Clinical and Biochemical Assessment of Hypogonadism in Men With Type 2 Diabetes

TLDR

The study aimed to determine how common clinical hypogonadism is among men with type 2 diabetes by evaluating symptoms and biochemical testosterone levels. In a cross‑sectional analysis of 355 diabetic men over 30, researchers measured total and bioavailable testosterone, SHBG, BMI, and waist circumference, defining overt hypogonadism as symptoms plus low testosterone (<8 nmol/L total or <2.5 nmol/L bioavailable) and borderline hypogonadism as symptoms with testosterone in the 8–12 nmol/L or 2.5–4 nmol/L ranges. Low testosterone was common, with 17 % overt (total < 8 nmol/L) and 14 % (bioavailable < 2.5 nmol/L), 25 % borderline (total 8–12 nmol/L or bioavailable 2.5–4 nmol/L), 42 % had free testosterone < 0.255 nmol/L, and BMI and waist circumference were significantly negatively correlated, especially waist, indicating obesity is linked to hypogonadism.

Abstract

OBJECTIVE—The aim of our study was to assess the prevalence of clinical hypogonadism, based on both symptoms and biochemical available measures of testosterone deficiency, in men with type 2 diabetes. RESEARCH DESIGN AND METHODS—In a cross-sectional study of 355 type 2 diabetic men aged &amp;gt;30 years, total and bioavailable testosterone, sex hormone–binding globulin, BMI, and waist circumference were measured and free testosterone was calculated. Overt hypogonadism was defined as the presence of clinical symptoms of hypogonadism and low testosterone level (total testosterone &amp;lt;8 nmol/l and/or bioavailable testosterone &amp;lt;2.5 nmol/l). Borderline hypogonadism was defined as the presence of symptoms and total testosterone of 8–12 nmol/l or bioavailable testosterone of 2.5–4 nmol/l. RESULTS—A low blood testosterone level was common in diabetic men, and a significant proportion of these men had symptoms of hypogonadism. Overt hypogonadism was seen in 17% of men with total testosterone &amp;lt;8 nmol/l and 14% with bioavailable testosterone &amp;lt;2.5 nmol/l. Borderline hypogonadism was found in 25% of men with total testosterone 8–12 nmol/l and bioavailable testosterone between 2.5 and 4 nmol/l; 42% of the men had free testosterone &amp;lt;0.255 nmol/l. BMI and waist circumference were both significantly negatively correlated with testosterone levels in men, with the association being stronger for waist circumference. CONCLUSIONS—Testosterone levels are frequently low in men with type 2 diabetes, and the majority of these men have symptoms of hypogonadism. Obesity is associated with low testosterone levels in diabetic men.