Associations between visceral adipose tissue, inflammation and sex steroid concentrations in men.

CONTEXT: In men, obesity and the metabolic syndrome are accompanied by decreased testosterone levels, but little is known about the associations between visceral adipose tissue (VAT), VAT-related inflammation and sex steroids. OBJECTIVE: To examine the relative impact of VAT, abdominal subcutaneous adipose tissue (SAT) and interleukin 6 (IL-6), a marker of VAT-induced inflammation, on testosterone (T) and 17ß-oestradiol (E2) levels in dysmetabolic men. METHODS: We study the NUMEVOX cohort of 229 men, aged 27-77 years, who all had at least one metabolic syndrome criterion (on average three). IL-6, C-reactive protein, Homeostasis Model Assessment of (HOMA) insulin resistance index (HOMA-IR), liver enzymes, E2, LH, sex hormone-binding globulin (SHBG), T, waist circumference and body mass index (BMI) were measured; bioavailable testosterone (BT) was calculated from T and SHBG; MRI-assessed VAT and SAT were analysed in 109 of these men. RESULTS: Visceral adipose tissue was strongly correlated with E2 (Spearman r = 0.38, P < 0.001) and with BT/E2 ratio (r = -0.42, P < 0.001), while SAT was not correlated with either. IL-6 was correlated with E2 (r = 0.19, P = 0.007), BT (r = -0.19, P = 0.006) and BT/E2 ratio (r = -0.30 P < 0.001). In multivariate linear analysis, the relation between VAT and E2 was independent of age, BMI (P = 0.008), leptin (P < 0.001), T and SHBG. Log(IL-6) was significantly inversely related with log(BT) (P = 0.032) independently of age, VAT, leptin and HOMA-IR. CONCLUSIONS: 17ß-oestradiol levels were positively associated with VAT, but not with SAT, while T and BT were negatively and independently associated with IL-6. The significant inverse association between IL-6 and T suggests an important role of low-grade visceral fat inflammation in the central hypogonadism associated with the metabolic syndrome.

Role of sex steroids, intrahepatic fat and liver enzymes in the association between SHBG and metabolic features.

BACKGROUND: SHBG and liver enzymes levels are both associated with the risk of type 2 diabetes. However, the relationship between SHBG with liver enzymes and intrahepatic fat content remain poorly understood. OBJECTIVE: To investigate whether SHBG is correlated with glucose and lipids levels and whether this association depends on fatty liver content, liver enzymes or sex hormone concentrations. DESIGN AND PATIENTS: We studied 233 dysmetabolic men with measures of plasma SHBG, total testosterone, 17ß-oestradiol, glucose, adiponectin, liver enzymes and hepatokines. Intrahepatic liver fat and visceral fat contents were measured by magnetic resonance imaging in 108 of these individuals. RESULTS: After adjustment for age, SHBG concentration was inversely correlated with fasting glucose (ßstandardized  = -0·21, P = 0·0007), HbA1c (ßstandardized  = -0·27, P < 0·0001), triglycerides (ßstandardized  = -0·19, P = 0·003) and positively correlated with HDL-Cholesterol (ßstandardized  = 0·14, P = 0·03). These correlations persisted after adjustment for either total testosterone or 17ß-oestradiol levels. SHBG was not related to either fetuin A or FGF 21 concentrations. The inverse association of SHBG with HbA1c and glycaemia was not altered after adjusting for liver markers but was no longer significant after adjustment for hepatic fat content. CONCLUSION: The significant association between SHBG and fasting glycaemia, HbA1c and lipid levels in dysmetabolic men was not related to either sex hormones or markers of liver function, but was dependent on intrahepatic fat. This suggests that intrahepatic fat, but not alterations in liver function markers, may be involved in the association between SHBG and glucose and lipid metabolism.

Markers of recurrence and long-term morbidity in craniopharyngioma: a systematic analysis of 171 patients.

CONTEXT: Craniopharyngiomas are often associated with an unfavorable prognosis, but data on their long-term consequences are sparse. OBJECTIVE: The aim of the study was to identify markers of recurrence and factors associated with compromised social rehabilitation and altered quality of life in a large cohort of patients with either childhood-onset (CO) or adult-onset craniopharyngioma. METHODS: Retrospective analysis was performed for 171 patients treated for craniopharyngioma in two academic centers in France between 1972 and 2009. For each subject, data were collected concerning clinical presentation, imaging features, visual sequelae, endocrine and metabolic impact, treatment modalities (surgery, radiotherapy), recurrence-free survival rate, and social insertion, as well as answers to the WHO-QOL BREF questionnaire. RESULTS: A total of 65 CO and 106 adult-onset patients were reviewed. If CO was diagnosed before the age of 10 yr, this was associated with a higher incidence of obesity, blindness, and panhypopituitarism, and only 40.7% of subjects had adequate work or school attendance compared to 72.4% of patients with later disease onset. Initial symptoms of intracranial hypertension (SIHT), pterional surgery, and multiple surgery were associated with obesity and poorer social insertion. No determinant of quality of life was identified. In the subgroup of patients treated in the 1990s and later, the progression rate was 59.4% in patients with residual tumor on magnetic resonance imaging compared with a 19.8% recurrence rate in the group with apparently complete resection. Recurrence/progression correlates significantly with male gender, early onset (before 10 yr), and SIHT, but only SIHT at presentation remained a significant predictor with multivariate analysis. CONCLUSIONS: Craniopharyngioma continues to be associated with severe outcomes. Higher morbidity rates are found in patients with early-onset disease (before 10 yr), initial SIHT, or in whom pterional surgery was required. Markers of recurrence are difficult to identify, with SIHT being the most powerful predictor.

