Association of early life exposure to bisphenol A with obesity and cardiometabolic traits in childhood

Background: Bisphenol A (BPA) is a chemical used extensively worldwide in the manufacture of plastic polymers. The environmental obesogen hypothesis suggests that early life exposure to endocrine disrupting chemicals such as BPA may increase the risk for wt gain later in childhood but few prospective epidemiological studies have investigated this relationship. Objectives: We examined the association of early life BPA exposure with offspring obesity and cardiometabolic risk factors in 500 mother-child pairs from the RHEA pregnancy cohort in Crete, Greece. Methods: BPA concentrations were measured in spot urine samples collected at the 1st trimester of pregnancy) and from children at 2.5 and 4 years of age. We measured birth wt, body mass index (BMI) from 6 months to 4 years of age, waist circumference, skinfold thickness, blood pressure, serum lipids, C-reactive protein, and adipokines at 4 years of age. BMI growth trajectories from birth to 4 years were estimated by mixed effects models with fractional polynomials of age. Adjusted associations were obtained via multivariable regression analyses. Results: The prevalence of overweight/obesity was 9% at 2, 13% at 3% and 17% at 4 years of age. Geometric mean BPA concentrations were 1.2 μg/g creatinine±7.9 in 1st trimester, 5.1 μg/g±13.3 in 2.5 years and 1.9. μg/g±4.9 in 4 years. After confounder adjustment, each 10-fold increase in BPA at 4 years was associated with a higher BMI z-score (adj. β=0.2; 95% CI: 0.01, 0.4), waist circumference (adj. β=1.2; 95% CI: 0.1, 2.2) and sum of skinfold thickness (adj. β=3.7 mm; 95% CI: 0.7, 6.7) at 4 years. Prenatal BPA was negatively associated with BMI and adiposity measures in girls and positively in boys. We found no associations of early life exposure to BPA with other offspring cardiometabolic risk factors. Conclusions: Prenatal BPA exposure was not consistently associated with offspring growth and adiposity measures but higher early childhood BPA was associated with excess child adiposity.