Urine bisphenol-A (BPA) level in relation to semen quality

Objective To determine whether urine bisphenol-A (BPA) levels are associated with lower semen quality. Design Cohort study. Setting Four regions in China where high exposure to BPA in the workplace existed. Patient(s) 218 men with and without BPA exposure in the workplace. Intervention(s) None. Main Outcome Measure(s) Semen parameters. Result(s) After adjustment for potential confounders using linear regression, increasing urine BPA level was statistically significantly associated with [1] decreased sperm concentration, [2] decreased total sperm count, [3] decreased sperm vitality, and [4] decreased sperm motility. Compared with men who did not have detectable urine BPA levels, those with detectable urine BPA had more than three times the risk of lowered sperm concentration and lower sperm vitality, more than four times the risk of lower sperm count, and more than twice the risk of lower sperm motility. The urine BPA level was not associated with semen volume or abnormal sperm morphology. Similar dose-response associations were observed among men with environmental BPA exposure at levels comparable with those in the U.S population. Despite a markedly reduced sample size, the inverse correlation between increased urine BPA levels and decreased sperm concentration and total sperm count remained statistically significant. Conclusion(s) These results provide the first epidemiologic evidence of an adverse effect of BPA on semen quality.