Effects of cumulative smoking exposure and duration of smoking cessation on carotid artery structure

Abstract

Background: While prior epidemiological studies have examined the association between cigarette smoking and carotid atherosclerosis, few studies have evaluated the association of both cumulative smoking exposure and the duration of smoking cessation with carotid artery structure. Methods and Results: The study population consisted of 2,503 community-dwelling Korean males aged 50 years and older. Common carotid artery intima-media thickness (CCA-IMT), carotid plaque, and the internal diameter of the common carotid artery (CCA-diameter) were determined by high-resolution B-mode ultrasonography. Data on the characteristics of the subjects, including smoking status, pack-years of smoking, and years since quitting smoking, were collected using a standardized questionnaire. The current smokers had significantly greater CCA-IMT and CCA-diameter and a significantly higher risk of carotid plaque than did the subjects who had never smoked (P=0.009, <0.001, and 0.036, respectively). Dose-response relationships between pack-years and CCA-IMT and CCA-diameter were found among the current smokers (P=0.001 and <0.001, respectively); however, no significant association between pack-years and the carotid artery parameters was observed among the former smokers. For the former smokers, CCA-IMT and CCA-diameter tended to decrease with increasing years since quitting smoking (P=0.009 and 0.012, respectively), whereas no significant association with carotid plaque was found. Conclusions: Cumulative smoking exposure in current smokers and the duration of smoking cessation in former smokers are significant risk factors for carotid atherosclerosis.