Impaired lung function and subclinical atherosclerosis. The ARIC Study.
An association between reduced pulmonary function and increased risk of atherosclerotic vascular events has been reported. The mechanisms underlying this association are unknown, but are unlikely to be entirely due to smoking given the presence of the association among non-smokers. Few studies have examined the cross-sectional association between subclinical atherosclerosis and pulmonary function. In 14,000 adults in the ARIC Study, we examined the cross-sectional relationship between lung function, measured by the forced expiratory volume at 1s (FEV(1)), and three markers of subclinical atherosclerosis: ankle-brachial index (ABI), carotid intimal-medial thickness (IMT), and presence of carotid plaques. Mean FEV(1) was computed by ABI category, IMT category, or plaque status, in the full cohort and after stratification by smoking status, adjusted for age, gender, race, study center, height, height-squared, smoking, and pack years. Decreased FEV(1) was associated with decreased ABI and increased IMT in the full cohort and in each smoking group. Further adjustment for CVD risk factors did not alter the ABI association, but attenuated the IMT association, eliminating it in never smokers. Plaque was not associated with FEV(1). These findings suggest a complex relationship between FEV(1) and atherosclerotic vascular disease that invites further study.