Biliopancreatic diversion: long-term effects on gonadal function in severely obese men

BACKGROUND: This study investigated hormonal parameters of gonadal function in severely obese men before and 1 year after undergoing biliopancreatic diversion (BPD). METHODS: This observational 1-year postoperative study conducted at medical and surgical clinics at an academic medical center in Italy followed 20 severely obese men age 21 to 63 years, with a mean (+/- standard deviation) body mass index (BMI) of 47.3 +/- 13.1. The following parameters were evaluated: body composition, using body impedance analysis (BIA), and serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone, estradiol 17beta, and leptin. RESULTS: At a mean 12 +/- 1 months after surgery, the patients showed a significant decrease in weight, from 132.1 +/- 36.9 before surgery to 93.5 +/- 20 kg (P < .0001), and BMI, from 47.3 +/- 13.1 before surgery to 33.5 +/- 7 (P < .0001). LH increased from 2.42 +/- 1.59 to 4.97 +/- 2.6 mIU/ml (P < .0001), FSH increased from 2.85 +/- 1.85 to 4.9 +/- 4.2 mIU/mL (P = .021), and total testosterone increased from subnormal presurgical values to within normal range (2.81 +/- 1.08 to 9.12 +/- 1.37 ng/mL; P < .0001), whereas estradiol 17beta decreased from elevated basal levels of 44.0 +/- 29 to 16.7 +/- 6.9 pg/mL (P < .0001). The basal leptin level dropped from 33.0 +/- 9.23 to 16.6 +/- 5.12 ng/mL (P < .0001), reflecting the decrease in body fat. Subjective improvement in sexual performance was reported by 80% of patients. CONCLUSIONS: Severe obesity is coupled with some significant alterations of the gonadotropin-testicular axis and estradiol 17beta and leptin blood levels. These derangements were substantially corrected by 1 year after BPD.