Prenatal Phthalate Exposures and Childhood Body Mass Index in Three Children’s Environmental Health Center Cohorts

Abstract

Prenatal Phthalate Exposures and Childhood Body Mass Index in Three Children’s Environmental Health Center CohortsAbstract Number:1954 Jessie Buckley*, Stephanie Engel, Amy Herring, Joseph Braun, Robin Whyatt, Julie Daniels, Michelle Mendez, David Richardson, Bruce Lanphear, Mary Wolff, and Andrew Rundle Jessie Buckley* University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , Stephanie Engel University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , Amy Herring University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , Joseph Braun Brown University, United States, E-mail Address: [email protected] Search for more papers by this author , Robin Whyatt Columbia University, United States, E-mail Address: [email protected] Search for more papers by this author , Julie Daniels University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , Michelle Mendez University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , David Richardson University of North Carolina at Chapel Hill, United States, E-mail Address: [email protected] Search for more papers by this author , Bruce Lanphear Simon Fraser University, Canada, E-mail Address: [email protected] Search for more papers by this author , Mary Wolff Mount Sinai School of Medicine, United States, E-mail Address: [email protected] Search for more papers by this author , and Andrew Rundle Columbia University, United States, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: Phthalate exposures, especially during fetal development, are hypothesized to be obesogenic with effects potentially differing by sex. We assessed the associations of maternal urinary phthalate biomarkers during pregnancy and children’s body mass index (BMI) in three prospective birth cohorts.Methods: The study sample included children in the Cincinnati (n=181), Columbia (n=285), and Mount Sinai (n=57) Children’s Environmental Health Center cohorts who had third trimester maternal urinary phthalate metabolite concentrations and height and weight data collected at ages 48-59 months. Linear regression was used to estimate associations between BMI z-score and standard deviation increases in natural log phthalate metabolite concentrations. Estimates from multi-metabolite models were adjusted for maternal demographics, height, and pre-pregnancy BMI; urine dilution and collection date; gestational tobacco exposure and weight gain; and pooled analyses were additionally adjusted for cohort.Results: In all three cohorts, mono-n-butyl phthalate was positively associated with BMI z- scores among girls (pooled ß=0.34, 95% CI=0.03, 0.66) but weakly negatively associated among boys (pooled ß=-0.13, 95% CI=-0.44, 0.18). Mono-ethyl phthalate was negatively associated with BMI z-scores in girls (pooled ß=0.17, 95% CI=-0.37, 0.04) but not among boys (pooled ß=0.05, 95% CI=-0.15, 0.25). In contrast, associations of summed di-(2- ethylhexyl) phthalate metabolites were not modified by sex, but there was some evidence of variability by cohort. Associations were inverse for Mount Sinai (ß=-0.30, 95% CI=-0.65, 0.06) and Columbia (ß=-0.12, 95% CI=-0.38, 0.13) but positive for Cincinnati (ß=0.18, 95% CI=-0.06, 0.41), though cohort-specific estimates were based on small numbers.Conclusions: Associations between prenatal exposures to certain phthalates and BMI varied according to child sex in this study of three birth cohorts.