Endocrine Abstracts

Objective: Obesity is a risk factor for hypogonadotrophic hypogonadism in men. Increase in body weight was found to be associated with decrease testosterone level and sex hormone-binding globulin (SHBG) level. The aim of this study was to evaluate the change in testosterone levels in extremely obese men after bariatric surgery.

Methods: This is a prospective study including 29 morbidly obese men undergoing bariatric surgery. Main outcomes were changes in serum levels of total testosterone (TT), free testosterone (cFT), SHBG, Estradiol, adiponectin and leptin at 1 and 6 months after bariatric surgery.

Results: The mean ages of patients were 31±8 years and the mean BMI was 57.8±11.2 kg/m². Sixteen patients underwent Roux-en-Y gastric bypass and 13 patients underwent sleeve gastrectomy. At baseline, 22 patients (75.9%) had low TT levels (<10.4 nmol/L) and 27 patients (93.1%) had low cFT levels (<0.31 nmol/L). Total testosterone and SHBG levels increased significantly at 1 month after surgery (P=<0.001) whereas cFT levels have not changed. At 6 months after surgery, TT, cFT and SHBG levels increased significantly (all p-values=<0.001) and 21 patients (72.4%) had normal TT levels. There were no changes in estradiol levels either at 1 month or 6 months after surgery. Leptin levels decreased and adiponectin levels increased significantly after surgery. Early increases in TT levels were associated with increases in SHBG levels (R=0.472, P=0.042) but not with changes in body weight, BMI, adiponectin or leptin.

Conclusions: Increases in TT and SHBG levels occurred early at 1 month after bariatric surgery while improvements in cFT levels were observed at 6 months after bariatric surgery. No change in estradiol levels was found. Changes in total testosterone levels tend to be correlated with SHBG levels but not with body weight or adipokines levels.