Blacks who survived a stroke caused by bleeding in the brain had higher blood pressure than whites a year later, according to a study published today in the journal Stroke. The finding might help explain why blacks have a greater risk of suffering a second stroke than whites.
The research, a part of the Georgetown University Medical Center (GUMC) Stroke Disparities Program led by Chelsea Kidwell, M.D., was designed to examine racial and ethnic differences in strokes known as intracranial hemorrhage or ICH. ICHs account for 10 percent of all strokes, but carry a death rate of about 40 percent in the first month after the stroke, much higher than other types of stroke. High blood pressure is the most important modifiable risk factor associated with ICH.
“Identifying how prevalent high blood pressure is this far out from a stroke can help us tailor intervention programs that can truly make a difference,” explains Kidwell, a professor in the department of Neurology at GUMC and director of its Stroke Center. “Another risk factor for having a stroke is age and that obviously can’t be changed, but we have numerous ways to help patients control their blood pressure which can be done with medication, diet and exercise. We know that reducing blood pressure can cut in half the risk of having a second stroke.”
Kidwell’s study included 162 patients (the average age was 59, 53 percent were male, and 77 were percent black) who were treated for their initial stroke at hospitals in the Washington, D.C. area. Researchers say half of those individuals in the study had high blood pressure a year after their stroke, even though most were taking medication to help lower their blood pressure. At 1 year, 63 percent of black patients had high blood pressure compared to 38 percent of whites.
African American study participant Donald Sisco, age 60, says he went on medication to control his high blood pressure immediately after his stroke four years ago. Since then, he has also followed a low-sodium diet.
Still, many others still have high blood pressure, even when on medication.
“Our data don’t reveal the reasons for these differences, though some possible factors to consider are diet, exercise and stress levels,” explains Kidwell.
The researchers did identify two social factors that independently predicted lower blood pressure among individuals: those who were married or those who lived in a health care facility.
Sisco can understand the benefit of being married. He credits his wife, Deborah, for helping him stay true to his diet. “She only cooks what I can have,” he says.
Kidwell’s group continues to investigate disparities between races that might account for why blacks are at a higher risk of having strokes. This summer, Kidwell and two Georgetown colleagues received a $6.1 million grant from the National Institute on Minority Health and Health Disparities to establish the Center of Excellence for Health Disparities in Our Nation’s Capital. The Center of Excellence seeks to dramatically reduce health disparities with a particular focus on minority populations in Washington, D.C. The program specifically involves disparities in stroke, the 4th leading cause of death in the District, and breast cancer.
Darin B. Zahuranec, M.D., M.S., assistant professor of neurology at the University of Michigan Cardiovascular Center in Ann Arbor is first author of the study. Other co-authors are Jeffrey J. Wing, M.P.H.; Dorothy F. Edwards, Ph.D.; Ravi S. Menon, M.D.; Stephen J. Fernandez, M.P.H.; Richard E. Burgess, M.D., Ph.D.; Ian A. Sobotka, B.S.; Laura German, B.S.; Anna J. Trouth, M.D.; Nawar M. Shara, Ph.D.; M. Chris Gibbons, M.D., M.P.H.; and Bernadette Boden-Albala, M.P.H., Dr. P.H.
This research was supported grants from the National Institute of Neurological Disorders and Stroke (U54NS057405) and the National Institute on Minority Health and Health Disparities (U54NS057405). Kidwell reports having no personal financial interests related to the study.
Georgetown University Medical Center