ABSTRACT
BACKGROUND: We investigated the individual and interaction effects of maternal plasma ð- and Ï-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 ð- and Ï-tocopherol, respectively. Associations between ð-tocopherol and asthma outcome variables were inverse but not statistically significant. In contrast, for Ï-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 ð-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 ð- or Ï-tocopherol concentrations with child asthma/wheeze. We detected some evidence of effect modification by maternal asthma history in associations between ð-tocopherol and child asthma.