Effects of Bariatric Surgery in Male Obesity-Associated Hypogonadism

The prevalence of obesity has grown exponentially over the last several decades. Research has linked male obesity to changes in the gonadal axis, which can induce functional hypogonadism. Bariatric surgery provides sustained weight loss and metabolic improvement. This was a retrospective cohort study to evaluate the male gonadal axis and metabolic profiles of obese individuals during the bariatric pre- and post-operative periods while comparing them to a normal body mass index (BMI) group.

Twenty-nine obese men, who underwent bariatric surgery between 2012 and 2016 at the Federal University of Santa Catarina Hospital and a control group (CG) of 29 age-matched men with normal BMI, were analyzed. Bariatric pre- and 6-month post-operative data were compared with the CG.

The study group (G1) presented an average age, weight, and BMI of 42.8 ± 9.5 years, 155.2 ± 25.8 kg, and 50.6 ± 7.1 kg/m², respectively. The pre-operative total testosterone (TT) G1 values were different from the CG (229.5 ± 96.4 versus 461.5 ± 170.8 ng/dL, p < 0.01). Bariatric surgery promoted a statistically significant improvement in weight, TT, and metabolic profiles in surgical patients.

Functional hypogonadism is prevalent in obese men, and we must be aware of this diagnosis. Although studies defining the best diagnostic parameters and indication of adequate hormone replacement therapy are lacking, an increase in TT levels during the first 6 months after bariatric surgery was identified in our study. Previous studies have shown that gonadal function can normalize after metabolic improvement.