Early-Life Phthalate Exposure and Adiposity at 8 Years of Age

Abstract

Background:Early-life phthalate exposure may influence child adiposity, but prior studies have not determined if there are periods of enhanced vulnerability to phthalates.Objective:To examine the relationship between child adiposity at 8 y of age and repeated urinary biomarkers of phthalate exposure from gestation through childhood to determine if there are distinct periods of vulnerability.Methods:In 219 mother–child pairs from Cincinnati, Ohio, we quantified nine urinary phthalate metabolites up to two times prenatally and six times from 1–8 y of age. We measured child body mass index (BMI), waist circumference, and percent body fat at 8 y of age. To identify periods of vulnerability, we used two statistical methods to estimate phthalate–adiposity associations at each visit, test differences in phthalate–adiposity associations across visits, and model trajectories of phthalate concentrations for children at different levels of adiposity.Results:Prenatal phthalate concentrations were not associated with excess child adiposity. Monobenzyl phthalate (MBzP) concentrations during pregnancy and childhood were inversely associated with adiposity. The associations of di(2-ethylhexyl) phthalate (∑DEHP) metabolites and monoethyl phthalate (MEP) with child adiposity depended on the timing of exposure. A 10-fold increase in ∑DEHP at 1 and 5 y was associated with a 2.7% decrease [95% confidence interval (CI): −4.8, −0.5] and 2.9% increase (95% CI: 0.3, 5.5) in body fat, respectively. MEP concentrations at 5 and 8 y of age were associated with higher child adiposity, but earlier childhood concentrations were not.Conclusion:In this cohort, we did not find evidence of an obesogenic effect of prenatal phthalate exposure. Positive associations between postnatal MEP and ∑DEHP concentrations depended on the timing of exposure. https://doi.org/10.1289/EHP1022

Association of Early Life Exposure to Phthalates With Obesity and Cardiometabolic Traits in Childhood: Sex Specific Associations

“…We did not observe statistically significant associations between prenatal phthalate metabolites and any of the examined adiposity measures in childhood, consistent with observations from US cohort, where no associations with fat mass in children aged 4–9 years were observed ( 24 ), a Mexican study that did not observe any relationships between prenatal phthalate exposure and child BMI after excluding children who had initiated puberty ( 27 ) and the HOME study from Ohio that reported no association between prenatal phthalate exposure and child adiposity at age 8. However, depending on age, sex, timing of exposure, and phthalate metabolites, other studies report discrepant findings ( 25 , 26 , 28 – 32 ). Prenatal exposure to MEP was associated with increased obesity outcomes at ages 5–12 years ( 30 ) and increased weight growth velocity at ages 2 and 4 years and increased BMI at 5 years in boys from the French EDEN cohort ( 26 ).…”

“…Results from cross-sectional studies in adults and children show that higher urinary phthalates concentrations are positively associated with adiposity and cardiometabolic markers ( 19 – 23 ). However, only a few longitudinal studies have examined the associations of early-life exposure to phthalate metabolites with childhood growth and obesity ( 24 – 32 ) and these studies have shown inconsistent results and sex-specific associations. In utero exposures were found to be associated with decreased BMI z-scores only in girls aged 4–7 years ( 25 ), or only in boys aged 4–7 years old ( 28 , 29 ).…”

Exposure to Bisphenol A and phthalates metabolites in the third trimester of pregnancy and BMI trajectories

“…Some previous studies have found positive associations between BPA and phthalates metabolites with child BMI; most longitudinal studies have outcomes in early childhood with few occurring in late childhood and early adolescence . Results from these longitudinal studies have been mixed, with differences reported by metabolites, sex, and age.…”

Perinatal exposures to phthalates and phthalate mixtures result in sex-specific effects on body weight, organ weights and intracisternal A-particle (IAP) DNA methylation in weanling mice

“…[7][8][9][10] However, epidemiological studies have presented conflicting evidence with some studies demonstrating associations between early-life phthalate exposure and increased risk for obesity and insulin resistance, whereas other studies found no associations or negative associations. 11,12 One factor that may contribute to inconsistencies in epidemiological literature is difficulty in interpreting effects of exposures to phthalate mixtures. 13,14 Humans are exposed to mixtures of several phthalates, as evidenced by data from the National Health and Nutrition Examination Survey indicating that metabolites from 13 different phthalates were detected in urine samples from a representative study population from the United States.…”