AUC(C-peptide) was noted in group 2 subjects at 4 months (P = 0.032). At 12 months, AUC(C-peptide) returned to values not significantly different from baseline in the two groups of subjects. At 4 months, the change in insulin sensitivity from baseline was significantly different between the two groups (80.6 +/- 43.2% vs. -8.6 +/- 9.9% in groups 1 and 2, respectively, P = 0.049). At 12 months, the differences between the two groups were even more marked (55.5 +/- 24.8% vs. -26.8 +/- 9.9%; P = 0.005). When the analysis was restricted to those subjects who completed the follow-up until 12 months, results did not show differences compared with the changes observed at 4 months, except for insulin sensitivity. A statistically significant increase in insulin sensitivity was observed in the blood-letting group (from 2.30 +/- 1.81 to 3.08 +/- 2.55 mg.dl(-1).min(-1) at 4 months, to 3.16 +/- 1.85 mg.dl(-1).min(-1) at 12 months; P = 0,045) in contrast with group 2 subjects (from 3.24 +/- 1.9 to 3.26 +/- 2.05 mg.dl(-1).min(-1) at 4 months, to 2.31 +/- 1.35 mg.dl(-1).min(-1) at 12 months). In summary, blood letting led simultaneously to decreased blood HbA(1c) levels and to changes in insulin secretion and insulin resistance that were significantly different from those observed in a matched observational group of subjects with high-ferritin type 2 diabetes. The mechanisms for improvement in peripheral insulin sensitivity after blood letting should be investigated further.

Abstract: AIM: The hypothesis that patients with hyperglycaemia during admission, regardless of previous diagnosis of diabetes, have worse prognosis than those with normal glucose values is controversial. The objective was to assess the role of hyperglycaemia on short-term mortality after myocardial infarction (MI). METHODS AND RESULTS: A cohort study nested in a prospective registry of MI patients in the reference hospital of Gerona, Spain was performed. All consecutive MI patients under 75 were registered between 1993 and 1996. Patient and clinical characteristics, including previous diagnosis of diabetes, glycaemia on admission and in the next four days, were recorded. Patients with glycaemia on admission or four day mean glycaemia >6.67 mmol/l were considered hyperglycaemic. The main outcome measure was mortality at 28 days. Of 662 patients with MI included, 195 (29.7%) had previously known diabetes mellitus, but 457 (69.0%) had glycaemia >6.67 mmol/l on admission. Patients with hyperglycaemia on admission were older, more often female, more frequently had a previous diagnosis of diabetes, developed more complications, and had higher 28 day mortality. The effect of admission glycaemia >6.67 mmol/l on 28 day mortality was independent of major confounding factors, particularly previous diagnosis of diabetes (OR=4.20, 95% confidence intervals 1.18 to 14.96). CONCLUSIONS: Higher 28 day mortality was observed among MI patients with glycaemia on admission >6.67 mmol/l compared with patients with lower levels, independently of major confounding variables and, particularly, previous diagnosis of diabetes. This early, simple, and inexpensive marker of bad prognosis after MI should prompt the application of more aggressive treatment of MI and risk factors and, probably, of glycaemia during admission.

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Abstract: Both infections and injuries activate the immunity system, leading to a series of metabolic changes which place the organism at a disadvantage and contribute to its elimination, thus facilitating the repair of the injured tissue. The study of the actions of tumour necrosing factor alpha (TNF-alpha) and interleukin-6 (IL-6), classically implicated in inflammatory processes and in fighting infection, has revealed numerous metabolic effects. Some gene polymorphisms of TNF-alpha and IL-6 (associated with a different TNF-alpha or IL-6 transcription rate) and the plasma concentrations of the soluble TNF-alpha receptor are found to be simultaneously associated with resistance to insulin, the proportion of body fat and with the mortality linked with different chronic infections. Therefore, it seems that the immune system is designed to fight infections effectively and to provide certain survival advantages during periods of intermittent fasting so frequent in the past. By inducing a resistance to insulin in the muscles, the energy substrates would thus be reserved for neuronal metabolism. In the presence of an insulin-resistance genotype and a westernization of the environment (carbohydrate-rich diet, an increase in saturated fat, low fibre and sedentary lifestyle), a genotype with a high cytokine response will contribute to a worsening of the resistance to insulin and, finally, to type 2 diabetes mellitus and atherosclerosis. The advantages for our ancestors of a large cytokine response (eradication of the lesion) or moderate resistance to insulin (protection against food shortage) have led in the present day to the development of atherosclerosis now that the characteristics of the environment have changed. It is contended that these changes constitute examples of good adaptation to the environment or poor concordance between our current lifestyle and our genome.

Abstract: Tumor necrosis factor-alpha (TNF-alpha) is increasingly recognized as a key component in the development of insulin resistance and increased blood pressure. In a sample of 368 individuals, the ratio of soluble TNF-alpha receptors (sTNFR2/sTNFR1) correlated positively with systolic and diastolic blood pressure (P < 0.01). This ratio was significantly greater in type 2 diabetic subjects (DM-2) than in type 1 diabetic patients and was greater than in control nondiabetic subjects (P < 0.00001). The TNF-alpha receptor 1 (TNFR1) density in peripheral blood monocytes was similar in DM-2 patients and in nondiabetic subjects. After phorbol 12-myristate 13-acetate, TNFR1 shedding was significantly decreased in DM-2 compared with control subjects, and it was directly associated with insulin sensitivity (r = 0.54, P = 0.03). Serum sTNFR1 concentration was also linked to the vasodilatory response to glyceryltrinitrate (P = 0.01). Conversely, TNF-alpha receptor 2 shedding was negatively associated with insulin sensitivity (r = -0.54, P = 0.03), whereas shedding of L-selectin showed no significant association. After exercise-induced lowering of blood pressure, a parallel decrease in sTNFR2/sTNFR1 was observed in DM-2 patients. Our findings suggest that insulin resistance and blood pressure are linked to altered shedding of TNF-alpha receptors in DM-2. The latter seems reversible and is not genetically determined.

Abstract: Emerging scientific evidence has disclosed unsuspected influences between iron metabolism and type 2 diabetes. The relationship is bi-directional--iron affects glucose metabolism, and glucose metabolism impinges on several iron metabolic pathways. Oxidative stress and inflammatory cytokines influence these relationships, amplifying and potentiating the initiated events. The clinical impact of these interactions depends on both the genetic predisposition and the time frame in which this network of closely related signals acts. In recent years, increased iron stores have been found to predict the development of type 2 diabetes while iron depletion was protective. Iron-induced damage might also modulate the development of chronic diabetes complications. Iron depletion has been demonstrated to be beneficial in coronary artery responses, endothelial dysfunction, insulin secretion, insulin action, and metabolic control in type 2 diabetes. Here, we show that iron modulates insulin action in healthy individuals and in patients with type 2 diabetes. The extent of this influence should be tested in large-scale clinical trials, searching for the usefulness and cost-effectiveness of therapeutic measures that decrease iron toxicity. The study of individual susceptibility and of the mechanisms that influence tissue iron deposition and damage are proposed to be valuable in anticipating and treating diabetes complications.

Abstract: OBJECTIVE: In a recent study, iron chelation with deferoxamine led to improvement of endothelial dysfunction in patients with coronary artery disease. We tested the hypothesis that decreasing circulating iron stores might improve vascular dysfunction in patients with type 2 diabetes and increased serum ferritin concentration. RESEARCH DESIGN AND METHODS: A total of 28 type 2 diabetic male patients with serum ferritin levels >200 ng/ml ( approximately 18% of consecutive type 2 diabetic men attending our outpatient clinic) were randomized to iron depletion (three extractions of 500 ml blood at 2-week intervals; group 1A) or to observation (group 1B). C282Y mutation was absent in all patients. Vascular reactivity (high-resolution external ultrasound) was evaluated at baseline and at 4 and 12 months thereafter. The two groups of patients were matched for age, BMI, pharmacological treatment, and chronic diabetic complications. RESULTS: Endothelium-dependent vasodilation remained essentially unchanged in both groups of patients. In contrast, the vasodilation induced by glyceryl trinitrate (GTN) improved significantly after iron depletion (P = 0.006). These changes occurred in parallel to decreases in transferrin saturation index and HbA(1c) levels (-0.6%, P < 0.05) only in group 1A patients. The best predictor of the modifications in endothelium-independent vasodilation was the change in HbA(1c) levels. Changes in endothelium-independent vasodilation also correlated with the change in serum ferritin (r = -0.45, P = 0.04). At 12 months, transferrin saturation index and GTN-induced vasodilation returned to values similar to those at baseline in both groups of subjects. CONCLUSIONS: Iron depletion improves vascular dysfunction in type 2 diabetic patients with high ferritin concentrations. The mechanisms by which these changes occur should be further investigated.

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Abstract: OBJECTIVE: To analyze the relationship between the peroxisome proliferator-activated receptor-gamma (PPARgamma2) Pro12Ala variant and type-2 diabetes mellitus and its correlation with some cytokine determinants of insulin resistance such as tumor necrosis factor (TNF)-alpha and leptin. METHODS: The PPARgamma2 Pro12Ala genetic polymorphism was studied in 167 type-2 diabetic patients and 63 healthy controls. Serum leptin and plasma-soluble TNF-R2 were measured. RESULTS: Women carriers of the Pro12Ala mutation exhibited higher leptin levels than women non-carriers (median 31.4 vs. 17.5 ng/ml; p < 0.005). sTNF-R2 levels did not show differences between the two genotypes. Analysis by the multiple linear regression model of leptin-body mass index controlled by the PPARgamma2 genotype showed that leptin levels were determined by the Pro12Ala mutation in type-2 diabetic women but not in men. CONCLUSIONS: PPARgamma2 seems to be implicated in leptin homeostasis in type-2 diabetic women.

Abstract: It has been suggested that a low grade inflammatory state could predispose for developing insulin resistance and contribute to the development of obesity and type 2 diabetes. Corticosteroid-binding globulin (CBG), the main plasma protein transport for cortisol, has been shown to be negatively regulated by insulin and IL-6, at least in vitro, suggesting that insulin resistance and inflammation may both contribute to decreasing CBG levels. In the present study we measured CBG concentrations in a human healthy population and investigated the relationships of CBG with anthropometric and biochemical markers for inflammation and/or insulin resistance. The data showed that the mean serum CBG level was significantly lower in males (n = 151) than in females (n = 113; 32.5 +/- 9.1 vs. 39.2 +/- 13.9 mg/liter; P < 0.0001). In both sexes serum CBG levels were correlated negatively with age (r = -0.12; P = 0.04), body mass index (r = -0.31; P < 0.0001), waist to hip ratio (WHR; r = -0.39; P < 0.0001), systolic (r = -0.15; P < 0.01) and diastolic (r = -0.15; P = 0.01) blood pressures, and HOMA, an index of insulin resistance (r = -0.12; P = 0.04). In addition, the CBG concentration was negatively associated with serum IL-6 concentrations (r = -0.23; P = 0.017) and with the soluble fraction of TNFalpha receptors, soluble TNF receptor 1 (sTNFR1; r = -0.35; P < 0.0001), and sTNFR2 (r = -0.56; P < 0.0001) in women. A stepwise regression analysis using CBG as an independent variable showed that sex (P < 0.00001), body mass index (P = 0.0002), and HOMA (P = 0.0005), but not systolic blood pressure, diastolic blood pressure, IL-6, sTNFR1, or sTNFR2, constituted significant independent factors that explained 21% of the CBG variance (14%, 2%, and 5%, respectively). In a subsample of 120 men and 68 women, fasting serum free cortisol (calculated as the ratio fasting cortisol/CBG) was significantly associated with WHR (r = 0.24; P = 0.001), systolic (r = 0.18; P = 0.01) and diastolic (r = 0.19; P = 0.007) blood pressures, and HOMA value (r = 0.20; P = 0.005), but not with BMI or age. BMI (P < 0.0001), free cortisol (P = 0.003), and CBG (P = 0.009), but not WHR and age, contributed to 20%, 6%, and 8%, respectively, of HOMA variance in women in a multiple regression analysis. In this model only BMI (P < 0.0001) independently contributed to HOMA variance in men. These findings support the hypothesis that the CBG level is an interesting indicator for both insulin resistance and low grade inflammation. Whether the decrease in CBG levels is genetic by nature or directly associated to increased insulin and/or IL-6 merits further investigation. Nevertheless, because CBG has been shown to be expressed by the adipose tissue, decreased CBG could create locally increased cortisol disposal, with no change in circulating cortisol, and facilitate fat accumulation, insulin resistance, and type 2 diabetes.

