Prenatal PFAS exposures and cardiometabolic health in middle childhood in the MIREC cohort.

Studies on prenatal exposure to per- and polyfluoroalkyl substances (PFAS) and cardiometabolic health in childhood have produced inconsistent results. In this study, we evaluated associations between prenatal PFAS exposures, individually and as a mixture, and cardiometabolic outcomes including insulin resistance, beta cell function, blood lipids, blood pressure and central adiposity during middle childhood (7-9 years of age) in a Canadian maternal-child cohort (n = 281). We also explored effect measure modification based on child sex and physical activity. We quantified maternal second trimester plasma concentrations of six PFAS and measured 11 offspring cardiometabolic outcomes at a 7-9-year follow-up. In single-exposure models, ten-fold higher prenatal PFDA (β: -0.82, 95% CI: -1.36, -0.28), PFNA (β: -0.8, 95% CI: -1.41, -0.19), and PFOA (β: -0.69, 95% CI: -1.18, -0.19) concentrations were associated with lower diastolic blood pressure z-scores. This association did not persist when considering PFAS exposures as a mixture using quantile g-computation. Associations between PFAS exposures, individually or as a mixture, and other cardiometabolic outcomes were null. We observed no effect measure modification by child sex or physical activity (p-values for interaction ≥0.2). Our results contradict existing studies that suggest prenatal PFAS exposures are associated with adverse childhood cardiometabolic outcomes. Future studies should consider alternative markers of cardiometabolic health, trajectories in cardiometabolic health throughout childhood, and further explore potentially protective health behaviors.