Serum tocopherol levels and vitamin E intake are associated with lung function in the normative aging study

Abstract

The results of studies assessing relationships between vitamin E intake and status and lung function are conflicting. This study aimed to evaluate the effect of vitamin E intake and serum levels of tocopherol isoforms on lung function in a cross-sectional sample of 580 men from the Normative Aging Study, a longitudinal aging study. Regression models were used to look at associations of serum tocopherol isoform levels and vitamin E intake with lung function parameters after adjustment for confounders. Vitamin E intake was measured using a food frequency questionnaire and serum levels of γ, α, and δ-tocopherol levels were measured using high-performance liquid chromatography. After adjustment for potential confounders, serum γ-tocopherol had a significant inverse association with forced vital capacity (β=-0.10, p=0.05). Alpha and δ-tocopherol were not associated with any lung function parameter. After classifying COPD status according to Global Initiative for Obstructive Lung Disease (GOLD) stage criteria, serum levels of δ-tocopherol were lower in participants with more severe COPD (p=0.01). Serum levels of δ-tocopherol were also lower in participants with greater levels of smoking (p=0.02). Both vitamin E intake (β=0.03, p=0.02; β=0.03, p=0.01) and use of vitamin E supplements (β=0.05, p=0.03; β=0.06. p=0.02) were positively associated with FEV1 and FVC, after adjusting for confounders. Subjects who took vitamin E supplements had significantly higher α-tocopherol levels (p<0.0001) and lower γ-tocopherol levels (p<0.0001) than non-users. In this study, there is a positive association between dietary vitamin E intake and lung function, and evidence of an inverse relationship between serum levels of γ-tocopherol and lung function.