Abstract: Bone mass is known to be under genetic control. Interleukin-1 (IL-1), interleukin-6 (IL-6) and TNF-alpha are strong inductors of bone resorption. The estrogenic deficiency that occurs during menopause leads to an increase in the production of these cytokines. We analyzed the genetic susceptibility of several polymorphisms of the interleukin-1 receptor antagonist (IL-1ra), IL-6 and TNF-alpha genes in lumbar spine and hip bone mass in a sample of post-menopausal Caucasian Mediterranean women with osteoporosis. 104 post-menopausal osteoporotic women (58.6+/-4.8 yr) and 51 post-menopausal women without osteoporosis as the control group (57.2+/-4.5 yr) were studied. The osteoporotic group was in turn sub-classified into severe and non-severe osteoporosis. The variable number of tandem repeats IL1-ra, IL-6 SfaNI and TNF-alpha NcoI genetic polymorphisms were studied. Biochemical markers of bone turnover were measured in blood and urine. Women carrying the A2 allele (A2+) of the IL-1ra gene showed greater BMD in the lumbar spine (p=0.02) and hip (p=0.006), compared to those not carrying the allele (A2-). The IL-6 polymorphism studied in its 5' flanking region did not show any association with BMD values. The TNF-alpha gene G allele was associated with a greater bone mass in the non-severe osteoporotic subgroup, both in the lumbar spine (p=0.0007) and in the hip (p=0.02). Likewise, genotype combination A2+GG was associated to a greater hip BMD at the femoral neck and Ward triangle levels (p=0.02). We conclude that both IL-1ra and TNF-alpha can be candidate loci to be studied in the susceptibility to develop post-menopausal osteoporosis.

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Abstract: OBJECTIVES: To estimate the prevalence of obesity and overweight in the population of Girona (Spain) between 1995 and 1999 and to divide the prevalences in geographical areas according to age and sex. METHODS: Height and weight were directly measures in 24,554 health care consumers older than 14 years (10,595 men and 13,959 women) treated in four primary health care areas: Girona 1, Girona 4, Salt and Camprodon and in one primary health care center in the province of Girona. Body mas index (BMI) was calcuted by dividing weight in kilograms bye height in meters squared. Obesity was defined as grades II and III of Garrow's index (BMI >= 30 kg/m2) and overweight as degree I (25 kg/m2 >= BMI < 30 kg/m2). Because the sample was not randomized, the prevalences were adequately weighted. The comparison between prevalences in two different primary health care areas for each sex (in the same Garrow's index and age group) was carried out using a parametric test of differences in proportions (Student's t-test). A hierarchical logistic regression was used to compare prevalences in the same grade Garrow's index, controlling for age and sex. RESULTS: The prevalence of obesity was estimated as 15.6% in men aged from 20-74 years (from 14.0% in Girona 1 to 22.4% in Camprodon) and 17.5% for women (15.6% in Girona 1, 22.7% in Camprodon). The weighted mean was 16.7%. The prevalence of overweight was 44% in men and 33% in women and the weighted mean was 37.8%. The prevalence of obesity was graduated with statistically significant differences between Girona 1, Salt, Girona 4, Camprodon and Sils. CONCLUSIONS: The estimates of the prevalences of obesity and overweight obtained in this study were closer to those of other studies in similar populations than previously believed. Indeed, the prevalences may be similar to those of the European Union and, in some age groups, to those of the United States.

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Abstract: BACKGROUND: Oral glucose tolerance test was evaluated, as well as, insulin sensitivity/secretion in a group of subjects at risk for type 2 diabetes mellitus. METHOD: Metabolic profile of subjects included in the new category, impaired fasting glucose (IFG), was also evaluated. RESULTS: IFG and impaired glucose tolerance identify different alterations in glucose homeostasis. CONCLUSIONS: Those subjects with IFG are heterogeneous in their oral glucose tolerance. They display defects not only in insulin sensitivity but also in their capacity to compensate for it.

Abstract: There is increasing evidence that systemic inflammation and insulin resistance constitute interrelated events that contribute to atherosclerosis. We studied the effect of the association between circulating interleukin 6 (IL-6) levels, one of the major mediators of inflammation, and C-reactive protein on insulin resistance and blood pressure in 228 healthy volunteers. The plasma IL-6 concentration was significantly and similarly associated with systolic (SBP) and diastolic (DBP) blood pressure, fasting insulin, and the fasting insulin resistance index (FIRI) in all subjects. When smokers were excluded from the analysis, plasma IL-6 levels correlated with percent fat mass (r = 0.19; P = 0.02), absolute fat mass (r = 0.17; P = 0.03), SBP, DBP, fasting insulin levels, and FIRI. The latter associations persisted after controlling for body mass index (r = 0.15 and r = 0.19; P = 0.02 and P: = 0.0004 for SBP and DBP, respectively; r = 0.24 and r = 0.19, P = 0.004 and P = 0.03, for fasting insulin and FIRI, respectively). Gender and smoking status significantly influenced the results. Although IL-6 levels were significantly associated with fasting insulin and FIRI in men, these significant correlations were not observed in women. Conversely, although IL-6 levels were significantly associated with SBP and DBP in women, these coefficients were not statistically significant in men. All of these associations were lost among smokers and remained significant in nonsmokers. As IL-6 is the major mediator of the acute phase response by hepatocytes and induces the synthesis of C-reactive protein (CRP), we also controlled for the latter. Serum CRP levels correlated significantly with IL-6 in all the subjects, but mainly in nonsmokers and men. Of note was that this significant relationship was lost among smokers. CRP was associated with fasting insulin (r = 0.28; P < 0.0001) and FIRI (r = 0.25; P < 0.0001), but not with SBP or DBP (P = NS), in all subjects. Unlike IL-6, the associations between CRP and these parameters were similar in men and women and in smokers and nonsmokers. For insulin and FIRI they were stronger in women and in nonsmokers. CPR significantly correlated with the WHR only in men (r = 0.22; P = 0.01). Using multiple linear regression in a stepwise manner to predict circulating IL-6 levels, smoking status (P = 0.0059) and FIRI (P = 0.03), but not fat mass or SBP, independently contributed to 11% of its variance in men. When CRP was introduced into the model, the latter (P < 0.0001) and smoking status (P = 0.02), but not FIRI, fat mass, or SBP, contributed to 33% of the variance in IL-6 levels. In women, only SBP (P = 0.04) contributed to 5% of its variance. When CRP was introduced into the model, again only SBP (P = 0.01) contributed to 10% of the variance in IL-6 levels. In 25 of these subjects, insulin sensitivity was determined using the frequently sampled iv glucose tolerance test with minimal model analysis, and circulating IL-6 levels were strongly associated with the insulin sensitivity index (r = -0.65; P < 0.0001). Again, this relationship was even stronger in men (r = -0.75; P < 0.001) and was not significant in women (r = -0.26; P = NS). In all of these subjects, only insulin sensitivity (P = 0.0037), not fat mass, contributed to 21% of the variance of IL-6 levels in a multiple linear regression analysis. In summary, circulating IL-6 levels, by inducing either hypertension in women or insulin resistance in men, constitute a significant proatherogenic cytokine. The mechanisms of these associations should be further investigated.

Abstract: BACKGROUND: Interleukin 6 (IL-6) is thought to play important roles in the development of reactive thrombocytosis caused by inflammation by its stimulatory effect on megakaryocytopoiesis. A G/C polymorphism of the IL-6 gene at position -174 has been found to be associated to different transcription rates. Specifically, subjects with the CC genotype showed lower plasma IL-6 levels compared with GC or GG subjects. Given this difference in transcription rates of IL-6 we speculated on different platelet count according to this IL-6 polymorphism. METHODS: The G/C polymorphism of the IL-6 gene at position -174, serum IL-6 concentration and platelet count were prospectively analyzed in 59 (25 women) consecutive healthy subjects. RESULTS: Subjects who were homozygotes for the C allele at position -174 of the IL-6 gene (Sfa NI genotype) showed significantly lower platelet count than carriers of the G allele, despite similar age, sex, body mass index and proportion of smokers (205400 +/- 44088 vs 239818 +/- 60194, p = 0.047). This was in parallel to differences in peripheral white blood cell count (5807 +/- 1671 vs 6867 +/- 1192 x 10(9)/ml, p = 0.01). CONCLUSION: This is the first description, to our knowledge, of a genetical influence on basal platelet counts, which appears to be partially dependent on a polymorphism of the IL-6 gene, even in the absence of inflammation.

Abstract: BACKGROUND: The World Health Organization (WHO) defines obesity as a condition of excessive fat accumulation to the extent that health and well-being are affected. For population studies, the measurement of weight, corrected for height, is still the method of choice (BMI). In Caucasian populations, the BMI cut-off point for obesity (30 kg/m2) corresponds with a percent body fat (PFM) of over 25% in young adult males and 35% in young adult females. However, the relation between BMI and PFM is not uniform among populations. It is important to define in each population the threshold of BMI which corresponds to the definition of obesity. PATIENTS AND METHOD: BMI was calculated in 282 subjects. PFM was analyzed using Bio-electrical impedance. Blood pressure, serum glucose and insulin, and the fasting insulin resistance index were also determined in all subjects to analyze the metabolic impact.Results: The PFM of 25% in males and 35% in females corresponded to a BMI of 27.5 and 27.4 kg/m2, respectively. The slope of the relationship between the degree of obesity and comorbilities (insulinemia, fasting insulin resistance index and blood pressure) was strengthened above 26 kg/m2 in men and 24 kg/m2 in women. CONCLUSIONS: BMI that corresponds to a PFM previously defined as obesity is lower in our population in comparison with other Caucasian populations. Our results confirm that is impossible to compare the prevalence of obesity among populations using exclusively the BMI. It will be important to define, using reference methods, whether these findings have physiological impact or not, and if this cut-off of BMI determines an increment in cardiovascular and overall mortality using epidemiological approaches.

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Abstract: OBJECTIVE: Different facts suggest that the insulin growth factor (IGF)/ insulin growth factor-binding protein (IGFBP) system may be regulated by factors other than growth hormone. It has been proposed that, in healthy subjects, free IGF-I plays a role in glucose metabolism. The role of free IGF-I in glucose homeostasis in insulin resistance is poorly understood. This study was undertaken to evaluate the effects of acute changes in plasma glucose and insulin levels on free IGF-I and IGFBP-1 in obese and non-obese subjects. RESEARCH METHODS AND PROCEDURES: Nineteen lean and 24 obese subjects were investigated. A frequently sampled intravenous glucose tolerance test was performed. Free IGF-I and IGFBP-1 were determined at 0, 19, 22, 50, 100, and 180 minutes. RESULTS: Basal free IGF-I levels tended to be higher and IGFBP-1 lower in obese than in lean subjects. IGFBP-1 levels inversely correlated with basal insulin concentration. To determine the effects of insulin on the availability of free IGF-I and IGFBP-1, changes in their plasma concentrations were measured during a frequently sampled intravenous glucose tolerance test. After insulin administration, a significant suppression of free IGF-I at 22% was observed in lean subjects. In contrast, plasma-free IGF-I levels remained essentially unchanged in the obese group. The differences between both groups were statistically significant at 100 minutes (p < 0.01) and 180 minutes (p < 0.05). Serum IGFBP-1 was suppressed to a similar extent in both groups. DISCUSSION: These data suggest that the concentrations of free IGF-I and IGFBP-1 are differentially regulated by obesity. Obesity-related insulin resistance leads to unsuppressed free IGF-I levels.

Abstract: Atherosclerosis is increasingly recognized as an inflammatory disease. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a proinflammatory cytokine, recently implicated as a prominent component of the regulatory network involved in atherogenesis. We aimed to study the relationship between circulating GM-CSF levels and serum fatty acid (FA) composition in 78 healthy subjects. The latter was analyzed by gas-liquid chromatography and GM-CSF by a high-sensitivity commercial enzyme-linked immunosorbent assay (ELISA). Among women (n = 40), serum GM-CSF levels were found to be positively associated with the proportion of palmitic acid (C16:0) and negatively with linoleic acid (C18:2omega-6), docosahexaenoic acid (DHA, C22:6omega-3), and the proportion of total essential FA. After excluding smoking women (n = 6), the associations among GM-CSF and serum linoleic acid concentration (r = -0.49, P =.003), arachidonic acid (r = -0.52, P =.001), and DHA (r = -0.34, P =.04) were strengthened. The ratio of palmitic to linoleic and DHA acids was the single best predictor of serum GM-CSF in all subjects. Together with arachidonic acid, it contributed to 22% of the GM-CSF variance in women, after taking into account the effects of age, body mass index (BMI), blood pressure, and smoking status. None of these associations were observed among men. In conclusion, serum FA composition is associated with circulating GM-CSF specifically in women. As human arterial and venous smooth muscle cells release GM-CSF, and treatment of endothelial cells with oxidized low-density lipoproteins results in a rapid expression of GM-CSF, the mechanisms involved in these associations and the sex-linked differences should be further explored.

