Background: In severe obesity, hypogonadism in men and androgen excess in women are frequently observed. Sex hormones play an important role in body composition and glucose and lipid metabolism. However, whether pre-operative gonadal dysfunction impacts weight loss after bariatric surgery is not fully known.
Methods: A total of 49 men and 104 women were included in a retrospective analysis. Anthropometric characteristics, glucose and lipid metabolism, and androgen concentrations were assessed pre-operatively and 17.9 ± 11 or 19.3 ± 12 months post-operatively in men and women. Men with (HYPOmale) and without (controls: CONmale) pre-operative hypogonadism, as well as women with (HYPERfemale) and without (controls: CONfemale) pre-operative hyperandrogenemia, were compared.
Results: In men, pre-operative hypogonadism was present in 55% and linked to a higher body mass index (BMI): HYPOmale 50 ± 6 kg/m2 vs. CONmale 44 ± 5 kg/m2, p = 0.001. Bariatric surgery results in comparable changes in BMI in HYPOmale and CONmale - 16 ± 6 kg/m2 vs. - 14 ± 5 kg/m2, p = 0.30. Weight loss reversed hypogonadism in 93%. In women, androgen excess was present in 22%, independent of pre-operative BMI: CONfemale 44 ± 7 kg/m2 vs. HYPERfemale 45 ± 7 kg/m2, p = 0.57. Changes in BMI were comparable in HYPERfemale and CONfemale after bariatric surgery - 15 ± 6 kg/m2 vs. - 15 ± 5 kg/m2, p = 0.88. Hyperandrogenemia was reversed in 61%.
Conclusions: Besides being frequently observed, hypogonadism in men and androgen excess in women have no impact on post-surgical improvements in body weight and glucose and lipid metabolism. Weight loss resulted in reversal of hypogonadism in almost all men and of hyperandrogenemia in the majority of women.
Keywords: Androgen excess; Functional hypogonadism; Testosterone deficiency.