Abstract 9713: Cigarette Smoking: Relationship with Inflammation, Arterial Stiffness, and Subclinical Atherosclerosis. The Multi-Ethnic Study of Atherosclerosis (MESA)

Abstract

Background: Smoking is a major reversible cardiovascular risk factor. Population studies, incorporating measures of inflammation and subclinical atherosclerosis, may provide a means to study the effects of smoking further. Methods: MESA is a population-based study of 6815 adults, free of baseline cardiovascular disease. We stratified participants based on smoking status into 3 groups: Never (NS), Former (FS), and Current (CS). FS and CS were further stratified into quartiles of pack-year history of tobacco exposure (PYH). We assessed cross-sectional associations of smoking with markers of inflammation (C-reactive protein [CRP], Fibrinogen, and InterleukinL-6), arterial stiffness (aortic distensibility by MRI), and subclinical atherosclerosis (SCA) (carotid intima-media thickness [cIMT], and coronary artery calcification [CAC]) by robust linear regression as well as prevalence ratio regression using a generalized linear model and binomial error distribution, after adjustment for covariates. We excluded 23 participants without information on smoking status from the analysis. Results: CS comprised 887 (13%, mean age 58yrs), FS 2487 (37%, 63yrs) and NS 3418 (50%, 62yrs) participants. CS were more likely to be younger, male, Caucasian or African American, and have lower LDL-C. The 3 inflammatory markers studied were all elevated in CS. Compared to NS, the adjusted odds ratios for prevalence of CRP≥2 were 1.2 (p<0.001) for former and 1.9 (p<0.001) for CS, respectively. Amongst FS and CS, increased inflammation was noted in the highest quartile of PYH. Aortic distensibility was reduced in CS only, and no association was seen with PYH. However, cIMT and CAC were elevated in both FS and CS, with a greater burden of disease in the highest quartile of PYH. Conclusion: These findings suggest a dose-response association between smoking and markers of inflammation as well as measures of SCA. Only current smoking was associated with reduced aortic distensibility.