Plasma concentrations of the antioxidants β-carotene and α-tocopherol in relation to lung function

Abstract

Objective: To study the association between plasma antioxidants (β-carotene and α-tocopherol) and lung function in Dutch adults aged 20–59 y.

Design: Cross-sectional.

Setting: Population-based study.

Subjects: A random sample (n=367) was drawn from all participants (men and women) aged 20–59 y with reproducible lung function measurements in 1995.

Intervention: Completion of general questionnaire and physical examination.

Main outcome measurements: Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and plasma levels of β-carotene and α-tocopherol.

Results: Subjects with a high plasma β-carotene level (90th percentile, that is 0.57 µmol/L) tended to have a higher FEV₁ (73 ml, s.e.m. 60 ml; P=0.22) and a higher FVC (147 ml, s.e.m. 76 ml; P=0.05) than subjects with a low plasma β-carotene level (10th percentile, that is 0.11 µmol/L) after adjustment for age, height, gender, smoking status, pack-years of smoking and alcohol consumption. There was no difference in lung function between subjects with high and low plasma α-tocopherol concentrations.

Conclusions: The results suggest that subjects with a high plasma β-carotene tended to have a higher FVC than subjects with a low plasma β-carotene concentration which was borderline statistically significant. The difference for FEV₁ between high and low levels of plasma β-carotene tended to be in the same positive direction as that of FVC but did not reach the pre-set statistical significance level. There is no relation between plasma α-tocopherol and lung function.

Sponsorship: Ministry of Public Health, Welfare and Sports of the Netherlands and the National Institute of Public Health and the Environment.