The male patient with obesity undergoing metabolic and bariatric surgery: changes in testosterone levels correlate with weight loss after one-anastomosis gastric bypass and Roux-en-Y gastric bypass

Male obesity secondary hypogonadism (MOSH) is a common disease among men with obesity and can be associated with metabolic syndrome and a variety of metabolic problems ultimately leading to androgen deficiency. Metabolic and bariatric surgery is a well-established treatment option associated with significant weight loss and reduction in metabolic co-morbidities. To evaluate the impact of surgery on plasma levels of sexual hormones and their effect on weight loss comparing 2 surgical methods (one-anastomosis gastric bypass [OAGB] and Roux-en-Y gastric bypass [RYGB]) in male patients with obesity. University hospital, Austria. Patients undergoing OAGB and RYGB between 2012 and 2017 were analyzed retrospectively. Follow-up in this study was up to 24 months. Systemic levels of sexual hormones (luteinizing hormone [LH]), follicle stimulating hormone [FSH], total testosterone [TT], sexual hormone binding globin [SHBG], 17 beta-estradiol [17bE], androstenedione [AS]) were retrieved at each visit. A linear mixed model was used to assess the correlation between changes in testosterone levels and percent excess weight loss (%EWL). In 30.8% of all patients, MOSH was present preoperatively. A significant increase of TT was observed postoperatively that led to a complete resolution of hypogonadism within the period observed. Bioavailable testosterone (bTT) and FSH levels significantly increased each month of follow-up after surgery (all P < .01). Levels of 17bE did not change significantly after surgery. The overall change of TT, comparing preoperative and 1-year postoperative TT levels (ΔTT), significantly correlated with %EWL. Changes in TT levels were not affected by the choice of surgical method. Serum plasma testosterone levels rise significantly after metabolic and bariatric surgery in male patients. The change of testosterone levels seems to play a role in continued weight loss after surgery. This is true irrespective of the surgical method used. •Bariatric-metabolic surgery leads to the biochemical resolution of male obesity secondary hypogonadism within the first two years•A steeper increase in testosterone levels (baseline to 12 months) corresponds to a higher %EWL•No difference between RYGB and OAGB was observed, none of the methods can be favoured in the male patient suffering with obesity suffering from hypogonadism