Sibling Had Stroke? Your Risk Goes Up
Study Shows Mexican-American Men Are Especially at Risk
May 2, 2007 (Boston) -- If your brother or sister has had a stroke, you’re almost twice as likely as the average American to suffer one yourself, a new study suggests.
Mexican-American men whose siblings have had a stroke are at particularly high risk: They’re nearly three times as likely to have a stroke themselves.
The findings apply to both ischemic strokes and transient ischemic attacks (TIAs). Both occur when blood flow to part of the brain is blocked or reduced, often by a blood clot. But with TIAs, blood flow resumes after a short time and symptoms go away. With a stroke, the blood flow stays blocked, and the brain has permanent damage.
“We don’t know whether it’s shared environmental factors such as diet and smoking habits or genetics at play,” says researcher Lewis B. Morgenstern, MD, professor of neurology and epidemiology at the University of Michigan in Ann Arbor.
“We think it’s a combination of both,” says Morgenstern, who says that his team now plans to draw blood from some of the study participants to look for possible genetic markers of stroke risk.
Genes May Be Key to Stroke Risk
Philip Stieg, MD, chairman of neurological surgery at New York Presbyterian/Weill Cornell Medical Center in New York, believes genetics plays a key role in explaining the findings.
“The question to answer now is whether Mexican-American men have a particular genetic alteration that makes them more susceptible,” he tells WebMD.
“That said, we also have to look at environmental factors such as smoking, obesity, diabetes, and blood pressure that are known to raise stroke risk,” Stieg says.
The study included 807 siblings, aged 45 to 64, of 181 people who had strokes in Nueces County, Texas. Nearly 60% were Mexican-American and the rest were non-Hispanic whites. About half were women.
Among the non-Hispanic whites, only siblings of women who have had strokes were at an increased risk.
The study was presented at the annual meeting of the American Academy of Neurology.