Lung function and blood levels of copper, selenium, vitamin C and vitamin E in the general population

Abstract

Increased dietary intake of antioxidants has been associated with higher lung function, but few studies have used biological markers of antioxidant intake. This study aimed to determine if antioxidant status, as measured by blood levels, influences lung function. Using a random subsample of 479 participants, aged 18-65 y old, from a larger cross-sectional observational study, the association of forced expiratory volume in 1 s (FEV1) with plasma copper, vitamin C, vitamin E and serum selenium was assessed. An s.d. increase in blood copper level was associated with a difference in FEV1 of -48 ml (95% confidence intervals: -95, -2 ml, P = 0.04), vitamin C +49 ml (+4, +94, P = 0.03), vitamin E -15 ml (-62, +32, P = 0.53) and selenium +52 ml (+7, +96, P = 0.02). The sizes of association were not appreciably altered in a mutually adjusted model. Higher levels of serum vitamin C and selenium appear to be associated with higher FEV1. The association between higher serum copper and lower FEV1 requires further study in view of the ubiquitous exposure to this mineral.