ACTIVE AND PASSIVE SMOKING ARE ASSOCIATED WITH INCREASED CAROTID WALLTHICKNESS - THE ATHEROSCLEROSIS RISK IN COMMUNITIES STUDY

Background: Active cigarette smoking has been established as a potent risk factor for carotid atherosclerosis in clinical populations; howev er, neither the role of active smoking in general populations nor the impact of environmental tobacco smoke has been well described. Methods : The association between carotid artery wall thickness and cigarette smoking was studied in 12953 black and white men and women, aged 45 to 65 years, examined in the Atherosclerosis Risk in Communities Study. Participants were classified as current smokers (n=3525), past smokers (n=4315), never smokers reporting weekly exposure to environmental to bacco smoke (ETS or ''passive smoking'') of at least 1 hour (n=3339), or never smokers reporting no weekly exposure to ETS (n=1774). Carotid artery intimal-medial thickness (IMT) was measured by B-mode ultrasou nd. Results: Increased IMT was observed in each category, in order fro m smallest to greatest increase: never smokers not exposed to ETS, nev er smokers exposed to ETS, past smokers, and current smokers. The larg er IMT observed in the nonsmoking group exposed to ETS compared with t he nonsmokers not exposed persisted after control for diet, physical a ctivity, body mass index, alcohol intake, education, and major cardiov ascular risk factors. Among past and current smokers, increased pack-y ears of exposure was associated with increased IMT. Among nonsmoking m en exposed to ETS, there was a significant increase in IMT with increa sing number of hours per week of ETS exposure. Conclusions: These data confirm the strong relationship between active smoking and carotid ar tery IMT and provide initial evidence that passive smoking exposure is related to greater IMT. Increasing exposure to cigarette smoke (eithe r pack-years of active smoking or hours of ETS) was significantly rela ted to increased IMT.