Is overweight a risk factor for reduced semen quality and altered serum sex hormone profile?

Objective: To evaluate whether overweight and obesity are related to changes in serum sex hormone concentrations and semen quality. Design: Cross-sectional study. Setting: Data from five previous population-based environmental studies of semen quality were combined into one database at a university hospital in Denmark. Patient(s): In total, 2,139 men provided data to the database. Intervention(s): Data on semen and blood samples and information on lifestyle and reproductive factors, including body mass index (BMI), were collected. Main Outcome Measure(s): Semen quality (volume, concentration, total sperm count, and motility) and serum concentration of sex hormones. Result(S): The T and inhibin B serum concentrations were 25%-32% lower in obese men in comparison with normal-weight men, whereas the E, concentration was 6% higher in obese men. Overweight men (BMI, 25.1-30.0 kg/m(2)) had a slightly lower adjusted sperm concentration and total sperm count than did men with a normal BMI (20.0-25.0 kg/m(2)), but no reduction in sperm count was observed among the obese men. Conclusion(s): These results corroborate earlier findings that overweight and obese men have a markedly changed sex hormone profile in serum, whereas reduction of semen quality, if any, was marginal and below the detection limit of this large study.