Abstract: We have previously described that serum corticosteroid binding globulin (CBG) concentrations are associated with insulin secretion. The present study was designed to evaluate the effects of changing insulin concentrations, both endogenous and after exogenous insulin administration, on circulating CBG levels in vivo. Serum CBG concentrations were measured during an insulin-modified frequently sampled intravenous (IV) glucose tolerance test (FSIVGT) in 14 lean and 19 obese otherwise healthy subjects with varying degrees of glucose tolerance. Acute insulin response to glucose (AIRg) correlated significantly with serum CBG concentrations at time 0 (r = -.38, P =.029), 22 minutes (r = -.41, P =.01), 50 minutes (r = -.41, P =.01), and 180 minutes (r = -.39, P =.02). Insulin sensitivity (S(I)) was not associated with serum CBG concentration at time 0 (r = -.16, P = not significant [NS]), but correlated significantly with CBG concentration at 22 minutes (r = -.41, P =.02) and 50 minutes (r = -.35, P =.048) of the FSIVGT. In lean subjects, serum CBG concentration decreased significantly after IV insulin from 37.9 +/- 5.4 to 35.4 +/- 3 mg/L (P =.02) and returned to basal levels thereafter. In contrast, obese, glucose-tolerant subjects had lower CBG levels than lean and obese glucose intolerant subjects (33.8 +/- 3.0 v 37.9 +/- 5.4 and 39.8 +/- 4.4 mg/L, respectively), and their serum CBG concentrations remained unchanged during FSIVGT. Mean serum-free insulin-like growth factor-I (IGF-I) concentrations steadily declined from 1.21 +/- 0.81 to 0.8 +/- 0.36 microg/L during the FSIVGT, and this effect was restricted to lean subjects. Basal serum-free IGF-I did not correlate with CBG levels at time 0, but correlated inversely with the serum CBG concentrations at 22 minutes (r = -.36, P =.04). Stepwise multivariant analysis showed that AIRg (P =.035) and S(I) (P =.046), but not free IGF-I levels, independently contributed to 28% of CBG variance at 22 minutes. These results suggest that insulin, but not IGF-I, constitutes an important negative regulator of CBG liver synthesis. Endogenous and exogenous insulin do not affect serum CBG concentrations in insulin-resistant obese subjects with preserved or decreased insulin secretion. Obese glucose-tolerant subjects are hypothesized to exhibit tonically inhibited serum CBG levels. In contrast, in lean subjects, the higher the insulin secretion the lower the serum CBG concentration. The mechanisms of this CBG inhibitory effect exerted by insulin and its implication on cortisol homeostasis and fat distribution in humans await further investigations.

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Abstract: BACKGROUND: A direct relationship between body mass index (BMI), visceral adipose tissue, insulin levels and growth hormone-binding protein (GHBP) activity has consistently been reported. It was recently described that GHBP directly depends on serum leptin levels. Since leptin co-varies with insulin secretion and/or sensitivity, we aimed to study the influence of these variables on plasma GHBP activity. SUBJECTS: In order to isolate the effects of obesity per se from those of insulin secretion, three groups of subjects were prospectively studied: 14 lean, 10 obese and nine obese subjects with glucose intolerance. MEASUREMENTS: The percentage of body fat was measured through bioelectric impedance. Insulin sensitivity and secretion were determined through a frequently sampled intravenous glucose tolerance test with minimal model analysis. Serum leptin was measured by radioimmunoassay. GHBP activity was determined by the high performance liquid chromatography-gel filtration method. RESULTS: Plasma GHBP activity was found to correlate with BMI (r = 0. 65, P < 0.0001), fat mass (r = 0.51, P = 0.003), waist circumference (r = 0.64, P < 0.0001), waist-to-hip ratio (r = 0.42, P = 0.01), insulin sensitivity (SI, r = - 0.61, P = 0.0001), insulin secretion (expressed as the acute insulin response to intravenous glucose, AIRg) (r = 0.48, P = 0.006) and leptin concentration (r = 0.49, P = 0.004). The associations with SI (r = - 0.42, P = 0.02) and AIRg (r = 0.38, P = 0.03) persisted even after controlling for fat mass. Since insulin secretion and insulin sensitivity usually covary in glucose tolerant subjects (an increased insulin secretion is necessary to compensate a decreased insulin sensitivity), we constructed a multiple linear regression to predict GHBP activity. In this model, SI (P = 0.005), AIRg (P = 0.02) and SD score-leptin (P = 0.03) independently contributed to 34, 10 and 8% of the variability in serum GHBP activity. CONCLUSIONS: Our results suggest that plasma GHBP activity is simultaneouslly influenced by insulin secretion and sensitivity and leptin. Perhaps leptin, through increased insulin secretion, might induce GHBP/GH secretion, explaining the normal to high insulin-like growth factor (IGF)-I levels found in overnutrition.

Abstract: Several lines of evidence indicate that interleukin-6 (IL-6) is involved not only in the hepatic acute phase response but also in adipose tissue metabolism, lipoprotein lipase activity, and hepatic triglyceride secretion. A polymorphism in the IL-6 gene, associated with differences in IL-6 transcription rate, has been recently described. We aimed to study whether this IL-6 gene polymorphism leads to differences in fasting and postglucose load plasma lipids in healthy subjects. Subjects with G at position -174 of the IL-6 gene were similar in age, sex, body mass index, and waist to hip ratio in comparison with carriers of the C allele. However, G carriers showed almost twice plasma triglycerides (1.5 +/- 0.9 vs. 0.90 +/- 0.37 mmol/L; P = 0.01), very low-density lipoprotein (VLDL)-triglycerides (0.97 +/- 0.69 vs. 0.42 +/- 0.2 mmol/L; P = 0.002), higher fasting (881 vs. 458 micromol/L; P = 0.01), and postglucose load free fatty acids (299 vs. 90.5 micromol/L; P = 0.03), slightly lower high-density lipoprotein-2 cholesterol (0.25 +/- 0.14 vs. 0.39 +/- 0.26 mmol/L; P = 0.058), and similar cholesterol and LDL-cholesterol levels than carriers of the C allele. Serum IL-6 levels correlated positively with fasting triglycerides, VLDL-triglycerides, and postload free fatty acids (r = 0.61, 0.65 and 0.60, respectively; P < 0.001) and negatively with high-density lipoprotein-cholesterol (r = -0.42, P < 0.05). A tendency toward higher serum IL-6 levels was observed among G carriers (9.9 +/- 6.9 vs. 6.85 +/- 1.7 pg/mL; P = 0.09). The -174G construct was recently reported to show higher expression of IL-6 in He La cells and was associated with higher plasma IL-6 levels than the -174C allele. Thus, the results of the present study suggest that subjects with the G allele, associated to higher IL-6 secretion, are prone to lipid abnormalities. Whether this polymorphism contributes to lipid alterations associated with other metabolic disorders awaits additional studies.

Abstract: BACKGROUND: Both insulin resistance and cortisol binding globulin (CBG) capacity have been found to correlate with plasma free fatty acid (FFA) concentration. OBJECTIVE: To examine the changes in CBG binding with varying degrees of insulin resistance and plasma FFA levels. SUBJECTS AND METHODS: Anthropometric parameters, serum cortisol levels, plasma CBG, CBG binding and insulin sensitivity (using the frequently sampled intravenous glucose tolerance test with minimal model analysis) were measured in a group of 38 healthy subjects (19 men, mean age 36.2 +/- 1.9; body mass index (BMI) 28.8 +/- 1.2, range 22.2-35.7), and 19 women, age 34.9 +/- 1.4; BMI 28.1 +/- 0.8, range 19-37.9)]. RESULTS: Plasma CBG levels did not differ between men and women. In men, CBG binding was associated with several parameters of the insulin resistance syndrome, including area under the curve for glucose during an oral glucose tolerance test (MBG, r = 0.45, P = 0.04), fasting insulin (r = 0.66, P = 0. 002), plasma triglycerides (r = 0.75, P < 0.0001), VLDL-triglycerides (r = 0.59, P = 0.007), fasting FFA (r = 0.72, P = 0.002), uric acid (r = 0.57 (P = 0.01) and insulin sensitivity (SI, r = - 0.58, P = 0.008). Free cortisol (estimated as the ratio of cortisol to CBG) was not associated with waist-to-hip ratio (WHR) or parameters of insulin sensitivity. In contrast to men, CBG binding was not associated with MBG, fasting insulin, plasma triglycerides, VLDL-triglycerides, FFA, uric acid or SI (all P = NS) in women. Serum free cortisol, however, correlated positively with WHR (r = 0. 62, P = 0.02) and negatively with SI (r = - 0.68, P = 0.01) in obese women. A multiple linear regression to predict CBG binding was constructed, with plasma CBG concentration and insulin sensitivity as independent variables. In this model, only SI entered the equation at a statistically significant level (P = 0.0012) contributing to 52% of the variance in CBG binding in men. When plasma FFA levels were added to the model, both SI (P = 0.04) and FFA levels (P = 0.039) contributed to 66% of the variance of CBG binding in men. In women, both plasma CBG concentration (P = 0.0005) and insulin sensitivity (P = 0.047) entered the equation at a statistically significant level, contributing to 60% of the variance in CBG binding. When plasma FFA levels were added to the model, only plasma CBG concentration (P = 0.043) was found to significantly contribute to 38% of the variance in CBG binding. The latter finding suggests that FFA levels constituted a confounding variable in the association between SI and CBG binding in women. CONCLUSIONS: Both plasma free fatty acid and insulin sensitivity influence cortisol binding globulin binding capacity in men. Whether cortisol binding globulin binding is a factor implicated in the pathophysiology of insulin resistance or represents an adaptative tool in this situation awaits further studies.

Abstract: OBJECTIVE: Recent experimental work in mice has demonstrated that leptin is synthesized by muscle cells. As this latter tissue is the main target for insulin-estimulated glucose disposal, we hypothesized that the muscular and fat-free mass (FFM) compartments might influence serum leptin levels in humans through increased insulin resistance. DESIGN AND METHODS: We evaluated body composition (through bioelectric impedance and anthropometrical parameters), insulin resistance (using the fasting insulin resistance index (FIRI) and insulin sensitivity (S(I)) from the minimal model analysis) and leptin levels in 140 men and 114 women. RESULTS: Serum insulin, FIRI and leptin levels were significantly increased in men in the highest quintile of FFM. Leptin levels positively correlated with FFM in men (r=0.24, P=0004) but not in women (r=0.02, P=not significant). With weight gain, however, approximately 25% of the additional weight is lean mass, so that obese people have higher fat-free mass than lean people. Hence, we performed a multiple linear regression analysis in a stepwise manner to predict leptin levels, in which fat mass (FM), FFM, and FIRI, but not age or waist-to-hip ratio (WHR) independently contributed to 32%, 6% and 3% of the variance in serum leptin levels in men. In women, FM (49%), FIRI (3.6%) and WHR (2.4%), but not FFM or age explained this variance. In a sample of 40 subjects, S(I) and leptin correlated with mid-arm muscle circumference (r=-0.51, P=0.03 and r=0.53, P=0.02) and mid-arm muscle area (r=-0.52, P=0.03 and r=0.53, P=0.02) in men (n=17) but not in women (n=23). CONCLUSIONS: The fat-free mass compartment contributes to the variability of serum leptin levels in men. Whether insulin resistance at this level mediates an increased production of leptin merits further research.

Abstract: Anabolic corticosteroids have been reported to enhance glucose effectiveness (SG). In experimental models of long-term cortisol infusion in diabetic dogs, the maintenance of normal SG during chronic hypercortisolemia prevented a significant deterioration of glucose tolerance. We hypothesized that in analogy with exogenous corticosteroids, endogenous cortisol might influence SG. We aimed to study the influence of serum cortisol on SG prior to a frequently sampled intravenous glucose tolerance test (FSIVGTT) in 18 otherwise healthy men. The serum cortisol level or free cortisol index (ratio of cortisol to cortisol-binding globulin [CBG]) were not associated with the body mass index (BMI), waist to hip ratio (WHR), fasting insulin, or insulin sensitivity ([SI] all r < .20, P = NS). Conversely, SG correlated with serum cortisol levels measured prior to the FSIVGTT (r = .60, P = .008) and with the free cortisol index (r = .48, P = .03). The association was stronger in lean subjects (BMI < 25 kg/m2, r = .90, P = .002, n = 8). Men with a pre-FSIVGTT serum cortisol level above the median (431 nmol/L) were similar by age, BMI, WHR, and SI to the subjects with cortisol levels below the median, but the latter presented a significantly decreased SG (0.0014 +/- 0.006 v 0.022 +/- 0.007 min(-1), P = .03). In multiple linear regression analysis, fasting glucose (P = .02) and serum cortisol (P = .027) independently predicted SG, contributing to 26% of its variance. In summary, our findings suggest that the prevailing cortisol level appears to be associated with SG. The lower cortisol levels usually found in abdominally obese men could contribute to their altered glucose tolerance, perhaps via decreased SG.

