Association between peak expiratory flow and the development of carotid atherosclerotic plaques

Background: Numerous population-based studies have suggested that impaired lung function is associated with subsequent coronary heart diseases-related mortality and cardiovascular disease-related mortality. The relative contr ibution of atherosclerosis in these associations is unknown. Objective: To examine the association of peak expiratory flow (PEF) with th e occurrence during 4 years of atherosclerotic plaques in the extracranial carotid arteries in a sample of 656 subjects (aged 59-71 years) free of cor onary heart disease and stroke at baseline. Methods: Peak expiratory flow was measured at the baseline examination. Pea k expiratory flow values relative to the predicted values (relative PEF val ues) were calculated, predicted values being obtained from previously publi shed sex-specific regression equations of PEF on age and height. A carotid B-mode ultrasonographic examination was performed at baseline and 2 and 4 y ears later. The occurrence of carotid plaques during follow-up was defined as the appearance of 1 plaque (or more) in previously normal carotid segmen ts and/or the appearance of new plaques in the carotid segments that previo usly had plaques. Results: The proportion of subjects who experienced an occurrence of caroti d atherosclerotic plaques during follow-up was 16.8% (110/656). The unadjus ted odds ratios from the highest to the lowest quintiles of relative PEF va lues were 1.00, 1.07 (95% confidence interval [CI], 0.69-2.79), 1.08 (95% C I, 0.52-2.24), 1.38 (95% CI, 0.69-2.79), and 3.07 (95% CI, 1.62-5.85) (P < .001 for trend). Adjustment for major known cardiovascular risk factors did not markedly change the results, and the multivariate-adjusted odds ratio of carotid plaque occurrence in subjects with the lowest quintile of PEF co mpared with those with the highest quintile remained highly significant (od ds ratio, 2.84; 95% CI, 1.45-5.71) (P = .002). Particularly in all smoking categories, carotid plaque occurrence was higher in subjects with the lowes t relative PEF values. In never smokers, the multivariate-adjusted odds rat io of carotid plaque occurrence in subjects with the lowest quintile of PEF compared with those with the highest quintile was 2.80 (95% CI, 1.14-6.88) . Conclusions: Reduced lung function predicts the development of carotid athe rosclerosis in elderly subjects. The nature of these associations remains l argely unknown and merits further investigations. Nevertheless, assessment of lung function, which is simple and inexpensive, could help identify a po pulation at high risk of atherosclerosis development and coronary heart dis ease.