Effects of bariatric surgery on male obesity-associated secondary hypogonadism: comparison of laparoscopic gastric bypass with restrictive procedures.

Bariatric surgery results in the complete resolution of male obesity-associated secondary hypogonadism (MOSH) in many patients. However, the effects of different bariatric surgical procedures on male sexual hormone profiles and sexual dysfunction have not been compared to date. We compared the pre- and post-operative (at least 6 months after initial surgery) sex hormone profiles of 20 severely obese men submitted to laparoscopic gastric bypass (LGB) with 15 similar patients submitted to restrictive techniques (sleeve gastrectomy in 10 and adjustable gastric banding in 5). We calculated free testosterone (FT) levels from total testosterone (TT) and sex hormone binding globulin (SHBG) concentrations. Fasting glucose and insulin levels served for homeostatic model assessment of insulin resistance (HOMAIR). MOSH was present in 25 and 16 of the 35 patients when considering TT and FT concentrations respectively, resolving after surgery in all but one of them. When considering all obese men as a whole, patients submitted to LGB or restrictive procedures did not differ in terms of excess weight loss, in the decrease of fasting glucose and insulin, HOMAIR and waist circumference, or in the increase of serum 25-hydroxyvitamin D, TT and FT levels. The improvement in TT correlated with the decrease in fasting glucose (r = -0.390, P = 0.021), insulin (r = -0.425, P = 0.015) and HOMAIR (r = -0.380, P = 0.029), and with the increase in SHBG (r = 0.692, P < 0.001). The increase in FT correlated with the decrease in fasting glucose (r = -0.360, P = 0.034). LGB and restrictive techniques are equally effective in producing a remission of MOSH.