Abstract: Adipsia and hypernatremia is a syndrome which can be observed among children and adults with various congenital or acquired diseases of the brain. We can include the primary neoplasms and the metastatic among the causes of this syndrome. We display the case of a 63-year-old man who presented time-space disorientation, loss of memory fixation, visual hallucinations, unstable walking and absence of the voluntary ingestion of liquids. The serum electrolytes showed serum sodium concentration of 188 mEq/l with plasma osmolality above 380 mOs/kg. Both the forced water intake and the intravenous rehydration restored the plasma osmolality and the normal levels of serum sodium. The magnetic resonance (MR) neurohypophyseal area showed a neoformative lesion at the middle line which affected septum ventricular and hypothalamic area. We analyse the pathophysiologic mechanisms, the clinical and laboratory data, as well as the therapeutic and the evolution of the cases which have been published in the literature.

Abstract: BACKGROUND: Iron-dependent free radicals formation has been related to greater damage in cerebral ischemia. The authors analyzed whether increased body iron stores were associated with early neurologic worsening and excitatory amino acid release in patients with acute ischemic stroke. METHODS: Ferritin, total iron, and glutamate concentrations in plasma and CSF were measured on admission in 100 consecutive patients with a cerebral infarction of <24 hours' duration. The authors diagnosed progressing stroke when the Canadian Stroke Scale score decreased one or more points between admission and 48 hours. Cranial CT was performed on admission and repeated on days 4 to 7 of hospitalization. RESULTS: Ferritin concentrations in plasma (median 391, range 119 to 500 versus 148, 21 to 399 ng/mL) and in CSF (17.4, 6.8 to 82, versus 4.8, 0.6 to 14 ng/mL) were significantly higher in the 45 patients with subsequent progressing stroke than in those with nonprogressing stroke (p < 0.001). There was a positive correlation between ferritin and glutamate concentrations in plasma (r = 0.81, p < 0.001) and CSF (r = 0.64, p < 0.001). Plasma ferritin concentrations >275 ng/mL in plasma (OR, 33.5; 95% CI, 4.7 to 235) and >11 ng/mL in CSF (OR, 11.4; 95% CI, 3. 1 to 41) were independently and significantly related to early neurologic worsening. The effect was reduced by >60% after controlling for glutamate concentrations, but remained significant. CONCLUSIONS: High plasma and CSF ferritin concentrations within the first 24 hours from the onset of ischemic stroke are associated with early neurologic deterioration. Increased body iron stores may contribute to stroke progression by enhancing the cytotoxic mechanisms in cerebral ischemia.

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Abstract: OBJECTIVE: In recent studies serum leptin levels were significantly higher in the luteal phase than in the follicular phase, but the mechanism of changing leptin levels are unknown. Several research lines indicate a potential role for tumor necrosis factor (TNF-alpha) in ovulation and reproductive events. As TNF-alpha appears to regulate leptin secretion, we speculated that TNF-alpha might be involved in leptin variations during the menstrual cycle. DESIGN AND METHODS: Nine healthy never obese and ten overweight normally cycling women were studied. TNF-alpha action - through the plasma levels of the soluble fraction of the tumor necrosis factor receptors 1 and 2 (sTNFR1 and sTNFR2) - and leptin concentrations were measured in the follicular (F), peri-ovulatory (PO) and luteal phases (L) of their menstrual cycles. RESULTS: Circulating leptin levels were significantly associated with the stage of the menstrual cycle (P<0.001), being higher in PO and L phases. However, only three of ten overweight subjects vs eight of nine lean women (Chi square P=0.014 after Fisher's exact test) showed significantly higher leptin levels in the PO and L than in the F phase (95% confidence interval (95% CI) of the differences, 3.7 to 10.2 ng/ml, paired t-test P=0.001). In these women (group 1), the changes in leptin levels parallelled the variations observed in plasma sTNFR1 (2.50+/-0.1 vs 2.11+/-0.05 ng/ml, P<0.0001, 95% CI, 0.21 to 0.56) and sTNFR2 levels (5.19+/-0.28 vs 4.55+/-0.25 ng/ml, P<0.0001, 95% CI, 0. 47 to 0.81). In the remaining women (group 2), leptin (95% CI, -1 to 9.2 ng/ml, P=not significant (NS)), sTNFR1 (95% CI, -0.3 to 0.14 ng/ml, P=NS) and sTNFR2 levels (95% CI, -0.95 to 0.39 ng/ml, P=NS) were essentially unaltered throughout the menstrual cycle. Group 2 women were similar in age (36.1+/-2.9 vs 37.3+/-1.4 years) and significantly overweight (body mass index 31+/-2.9 vs 23.9+/-1. 2 kg/m(2)) compared with group 1 women. A negative correlation was observed between leptin levels in the follicular phase and the change in plasma leptin from F to L phase in all subjects (r=-0.67, P=0.002). CONCLUSIONS: Circulating leptin and sTNFRs levels change significantly during the menstrual cycle of most lean women. In contrast, the levels of these molecules remain essentially unaltered during the F, PO and L phases in the majority of overweight women. Obesity might be associated not only with blunted diurnal excursions and dampened pulsatility, but also with blunted excursions during the menstrual cycle.

Abstract: Type 2 diabetes and the insulin resistance syndrome have been hypothesized to constitute manifestations of an ongoing acute-phase response. We aimed to study an interleukin-6 (IL-6) gene polymorphism in relation to insulin sensitivity (IL-6 is the main cytokine involved in an acute-phase response). Subjects homozygous for the C allele at position -174 of the IL-6 gene (SfaNI genotype), associated to lower plasma IL-6 levels, showed significantly lower integrated area under the curve of serum glucose concentrations (AUCglucose) after an oral glucose tolerance test, lower blood glycosylated hemoglobin, lower fasting insulin levels, lower total and differential white blood cell count (a putative marker of peripheral IL-6 action), and an increased insulin sensitivity index than carriers of the G allele, despite similar age and body composition. A gene dosage effect was especially remarkable for AUCglucose (6.4 vs. 9.3 vs. 9.7 mmol/l in C/C, C/G, and G/G individuals, respectively). The serum concentration of fully glycosylated cortisol binding globulin (another marker of IL-6 action), suggested by concanavalin A adsorption, was lower in C/C subjects than in G/G individuals (32.6+/-2.9 vs. 37.6+/-4.6 mg/l, P = 0.03). In summary, a polymorphism of the IL-6 gene influences the relationship among insulin sensitivity, postload glucose levels, and peripheral white blood cell count.

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Abstract: OBJECTIVE: Mice lacking the tumor necrosis factor-alpha receptor 2 (TNFR2) gene fed a high-fat diet gain less weight and display reduced leptin and insulin levels. In humans, plasma levels of the soluble fraction of TNFR2 (sTNFR2) circulate in proportion to the degree of insulin resistance. The purpose of this study was to evaluate a polymorphism in the 3' untranslated region of the TNFR2 gene on chromosome 1 in relation to BMI, leptin levels, and insulin resistance. RESEARCH DESIGN AND METHODS: Using single-strand conformation polymorphism, the polymorphism was analyzed in 107 nondiabetic subjects (60 women, 47 men) and in 110 consecutive patients with type 2 diabetes (79 women, 31 men). In a subset of 33 healthy subjects, insulin sensitivity (minimal model analysis) was also evaluated. RESULTS: Four alleles of the TNFR2 gene were identified (A1, A2, A3, and A4). BMI and serum leptin levels were significantly increased in young carriers of the A2 allele. Plasma sTNFR2 levels were similar among the different TNFR2 gene variants. However, in subjects who did not carry the A2 allele, in young subjects, and in women, plasma sTNFR2 levels were proportional to BMI and leptin levels. In the study sample, carriers of the A2 allele (n = 18) showed significantly increased BMI, fat mass, waist-to-hip ratio, serum total and VLDL triglyceride levels, and leptin levels and had a lower insulin sensitivity index than noncarriers of the A2 variant (n = 15). The frequency of the different alleles among diabetic subjects was similar to that in the control population. However, diet-treated diabetic subjects (n = 49) who were carriers of the A2 allele exhibited significantly higher BMI and leptin levels than diet-treated noncarriers of the A2 allele. CONCLUSIONS: The presence of the A2 allele in the TNFR2 gene may predispose subjects to obesity and higher leptin levels, which may in turn predispose them to insulin resistance or vice versa. The TNFR2 gene may be involved in weight-control mechanisms.

Abstract: Myotonic dystrophy (MyD) is a multisystem autosomal dominant disorder associated with progressive muscle wasting and weakness. The striking metabolic abnormality in MyD is insulin resistance. The mechanism by which target tissues are insensitive to insulin action remains uncertain. In a recent study, plasma soluble tumor necrosis factor receptor (sTNFR)2 levels were found to be associated with muscle tissue mass and insulin resistance. Given these associations, we speculated that disorders of the muscle cell membrane could lead simultaneously to insulin insensitivity and sTNFR2 leakage in MyD. To test this hypothesis, we measured the levels of circulating sTNFR1 and sTNFR2 and insulin resistance in MyD patients. We studied 22 MyD patients and 24 age-, BMI-, and fat mass-matched control subjects. Both MyD men and women showed higher plasma insulin levels in the presence of comparable glucose concentrations than did control subjects. sTNFR2, but not sTNFR1, levels were approximately 1.5-fold higher in MyD patients. In parallel with these findings, the fasting insulin resistance index (FIRI) was also higher in MyD patients. In fact, in the whole population, fasting insulin and FIRI strongly correlated with sTNFR2 in both men (r = 0.77 and r = 0.81, P<0.0001, respectively) and women (r = 0.67 and r = 0.64, P = 0.001, respectively). sTNFR2 levels were also associated with the insulin sensitivity index (S(I)), calculated from an oral glucose tolerance test (OGTT) according to the method by Cederholm and Wibell (r = -0.43, P = 0.006). We constructed a multiple linear regression to predict FIRI, with BMI, waist-to-hip ratio, and sTNFR2 as independent variables. In this model, both BMI (P = 0.0014) and sTNFR2 (P = 0.0048) levels contributed independently to 46% of the variance of FIRI. In another model, in which FIRI was substituted for S(I) from the OGTT, both BMI (P = 0.0001) and sTNFR2 (P = 0.04) levels contributed independently to 48% of the variance of S(I) from the OGTT. Plasma cholesterol and triglyceride concentrations were significantly increased in MyD patients. sTNFR1 and sTNFR2 levels were found to be strongly associated with plasma cholesterol, LDL cholesterol, and triglycerides. sTNFR1 and sTNFR2 also correlated with serum creatine kinase activity in MyD patients (r = 0.57, P = 0.006; r = 0.75, P<0.0001, respectively). In conclusion, here we describe, for the first time to our knowledge, a relationship between insulin action and plasma sTNFR2 concentration in MyD patients. We have also found increased concentrations of plasma triglycerides and cholesterol levels in parallel with sTNFR1 and sTNFR2 concentrations in MyD patients. We speculate that the latter associations are dependent on, and secondary to, increased tumor necrosis factor (TNF)-alpha action. Whether TNF action is implicated in the pathogenesis of MyD or is a simple marker of disease activity awaits further studies.

