Study adds to evidence of the drug’s harmful effects
SAN DIEGO — Just as cocaine use hikes heart attack risk in young and middle-aged adults, using the drug also seems to increase stroke susceptibility — and with quick effect. A study of stroke patients finds that the stroke risk is six times greater within 24 hours of using cocaine than at other times, researchers reported February 12 at a meeting of the American Stroke Association.
The long-term risk factors underlying stroke include high blood pressure, diabetes and smoking. But these chronic problems typically don’t concern young people, who see stroke as a problem confined to an older demographic, says Philip Gorelick, a vascular neurologist at Michigan State University in East Lansing.
The addition of cocaine changes this formula. “Cocaine in the body is so powerful and so overwhelming that it trumps all those factors,” says Gorelick, who wasn’t involved in the new analysis.
Previous studies have linked cocaine use and stroke, and doctors are aware of the association. But those reports were often based on small case studies or analyses that lumped together use of multiple drugs such as cocaine and amphetamines.
For the new study, scientists interviewed 1,101 people ages 15 to 49 who had been treated for a stroke between 1992 and 2008 in the Baltimore-Washington, D.C., region. For a control group, the team used random-digit dialing to reach and interview 1,154 healthy people who never had a stroke but were of a similar age.
More than a quarter of the people in each group said they had used cocaine at some point, so simply having a history of cocaine use wasn’t associated with increased stroke risk. But among the stroke patients, 2.4 percent had used the drug within 24 hours of having a stroke. Among the healthy people, the likelihood of using the drug in a random 24-hour period — the day preceding their unplanned chat with a researcher — was 0.4 percent, says epidemiologist Yu-Ching Cheng of the University of Maryland School of Medicine and the Baltimore Veterans Affairs Medical Center, who presented the data. After accounting for the effect of smoking cigarettes, the 24-hour risk of stroke remained four times greater with cocaine use.
Most strokes result from clots in arteries that feed the brain. In 2011, researchers at Wayne State University in Detroit examined stroke patients of various ages and concluded that the cocaine-stroke risk could arise from decreased oxygen reaching the brain due to vessel spasms, artery inflammation, clot formation in the heart or high blood pressure.
Study coauthor Steven Kittner, a stroke neurologist also at the University of Maryland and the Baltimore VA Center, notes that cocaine ingestion triggers a flood of adrenaline-like compounds that can stun the heart and disrupt its rhythm. That can slow blood flow and invite clotting. Gorelick points out that such flow disruption allows platelets, the sticky blood particles that form clots, to linger in vessels and adhere to vessel walls.
In any case, he says, vascular health is not on the mind of the average cocaine user. “Strokes are viewed as something for older folks, which of course is not true,” Gorelick says. About 15 percent of strokes occur in people under age 50.
Duke University neurologist Larry Goldstein says that young adults need to appreciate all the risks of cocaine use. “You could end up not being able to talk or use one side of your body from doing this,” he says.
Y-C. Cheng et al. Illicit cocaine use and risk of ischemic stroke: The Stroke Prevention in Young Adults Study. International Stroke Conference, San Diego, February 12, 2014.
P. Bhattacharya et al. Clinical profiles, complications, and disability in cocaine-related ischemic stroke. Journal of Stroke and Cerebrovascular Diseases. Vol. 20, September-October 2011, p. 443. doi:10.1016/j.jstrokecerebrovasdis.2010.02.017.
N. Seppa. Amphetamine abusers face blood vessel risk. Science News Online, August 23, 2010.