Smoking characteristics, antioxidant vitamins, and carotid artery wall thickness among life-long smokers

We studied the associations between the common carotid-intima-media thickness (IMT), as a marker of atherosclerosis, and smoking characteristics and antioxidant vitamins among 158 male life-long cardiovascular disease (CVD)-free smokers. An "increased" carotid IMT was defined as the upper 25%. The prevalence of increased IMT was 2.5 times (odds ratio (OR) = 2.5; 95% CI: 1.1, 5.6) higher among smokers inhaling smoke deeply into the lungs than among moderate and non-inhalers. This association decreased when adjusted for other CVD risk factors. Smokers with an increased carotid IMT did not differ significantly in mean antioxidant vitamin intake and status with the remaining group. However, classical CVD risk factors contributed importantly to increased carotid IMT. In our study, depth of inhalation was the only smoking characteristic associated with carotid IMT although attenuated after adjustment for traditional risk factors for CVD. Furthermore, in these life-long smokers not using any vitamin supplements, no associations were found for antioxidant vitamins.