Impact of age at smoking initiation, dosage, and time since quitting on cardiovascular disease in African Americans and whites: The Atherosclerosis Risk in Communities Study

Despite reportedly having less tobacco exposure compared with whites, African Americans account for a disproportionate number of smoking-related deaths. The purpose of this study was to compare the prospective associations between smoking and cardiovascular risk in whites and African Americans. Smoking status was obtained on 14,200 participants from the Atherosclerosis Risk in Communities Study. Incidence of cardiovascular disease (CVD) was ascertained from 1987 through 2007. Adjusted Cox proportional hazard models were used to estimate the CVD incidence associated with smoking behavior. Over 17 years' follow-up, there were 2,777 cardiovascular events. In men, compared with never smoking, current smoking was independently associated with 67% (95% confidence interval (CI): 43, 95) and 72% (95% CI: 30, 126) greater risk of CVD in whites and African Americans, respectively. In women, the smoking-related cardiovascular risk was higher: 136% (95% CI: 88, 196) and 169% (95% CI: 126, 219) in African-American and white women, respectively. Early age at smoking initiation was independently associated with increased risk among all participants irrespective of race. Smoking cessation during follow-up was equally beneficial in both whites and African Americans. African Americans who smoke incur a similar level of cardiovascular risk as white smokers and would derive the same benefits from quitting as whites.