Serum carotenoids, vitamins A and E, and 8 year lung function decline in a general population

Abstract

Background: Oxidative stress is thought to have a major role in the pathogenesis of airway obstruction. A study was undertaken to determine whether subjects with low levels of antioxidants (serum b-carotene, acarotene, vitamins A and E) would be at a higher risk of accelerated decline in forced expiratory volume in 1 second (FEV 1 ) as their lungs would be less protected against oxidative stress. Methods: 1194 French subjects aged 20-44 years were examined in 1992 as part of the European Community Respiratory Health Survey (ECRHS); 864 were followed up in 2000 and 535 (50% men, 40% lifelong non-smokers) had complete data for analysis. Results: During the 8 year study period the mean annual decrease in FEV 1 (adjusted for sex, centre, baseline FEV 1 , age, smoking, body mass index and low density lipoprotein cholesterol) was 29.8 ml/ year. The rate of decrease was lower for the subjects in tertile I of b-carotene at baseline than for those in the two other tertiles (236.5 v 227.6 ml/year; p = 0.004). An increase in b-carotene between the two surveys was associated with a slower decline in FEV 1 . No association was observed between a-carotene, vitamin A, or vitamin E and FEV 1 decline. However, being a heavy smoker (>20 cigarettes/day) in combination with a low level of b-carotene or vitamin E was associated with the steepest decline in FEV 1 (252.5 ml/year, p = 0.0002 and 250.1 ml/year, p = 0.010, respectively). Conclusions: These results strongly suggest that b-carotene protects against the decline in FEV 1 over an 8 year period in the general population, and that b-carotene and vitamin E are protective in heavy smokers.

Does educational level influence lung function decline (Doetinchem Cohort Study)?

“…The present findings on the effect of baseline smoking status on FEV1 decline are consistent with those of other studies [18][19][20][21][22]. In addition, within strata for educational level, the FEV1 decline was always fastest in those smoking at baseline.…”

“…In the present study, FEV1 decline tended to be slower in never-smoking males of low (versus high) educational level. In addition, in a few studies which used socioeconomic status as a covariate, crude effects on lung function decline were inconsistent [19][20][21].…”

Inhaled steroids are associated with reduced lung function decline in subjects with asthma with elevated total IgE

“…For example, subjects who get access to and regularly take prescribed medications may be more likely to adopt generally healthier lifestyles (such as healthy diet and exercise). High dietary intake of antioxidants has been associated with lung function, 47 but we have no information on this for our sample. On the other hand, one might expect subjects with more severe disease to be prescribed more medication.…”

Effect of an antioxidant-rich multivitamin supplement in cystic fibrosis

“…Epidemiologic surveys among the general population have found that higher dietary antioxidant vitamin consumption (including β-carotene and vitamin E) and/or higher circulating levels of these antioxidants are associated with better pulmonary function and lower rates of lung function decline [29][30][31]. Similarly, in CF, correlations between antioxidant concentrations and lung function have been reported [11,26].…”