A prospective cohort study of the association between bisphenol A exposure and the serum levels of liver enzymes in children

Background Bisphenol A (BPA) is an endocrine disrupter that acts in an estrogen-like manner. Few studies have investigated the association between urinary BPA concentrations and adverse liver function. Additionally, most studies were cross-sectional in nature and included only adults. Objectives We evaluated BPA exposure levels and prospectively explored the association between BPA exposure and liver function in children. Methods Data were retrieved from the ongoing prospective Ewha Birth and Growth Cohort Study. Urinary BPA concentrations were measured in 164 children at 3–5 and 7–9 years of age. At each visit, fasting blood and urine samples were collected, and questionnaires were completed. The associations between the BPA concentrations at these ages and the serum levels of liver enzymes measured at 10–13 years of age were analyzed (n = 113). Multiple regression analysis was performed with adjustment for covariates. We also explored whether the BPA level exhibited dose-response relationships with liver enzyme levels. Results The median urinary BPA concentrations were 0.76 μg/g creatinine at 3–5 years and 0.61 μg/g creatinine at 7–9 years of age. The urinary BPA concentrations at the two ages were correlated significantly (r = 0.23, p < 0.01). The urinary BPA concentrations at 7–9 years, but not that at 3–5 years, was associated significantly with the serum levels of liver enzymes at 10–13 years of age (p < 0.05). Those in the top tertile of urinary BPA concentration had higher levels of liver enzymes than did others. After adjustment for covariates, dose-response relationships of the BPA level with liver enzyme levels were evident at 7–9 years, but not at 3–5 years. Notably, the effect size was larger and the dose-response relationships were more evident in boys than in girls. Conclusions Exposure of children to even low doses of BPA may adversely affect later liver function.