Women More Likely to Inherit Risk of Stroke
Friday, December 22, 2006; 12:00 AM
FRIDAY, Dec. 22 (HealthDay News) -- Women are at higher inherited risk for the most common type of stroke than men, a British study finds.
The study of 806 men and women who suffered ischemic strokes or the minor artery blockages called transient ischemic attacks showed women were more likely to have at least one close relative who suffered a stroke, and that was due entirely to an excess of affected female relatives.
"The main implication for clinical practice is that when you consider who is at risk for stroke, it looks like family history in particular is more important in women than men, particularly if there is a family history of stroke in female relatives," said study author Dr. Peter M. Rothwell, director of the Stroke Prevention Research Unit at the Radcliffe Infirmary in Oxford.
The study was published in the Dec. 22 online issue ofThe Lancet Neurology.
Ischemic strokes occur when an artery in the brain becomes blocked. They account for about 83 percent of all strokes, according to the American Stroke Association.
The new study found that women who had strokes were 40 percent more likely to have at least one close relative who suffered a stroke than were men with strokes. Having a mother who had a stroke was 80 percent more common in women stroke patients than in men.
Age was also a factor. Women whose mothers had a stroke at an early age were more likely to suffer a stroke at about the same age.
The British results support the findings of an American study reported earlier this year, said Dr. Steven J. Kittner, a researcher at the Baltimore Veterans Administration Medical Center and a professor of neurology at the University of Maryland.
"They are comparing women and male cases," Kittner said. "We did a study that looked at stroke in young women and compared them with controls who had not had a stroke. We found more association between maternal stroke and stroke in daughters than a paternal history of stroke."
The Baltimore study found that a mother's stroke doubled the risk of a daughter having a stroke, which is "in the range" of the British finding, he said.
"That is especially so if a women had a mother with a stroke at an early age," Kittner said. "The older the age that the mother had a stroke, the less important it is for the daughter's risk."
The British finding has research implications, Rothwell said. His group is doing further research to determine if the inherited risk is confined to women "with some specific subtypes of stroke," he said.
"Stroke is a very heterogeneous condition," Rothwell said. "Many are of undetermined etiology; people have a stroke with no obvious cause. There is a suggestion that a particular subtype may be one where genetic processes are most at play."
And while family history is important in assessing stroke risk in women, it should not be neglected in men, Kittner said.
"Family history is always important," he said. "We should not say there is no familial effect in men, although it appears to be more important in women than in men."
For more about stroke risk in women, visit the U.S. National Women's Health Information Center.
SOURCES: Peter M. Rothwell, M.D., director, Stroke Prevention Research Unit, Radcliffe Infirmary, Oxford, England; Steven J. Kittner, M.D., researcher, Baltimore Veterans Administration Medical Center, and professor of neurology, University of Maryland; Dec. 22, 2006,The Lancet Neurology, online