Exposure to per- and polyfluoroalkyl substances and body composition in US adolescents aged 12-18 years: an analysis of data from the National Health and Nutrition Examination Surveys 2011-2018

Background: The associations between per- and polyfluoroalkyl substances (PFAS) and obesity in adolescent remained unclear when considering imaging based methods such as dual-energy X-ray absorptiometry (DXA) scanning. Methods: The 2011-2018 National Health and Nutrition Examination Survey (NHANES) was used in this study. There were four highly detected PFAS including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). We calculated total mass, fat mass and fat-free mass (i.e., lean mass including bone mineral content) indexes (mass/height2) of total body and three regions [head, trunk and subtotal (i.e., total minus head)]. We assessed the associations using weighted multivariable linear regression and weighted quantile sum (WQS) regression. Results: A total of 1067 participants aged 12-18 years were included in this study. When adjusting for potential covariates, PFHxS exposure was negatively associated with total fat mass index while positively associated with total fat-free mass index [β=-0.16, 95% confidence interval (CI): -0.27 to -0.04; β=0.16, 95%CI: 0.05 to 0.28]. When entering the PFAS mixture in the WQS model, we found similar associations of WQS index with total fat or fat-free mass index (β=-0.04, 95%CI: -0.08 to -0.00; β=0.04, 95%CI: 0.00 to 0.08). Within the PFAS mixture, PFOA exposure made major contributions to the overall effect (56.6% and 44.1% for total fat and fat-free mass index). We did not find any significant association with regard to PFAS exposure and total mass index. Conclusions: Among US adolescents, higher PFHxS exposure was associated with lower body fat mass and higher fat-free mass in single PFAS models. We observed similar associations of the PFAS mixture with fat and fat-free mass, and PFOA exposure made major contributions to the overall effect. Overall, PFAS exposure might disturb energy balance and body composition in adolescents, and more studies are needed to confirm our findings.