Effects of genetic susceptibility for type 2 diabetes on the evolution of glucose homeostasis traits before and after diabetes diagnosis: data from the D.E.S.I.R. Study.

OBJECTIVE: To assess the impact of genetic susceptibility on evolution toward type 2 diabetes (T2D) by analyzing time trajectories of fasting glucose, glycated hemoglobin (HbA(1c)), insulin sensitivity (homeostasis model assessment [HOMA2%S]), and ß-cell secretion (HOMA2%B) in a large nondiabetic cohort. We also examined whether baseline HbA(1c) modified the effect of genetic predisposition on the time trajectories. RESEARCH DESIGN AND METHODS: Time trajectories were drawn in 4,744 participants from the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (D.E.S.I.R.) cohort based on samples collected every 3 years over a 9-year follow-up. Trajectories were analyzed according to the TCF7L2 common variant, a family history of T2D, and a combination of at-risk alleles from nine T2D-associated genes. RESULTS: There was a marked decrease in HOMA2%B in parallel to a steep increase in HbA(1c) over the 3 years before incident diabetes, which was not influenced by genetic predisposition when considered alone. However, after the onset of T2D, the TCF7L2 at-risk variant was associated with a greater decrease in HOMA2%B. There was a joint effect of a family history of T2D with the presence of the TCF7L2 risk allele with a greater rise in HbA(1c) conferred by the coexistence of a family history and the T risk allele. An HbA(1c) ≥5.7% at baseline was associated with a greater increase in both glycemia and HbA(1c) levels in the presence of a combination of diabetes at-risk alleles. CONCLUSIONS: After incident T2D, TCF7L2 at-risk variants were associated with a faster decrease in ß-cell function compared with those with the CC genotype. There was a joint effect of family history of T2D and TCF7L2 risk variant on the rise in glycemia and the decrease in insulin secretion at the end of follow-up, suggesting the joint influence of the combination of diabetes genetic predisposition with familial factors on the evolution of glycemia over time.

Liver iron overload is associated with elevated SHBG concentration and moderate hypogonadotrophic hypogonadism in dysmetabolic men without genetic haemochromatosis.

AIMS: To assess the relation between moderate iron overload on sex hormone binding globulin (SHBG) levels and gonadotroph function in men with dysmetabolic iron overload syndrome and the effects of phlebotomy. METHODS: The relationship between magnetic resonance imaging assessed liver iron concentration (LIC) and plasma ferritin levels with total testosterone, bioavailable testosterone (BT), SHBG and LH levels, were studied in 50 men with moderate dysmetabolic iron excess, in the absence of genetic haemochromatosis, who were randomised to phlebotomy therapy or to normal care. RESULTS: Four patients (8%) had low total testosterone (<10.4 nmol/l) and 13 patients (26%) had low BT (<2.5 nmol/l). In the entire population, those with LIC above the median (90 µmol/l) had a higher mean SHBG (P=0.028), lower LH (P=0.039) than those with LIC below the median. In multivariable analysis (adjusted for age, and fasting insulin) LIC was significantly associated with SHBG (positively) and LH (negatively). Patients in the highest quartile of SHBG had higher LIC (P=0.010) and higher ferritinaemia (P=0.012) than those in the three other quartiles. Iron depletion by venesection did not significantly improve any hormonal levels. CONCLUSIONS: Hypogonadism is not infrequent in men with dysmetabolic iron overload syndrome. Liver iron excess is associated with increased plasma SHBG and moderate hypogonadotrophic hypogonadism. Phlebotomy therapy needs further investigation in symptomatic hypogonadal men with dysmetabolic iron excess.

Are the same clinical risk factors relevant for incident diabetes defined by treatment, fasting plasma glucose, and HbA1c?

OBJECTIVE: To compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA(1c) ≥6.5%. RESEARCH DESIGN AND METHODS: Participants aged 30-65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years. RESULTS: More men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA(1c) ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA(1c) alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions. CONCLUSIONS: In men, FPG definitions yielded more incident cases of diabetes than HbA(1c) definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA(1c)-defined diabetes.

Increases in waist circumference and weight as predictors of type 2 diabetes in individuals with impaired fasting glucose: influence of baseline BMI: data from the DESIR study.

OBJECTIVE: To evaluate in impaired fasting glucose (IFG) the relative importance of increases in waist circumference and weight on progression to type 2 diabetes. RESEARCH DESIGN AND METHODS: The 9-year incidence of diabetes was studied in 979 men and women with baseline IFG, from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort. RESULTS: Increases in both waist circumference and weight were significantly associated with diabetes incidence. Standardized odds ratios (95% CI) were 1.79 (1.45-2.21) and 1.86 (1.51-2.30), respectively, after controlling for baseline risk factors. The impact of waist circumference increase was greater for BMI <25 kg/m(2) (2.40 [1.63-3.52]) than for BMI >or=25 kg/m(2) (1.66 [1.28-2.16]) and persisted after adjusting for concurrent changes in either insulinemia or the homeostasis model assessment of insulin resistance index. Weight change had a similar impact in both BMI groups. CONCLUSIONS: In individuals with IFG, it is important to monitor and prevent increases in waist circumference, in particular for those with BMI <25 kg/m(2).