Prenatal exposure to per- and polyfluoroalkyl substances and childhood adiposity at 7 years of age

An increasing number of studies have reported that prenatal per- and polyfluoroalkyl substances (PFAS) exposure may increase childhood adiposity. However, limited data is available in China, and the overall effects of PFAS mixture remain unclear.To examine the association of prenatal exposure to individual PFAS and their mixture with childhood adiposity at 7 years of age.A total of 206 mother-infant pairs were recruited from the Laizhou Wan (Bay) Birth Cohort in China between 2010 and 2013. Ten PFAS were measured in maternal serum. The measurements of fat mass, body fat percentage, body mass index, waist circumference, waist-to-height ratio and overweight/obesity were used to assess adiposity in children aged 7. We fitted logistic regression, linear regression and weighted quantile sum (WQS) regression models to estimate the association of prenatal exposure to individual PFAS and their mixture with childhood adiposity.We found negative associations of perfluoroheptanoic acid (PFHpA) and perfluorooctane sulfonamide (PFOSA) exposure with adiposity measurements in all children. The result from the WQS model consistently revealed that the PFAS mixture was inversely related to adiposity measurements. Each quartile increase of the PFAS mixture was associated with a 1.14 kg decrease (95% CI: -2.27, -0.02) in fat mass and a 2.32% decrease (95% CI: -4.51, -0.14) in body fat. Moreover, significant sex differences were found. PFAS mixture was negatively associated with five adiposity measurements in boys, but positively associated with all adiposity measurements except body fat percentage in girls. PFOSA, PFHpA and perfluorobutanesulfonate (PFBS) with weights >0.300 were the main contributors to the overall effects observed among all children, boys and girls, respectively.This study suggests potential sex-specific associations of prenatal exposure to individual PFAS and their mixture with childhood adiposity, with the observed relationship being negative for boys but positive for girls.