Body mass index in relation to semen quality, sperm DNA integrity, and serum reproductive hormone levels among men attending an infertility clinic

Objective: To examine the association between body weight and measures of male reproductive potential. Design: Cross-sectional study. Setting: Fertility clinic in an academic medical center. Patient(s): Four hundred eighty-three male partners of subfertile couples. Intervention(s): None. Main Outcome Measure(s): Standard semen analysis, sperm DNA fragmentation, and serum levels of reproductive hormones. Result(s): As expected, body mass index (BMI) was positively related to estradiol levels and inversely related to total testosterone and sex hormone-binding glogulin (SHBG) levels. There was also a strong inverse relation between BMI and inhibin B levels and a lower testosterone: LH ratio among men with a BMIR >= 35 kg/m(2). Body mass index was unrelated to sperm concentration, motility, or morphology. Ejaculate volume decreased steadily with increasing BMI levels. Further, men with BMI >= 35 kg/m(2) had a lower total sperm count (concentration x volume) than normal weight men (adjusted difference in the median [95% confidence interval] = -86 x 10(6) sperm [-134, -37]). Sperm with high DNA damage were significantly more numerous in obese men than in normal-weight men. Conclusion(s): These data suggest that despite major differences in reproductive hormone levels with increasing body weight, only extreme levels of obesity may negatively influence male reproductive potential. (Fertil Steril (R) 2010;93:2222-31. (C)2010 by American Society for Reproductive Medicine.)