Prenatal and childhood exposure to perfluoroalkyl substances and fat distribution in 9-year-old children: A prospective cohort study in the Faroe Islands

Background: Per- and polyfluoroalkyl substances (PFASs) are known to cause adverse health effects, especially in children, and they might also be obesogenic. Given the rise in global obesity and overweight, and the likely origin in childhood, we aimed to examine the association between childhood PFAS exposure and body fat distribution at age 9 years. Methods: In 378 children from a Faroese birth cohort, we measured serum-PFAS concentrations in samples from birth, 18 months, 5 years, and 9 years. Body fat was assessed by dual-energy x-ray absorptiometry (DXA) scans and body mass index (BMI) z-scores at age 9 years. Associations between PFAS concentrations and body fat were assessed in adjusted multiple linear regression models and quantile g-computations. Results: Serum-PFAS concentrations were inversely associated with body fat in most analyses. Each doubling in serum concentrations of perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) concentrations at 18 months were associated with 2.29 (95% CI: 0.69, 3.89), 0.65 (95% CI: 0.00, 1.31), 2.62 (95% CI: 1.25, 4.00), 2.53 (95% CI: 1.20, 3.85), and 2.44 (95% CI: 1.09, 3.79) percent-point lower body fat %, respectively. Quantile g-computation likewise showed negative associations between PFAS mixtures and body fat, although the associations with birth-PFAS were mostly close to zero. Conclusion: Inverse associations between PFAS exposure and subsequent fat distribution at age 9 years were consistent across outcome measures within examination timepoints. The results could reflect a PFAS-effect in regard to early life fat accrual.