Better lung function in toddlers with high α-tocopherol, low γ-tocopherol in early childhood

Higher levels of α-tocopherol (α-T) in infancy appears to promote better lung function during mid-childhood, but only among kids with low γ-tocopherol (γ-T), reports a recent study.

A total of 622 mother-infant dyads participated in the study, all of whom had available second-trimester or early-childhood (3 years) plasma tocopherol measurements. Having a mid-childhood (6–10 years) spirometry visit was also a key eligibility criterion.

The median α-T and γ-T concentrations in the children at age 3 years were 25.84 and 2.67 µM, respectively. In mothers, during the second trimester, the corresponding levels were 63.13 and 4.40 µM. The use of prenatal vitamins or multivitamins did not have a clear impact on tocopherol levels.

The researchers then performed linear regression analyses to evaluate the effect of either tocopherol isoform on the percent-predicted forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) at 7 years of age; the statistical models were each stratified according to tertiles of the opposite isoform.

They found that each 10-µM increase in α-T at age 3 years was correlated significantly with better percent-predicted FEV1 (β, 3.13, 95 percent confidence interval [CI], 0.63–5.84; p=0.01) and FVC (β, 2.85, 95 percent CI, 0.58–5.12; p=0.01) at age 7 years, but only in children who belonged to the lowest tertile of γ-T.

This beneficial effect of α-T on lung function was attenuated in the higher categories of γ-T, underscoring the opposing actions of each isoform. Levels of γ-T in early life had no impact on either respiratory outcome in mid-childhood, as did neither tocopherol isoform when measured during the second trimester of pregnancy.