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

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 contribution of atherosclerosis in these associations is unknown.

To examine the association of peak expiratory flow (PEF) with the occurrence during 4 years of atherosclerotic plaques in the extracranial carotid arteries in a sample of 656 subjects (aged 59-71 years) free of coronary heart disease and stroke at baseline.

Peak expiratory flow was measured at the baseline examination. Peak expiratory flow values relative to the predicted values (relative PEF values) were calculated, predicted values being obtained from previously published sex-specific regression equations of PEF on age and height. A carotid B-mode ultrasonographic examination was performed at baseline and 2 and 4 years later. The occurrence of carotid plaques during follow-up was defined as the appearance of 1 plaque (or more) in previously normal carotid segments and/or the appearance of new plaques in the carotid segments that previously had plaques.

The proportion of subjects who experienced an occurrence of carotid atherosclerotic plaques during follow-up was 16.8% (110/656). The unadjusted odds ratios from the highest to the lowest quintiles of relative PEF values were 1.00, 1.07 (95% confidence interval [CI], 0.69-2.79), 1.08 (95% CI, 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 compared with those with the highest quintile remained highly significant (odds 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 lowest relative PEF values. In never smokers, the multivariate-adjusted odds ratio 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).

Reduced lung function predicts the development of carotid atherosclerosis in elderly subjects. The nature of these associations remains largely unknown and merits further investigations. Nevertheless, assessment of lung function, which is simple and inexpensive, could help identify a population at high risk of atherosclerosis development and coronary heart disease.