AMOUNT OF SMOKING INDEPENDENTLY PREDICTS CAROTID-ARTERY ATHEROSCLEROSIS SEVERITY

Background and Purpose: Cigarette smoking is correlated with extracranial carotid artery plaque thickness. Our aim in the present study was to determine whether the level of prior cigarette use is a significant predictor of carotid artery plaque thickness when age, history of hypertension, and history of diabetes are controlled. Methods: We studied a continuous sample of 790 patients with a history of smoking referred for diagnostic ultrasound imaging of the carotid arteries. Subjects (mean age 61 years) had an average of 51 pack-years of cigarette use. History of hypertension was present in 44% and history of diabetes in 18%. Results: Right and left maximum carotid artery plaque thicknesses were averaged for each patient; the average of this value for all 790 subjects was 1.9 mm. In bivariate analysis, age (p < 0.0001), pack-years (p < 0.0001), history of hypertension (p = 0.0003), and history of diabetes (p = 0.037) were each positively associated with carotid artery plaque thickness. In multiple regression analysis, age (p < 0.0001), pack-years (p = 0.0005), and history of hypertension (p = 0.0044) were statistically significant independent predictors of carotid artery plaque thickness, but history of diabetes (p = 0.2451) was not. Conclusions: In smokers, the level of cigarette use is associated with an acceleration of carotid artery atherosclerosis development. This effect is independent of age, hypertension, and diabetes. These results support smoking abatement as an important element to stroke prevention in clinical practice.