Abstract: BACKGROUND: Relatives of type 2 diabetes mellitus (DM2) patients present or can develop the plurimetabolic syndrome (MS). Insulin sensitivity determination could be useful to detect relatives with higher risk. PATIENTS AND METHODS: Insulin sensitivity (IS) and MS in 106 first degree relatives of DM2 and 52 control subjects, matched for age, sex and body mass index (BMI). Insulin sensitivity was evaluated by the HOMA method. Insulin sensitivity was classified as high, middle or low according to the percentiles 33 and 66 observed in the control group. MS was diagnosed if hyperglycemia, hypertension, hypertriglyceridemia and overweight (two or more) were present. RESULTS: Insulin sensitivity was lower in relatives (36.3 vs 51.8%; p = 0.0001). Relatives with lower insulin sensitivity (n = 56) have higher BMI (29.2 vs 25.6 kg/m2), higher systolic (128 vs 116 mmHg) and diastolic (80 vs 74) blood pressure, hyperglycemia (5.7 vs 5.1 mmol/l), hyperinsulinemia (116 vs 59 pmol/l) and hypertriglyceridemia (1.4 vs 1.0 mmol/l) when compared with the remainder relatives (n = 50). Age, sex, waist/hip ratio and cholesterol level were similar in both groups. 23 relatives have MS (20 of them with low insulin sensitivity, relative risk = 8.7; 95% confidence interval 2.4-31.6). In multiple logistic regression analysis, only age and IS have a significant value to predict the presence of MS. CONCLUSIONS: Relatives of DM2 are insulin-resistant and present a high prevalence of MS. Both insulin sensitivity and MS are highly correlated. Insulin sensitivity evaluation using a simple methodology like HOMA can be useful in the selection of relatives at higher risk of MS.

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Abstract: In the last few years, it has been demonstrated that tumor necrosis alpha (TNF-alpha) has important effects on whole-body lipid metabolism. TNF-alpha administration has been found to produce an increase in serum cholesterol levels and increased hepatic hydro-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase activity in mice. The purpose of this study was to test whether plasma levels of the soluble forms of the TNF-alpha receptors 1 and 2 (sTNFR1, sTNFR2) are associated with lipid abnormalities. A total of 36 healthy subjects (19 males, mean age 36.2 +/- 1.9, and 17 females, mean age 34.9 +/- 1.4) were studied. Plasma sTNFR1 levels correlated with total (r = 0.43, P = 0.01) and LDL-cholesterol (r = 0.52, P = 0.002) levels, but not with total or HDL2-HDL3 subfractions of HDL-cholesterol, total plasma triglycerides, VLDL-cholesterol or VLDL-triglycerides (all r < 0.11, P = NS). Plasma sTNFR2 levels also correlated with total (r = 0.44, P = 0.009) and LDL-cholesterol (r = 0.57, P < 0.0001) levels, and negatively with HDL2-cholesterol (r = -0.37, P = 0.029). A stepwise multiple linear regression was constructed to predict total cholesterol levels, with BMI, sex, age, sTNFR1 or sTNFR2 as independent variables. Both sTNFR1 and sTNFR2 were significantly associated with total cholesterol (P = 0.031 and 0.009), contributing to 26 and 19%, respectively, of its variance. In another model in which LDL-cholesterol was substituted for total cholesterol, sTNFR1 or sTNFR2 (P = 0.0084 and 0.0005) were significantly associated with LDL-cholesterol, contributing to 39 and 32% of its variance. In summary, plasma levels of sTNFR1 and sTNFR2 circulate in proportion to total and LDL-cholesterol in healthy subjects.

Abstract: AIMS/HYPOTHESIS: To describe a unifying hypothesis of the relation between insulin resistance and inflammatory response in the development of diabetes. METHODS: Review of the literature and authors' research. RESULTS: Infection and injury activate the immune system and bring about widespread metabolic changes which disadvantage and destroy the invading organism and facilitate repair of damaged tissue. Tumour necrosis factor-alpha is involved in inflammatory events and fight against infection. No study has extensively investigated its numerous metabolic effects. From induction of hyperlipidaemia to regulation of intracellular insulin signalling, TNF-alpha has been even associated with nutrient-sensing pathways. Certain TNF-alpha gene polymorphisms (linked to a high transcription rate of TNF-alpha), and the plasma concentrations of the TNF-alpha soluble receptor are simultaneously associated with insulin resistance, body fat, and with mortality after chronic infections. Thus, the TNF system seems to be designed for an effective fight against infection and for providing survival advantages during periods of food shortage. By inducing muscle insulin resistance, the energetic substrates are safeguarded for brain metabolism. CONCLUSION/INTERPRETATION: In the presence of an insulin resistance genotype and westernization (high carbohydrate diet, increased saturated fat, low fibre and sedentary habit), a high cytokine responder genotype would be prone to deterioration of insulin resistance and, finally, to Type II (non-insulin-dependent) diabetes mellitus and atherosclerosis. For our ancestors, the advantages of a high cytokine responder (eradication of injury) or moderate insulin resistance (protection against starvation) overcame the possible inconveniences of atherosclerosis. We propose that the latter are good adaptations to the environment or "maladaptations" of actual lifestyle to our genome. [Diabetologia (1999) 42: 1367-1374]

Abstract: BACKGROUND: Recently, the American Diabetes Association (ADA) concluded that pregnant women with low risk factors for gestational diabetes need not to be tested. The aims of this study was to determine the prevalence of gestational diabetes in a Spanish low risk pregnant women population, to analyze the criteria that define low risk pregnancies for gestational diabetes, and to compare the differences in morbidity between pregnant women with and without gestational diabetes. DESIGN AND METHODS: Cohort study of 2,262 gestations (2,085 Caucasians) during a period of 7 years in a reference hospital. RESULTS: The gestational diabetes prevalence was 15%. Two-hundred and seventy-four (12.1%) women were considered as a low risk group for gestational diabetes. Among these, 13 (4.7%) presented gestational diabetes in comparison with 16.6% in the remaining women (p = 0.0001). Gestational diabetes in the low risk pregnant women constituted the 3.8% of all gestational diabetes. We did not find differences in gestational outcomes or fetal antropometry between the groups. The relative risk of macrosomia in the low risk pregnant was 0.9% (95% confidence interval for the mean: 0.86-0.94). CONCLUSIONS: In spite of their capacity of identifying current complications, 4% of gestational diabetes would not have been diagnosed with the new ADA criteria. The misdiagnosis will prevent in this small group of women the adoption of preventive measures for subsequent pregnancies and for diabetes in later life.

Abstract: BACKGROUND: Although its effects in man are still unknown, leptin may play a role in the regulation of insulin sensitivity and insulin secretion. The aim of this study was to determine if these parameters are independent predictors of serum leptin levels. SUBJECTS AND METHODS: Twenty men and 22 women were evaluated through several anthropometric parameters, including percent fat mass (PFM), which was calculated using bioelectric impedance. A standard oral glucose tolerance test (OGTT) was performed in all subjects. Insulin sensitivity (SI) and insulin-secretion (AIRg) were determined through minimal model analysis. RESULTS: Area under the curve for glucose (AUCglu) and insulin (AUCins) levels after OGTT correlated with serum leptin level in men (r = 0.58, p = 0.005 and r = 0.72, p < 0.0001, respectively). Only AUCins was associated with serum leptin levels in women (r = 0.50, p = 0.01), but this correlation disappeared after controlling for PFM. A linear correlation between serum leptin level and SI was observed (r = -0.67, p = 0.001, in men; r = -0.82, p < 0.0001, in women). In a multiple regression analysis, PFM (p = 0.0005), waist-to-hip ratio (p = 0.007) and SI (p = 0.007) independently predicted serum leptin level in men (R2 = 0.82). In women with normal OGTT, only PFM (p = 0.0005) and insulin-secretion (p = 0.02) predicted serum leptin level (R2 = 0.85). CONCLUSIONS: Insulin-sensitivity in men, and insulin-secretion (calculated after intravenous glucose) in women independently predict serum leptin level. Furthermore, insulin response after oral glucose is independently associated with serum leptin level only in men. Leptin is a marker of insulin resistance in man, and, in this sense, might confer cardiovascular risk.

Abstract: In humans, steroid hormones circulate in the blood mainly bound to specific steroid transport proteins, namely corticosteroid-binding globulin (CBG) for cortisol and sex hormone-binding globulin (SHBG) for testosterone and estradiol. The binding activities of these proteins are believed to modulate the biodisposal of steroids to target cells. It has been shown in vitro that insulin is a potent inhibitor of both CBG and SHBG secretion by a human hepatoblastoma cell (HepG2) line. To further investigate this potential effect of insulin in vivo, we prospectively studied three groups of lean subjects, obese subjects, and obese subjects with glucose intolerance, all of whom were otherwise healthy. The three groups were comparable in sex and age, and in the two obese groups, body mass index, waist to hip ratio, and blood pressure were similar. Plasma total CBG concentrations (38.2 +/- 5.4 vs. 31.7 +/- 4.05 mg/L; P = 0.016) and glycosylated CBG levels (37.3 +/- 5.2 vs. 31 +/- 3.9 mg/L; P = 0.018) were significantly increased in obese subjects with glucose intolerance. Plasma CBG correlated positively with fasting glucose levels (r = 0.49; P = 0.002), hemoglobin A1c levels (r = 0.35; P = 0.03), and area under the curve of glucose after an oral glucose tolerance test (r = 0.45; P = 0.005) and correlated negatively with the insulin response to i.v. glucose (AIRg; -0.38, P = 0.02) as well as to oral glucose (r = -0.40; P = 0.01) challenge tests. CBG levels did not covariate with insulin sensitivity. Multiple linear regression analysis showed that only AIRg contributed to the variability of the CBG concentration (P = 0.03), explaining 41% of its variance. Morning cortisol levels did not differ between the groups and did not correlate to any of the glucose or insulin metabolism parameters. Because carbohydrate chains influence the biological activity and half-life of glycoproteins, we analyzed the migration profile of CBG by Western blot and the interaction of CBG with lectin, Con A. The results indicated that the CBG mol wt and interaction with Con A did not differ between lean and obese patients. These data favor the hypothesis that the inhibitory effect of insulin on CBG liver secretion might be relevant in vivo and therefore contribute to decrease CBG levels in obese patients with enhanced insulin secretion. In both men and women, SHBG levels correlated negatively with fasting glucose (r = -0.55; P < 0.0001) and hemoglobin A1c (r = -0.38; P = 0.02) and positively with insulin sensitivity (S(I); r = 0.65; P = 0.003 and r = 0.63; P = 0.007 in men and women, respectively), but not with insulin secretion. The disposition index (S(I) x AIRg) was significantly decreased in the obese, glucose-intolerant subjects, suggesting that AIRg was inadequate for their degree of insulin resistance. The disposition index correlated positively with plasma SHBG levels (r = 0.52; P = 0.001) and negatively with plasma CBG levels (r = -0.54; P = 0.001). Our data suggest that CBG is a marker of insulin secretion in a similar way as SHBG is a marker of insulin sensitivity. As high plasma CBG levels have been associated with increased incidence of type 2 diabetes, this important issue merits further investigations.

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Abstract: OBJECTIVE: The metabolites of steroidal hormones, including sulphate, glucuronide, and fatty acid (FA) ester derivatives, have received little attention, although these steroid derivatives are essential components in the global assessment of steroid metabolism. The study of FA-derivatives could, in obesity, contribute some insights into factors modulating steroid metabolism and their plasma levels. In a recent study we found that, in rats, an oestrone-fatty acid ester (E1-FA) was produced by white adipose tissue and released into lipoproteins in the blood-stream. We have examined whether E1-FA levels correlate with body fat and insulin sensitivity in humans. SUBJECTS: A sample of 20 men and 22 women with varying levels of total body fat (mean body mass index (BMI) 29.2 +/- 4.7, range 22.2-35.8 in men; mean BMI 27.6 +/- 6.3, range 16.8-37.9 in women). All participants were healthy. MEASUREMENTS: We measured oestrone fatty acid esters (E1-FA), body fatness, and body fat distribution variables, as well as insulin sensitivity through a frequently sampled intravenous glucose tolerance test. Plasma E1-FA and serum leptin levels were measured by radioimmunoassay. RESULTS: E1-FA levels strongly correlated with BMI (r = 0.69, P = 0.001 in men; r = 0.75, P < 0.0001, in women) percent body fat (PBF, r = 0.52. P = 0.018 in men; and r = 0.69, P < 0.0001, in women) and with the sum of 4 fat skinfolds (sigma skinfolds). E1-FA level was significantly and positively associated with fasting insulin (r = 0.62, P = 0.003 in men, and r = 0.48, P = 0.023 in women) but not with fasting glucose levels. E1-FA correlated with insulin sensitivity (SI, r = -0.72 in men; and -0.76, in women, both P < 0.0001). In men, E1-FA levels also correlated with systolic blood pressure (r = 0.59, P = 0.01), total triglycerides (r = 0.63, P = 0.003), VLDL-triglycerides (r = 0.62, P = 0.004) and VLDL-cholesterol (r = 0.48, P = 0.03), but not with diastolic blood pressure, serum total or LDL-cholesterol, or total and HDL2 and HDL3 subfractions of HDL cholesterol. After controlling for fat mass, only the correlation between VLDL-triglycerides and E1-FA levels remained significant. In women, E1-FA levels correlated with total triglycerides (r = 0.66, P = 0.001), VLDL-triglycerides (r = 0.65, P = 0.001), VLDL-cholesterol (r = 0.63, P = 0.002), LDL-cholesterol (r = 0.57, P = 0.005) and total and HDL2 and HDL3 subfractions of HDL cholesterol (r = -0.58, -0.48, -0.61, P = 0.004, 0.02 and 0.002, respectively), but not with systolic or diastolic blood pressure or total cholesterol. However, covariance analysis revealed that controlling for the concomitant variation in body fat mass eliminated all these associations. Fasting plasma E1-FA concentration correlated with serum leptin (r = 0.60, P = 0.005 in men; r = 0.75, P = 0.0001, in women). However, these correlations no longer persisted after controlling for fat mass (r = 0.33 and 0.36, P = NS). Stepwise regression analysis models were tested, with E1-FA as the dependent variable, and sigma skinfolds and SI as independent covariables. Both the sigma skinfolds (P = 0.03) and SI (P = 0.01) entered the equation at a statistically significant level in men. Therefore, insulin sensitivity was related to E1-FA independently of fat in men. In women only sigma skinfolds (P = 0.04) entered the regression model at a statistically significantly level. Fifty-seven percent of the variance in plasma E1-FA levels in men, and 50% in women, was accounted for using a regression model that combined these variables. CONCLUSIONS: Oestrone-fatty acid esters circulate in human blood in proportion to body fat, independently of gender. Plasma oestrone-fatty acid ester levels are associated with insulin sensitivity in men, independently of body fat. These findings may widen our perspective on the regulation of insulin action and control of body weight.

