Diabetes mellitus is associated with subnormal serum levels of free testosterone in men

Abstract

Objective: To evaluate the relationship between diabetes mellitus (DM) and serum levels of free (FT) and total (TT) testosterone.

Patients and methods: A cross-sectional study was carried out including 746 men, of whom 116 (15.6%) were diabetics. Both groups, diabetic and nondiabetic, were paired according to age. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated, and a stratification analysis correlating DM and elevated BMI (>25 kg/m(2)) and WHR (>1) with the presence of subnormal FT and TT levels was performed.

Results: FT and TT serum levels were subnormal in 46% and 34% of diabetics, respectively, and in 24% and 23% of nondiabetics. Subnormal FT levels were strongly correlated with DM (odds ratio (OR) 2.7; 95% confidence interval (CI) 1.8-4.1) but not with elevated BMI (OR 1.4; 95% CI 1.0-2.0). Subnormal TT levels were more strongly associated with elevated BMI and WHR (OR 2.6; 95% CI 1.7-3.9 and 2.0; 1.4-2.9) than with DM (1.7; 1.1-2.6 and 2.0; 1.3-3.2).

Conclusion: These data strongly suggest that DM is associated with subnormal FT levels, and that TT levels are influenced more by obesity and central adiposity.