Written by Joyce Smith, BS. This study finds that current African American smokers were at more than double the risk of experiencing a stroke event, and those smoking 20 or more cigarettes per day were at 2.8 times greater risk of having a stroke than nonsmokers.
Stroke, a leading cause of death 1,2, is more prevalent among African American blacks than any other racial group in the U.S. 2. In fact, African American blacks have almost double the risk of having a stroke and are twice as likely to die from stroke as Caucasians 2 due in part to their higher prevalence of hypertension, obesity, and diabetes mellitus 3. Cigarette smoking is a known modifiable risk factor for stroke 4,5; however, its role in the etiology of stroke in African American smokers has not been well-studied. Several mechanisms may contribute to an association between cigarette smoking and stroke in the black community. They include inflammation 6, atherosclerosis, and increased platelet aggregation 7,8.
Using data from the Jackson Heart Study (the largest study of cardiovascular disease in African Americans), Hall and colleagues 9 investigated a potential relationship between cigarette smoking and stroke incidence. Based on a baseline questionnaire of 4,410 participants’ self-reported cigarette smoking status, researchers classified the participants, average age of 54, into three groups based on their self-reported smoking history: current smokers, past smokers who smoked at least 400 cigarettes in their lifetimes, and never smokers. Study participants were classified as current smokers (n = 546; mean age, 52 years of age, 51% men), never smokers (n = 3,083; mean age, 53 years; 30% men), and past smokers (n = 781; mean age, 59 years; 47% men).They were followed up from their baseline evaluations beginning in 2000 through 2015 for incident stroke, defined on the bases of stroke history, transient ischemic attack, or angioplasty and carotid endarterectomy, or both.
After accounting for multiple risk factors for stroke, such as high blood pressure, diabetes, high “bad” cholesterol levels, and older age, researchers calculated that during a median follow-up of 11.8 years, 183 participants had a stroke. Current smokers carried a significantly higher risk for stroke that was more than double the risk for never smokers. For those smoking 20 or more cigarettes per day the risk nearly tripled (2.8 times greater); however, for past smokers the risk was almost identical to the risk for never smokers. Stroke risk in current smokers was significantly higher compared with never-smokers after adjusting for CV risk factors. A significant difference was not observed when comparing past smokers with never-smokers.
The research team also looked more closely at the already-established link between inflammation and atherosclerosis and smoking. When they measured for C-reactive protein (CRP), a marker of inflammation, and carotid intima-media thickness (CIMT) to assess the buildup of atherosclerotic plaque in the carotid arteries that supply blood to the brain, they found that African American smokers who smoked 20 or more cigarettes a day had higher CIMT compared to never smokers, suggesting that plaque accumulation in the major blood vessels of the brains of African American smokers could increase their risk of stroke. Further research that assesses the risks and harmful health implications of other tobacco products such as e-cigarettes and cigars is warranted.
Source: Oshunbade, Adebamike A., Wondwosen K. Yimer, Karen A. Valle, Donald Clark III, Daisuke Kamimura, Wendy B. White, Andrew P. DeFilippis et al. “Cigarette Smoking and Incident Stroke in Blacks of the Jackson Heart Study.” Journal of the American Heart Association (2020): e014990.
© 2020 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial-No Derivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
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Posted June 23, 2020.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
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- Oshunbade AA, Yimer WK, Valle KA, et al. Cigarette Smoking and Incident Stroke in Blacks of the Jackson Heart Study. J Am Heart Assoc. 2020;9(12):e014990.
