Risk of stroke may more than double for African Americans who smoke

Current cigarette smoking and the number of cigarettes smoked per day are associated with more than twice the risk for all stroke—ischemic and hemorrhagic—among African Americans compared to nonsmokers, according to new research published today in the Journal of the American Heart Association, an open access journal of the American Heart Association.

In a study investigating the relationship between cigarette smoking and stroke among African Americans, researchers reviewed more than a decade of data from participants in the Jackson Heart Study (JHS). JHS is the largest study in the U.S. assessing cardiovascular risk factors among African Americans.

"Smoking increases the risk of developing stroke among African Americans, and that risk becomes higher as the number of cigarettes smoked per day increases. The more you smoke, the more you stroke," said Adebamike Oshunbade, M.D., M.P.H., lead study author and post-doctoral research fellow at the University of Mississippi Medical Center in Jackson, Mississippi, and fellow of the American Heart Association Tobacco Regulation and Addiction Center.

This study included 5,306 participants ages 21 to 84 who were recruited from the tri-county area surrounding Jackson, Mississippi. They were evaluated at baseline from 2000 to 2004 and completed two subsequent follow-up visits: in 2005 to 2008 and 2009 to 2013. For the final analysis, there were 546 current smokers, 781 past smokers and 3,083 never smokers. During follow-up, 183 participants suffered strokes.

Researchers found:

• The risk for stroke was 2.5 times higher for current smokers compared with never smokers. No significant difference was found between past and never smokers.
• Dose-dependent increases in the risk of stroke from smoke intensity was reported at 2.3 times and 2.8 times greater for current smokers smoking 1-19 cigarettes per day and more than 20 cigarettes per day, respectively.

"We also assessed the extent of fatty plaque build-up in the carotid arteries of African American smokers by a non-invasive procedure called carotid intima media thickness. We found accelerated build-up of fatty plaques in some of the major blood vessels of the brains of smokers, which could play a role in the development of stroke among African Americans," Oshunbade said.

Oshunbade noted the study results should strengthen calls to action for African Americans, public health officials and the tobacco industry. "Our findings support public health initiatives directed toward smoking cessation, especially among vulnerable groups like African Americans. This is particularly important because these populations have been targeted by tobacco companies.

"More public enlightenment campaigns should be geared toward warning African Americans about the modifiable risk of developing stroke from cigarette smoking," Oshunbade concluded.