Pregnancy urinary bisphenol-A concentrations and glucose levels across BMI categories

Background: Pregnancy exposure to bisphenol-A (BPA) may be associated with gestational diabetes (GDM), but evidence from human studies is limited. Moreover, adiposity is associated with both higher BPA concentrations and GDM risk, and may act as a confounder or an effect modifier of the association. Methods: We included 350 term births from the Lifecodes pregnancy cohort (Boston, MA), who had 1st and 2nd trimester measures of urinary BPA concentrations available. BPA measures were SG-adjusted and categorized into quartiles (Q). Multivariable-adjusted linear regressions were used to determine the association between BPA, at both 1st and 2nd trimester, and glucose, in the overall population and by categories of 1st trimester BMI. Results: No clear associations were seen between BPA and glucose levels in the overall population. From stratified analyses there was suggestive evidence of effect modification by maternal 1st trimester BMI, with significant associations observed among obese/overweight participants (1st trimester BPA concentrations for Q3 vs Q1: adj. beta = 14.1 mg/dL; 95% CI: 1.5, 26.6) (2nd trimester BPA concentrations for Q2 vs Q1: adj. beta = 16.9 mg/dL; 95% CI: 2.6, 31.2). Conclusion: No associations were found between BPA and glucose levels in the overall population. However, moderately high BPA concentrations were associated with increased glucose levels among overweight/obese women-a subgroup at high-risk of elevated glucose levels in pregnancy.