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Abstract: BACKGROUND: Some patients with primary hypothyroidism (HP) develop massive thyrotrope cell hyperplasia determining pituitary hyperplasia with suprasellar enlargement and pituitary dysfunction. Although TRH secretion undoubtedly has some influence, the intervention of other possible factors determining this hyperplasia and dysfunction has been little assessed. PATIENTS AND METHODS: Two patients with primary hypothyroidism with a serum TSH > 1,000 mU/I were studied. By means of CT and MR a pituitary hyperplasia was ascertained in the two patients. The pituitary functional reserve was investigated by the serum response of TSH and prolactin to the administration of TRH (400 micrograms, i.v.), bromocriptine (BRC, 5 mg, oral route), somatostatine (ST, 50 micrograms/kg/min, i.v. perfusion), and gonadotropin releasing hormone (GnRH, 100 micrograms, i.v.). RESULTS: The TRH induced increment of TSH was 145% and 193%, respectively, compared with basal values. After the administration of BRC, TSH decreased to 57% and 84% of basal values, and PRL to 46% and 43%, respectively. TSH and PRL concentrations did not change after the administration of ST or GnRH. In both cases, hyperplasia and pituitary dysfunction returned to normality after substitutive therapy with levothyroxine. CONCLUSIONS: Basal hyperprolactinemia and TSH and PRL responses to BRC administration suggest that central dopaminergic activity is decreased or abolished in patients with HP and pituitary hyperplasia. The massive thryrotrope cell hyperplasia and hypothyroidism itself determine pituitary dysfunction, which reverts after therapy with levothyroxine, a fact which is scarcely documented in literature.

Abstract: INTRODUCTION: The beta 3-Adrenergic receptor (beta 3AR) and leptin are molecules involved in the regulation of energy balance. Recently, a mutation in the beta 3AR gene (Trp64Arg) has been reported to be associated with features of insulin resistance, weight gain and early onset of Type 2 Diabetes Mellitus. The aim of this study was to determine the frequency and clinical characteristics of the Trp64Arg mutation in the beta 3AR gene in Type 2 diabetic patients, its relationship with leptin levels, and its role in microangiopathic complications. SUBJECTS AND METHODS: 187 Type 2 diabetic patients and 100 unrelated non-diabetic subjects were studied. There was no difference between the diabetic and nondiabetic subjects in the frequency of the Trp64 and Arg64 alleles (92.5% vs. 92.3% and 7.5% vs. 7.7%, respectively). Type 2 diabetic patients were divided into two groups according to the presence (n = 27) or absence of the mutation (n = 160). RESULTS: Mutation of the beta 3AR gene was not associated with any differences either in the clinical and metabolic parameters or microangiopathic complications. Type 2 diabetic patients carrying the Arg64 allele tended to have a lower diabetes duration, but this was not statistically significant. Plasma leptin levels were not different according to the beta 3AR genotype. CONCLUSIONS: The Trp64Arg mutation is not a major determinant of Type 2 diabetes and its microangiopathic complications. Moreover, this mutation was not clinically relevant in leptin regulation.

Abstract: BACKGROUND: Although the effects of insulin on leptin levels are relatively well characterized, the possible actions of leptin on insulin sensitivity are not so well studied. This study was undertaken to examine whether gender-related differences in insulin sensitivity could be explained partially by leptin levels. SUBJECTS: The study involved 22 women (13 obese) and 20 (11 obese) fat mass- and age-matched men. All participants were healthy. MEASUREMENTS: Several anthropometric measures of body fatness were quantified and the percentage of body fat was determined through bioelectric impedance. Oral glucose tolerance test and a frequently sampled intravenous glucose tolerance test was performed in all subjects. Serum leptin was measured by radioimmunoassay. RESULTS: Nine lean women (BMI 20.4 +/- 2 kg m2 mean +/- SD) showed increased leptin levels (7.8 +/- 2.7 vs. 4.3 +/- 1.3 micrograms/l, P = 0.003), increased insulin sensitivity (5.2 +/- 1.3 vs. 2.9 +/- 0.9 min-1/mU/l, P = 0.001) and similar fat mass (11.1 +/- 3.7 vs. 13.2 +/- 7.8 kg, P = NS) in comparison with 9 age-matched lean men (33.6 +/- 6 vs. 34.5 +/- 6.3 years, P = NS). Thirteen obese women (BMI 32.5 +/- 2.7) kg m2 also showed increased leptin levels (29.6 +/- 8.4 vs. 11.7 +/- 4.8 micrograms/l, P < 0.0001), increased insulin sensitivity (1.7 +/- 0.7 vs. 0.95 +/- 0.9 min-1 mU/l, P = 0.04) and similar fat mass (34.4 +/- 8.0 vs. 30.9 +/- 9.6 kg, P = NS) in comparison with 11 age-matched obese men (34.5 +/- 7.8 vs. 38.7 +/- 8.2 years, P = NS). A strong linear association between leptin levels and insulin sensitivity (Si) was found (r = -0.67, P = 0.001, in men; r = -0.82, P < 0.0001, in women). After controlling for percentage of body fat, this association remained significant only in men (r = -0.56, P = 0.01, in men; r = -0.30, P = NS in women). In stepwise regression analysis models, both gender (P = 0.00001) and leptin (P = 0.00001) contributed to 67% of the variance in Si independently of body fat. CONCLUSIONS: Leptin levels and gender contribute to the variance of insulin sensitivity, independently of body fat. These results suggest that leptin could affect insulin sensitivity.

Abstract: OBJECTIVE: Clinically silent cortisol hypersecretion has been frequently observed in recent series of adrenal 'incidentalomas'. A significant body of data indicates that a spectrum of cortisol excess exists. Up to 90% of patients with cortisol hypersecretion are glucose intolerant. The aim of this study was (1) to assess glucose tolerance in consecutive patients with 'nonfunctioning' adrenal adenomas, and (2) to study the influence of the status of the hypothalamo-pituitary-adrenal axis (HPAA) on carbohydrate tolerance. PATIENTS AND METHODS: Sixty-four consecutive patients with nonfunctioning adrenal adenomas (non-hypersecretory) diagnosed between September 1995 and July 1996 in five hospitals were included in the study. The prevalence of glucose intolerance or diabetes mellitus was determined with an oral glucose tolerance test (oGTT) according to the recommendations of the National Diabetes Data Group. Twenty-three consecutive unselected patients diagnosed with 'nonfunctioning' adrenal adenoma were enrolled in a study to determine the influence of HPAA status on carbohydrate tolerance. In these patients, in addition to basal and post-dexamethasone serum and urinary free cortisol concentrations, assessment of peripheral sensitivity to insulin (estimated during the oGTT according to a previously validated method) and adrenal sensitivity to ACTH (calculated from the CRH test) were performed. RESULTS: Twenty-five patients were considered to have normal glucose tolerance (95% confidence interval (95% CI) for the mean of 2 h glucose, 5.5-6.5 mmol/l); 17 showed glucose intolerance (95% CI 8.5-9.3 mmol/l); and 22 were classified as having diabetes mellitus (95% CI 12.1-14.6 mmol/l), including six patients with previously known diabetes mellitus. These three groups were comparable in age, sex, body mass index, waist-hip ratio and concomitant diseases. Thus, the prevalence of disturbed glucose tolerance was 39/64 (61%), well above the prevalence of NIDDM described in a population of similar age in our area. Among the 23 patients included in the study of HPAA status, the size of the tumour correlated with serum cortisol after dexamethasone (DXM) (r = 0.52, P < 0.01) and 24-h urinary free cortisol (UFC) after DXM (r = 0.55, P < 0.01), and negatively with DHEAs (r = -0.42, P = 0.04). The area under the curve for ACTH after hCRH (AUCacth) correlated negatively with both UFC (r = -0.40, P = 0.04) and serum cortisol after dexamethasone (r = -0.47, P = 0.02). The degree of peripheral sensitivity to insulin (SI) positively correlated with adrenal sensitivity (r = 0.56, P = 0.005). CONCLUSIONS: A high prevalence (61%) of disturbed glucose tolerance was found among consecutive patients harbouring incidental 'nonfunctional' adrenal adenomas. Therefore, patients with incidental adrenal tumours should be tested for glucose tolerance. The positive correlation between insulin sensitivity and adrenal sensitivity to ACTH suggests that, in these patients, insulin resistance hampers ACTH action at the level of the adrenal.

Abstract: OBJECTIVE: In epidemiological studies, serum ferritin was the second-strongest determinant of blood glucose (after BMI) in regression models and the third-strongest determinant of serum insulin (after BMI and age). Its concentration also correlated positively with plasma triglycerides and apolipoprotein B concentrations, and negatively with HDL2 cholesterol. We hypothesized that serum ferritin could be a marker of insulin resistance. RESEARCH DESIGN AND METHODS: Oral glucose tolerance and insulin sensitivity (SI, minimal model method) were prospectively evaluated in 36 healthy subjects. The relationship between serum ferritin and metabolic control (as measured by HbA1c levels) was also studied in 76 consecutive NIDDM patients. RESULTS: In healthy subjects, log-transformed serum ferritin (LOGFER) correlated with basal serum glucose (r = 0.44, P = 0.007), but not with BMI, age, systolic or diastolic blood pressure, total cholesterol, VLDL cholesterol, HDL cholesterol, total triglycerides, VLDL triglycerides, serum insulin, or HbA1c (all P = NS). Identical results were obtained when the two lowest quartiles of serum ferritin were evaluated separately. However, in the two highest quartiles, LOGFER correlated with BMI (0.50, P = 0.02), diastolic blood pressure (r = 0.8, P < 0.0001), serum LDL cholesterol (r = 0.57, P = 0.01), VLDL cholesterol (r = 0.48, P = 0.03), total cholesterol and HDL2 and HDL3 subtractions of HDL cholesterol (r = -0.68, -0.76, -0.55, P = 0.001. < 0.0001, and 0.01, respectively), total triglycerides (r = 0.60, P = 0.006), HDL2/HDL3 quotient (P = -0.71, P = 0.001), VLDL triglycerides (r = 0.65, P = 0.004), and serum uric acid (r = 0.51, P = 0.03), but not with systolic blood pressure (r = 0.38, P = 0.15). After adjusting for BMI, only the correlations between LOGFER and diastolic blood pressure (r = 0.7, P = 0.002) and HDL2/HDL3 quotient (r = -0.63, P = 0.01) remained significant. Strong correlations between LOGFER and glucose area under the curve during oral glucose tolerance test (Pearson's r = 0.73, P = 0.001) and SI (r = -0.68, P = 0.001), which remained significant after controlling for BMI, were observed. LOGFER (beta = -0.44, P = 0.01) and BMI (beta = -0.52, P = 0.004) constituted independent predictors of insulin sensitivity in a multivariate analysis (R2 = 0.68). In 76 consecutive NIDDM outpatients, serum glucose (P < 0.00001) and LOGFER (P = 0.03) independently predicted the value of HbA1c (R2 = 0.40) in a multiple linear regression analysis. CONCLUSIONS: The correlations among serum ferritin and diastolic blood pressure, HDL quotient, glucose area under the curve, and SI suggest that serum ferritin could be a marker of the insulin resistance syndrome. Serum ferritin may also be an independent determinant of poor metabolic control in the diabetic patient.

