Clinical and biochemical correlates of hypogonadism in men with type 2 diabetes mellitus

INTRODUCTION: there is an association between hypogonadism and obesity, chronic hyperglycaemia, and ageing in men with type 2 diabetes mellitus (T2DM). T2DM is known to be associated with low testosterone. There is a paucity of data on the risk factors of hypogonadism in Nigerian men with T2DM. The objective of this study was to determine the clinical and biochemical correlates of hypogonadism and clinical predictors of low total testosterone levels in men with T2DM. METHODS: this was a cross-sectional study consisting of 358 men with T2DM and 179 non-diabetic men (controls). Structured Androgen Deficiency in the Ageing Male questionnaire was administered. Clinical and biochemical parameters were measured. Free testosterone was calculated from albumin, SHBG and total testosterone using Vermeulen´s method. Hypogonadism was defined as fasting TT as < 8 nmol/L with or without symptoms or TT of 8-12 nmol/L with symptoms of androgen deficiency. Low testosterone was defined as serum total testosterone levels ≤ 12 nmol/L. RESULTS: the mean (±SD) total testosterone of men with T2DM and controls were 8.79±3.35 nmol/L and 15.41±3.79 nmol/L respectively (p < 0.001). The risk of hypogonadism was associated with central obesity (Odds ratio [OR] 2.24, 95% confidence interval [CI] 0.38-13.07), systolic hypertension (OR 3.93, 95% CI 0.67-23.10), hyperglycaemia (OR 2.48, 95% CI 0.37-16.46) and hypercholesterolaemia (OR 2.50, 95% CI 0.43-14.61). In a multivariable regression analysis, there was a significant negative correlation between total testosterone and triglycerides (r -1.85, 95% CI -3.58 - 0.12, P = 0.04) and HDL cholesterol (r -1.25, 95% CI -5.95-3.45, P = 0.02). CONCLUSION: this study shows that in men with T2DM, triglycerides and HDL cholesterol are independent correlates of hypogonadism but not central adiposity, systolic blood pressure and glycaemia. Further large prospective studies are recommended.