Relationship between the plasma levels of beta-carotene and lung functions in cigarette smokers

Relationships between the plasma levels of beta-carotene (BC) and spirometry were studied in 30 asymptomatic male cigarette smokers and 34 age-matched non-smoking control subjects. Plasma BC-levels, determined by high performance liquid chromatography (HPLC), were decreased on average by 18% (p 0.1251) in the smokers relative to the non-smokers and by 28% (p 0.015) following correction for blood cholesterol. The spirometric values, FEV1 and FEF25-75, determined from the flow-volume loops of each subject, were decreased by 5% (p 0.095) and 12% (p 0.0072) respectively in the smokers relative to the non-smokers. In the smokers, but not in the non-smokers, the plasma levels of BC correlated significantly and positively with the spirometric values, FEV1 (r 0.48, p 0.01) and FEF25-75 (r 0.58, p 0.0008). The results suggest that BC-status may determine susceptibility to oxidant-mediated pulmonary dysfunction in cigarette smokers.