Sleep Disorders | Sleep Review
A new study, led by a University of Cincinnati (UC) researcher, sheds light on risk factors for certain types of stroke among different races and ethnic groups.
Daniel Woo, MD, assistant director of research in the UC Department of Neurology and a physician for UC Health, was the principal investigator in a study published in JAMA on Aug. 23.
The study focused on patients with intracerebral haemorrhage (ICH). This type of stroke is caused by the rupture of a blood vessel in the brain, as opposed to ischemic strokes, in which a blood clot prevents oxygen from flowing to the brain. ICH strokes are less common than ischemic strokes, but they are often fatal and cause high levels of disability, says Woo.
ICH strokes are twice as common in black and Hispanic populations and on average 10 years earlier in life compared to their white counterparts, but Woo says previous studies were not large enough to determine statistically significant risk factors for non-white populations.
This nationwide study recruited 1,000 black, 1,000 Hispanic, and 1,000 white patients, as well as 1,000 demographically matched controls from each group, to examine both genetic and environmental risk factors.
“Every time I told someone how important it was, everyone said you’d never make it,” Woo said in a press release. “And we completed the study on time and on budget because of the great work of my employees from across the country.”
Hypertension had previously been identified in white patients as a risk factor for ICH strokes, which occur deeper in the brain, brain stem and cerebellum (non-lobar ICH). But this study found that high blood pressure was a significant risk factor for Black and Hispanic patients for stroke in both the brain stem and lobes (lobar ICH).
Black and Hispanic people are three times more likely to have brain haemorrhage if they’ve treated high blood pressure, Woo says, but ME is 12 times more likely in these populations if left untreated.
A lack of health insurance is one of the biggest predictors of untreated high blood pressure, says Woo. The study also found that between 20% and 30% of all ICH in black and Hispanic patients would not have occurred if they had adequate access to medical care. About 6% of the ICH in white patients would have been prevented with adequate insurance access.
For the first time, this study also found sleep apnea as a novel risk factor for ICH strokes. Woo says sleep apnea’s place as a stroke risk could appear now as obesity rates rise as sleep apnea becomes more common among obese populations.
Woo’s main focus of research is the genetic factors that lead to cerebral hemorrhage, but he found that genetic factors are minor risk factors compared to other factors that can be changed, such as: B. high blood pressure, access to health care, obesity, sleep apnea, alcohol use, and smoking. Addressing these issues could help close the racial / ethnic differences in ICH strokes.
“These are all treatable, modifiable factors that have a huge impact on people’s risk,” says Woo. “We can keep searching for those magical remedies that will help keep these risk factors from affecting our brains, but it is probably better to treat the risk factors yourself.”
Woo says ICH strokes are among the most expensive strokes when you consider the cost of treatment, hospitalization, and rehabilitation. A public health move to lower risk factors could pay for itself in reducing the number of ICH cases, he says.
“Providing effective preventive care is likely to be cost-effective,” he says. “Billions of dollars are wasted on cases in a single year. If we could prevent 10% of this, it would more than cover the cost of treating high blood pressure, for example. Then there are things that are almost free of charge, like exercise, diet, and the economic benefits for individuals and society are enormous for this type of public health effort. “
Going forward, Woo says, plans are in the works for a follow-up study on ICH risk factors in Asian Americans.
This study was funded by the National Institutes of Health.
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