Abstract: Recent studies have shown that the tumor necrosis factor (TNF) system is implicated in the insulin resistance of human obesity. Plasma concentrations of the soluble fraction of the TNF receptors 1 and 2 (sTNFR1 and sTNFR2) are thought to reflect the degree of activation of the TNF system. The purpose of this study was to explore whether this activation, as measured by the levels of circulating sTNFR1 and sTNFR2, is associated with insulin resistance. A total of 19 men (mean age 36.2 +/- 1.9; BMI 28.8 +/- 1.2, range 22.2-35.7) and 17 premenopausal women (age 34.9 +/- 1.4; BMI 28.1 +/- 0.8, range 19-37.9) were studied. Men showed higher levels of plasma sTNFR1 and sTNFR2 than women. However, obese men showed increased levels of sTNFR2 but similar levels of sTNFR1 in comparison with obese women. In fact, sTNFR2 levels correlated with BMI (r = 0.50, P = 0.002), fat-free mass (FFM) (r = 0.61, P < 0.0001), and waist-to-hip ratio (WHR) (r = 0.39, P = 0.02), but not with fat mass or percent fat mass. sTNFR2 levels correlated with basal glucose levels (r = 0.45, P = 0.007), area under the curve (AUC) for glucose during an oral glucose tolerance test (r = 0.42, P = 0.013), and with the quotient AUC glucose/log AUC insulin (r = 0.41, P = 0.015). sTNFR2 also correlated negatively with insulin sensitivity (S(I)), evaluated using the frequently sampled intravenous glucose tolerance test with minimal model analysis (r = -0.38, P = 0.02). Plasma sTNFR1 levels were not associated with any of these variables. Because WHR influenced both S(I) and sTNFR2 levels, we constructed a multiple linear regression to predict S(I), with WHR and sTNFR2 as independent variables. In this model, both WHR (P = 0.0078) and sTNFR2 levels (P = 0.025) contributed to 47% of the variance in S(I). In parallel with higher FFM, lean and obese men showed a lower S(I) (2.9 +/- 0.9 vs. 5.2 +/- 1.3 min(-1) x mU x l(-1), P = 0.001; and 1.15 +/- 1.1 vs. 1.8 +/- 0.8 min(-1) x mU x l(-1), P = 0.035, respectively) and higher sTNFR2 levels in comparison with lean and obese women, respectively. After controlling for FFM, the correlation between S(I) and sTNFR2 levels disappeared, indicating that FFM was significantly influencing these associations. In summary, plasma sTNFR2 levels, but not sTNFR1, were proportional to BMI, WHR, FFM (a well-known confounder in the evaluation of insulin sensitivity), basal and postload glucose levels, and insulin resistance. These findings support TNF-alpha as a system regulating insulin action in human obesity.

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Abstract: This report describes a patient with cerebellar ataxia, hypogonadotropic hypogonadism, and chorioretinal dystrophy, associated with mitochondrial respiratory chain complex I deficiency and a 5.5 kb mtDNA single deletion in skeletal muscle.

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Abstract: Interindividual differences in TNF-alpha monocyte responses can be accounted for by genetic polymorphisms at the TNF-beta locus defined by the Nco I restriction enzyme. Higher triglyceride levels in non-insulin-dependent diabetic patients homozygous at the 10.5-kb fragment of the TNF-beta gene have been described. The aim of this study was to investigate whether the Ncol polymorphism of the TNF-beta gene influences the relationship between insulin resistance and triglyceride levels. Thirty-eight healthy volunteers were divided into two groups according to the absence [homozygous for class 1 allele (1/1), n=16] or presence of the class 2 allele [n=22; 19 heterozygous (1/2), and 3 homozygous (2/2)]. Both groups were comparable in sex, age, BMI, waist/hip ratio, fat mass and percentage of body fat as measured by bioelectric impedance, skinfold measurements, and blood pressure (all p>0.05). There were no differences in serum cholesterol (total, or HDL and VLDL fractions) or in total or VLDL triglycerides between the groups (all p>0.05). The insulin sensitivity index (Minimal Model method) was comparable for the two groups. In summary, the 10.5-kb homozygous genotype of the TNF-beta locus does not contribute to differences in triglyceride levels or insulin sensitivity among nondiabetic subjects.

Abstract: Tumor necrosis factor-alpha (TNF-alpha), acting as a modulator of gene expression in adipocytes, is implicated in the development of insulin resistance and obesity. The aim of this study was to investigate whether the Nco I polymorphism of the TNF-alpha gene influences the relationship among insulin resistance, percent body fat, and serum leptin levels. A sample of 38 subjects (19 men, mean age 36.2 +/- 1.9 years, BMI 28.8 +/- 1.2 kg/m2, range 22.2-35.7; and 19 women, age 34.9 +/- 1.4 years, BMI 28.1 +/- 0.8 kg/m2, range 19-37.9) was divided into two groups on the basis of the Nco I genotype. Twenty-three subjects were (+/+) homozygotes for the presence of the Nco I restriction site that is associated with a guanine at position -308 of the TNF-alpha promoter. Of the other subjects, 12 were (+/-) heterozygotes and 3 (-/-) homozygotes for the absence of the restriction site, resulting from a guanine-to-adenine substitution at position -308 of the TNF-alpha promoter. This substitution (termed TNF-2) leads to higher rate of transcription of TNF-alpha than the wild-type allele TNF-1 in vitro. TNF-1 (+/+) and TNF-2 (+/- and -/-) groups of subjects were comparable in sex, age, BMI, waist-to-hip ratio, and several skinfold measurements. Basal serum insulin was greater (14.2 +/- 2 vs. 9.2 +/- 0.9 mU/l, P = 0.041) in the TNF-2 group in the presence of comparable serum glucose concentration. The integrated area under the curve of serum insulin concentrations, measured in response to a 75-g oral glucose challenge, and the percent body fat, measured by bioelectric impedance, were significantly increased in TNF-2 subjects (226.8 +/- 33 vs. 139.4 +/- 17.8 mU/l, P = 0.032; 33.6 +/- 2.8 vs. 24.9 +/- 2%, P = 0.01). TNF-2 subjects also showed a decreased insulin sensitivity index, as determined by the frequently sampled intravenous glucose tolerance test with minimal model analysis (1.9 +/- 0.4 vs. 3.05 +/- 0.3 min(-1) x mU(-1) x l(-1), P = 0.03). These differences were more marked among women. Paralleling the known relationship between insulin and leptin levels, serum leptin concentration was clearly increased in the TNF-2 group (19.6 +/- 3.4 vs. 11.1 +/- 1.5 ng/ml, P = 0.03). Therefore, (+/-) heterozygotes and (-/-) homozygotes may be more susceptible to developing insulin resistance and increased percent body fat. Results of the present study suggest that TNF-alphaNco I polymorphism may exacerbate the alterations in leptin levels normally found among insulin-resistant subjects.

Abstract: BACKGROUND: It has been shown previously that morning cortisol levels decline after oral glucose, but no report has been published regarding the changes in serum cortisol in relation to insulin sensitivity or degree of obesity. SUBJECTS AND DESIGN: We studied the effects of oral glucose during a standard oral glucose tolerance test on cortisol levels in 7 obese subjects (body mass index (BMI) 29.7 +/- 3.3 kg/m2) and in 8 control subjects (BMI 24.9 +/- 3.2 kg/m2). Cortisol concentrations were normalized to time 0 because of wide between subject variation. On another day, a frequently sampled intravenous glucose tolerance test with minimal model analysis was performed, obtaining the insulin sensitivity index (SI). Anthropometric measurements included different skinfolds and bioelectric impedance. RESULTS: The waist-to-hip ratio (WHR) was similar between the 2 groups, but abdominal skinfold was significantly higher in the obese group (OG) (158.8 +/- 42.9 vs. 113.6 +/- 27.7, P = 0.03). Fat mass, percentage of fat mass, triceps and subscapular skinfolds, systolic and diastolic blood pressure, VLDL-cholesterol, total triglycerides and VLDL-triglycerides were slightly higher in the obese group (OG). Area under the curve for glucose (AUCg) after OGTT was also significantly higher in OG (9.9 +/- 2.4 vs. 7.1 +/- 0.5 mmol/l, P = 0.02) in contrast to area under the curve for insulin (102 +/- 60 vs. 73.8 +/- 26.7 mU/l, P = NS), or glucose effectiveness (0.015 +/- 0.004 vs. 0.015 +/- 0.009 min-1, P = NS). Subjects with the highest WHR of both groups exhibited a greater cortisol suppression (56 +/- 0.09 vs. 41 +/- 0.17, P = 0.05). Normalized serum cortisol after OGTT was significantly lower from minute 60 to 120 in the OG (P = 0.001, 0.003 and 0.01 at 60, 90 and 120 minutes, respectively). The maximal cortisol suppression was 59.2% in the OG in comparison with 43% in the control group (P = 0.027). This maximal cortisol suppression correlated weakly with the maximal insulin response after oral glucose (r = 0.49, P = 0.07). In a multiple linear regression analysis, with maximal cortisol suppression as dependent variable, both BMI (P = 0.03) and SI (0.02) contributed to the variance of maximal cortisol suppression (R2 = 0.40). CONCLUSION: We show that differences in cortisol decline are at least partially attributed to differences in insulin sensitivity and to differences in abdominal fat. This abdominal-related decrease of cortisol might support the concept that the increased visceral adipose tissue mass with a high density of glucocorticoid receptors enhances the metabolism of cortisol. Perhaps the subjects with higher abdominal fat or insulin resistance are prone to lower cortisol levels after carbohydrate-rich intakes in the morning. These lower cortisol levels, behaving as a positive feed-back signal, might generate higher ACTH and cortisol responses after protein-rich meals at mid-day.

Abstract: OBJECTIVE: The effects of human immunodeficiency virus (HIV) infection on thyroid function have been reported in only a few studies with discrepant results. The aim of this study was to assess the relation between nutritional status and thyroid function in HIV infected patients. DESIGN: Prospective, cross-sectional study. SETTING: A 500-bed teaching and referral hospital serving a population of 450,000. PATIENTS: Seventy-five consecutive HIV infected patients between 21 and 40 years of age (mean 31.8 +/- 0.9 years). MEASUREMENTS: Nutritional status was evaluated using the body mass index (BMI), triceps skinfold thickness (TSF), mid-arm muscle circumference (MAMC), and serum albumin concentration (SA). Hormone assays for serum T4, free thyroxine index (FTI), T3, reverse triiodothyronine (rT3), thyroxine-binding globulin (TBG), TSH and simultaneous CD4 lymphocyte counts were determined in all patients. RESULTS: Clinical stage was significantly related to nutritional status (P = 0.0001 for BMI, P = 0.0002 MAMC). The more poorly nourished groups had low mean serum T3 and rT3 levels, particularly for muscular (P = 0.0001 for T3 and P = 0.0076 for rT3) and visceral (P = 0.00001 for T3 and P = 0.0021 for rT3) protein compartments. Multivariate analysis showed that two factors, SA and MAMC, correlated significantly and independently with serum T3 and rT3. CONCLUSIONS: A close relation exists between serum thyroid hormone levels and nutritional status in HIV infected patients. These patients are probably euthyroid and the abnormal findings in the thyroid function tests are thus a reflection of the severity of illness.

Abstract: BACKGROUND: To our knowledge, only three cases with ectopic submandibular thyroid have been reported. No patient with simultaneous presence of ectopic submandibular thyroid and normal thyroid gland has been reported. Literature on this topic is reviewed. METHODS: A 34-year-old woman with a longstanding asymptomatic right submandibular mass was evaluated by ecography, computer tomography scan, and fine-needle aspiration. Literature review was performed using EBSCO-Medline Results. The mass was hard, nontender, and not movable with swallowing. A fine-needle aspiration revealed hyperplastic thyroid tissue. A second ecographic-guided fine-needle aspiration confirmed cytologically ectopic thyroid tissue. A computer tomography scan showed a calcified mass with cystic areas beneath and medial to the submandibular gland. Rests of thyroid tissue lateral to the trajectory of thyroglossal duct were seen. Thyroid gland was atrophic. No metastatic lymph nodes were noted. Total serum thyroxine and triiodothyronine were normal. Basal and TRH-stimulated serum thyrotropin was suppressed. A 99Tc scintigraphy disclosed a nodular uptake of tracer in the submandibular area, and no uptake by normal thyroid. CONCLUSIONS: We describe the first case, to our knowledge, with lateral multiple aberrant thyroid tissue and hypoplastic thyroid gland.

