African-American women at increased risk for stroke

By Marguerite Beck

A groundbreaking study conducted by researchers at the U.Va. Health System has found that African-American women have alarmingly high rates of stroke risk factors, exceeding those of African-American men. The study is reported in the April issue of Stroke.

The researchers found that African-American women exercise less and have higher rates of hypertension, diabetes and obesity than African-American men. Prior to this study, researchers and physicians had little data regarding risk factors associated with stroke in the African-American population — especially among women, for whom it is the third-leading cause of death.

“Our research clearly shows that African-American men and women are different, so we should be tailoring stroke prevention strategies based on sex,” said Karen Johnston, assistant professor of neurology and the study’s principal investigator.

The data presented were generated from a multi-center study focusing on a subgroup of 1,087 stroke victims. This subgroup was selected from the larger African-American Antiplatelet Stroke Prevention Study, led by Philip B. Gorelick at Rush Medical College in Chicago.

Study participants were enrolled within seven to 90 days following non-cardioembolic stroke. Johnston and Bradford Worrall, lead author of the paper and instructor of clinical neurology at U.Va., focused on clinically relevant risk factors associated with stroke, including hypertension, diabetes, high cholesterol, family history of stroke, lack of leisure exercise, obesity and cigarette use. They used the Federal Obesity Clinical Guidelines to define overweight and obese subjects. Lack of leisure exercise was defined as not exercising at least twice a week vigorously enough to work up a sweat. Data on cigarette use and family history of stroke were obtained by survey. Hypertension and diabetes data were collected from the patients’ medical records, as well as by physical examination during their enrollment in the study.

Both Johnston and Worrall emphasized that most of the risk factors profiled are modifiable and said they hope this study will help educate the African-American population and their healthcare teams on stroke prevention.

The large number of risk factors examined provides doctors and researchers with much-needed data and also opens the door for more research on individuals with multiple stroke risk factors.

“We hypothesize that having multiple risk factors for stroke increases the risk by much more than would be expected,” Worrall said. “If we are correct, that finding could have major implications in assessing individual risk and developing individualized prevention strategies.”