A first-of-its-kind study found that young blacks, age 45, are at a three times greater risk of having a first stroke than their white counterparts. However, they may not be at a higher risk for the second stroke.
George Howard, DrPH, a professor in the UAB School of Public Health, recently published key findings from his ongoing research of the Reasons for Geographic and Racial Differences in Stroke Study in Neurology, the medical journal of the American Academy of Neurology.
“The interaction between black race and age appears to be remarkably different for the risk of first versus second stroke,” said Howard, principal investigator for the REGARDS Study. “Race has little impact in the risk for a second stroke.”
More than 29,682 people are enrolled in the REGARDS Study. Of those, 2,993 people had a history of stroke at their first evaluation, with 301 of them having a second stroke. Of the 26,689 people who did not have a stroke previous to the study, 818 people experienced a first-time stroke during the study.
Howard looked at the relationship between blacks and whites who had had a stroke, and blacks and whites who have not had a stroke, to see if there is a relationship between having a stroke and the person’s race. Black participants age 45 who have never had a stroke are 2.7 times more likely to have a stroke than are white participants at age 45.
By age 85, there is no difference in stroke risk for the two races. Also, race did not appear to increase second stroke risk for black participants in relation to white participants at any age. Overall, blacks are at a higher risk of having a stroke; but this rate appears to be declining. Whites are also seeing a decline in the risk of having a stroke; but the rate is decreasing more rapidly in whites, increasing the disparity between the two races.
The additional strokes in blacks are associated with an estimated cost of $5.2 billion each year, and this work may help doctors know where to focus their efforts to reduce the disparity in stroke risk, as well as to reduce these extra costs.
The study also assessed whether risk factors play the same role for a first versus second stroke.
“Almost all of the ‘traditional’ risk factors for a first stroke proved to also be risk factors for a second stroke, suggesting that controlling these risk factors may help avoid both conditions,” Howard said. “These risk factors include heart disease, high blood pressure, diabetes, smoking, irregular heartbeat and others.”
Other investigators on the report include Drs. Brett Kissella and Dawn Kleindorfer from the University of Cincinnati, Dr. Leslie McClure from Drexel University, Dr. Mary Cushman from the University of Vermont, Dr. Claudia Moy from the National Institute of Neurological Disorders and Stroke, Drs. Suzanne Judd, Kara Sands and Virginia Howard from UAB, and David Rhodes also from UAB.
REGARDS is one of the largest longitudinal cohort studies in the U.S., following a large group of people randomly selected from the population. As an observational study, REGARDS has examined the study participants, and then studies factors related to higher stroke risk. With the ongoing important cooperation of study participants, REGARDS continues to look at demographic and geographic disparities in strokes.