Decreased Visceral Fat Area Correlates with Improved Total Testosterone Levels After Roux-en-Y Gastric Bypass in Obese Chinese Males with Type 2 Diabetes: a 12-month Follow-up

Background: Obesity and type 2 diabetes (T2D) are recognized as risk factors for hypogonadism in males. Serum sex hormone profiles have not been assessed adequately in obese Chinese males with T2D who have undergone Roux-en-Y gastric bypass (RYGB).

Objective: This study was conducted to examine the changes in sex hormone profiles, anthropometric parameters, and metabolic indexes before and after RYGB.

Setting: University Hospital, China.

Methods: There were 45 obese males with T2D who had undergone RYGB enrolled in this retrospective study, focusing on anthropometric parameters, metabolic indexes, and sex hormone profiles before and after surgery.

Results: The baseline prevalence of hypogonadism (defined by total testosterone [TT] levels<8 nM) was 33.33%. After surgery, both the levels of TT and sex hormone-binding globulin increased, while the levels of estradiol decreased. However, the calculated free testosterone, follicle-stimulating hormone, and luteinizing hormone levels remained unchanged. Multiple linear regression analysis showed that the visceral fat area was the only significant and independent parameter associated with TT levels at baseline (β = -.479, P = .001). After surgery, decreases in the visceral fat area continued to be negatively associated with increases in TT (r = -.411, P = .024).

Conclusion: These preliminary results demonstrated that TT could be significantly increased in obese Chinese males with T2D after RYGB; this occurs in part via a reduction in adipose tissue, especially visceral fat. Therefore, RYGB might be a promising therapy to treat hypogonadism in obese men with T2D.