A new study led by a University of Cincinnati researcher sheds light on risk factors for certain kinds of strokes among different racial and ethnic groups.
Daniel Woo, MD, vice chair of research in UC's Department of Neurology and a UC Health physician, was the principal investigator in a study published Aug. 23 in JAMA.
The study focused on intracerebral hemorrhage (ICH) patients. Woo said this particular type of stroke is caused by a blood vessel within the brain rupturing, compared to the more common ischemic strokes where a blood clot prevents oxygen from flowing to the brain. ICH strokes are less common than ischemic strokes, but they are often deadly and cause high disability, he said.
ICH strokes occur in Black and Hispanic populations twice as often and an average of 10 years earlier in life compared to their white counterparts, but Woo said previous studies did not have large enough sample sizes to determine statistically significant risk factors for nonwhite populations.
This unprecedented nationwide study recruited 1,000 Black, 1,000 Hispanic and 1,000 white patients, as well as 1,000 demographically matched control subjects from each group, to look at both genetic and environmental risk factors.
"Every time I pitched to somebody how important this was, everybody said you'll never be able to do it," Woo said. "And we finished the study on time, under budget because of the amazing work of my collaborators from around the country."
High blood pressure had previously been identified as a risk factor for white patients for ICH strokes occurring deeper in the brain, brainstem and cerebellum (nonlobar ICH), but this study found high blood pressure was a significant risk factor for Black and Hispanic patients for strokes both in the brainstem and in the lobes of the brain (lobar ICH).
Woo said Black and Hispanic individuals are three times more likely to suffer a brain hemorrhage if they have treated hypertension, but ICH is 12 times more likely in these populations if it is untreated.
