Hypogonadotropic hypogonadism among a population of obese men: Prevalence, risk factors and reversibility after weight loss induced by bariatric surgery

SummaryBackground and aimsObesity in men is frequently associated with low levels of testosterone, loss of libido and/or erectile dysfunction. Our goal was to estimate the prevalence of hypogonadism among obese men and to determine its risk factors and reversibility after bariatric surgery.MethodsSeventy-five obese men were studied at baseline. Metabolic and hormonal parameters were measured, body composition was assessed by bioelectrical impedance and hypogonadism was evaluated by the ADAM (Androgen Deficiency in Aging Males) questionnaire. Twenty-one patients were re-evaluated after bariatric surgery.ResultsAt baseline, 39% of obese men had hypotestosteronemia, while symptoms of androgen deficiency were present in 93%. Total Testosterone (TT) was inversely related to body mass index (BMI) (P < 0.05), waist circumference (P = 0.012) and body fat mass (P = 0.022). Bariatric surgery was associated with an increase in TT (P = 0.001) and decreases in estradiol (E2) (P = 0.008) and in the E2/TT ratio (P = 0.001).ConclusionsLow testosterone levels are frequently observed among morbidly obese men and are correlated with the degree of abdominal adiposity, but not strongly with the presence of sexual dysfunction. Bariatric surgery leads to normalized TT and to decreased E2 and E2/TT ratio, suggesting a role of excessive aromatization in the hypotestosteronemia associated with obesity.