Prenatal exposure to phthalate esters and its associations with childhood allergies (TMICS Study)

Abstract

TPS 752: Respiratory effects and allergies, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Background/Aim: The relationships between prenatal exposure to specific phthalate and childhood allergies were inconsistent in previous epidemiologic studies. Various exposure levels may explain it. The Taiwanese reduced phthalates exposure after the food scandal in 2011. We aimed to examine the associations between prenatal exposure to selected phthalates and childhood allergies. Methods: The Taiwan Maternal and Infant Cohort Study (TMICS) enrolled pregnant women at third trimester in 2012-2015. Data for maternal urinary phthalate metabolites and health conditions in 3-year-old child were collected from 213 singleton-and-mother pairs. Eight phthalate metabolites in maternal urine were measured by liquid chromatography/electrospray tandem mass spectrometry (LC–ESI-MS/MS). Level of di-2-ethylhexyl phthalate (DEHP) was sum of nanomolar concentration of mono-(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP). Titers of total immunoglobulin E (total IgE) in children were measured by paper radio immuno-sorbent test (PRIST). Sociodemographic characteristics, delivery records, and living environment information were collected via questionnaire. Allergic symptoms and diagnoses were self-reported by mothers in the questionnaire developed by International Study of Asthma and Allergies in Childhood (ISAAC). Binary logistic regression model and linear regression model were used to examine relationships between childhood allergies and dichotomized phthalate metabolites (> 2nd tertile vs. <=2nd tertile). Results: After adjustment for potential confounders, increased risk of symptomatic rhinoconjunctivitis in children was associated with higher prenatal exposure to monoethyl phthalate (adjusted odds ratio [95% confidence interval]): 0.34[0.12-0.93], symptoms and diagnoses of eczema were both positively associated with MEHP (3.32 [1.05-10.53] and 3.93 [1.20-12.89], respectively) and MEOHP (3.93 [1.26-12.24] and 4.14 [1.34-12.79], respectively). None of eight phthalates was associated with total IgE concentration in children. Conclusions: According to exposure level in TMICS, prenatal exposure to MEHP and MEOHP were still related to increased risk of eczema; however, prenatal exposure to MEP may be associated with decreased risk of rhinoconjunctivitis in toddlers.