Cigarette Smoking, Incident Coronary Heart Disease, and Coronary Artery Calcification in Black Adults: The Jackson Heart Study.

Background Although Black adults are more likely to die from coronary heart disease (CHD) compared with White adults, few studies have examined the relationship between cigarette smoking and CHD risk among Black adults. We evaluated the relationship between cigarette smoking, incident CHD, and coronary artery calcification in the JHS (Jackson Heart Study). Methods and Results We classified JHS participants without a history of CHD (n=4432) by self-reported baseline smoking status into current, former (smoked at least 400 cigarettes/life) or never smokers at baseline (2000-2004). We further classified current smokers by smoking intensity (number of cigarettes smoked per day [1-19 or ≥20]) and followed for incident CHD (through 2016). Hazard ratios (HR) for incident CHD for each smoking group compared with never smokers were estimated with adjusted Cox proportional hazard regression models. At baseline, there were 548 (12.4%) current, 782 (17.6%) former, and 3102 (70%) never smokers. During follow-up (median, 13.8 years), 254 participants developed CHD. After risk factor adjustment, CHD risk was significantly higher in current smokers compared with never smokers (HR, 2.11; 95% CI, 1.39-3.18); the difference between former smokers and never smokers (HR, 1.37; 95% CI, 1.0-1.90) did not achieve statistical significance. Among current smokers, we did not observe a dose-response effect for CHD risk. Additionally, in multivariable logistic regression models with a subset of our analytic cohort, current smokers had greater odds of coronary artery calcification score >0 compared with never smokers (odds ratio, 2.63; 95% CI, 1.88-3.68). Conclusions In a large prospective cohort of Black adults, current smoking was associated with a >2-fold increased risk of CHD over a median follow-up of greater than a decade.

Cigarette Smoking and Incident Stroke in Blacks of the Jackson Heart Study.

Background Blacks are disproportionately affected by stroke compared with whites; however, less is known about the relationship between stroke and cigarette smoking in blacks. Therefore, we evaluated the relationship between cigarette smoking and all incident stroke in the JHS (Jackson Heart Study). Methods and Results JHS participants without a history of stroke (n=4410) were classified by self-reported baseline smoking status into current, past (smoked at least 400 cigarettes/life), or never smokers at baseline (2000-2004). Current smokers were further classified by smoking intensity (number of cigarettes smoked per day [1-19 and ≥20]) and followed up for incident stroke (through 2015). Hazard ratios (HRs) for incident stroke for current and past smoking compared with never smoking were estimated with adjusted Cox proportional hazard regression models. After adjusting for cardiovascular risk factors, the risk for stroke in current smokers was significantly higher compared with never smokers (HR, 2.48; 95% CI, 1.60-3.83) but there was no significant difference between past smokers and never smokers (HR, 1.10; 95% CI, 0.74-1.64). There was a dose-dependent increased risk of stroke with smoking intensity (HR, 2.28 [95% CI, 1.38-3.86] and HR, 2.78 [95% CI, 1.47-5.28] for current smokers smoking 1-19 and ≥20 cigarettes/day, respectively). Conclusions In a large cohort of blacks, current cigarette smoking was associated with a dose-dependent higher risk of all stroke. In addition, past smokers did not have a significantly increased risk of all stroke compared with never smokers, which suggests that smoking cessation may have potential benefits in reducing the incidence of stroke in blacks.