The risk of a blocked vessel stroke increases nearly twofold in young women with a history of stroke in any first-degree relative, Helen Kim, Ph.D., of the University of Washington and colleagues conclude in the December issue of the American Journal of Preventive Medicine. The researchers also found a 2.4-fold increase in the risk of ruptured-vessel stroke among women with a family history of the vascular disease.
The Washington state women interviewed by Kim and colleagues ranged in age from 18 to 44 -- relatively young for stroke victims.
"A positive family history of stroke is thought to be an important risk factor for stroke, although this relationship is not clearly established. The few studies that have examined this association have mainly focused on middle-aged to elderly populations and the results have been inconsistent," Kim says.
"Strokes are of particular concern in these early-onset cases because of the potential for serious, long-term disability and associated healthcare costs," she adds.
The researchers compared 109 Washington state young women diagnosed with stroke to 428 young women without a stroke who lived in the same areas of Washington state and were of similar age and background. Almost half of the women who had a stroke reported having a family history of the disease.
The effect of family history remained even after accounting for other factors such as diabetes, high blood pressure, high cholesterol, physical activity, smoking and alcohol use and family history of heart disease, Kim and colleagues found.
However, the researchers concluded that high blood pressure and smoking were good independent predictors of the risk of ruptured-vessel strokes. Diabetes, high blood pressure, lack of exercise and body mass index predicted the risk of blocked-vessel strokes.
Kim and colleagues say it's unclear exactly why a family history of stroke affects a woman's risk of stroke at any age.
"Considering that stroke is the second major cause of mortality in women, further research should be focused on identifying the reasons for familial aggregation of stroke, be they genetic, environmental or, more likely, a combination of both," Kim says.
The study was supported by the National Institute for Child Health and Human Development and the National Heart, Lung, and Blood Institute.
By Becky Ham, Science Writer
Health Behavior News Service
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American Journal of Preventive Medicine: Contact the editorial office at (858) 457-7292.