Plasma concentrations of the antioxidants beta-carotene and alpha-tocopherol in relation to lung function.

OBJECTIVE

To study the association between plasma antioxidants (beta-carotene and alpha-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 beta-carotene and alpha-tocopherol.

RESULTS

SUBJECTS with a high plasma beta-carotene level (90th percentile, that is 0.57 micromol/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 beta-carotene level (10th percentile, that is 0.11 micromol/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 alpha-tocopherol concentrations.

CONCLUSIONS

The results suggest that subjects with a high plasma beta-carotene tended to have a higher FVC than subjects with a low plasma beta-carotene concentration which was borderline statistically significant. The difference for FEV1 between high and low levels of plasma beta-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 alpha-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.