Association of prenatal vitamin E levels with child asthma and wheeze.

Background: We investigated the individual and interaction effects of maternal plasma 훂‐ and ϒ‐tocopherol levels (vitamin E isomers) on child asthma and wheeze at age 8–9. Methods: Mother–child dyads were enrolled between 2006 and 2011 into the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) prenatal cohort. Maternal second‐trimester samples were analyzed for tocopherol and lipid concentrations. We assessed child asthma/wheeze using the International Study of Asthma and Allergies in Childhood (ISAAC) and other self‐reported Ent wheeze. In multivariable logistic regression analyses, we assessed associations between vitamin E isomers and child asthma/wheeze outcomes (n = 847 mother–child dyads) and tested for prespecified interaction terms. Results: Median cholesterol‐corrected tocopherol levels (interquartile range (IQR)) were 5.0 (4.3–5.7) and 0.8 (0.7–0.9) (umol/mmol) for 훂‐ and ϒ‐tocopherol, respectively. Associations between 훂‐tocopherol and asthma outcome variables were inverse but not statistically significant. In contrast, for ϒ‐tocopherol, associations were in the positive direction, but also nonsignificant. Interactions analysis between tocopherols did not reach statistical significance for any outcome. Among children of women with a history of asthma, the likelihood of ever asthma in the child appears to be decreasing with increasing maternal 훂‐tocopherol levels, whereas this trend was not observed among those without a history of asthma (p‐interaction =.05). Conclusion: We observed no associations for prenatal 훂‐ or ϒ‐tocopherol concentrations with child asthma/wheeze. We detected some evidence of effect modification by maternal asthma history in associations between 훂‐tocopherol and child asthma. [ABSTRACT FROM AUTHOR]