Bisphenol A Exposure in Children With Autism Spectrum Disorders

The etiology of autism spectrum disorders (ASD) is believed to involve genetic and environmental components. This study focused on the plasticizer, Bisphenol-A (BPA). The major pathway for BPA metabolism and excretion is via glucuronidation. To determine whether there was a relationship between BPA exposure and ASD, urine specimens were collected from 46 children with ASD and 52 controls. Free and total BPA concentrations were determined by mass spectrometry. The fraction glucuronidated was calculated from the difference. A metabolomics study was done to investigate metabolite distribution in the urine. (i) Most of the BPA excreted in the urine was as the glucuronide; (ii) about 20% of the ASD children had BPA levels beyond the 90th percentile (>50 ng/mL) of the frequency distribution for the total sample of 98 children; (iii) Mann-Whitney U tests and multiple regression analyses found significant differences (P < 0.05) between the groups in total and % bound BPA; and (iv) the metabolomics analyses showed the number of absolute partial correlations >|0.30| between metabolite concentrations and total BPA was ∼3 times greater with the ASD group than the controls (P < 0.001), and the number of absolute partial correlations > |0.30| for % bound BPA was ∼15 times higher with ASD (P < 0.001). The results suggest there is an association between BPA and ASD.