Reduced Circulating Androgen Levels After Gastric Bypass Surgery in Severely Obese Women

Background

Previous studies have shown a reduction of elevated androgen levels in premenopausal women after marked weight loss induced by bariatric surgery. In this study, we aimed to assess whether circulating androgen levels also decline after bariatric surgery in women displaying normal values preoperatively as well as in postmenopausal women.

Methods

In 36 severely obese women (six postmenopausal), levels of total testosterone, dehydroepiandresterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG) were assessed before and at ~1 year after gastric bypass. Free and bioavailable testosterone levels as well as the free androgen index were calculated by established formulas.

Results

After the surgery, women had lost on average 43.1?±?1.8 kg. Independently of the pre/postmenopausal state, women showed a marked reduction in all testosterone-related androgen markers and DHEA-S levels, while SHBG levels markedly increased (all P?<?0.001). Respective changes were found in both women with and without preoperatively elevated levels. Changes after the surgery in testosterone-related markers as well as in SHBG levels but not in DHEA-S levels were correlated with changes in insulin levels independently of body weight changes.

Conclusions

Data show a marked reduction of androgen levels in severely obese women after a surgically induced weight loss, which is independent from the menopausal state and preoperative levels. The mechanisms and consequences of these hormonal changes induced by bariatric surgery should be addressed in further studies.