Abstract: Distant metastasis from follicular thyroid carcinoma developed in a 48-year-old woman 11 yr after the resection of the primary tumor. Distant metastasis consisted in invasion of the left infraspinatus muscle by malignant thyroid cells. After its surgical removal, in the following 6-8 months multiple metastasis to distant skeletal muscle and brain appeared, and despite chemotherapy and local radiotherapy, the patient finally died. Intercellular adhesion molecule-1 (ICAM-1), a single chain transmembrane glycoprotein, was detected on the surface of cells of the metastatic tissue. Although ICAM-1-positive staining has been recently described in primary tumors such as papillary adenocarcinoma, and metastatic tumors from skin, brain, thymus, liver, adrenal gland and prostate, to our knowledge its expression on distant metastasis from thyroid carcinoma has not been previously reported.

Abstract: To evaluate whether or not activated coagulation is present in the preclinical phases of type 2 diabetes mellitus, we studied 46 non-diabetic first-degree relatives of type 2 diabetic patients and 21 matched controls with no family history of diabetes. We determined the plasma levels of prothrombin fragment 1 + 2, D-dimer, fibrinogen, plasminogen activator inhibitor type 1, tissue plasminogen activator, von Willebrand factor and coagulation factors VII and VIII. Glucose tolerance, beta-cell function and insulin sensitivity were assessed in all subjects by a continuous glucose infusion of 5 mg.kg ideal body weight-1.min-1 for 60 min with model assessment of glucose, insulin and C-peptide values. Plasma levels of prothrombin fragment 1 + 2 (median 1.24 vs 0.68 nmol.l-1; P = 0.0001) and D-dimer (331 vs 254 micrograms.l-1 UEF; P = 0.018) were higher in relatives, without significant differences in the other haemostatic variables. Relatives showed higher fasting (5.5 vs 4.9 mmol.l-1, P = 0.004) and post-infusion (9.3 vs 8.3 mmol.l-1, P = 0.02) serum glucose, no differences in insulin or C-peptide levels, lower beta-cell function (122% vs 147%; P = 0.02) and no significant differences in insulin sensitivity. Fifteen relatives were glucose-intolerant and had lower beta-cell function and insulin sensitivity than glucose-tolerant relatives. Both subsets of relatives exhibited higher levels of prothrombin fragment 1 + 2 and D-dimer than control subjects. Thus, first-degree relatives of type 2 diabetic patients present an activated coagulation, even in the absence of minor degrees of glucose intolerance. These abnormalities can play a role in the pathogenesis of cardiovascular diseases frequently seen at diagnosis of type 2 diabetes.

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Abstract: Pituitary apoplexy into nonadenomatous tissue is extremely rare. The authors describe a 20-year-old woman with symptomatic pituitary hemorrhage into an apparently intrasellar malignant teratoma, which caused headache, visual impairment, involvement of III, IV, VI, and 1st division of the V cranial nerves, and hypopituitarism. Diabetes insipidus had developed previously. Magnetic resonance scans had a high-intensity signal in the pituitary on T1- and T2-weighted images, and lack of the signal of the posterior pituitary. Transsphenoidal approach, radiotherapy, and chemotherapy management did not preclude a fatal outcome.

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Abstract: Pre-Cushing's syndrome (PCS) is defined as an overproduction of cortisol by an adrenal adenoma, without physical changes on clinical examination. Three patients with PCS were recently diagnosed among 21 consecutive patients suffering from adrenal 'incidentaloma'. All patients showed nonsuppression of serum and urinary cortisol following 2 and 8 mg of dexamethasone (DXM), and suppressed or normal baseline plasma ACTH. Unilateral uptake of radiolabelled iodocholesterol, which persisted after DXM, was uniformly present. The authors review 36 patients with PCS previously reported. This entity probably constitutes a transition from classic 'nonfunctional' adrenal adenoma to cortisol-producing adenoma. Uniform guidelines in the management of PCS cannot yet be given, but surgical intervention is usually required to prevent the development of long-term complications of subtle corticoid excess.

Abstract: A 52-year-old woman was admitted to our hospital presenting with subarachnoid hemorrhage, left ophthalmoplegia, and right hemiparesis. Previous symptoms and signs suggested the presence of panhypopituitarism. A giant intracranial aneurysm of the internal carotid artery, diagnosed by magnetic resonance imaging, showed the characteristic flow void phenomenon with black appearance. Analysis of endocrine function disclosed panhypopituitarism and hyperprolactinemia. After proximal balloon occlusion of the aneurysm, diabetes insipidus developed. Pituitary function reassessed 6 months after initial admission confirmed anterior and posterior hypopituitarism and hyperprolactinemia. Possible mechanisms are discussed. A review of the literature on pituitary dysfunction caused by carotid artery aneurysms discloses that the pituitary-gonadal axis is the most frequently involved (67.5% of cases), followed by the pituitary-adrenal axis (48.6%) and the pituitary-thyroid axis (40.5%). These frequencies are very similar to those described in other types of hypopituitarism.

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Abstract: BACKGROUND AND PURPOSE: Although iron-mediated mechanisms are important in experimental brain injury after carotid occlusion, their clinical role in acute ischemic stroke has not been determined. We evaluated the influence of iron stores, measured as serum ferritin, on the outcome of acute cerebral infarct. METHODS: Admission and fasting glycemia, glycosylated hemoglobin, serum cortisol, serum ferritin, and 24-hour urinary free cortisol levels were measured on the first day of hospitalization in 67 patients admitted with an acute ischemic stroke of less than 24 hours' duration. Patients were classified into two groups according to their Canadian Stroke Scale (CSS) score on day 30: good outcome group (alive and CSS score > 7 points) and poor outcome group (dead or CSS score < or = 7 points). RESULTS: Thirty-three patients (49%) had good outcome and 34 (51%) poor outcome. Fasting glycemia (P = .001), serum cortisol (P < .001), and urinary free cortisol (P = .001) but not admission glycemia and glycosylated hemoglobin had higher levels in patients with poor outcome. Serum ferritin values were greater in the poor outcome group (218 +/- 156 micrograms/L versus 133 +/- 125 micrograms/L; P = .004), and a correlation between ferritin values and degree of worsening or improvement of the CSS score on day 30 was found (P = .002). Serum cortisol (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.7 to 26), fasting glycemia (OR, 5.4; 95% CI, 1.2 to 24), and serum ferritin (OR, 4.6; 95% CI, 1.1 to 19) were independently related to poor outcome in a logistic regression analysis. CONCLUSIONS: High serum ferritin levels within the first 24 hours of hospitalization for an acute ischemic stroke are related to a poor prognosis, independent of the stress response. More research is needed to determine the origin of increased serum ferritin levels and the therapeutic implications.

Abstract: Growth hormone (GH) levels were measured in 12 patients with myotonic dystrophy (MD; 7 men and 5 women, aged 21-49 years) and 14 volunteers after administration of 100 micrograms GH-releasing hormone (GHRH; 1-29). A 75-g oral glucose tolerance test was carried out to determine glucose, insulin, plasma C-peptide, and urinary C-peptide. The GH level in six MD patients responded normally to GHRH (group I), with a peak of 17.1 +/- 1.46 micrograms/l, compared with controls (27.8 +/- 19.6 micrograms/l, NS), and that in the other six patients responded subnormally, with a peak of 3.15 +/- 1.46 micrograms/l, lower than in controls and in group I patients (P < 0.001). In group I the insulin response to the glucose tolerance test showed hyperinsulinism and was lower than that in group II patients; stimulated C-peptide was also higher in group II than in group I and in controls; urinary C-peptide levels were parallel to those in previous data. In all MD patients there were a negative correlation between absolute values of GH response to GHRH and insulin response to glucose tolerance test (r = -0.79, P < 0.001). Our data suggest that the failure in GH release and peripheral insulin action is due to a generalized defect in cellular membrane function in MD patients.

Abstract: The period of time between clinical manifestations and admission of 18 patients with pituitary apoplexy (PA) was of a mean of 6 days with the exception of two cases. Distribution by age and sex, absence of previous endocrinal clinical manifestations in 38.8% of the patients was similar to that of larger series described. Headache constituted an almost constant symptom. The most affected cranial pairs were II (12 patients), III and IV, both in 8 cases. Following decompression surgery, great improvement was observed in visual acuteness in 5 of these patients, and in the ophthalmoplexy in 8. Alterations in the level of consciousness is less and less frequent in the context of PA thanks to the diagnosis of less severe clinical episodes. Similarly, a high rate of clinical suspicion and the use of new imaging techniques (NMR) have contributed notably with the most outstanding findings being resumed. Moreover, a case of PA with associated intracranial aneurysm verified by carotid angiography is described.

Abstract: Frequent endocrine alterations and abnormal growth hormone (GH) secretion have been reported in myotonic dystrophy (MD). To evaluate GH secretion status in MD, GH response to 100 micrograms of growth hormone releasing hormone (GHRH) with or without pyridostigmine pretreatment and its relation with insulin-induced hypoglycemia was investigated in MD patients and compared with normal controls. The mean peak plasma GH response to GHRH was 27.8 +/- 19.2 micrograms/l normal subjects and 11.4 +/- 8.7 micrograms/l in MD patients. In five of seven patients GH reached a mean peak of 12.6 +/- 4.2 micrograms/l after insulin-induced hypoglycemia, compared with 5 +/- 2.8 micrograms/l after GHRH. Conversely, in two patients GH reached a peak of 16.1 and 32 micrograms/l after GHRH, and only 2.5 and 5.3, respectively, after hypoglycemia. Pretreatment with pyridostigmine in nine patients tested potentiated GHRH-induced GH release with a peak of 17.6 +/- 12.5 micrograms/l, compared with 10.05 +/- 6.7 micrograms/l after GHRH alone; IGF-I levels were normal in all patients.

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Abstract: The computed tomographic (CT) findings in five patients with tuberculous Addison's disease were evaluated. All patients had extra-adrenal tuberculosis. Two patients had enlarged adrenal glands with calcifications at the times of diagnosis. Follow-up CT from 4 to 30 months showed a progressive decrease in the size of adrenal glands from bilateral enlargement to small calcified glands and provides a clue to the etiology of Addison's disease and proper therapy.

Abstract: Sixteen cases of newly diagnosed Addison disease were studied by CT scan. An initial diagnosis was performed according to the clinical data of each patient, and a second diagnosis after examining the abdominal CT scan. According to the second diagnosis there were six patients with primary adrenal failure of probable autoimmune origin, six tuberculosis, two metastatic, one undetermined and one hemorrhagic. The second diagnosis coincided with the first one in 10 cases (62.5%), but was different in six cases (37.5%). Information obtained by CT scan modified the therapeutic attitude in 4 cases (25%). The main morphologic patterns of adrenal glands in CT scan (atrophy, calcification and enlargement) are commented as well as the importance of CT scan in the study of the more common etiologies of Addison's disease (tuberculosis, autoimmune, neoplastic metastasis and hemorrhage). It is concluded that the information obtained by CT scan is important in the etiological diagnosis of Addison disease and it is advised to perform it in all newly diagnosed cases.

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Abstract: BACKGROUND: From a neurological standpoint, pituitary apoplexy (PA) is a well defined syndrome. There are few systematic studies addressing pituitary hormone secretion after a PA episode. The aim of the present study was to assess the frequency and degree of endocrine dysfunction due to PA. METHODS: In 17 consecutive patients, the secretion of growth hormone (GH), the pituitary-adrenal axis status, thyrotropin (TSH), prolactin and gonadotropins (LH, FSH) were evaluated after the administration of insulin, thyrotropin releasing hormone (TRH) and gonadotropin-releasing hormone (LHRH) after an episode of PA. 20-90 days after surgery the measurements were repeated. Antidiuretic hormone (ADH) was measured by plasma/urine osmolality after water deprivation and, in some cases, by administration of hypertonic saline. RESULTS: The most commonly found deficiency was that of GH (84%), which in two cases resulted in cure of acromegaly, followed by that of LH (78%). Pituitary-adrenal dysfunction was improved in two patients after surgery. In all cases except one there was a reduced secretion of at least two hormones. If serum prolactin was reduced, the rest of pituitary function was usually impaired. In one case, permanent diabetes insipidus developed after PA. The prevalence of PA in pituitary adenomas was 9%. CONCLUSIONS: Pituitary hormone secretion after a PA episode is almost invariably impaired. This impairment may be reversed after surgery. Hypoprolactinemia is an indicator of pituitary hypofunction.