Rationale: Studies evaluating the relationship between E and lung function demonstrate mixed results. A potential explanation could be that different isoforms of vitamin E tocopherols may have differents effects. The goal of this was to evaluate the effect of vitamin E intake and serum levels of tocopherols on lung function in a cross-sectional sample of men from the Normative Aging Study, a longitudinal cohort of normal aging.

Methods: This analysis included a random sample of 580 subjects from the Normative Aging Study who had lung function measurements and stored serum samples available. Vitamin E was measured using a food frequency questionnaire; serum levels of y, a, and δ-tocopherols were measured using high-performance liquid chromatography. Spearman correlation coefficients were use to look at associations of lung function with serum and intake levels of vitamin E. Multiple regression models were used to adjust for age, height BMI. and smoking. The Krustal-Wallis tests were used to compare median nutrient levels between groups.

Results: Serum levels of y-tocopherol were inversely associated with FEV and FVC (r=0.10, p=0.01; r=0.12, p=0.003). Alpha and δ-tocopherol were positively associated with FEV 1 (r=0.02, p=0.5; r=0.04, p=0.33) and with FVC  (r=0.02, p=0.67; r=0.04, p=0.37) although these relationships were not significant. After adjustment for confounders y tocopherol retained a significant inverse association with FVC (Β=0.10, P=0.058), while the relationship with FEV 1 was somewhat attenuated (Β=0.06, P=0.23). A marginally significant association was found between  a tio of α-tocopherol/γ-tocopherol and FEV (r=0.07,p=0.07). When classified according to GOLD stage, serum levels of δ-tocopherol decrease as GOLD classification increased (p=0.04, table 1). Serum levels of δ-tocopherol decreased as level of smoking increased (p=0.02). Associations of FEV 1 and FVC with both vitamin E intake (β=0.03, p=0.02; β=0.03, p=0.01) and use of vitamin E suplements (β=0.05, p=0.03; β=0.06, p=0.02) were observed after adjusting for confounders. When vitamin E intake from supplements was excluded from total vitamin E intake, the relationships between vitamin E intake and FEV 1 and FVC were no longer significant (β=0.007, p=0.9; β=0.04, p=0.4). Subjects who took vitamin E supplements had significantly higher α-tocopherol levels (p‹0.0001) and lower γ-tocopherol levels (p‹0.0001) when compared to non-users.

Conclusions: It is possible that differing outcomes of studies evaluating the effect of vitamin E on lung function may be explained in part by differing actions of various vitamin E isoforms.