# Metabolic and bariatric surgery and male endocrine and reproductive health: a GRADE-assessed meta-analysis

## TL;DR

Bariatric surgery improves testosterone levels and sexual function in obese men, suggesting it can help with both weight loss and reproductive health.

## Contribution

This is the first GRADE-assessed meta-analysis examining the effects of bariatric surgery on male endocrine and reproductive health.

## Key findings

- Bariatric surgery significantly increases total and free testosterone levels in obese men.
- The surgery improves sexual function as measured by the International Index of Erectile Function.
- Bariatric surgery reduces estradiol and prolactin levels in obese men.

## Abstract

The negative impact of obesity on male fertility and sexual health is well-established. Although metabolic and bariatric surgery (MBS) offers a powerful solution for severe obesity, its impact on the male androgens, semen quality, and sexual function are not yet fully understood.

A comprehensive systematic search of the literature was conducted in PubMed, Embase, the Cochrane Library, and Web of Science for relevant studies published up to July 2024. Data about reproductive hormones, semen parameters, and sexual function in men with obesity undergoing bariatric surgery was extracted. For data synthesis, weighted mean differences (WMDs) and their 95% confidence intervals (CIs) were calculated using random- or fixed-effects models, as appropriate.

Fifty-nine studies with 60 arms were included in our meta-analysis. Metabolic and bariatric surgery indicated elevated levels of total testosterone (TT) (WMD: 5.46 nmol/L, p < 0.001; WMD: 6.58 nmol/L, p < 0.001; and WMD: 8.02 nmol/L, p < 0.001), sex hormone-binding globulin (SHBG) (WMD: 14.56 nmol/L, p < 0.001; WMD: 18.08 nmol/L, p < 0.001; and WMD: 23.64 nmol/L, p < 0.001), international index of erectile function (IIEF) (WMD: 9.36, p < 0.001), and diminished levels of PRL (WMD: −76.48 mIU/L, p = 0.003) at all intervals. Moreover, increased levels of free testosterone (FT) at 6–9 month (WMD: 66.61 nmol/L, p < 0.001), and >12 months (WMD: 78.94 nmol/L; p < 0.001) were observed pos-operative state among obese men. Also, decreased levels of estradiol (E2) at 6–9 month (WMD: −14.52 nmol/L, p = 0.005), and ≥12 months (WMD: −11.63 nmol/L; p < 0.001) was seen after bariatric surgery.

Overally, this meta-analysis illustrated that bariatric surgery improves the hormonal profile and sexual function in obese men profoundly. These findings introduce bariatric surgery as an effective therapeutic strategy for weight loss management and male reproductive health improvement.