Standard Stroke Risks Don't Account for Disparity in Stroke Deaths Between Blacks and Whites, UB Study Shows

By Lois Baker

Release Date: February 20, 2003

BUFFALO, N.Y. -- A 30 percent greater incidence of stroke-related deaths between African Americans and whites is not accounted for by differences in conventional risk factors -- such as hypertension, diabetes and high cholesterol -- known to affect a person's chances of suffering a stroke, research conducted at the University at Buffalo Toshiba Stroke Research Center has shown.

"There are additional unidentified factors that contribute to the higher stroke-related mortality among African Americans," said lead researcher Adnan Qureshi, M.D. "If these risk factors are not identified and eliminated, the ethnic disparities in stroke-related mortality would continue."

Results of the study were presented Feb. 14 at the 28th International Stroke Conference held in Phoenix, Ariz.

The fact that African Americans suffer more stroke mortality than whites is well known, but the reasons for this disparity remain a mystery. The UB study looked at whether differences in any of the major risk factors of stroke were to blame.

The study group was composed of 21,443 adults who participated in one of two National Health and Nutrition Examination Surveys (NHANES) and their follow-up studies. These surveys of a randomly selected segment of the general U.S. population, conducted by the Centers for Disease Control since 1971, collect extensive information on each individual's health status, vital statistics and lifestyle habits.

Qureshi and colleagues analyzed data from both whites and African Americans who had died between the initial survey collection and follow-up.

Results showed the annual incidence of stroke-related death was 156 per 100,000 among African Americans, compared to 118 per 100,000 among whites. Comparing such traditional risk factors as diabetes, cigarette smoking, cholesterol, poverty index and body-mass index (a standard measure of obesity) in the two ethnic groups made little difference, results showed.

These findings suggest that control of hypertension and diabetes mellitus will help reduce the excess burden of stroke mortality in African Americans, but these efforts will not be enough," Qureshi added.

Additional authors on the study from the UB Department of Neurosurgery and the UB Toshiba Stroke Research Center are: M. Fareed K. Suri, M.D.; Amir M. Siddiqui, M.D.; Muhammed A. Sayed, M.D., and L. Nelson Hopkins, M.D., chair of the Department of Neurosurgery. Also participating were Andrew R. Xavier, M.D., and Jawad F. Kimani, M.D., from the UB Department of Neurology.

Qureshi was an associate professor of neurosurgery at UB at the time of the study. He now is director of the Cerebrovascular Program at the University of Medicine and Dentistry of New Jersey (UMDNJ) - New Jersey Medical School.