Association of prenatal vitamin E levels with child asthma and wheeze

Background: We investigated the individual and interaction effects of maternal plasma α- 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 α- and ϒ-tocopherol, respectively. Associations between α-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 α-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 α- or ϒ-tocopherol concentrations with child asthma/wheeze. We detected some evidence of effect modification by maternal asthma history in associations between α-tocopherol and child asthma.