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

Abstract

Low socioeconomic status is associated with reduced lung function in adults. In addition, there are indications that lung function decline with age is accelerated in low socioeconomic groups, but, to date, findings have been inconclusive. In order to investigate the relation between educational level, forced expiratory volume in 1 s (FEV1) and decline in FEV1 over time, linear mixed-effects models were fitted to baseline and 10-yr-follow-up data from the Doetinchem Cohort Study. The study population (26-66 yrs at baseline) consisted of 2,679 males and 3,026 females with an FEV1 measurement in at least one of the three rounds of follow-up and information on relevant covariables. High educational level was used as the reference class. Low educational level was associated with a higher prevalence of smoking and with a lower smoking-adjusted FEV1 at baseline (-148 mL in males and -47 mL in females). In females, low educational level was associated with a faster FEV1 decline (3.4 mL x yr(-1), age- and height-adjusted), which was not explained by smoking. In males, no differences in rates of decline between educational levels were observed. FEV1 decline was faster in less-educated females, independent of smoking. In males, FEV1 decline did not differ between educational levels.