Association of Testosterone, Insulin-Like Growth Factor-I, and C-Reactive Protein with Metabolic Syndrome in Chinese Middle-Aged Men with a Family History of Type 2 Diabetes

Abstract

Context: Age-related declines in testosterone and IGF-I are associated with deposition of visceral fat, a component of the metabolic syndrome (MES). Objective: Testosterone and IGF-I may interact with familial disposition to diabetes mellitus to increase the association with MES. Design: We conducted a cross-sectional cohort study. Setting: The study was conducted in a university teaching hospital. Subjects: Study subjects included 179 middle-aged men with a family history of diabetes (FH) (aged 39.1 ± 8.1 yr) and 128 men without FH (aged 43.8 ± 8.5 yr). Main Outcome Measures: Clinical characteristics, frequency of MES using the World Health Organization criteria with Asian definitions of obesity (body mass index ≥ 25 kg/m2), and serum levels of total testosterone, IGF-I, and high-sensitive C-reactive protein (hs-CRP) were measured. Results: Men with FH had higher frequency of MES than those without FH [39.1 vs. 23.4% (P = 0.004)]. On multivariate analysis, smoking (former and current smokers), low total testosterone, and IGF-I but elevated hs-CRP levels explained 35% of the MES variance in men with FH. The frequency of MES increased with declining tertiles of total testosterone and IGF-I but increasing tertiles of hs-CRP. After adjustment for age and smoking history, subjects with all three risk factors had a 13-fold increase in risk association with MES compared with those without hormonal and inflammatory risk factors. These risk associations were not found in men without FH in whom only smoking (ex and current) and low total testosterone level were independent predictors for MES, which explained 14% of the variance. Conclusions: Clustering of FH, hormonal abnormalities, and high hs-CRP is associated with MES in Chinese middle-aged men.