Predictors of loss of lung function in the elderly: the Cardiovascular Health Study

Pulmonary function, as measured by spirometry (FEV1 or FVC), is an important independent predictor of morbidity and mortality in elderly persons. In this study we examined the predictors of longitudinal decline in lung function for participants of the Cardiovascular Health Study (CHS). The CHS was started in 1990 as a population-based observational study of cardiovascular disease in elderly persons. Spirometry testing was conducted at baseline, 4 and 7 yr later. The data were analyzed using a random effects model (REM) including an AR(1) error structure. There were 5,242 subjects (57.6% female, mean age 73 yr, 87.5% white and 12.5% African-American) with eligible FEV1 measures representing 89% of the baseline cohort. The REM results showed that African-Americans had significantly lower spirometry levels than whites but that their rate of decline with age was significantly less. Subjects reporting congestive heart failure (CHF), high systolic blood pressure (> 160 mm Hg), or taking beta-blockers had significantly lower spirometry levels; however, the effects of high blood pressure and taking beta-blockers diminished with increasing age. Chronic bronchitis, pneumonia, emphysema, and asthma were associated with reduced spirometry levels. The most notable finding of these analyses was that current smoking (especially for men) was associated with more rapid rates of decline in FVC and FEV1. African-Americans (especially women) had slower rates of decline in FEV1 than did whites. Although participants with current asthma had a mean 0.5 L lower FEV1 at their baseline examination, they did not subsequently experience more rapid declines in FEV1.