Early Life Triclosan Exposure and Child Adiposity at 8 Years of Age

Introduction: Triclosan is an antimicrobial agent that may affect the gut microbiome and endocrine system to influence adiposity. However, little data from prospective studies examining prenatal and childhood exposures exist. We investigated the relationship of prenatal and childhood triclosan exposure with child adiposity. Methods: In a prospective cohort of 222 mother-child pairs from Cincinnati, OH, we quantified triclosan in spot urine samples collected twice during pregnancy between 2003-6, annually from 1-5 years of age, and once at 8 years. We assessed child adiposity at 8 years using BMI, waist circumference, and body fat percentage. We used multivariable linear regression to estimate covariate-adjusted associations of child adiposity with triclosan concentrations during pregnancy (average), at 1-5 years (average), and at 8 years. Results: Median (range) prenatal, early childhood, and 8 year triclosan concentrations were 15 (1.6-853), 9 (1.6-515), and 10 ng/ml (1.0-1,610), respectively. Child sex modified the association between all three triclosan measures and adiposity (effect measure modification p-values=0.03-0.38), such that they were associated with reduced adiposity in girls. For example, among girls each 10-fold increase in triclosan during pregnancy, early childhood, and at 8 years was associated with a 3.3 (95% CI:-6.0,-0.6), 3.8 (95% CI:-7.5,-0.1) and 2.8 (95% CI:-5.0,-0.6) decrease in waist circumference (cm), respectively. This association was strongest for prenatal exposure when mutually adjusting for all three triclosan measures in the same model. Boys showed inconsistent associations between triclosan and waist circumference prenatally (0.5, 95%CI:-2.0, 3.0), in early childhood (1.6, 95% CI:-2.8, 6.0), and at 8 years (-1.0, 95% CI: -3.4, 1.3). Discussion: In this cohort, urinary triclosan concentrations during pregnancy, early childhood, and at 8 years of age were inversely associated with adiposity among 8 year old girls, but not boys.