Researchers at the University of Michigan have found a notable link between higher readings of systolic blood pressure, the top number in a blood pressure reading, and increased risk of the two most common stroke types. The findings were published in JAMA Network Open and are drawing attention from clinicians and public health experts across North America (University of Michigan researchers, JAMA Network Open).
Involving 38,167 adults with no prior stroke history, the study began by grouping participants into three racial and ethnic categories: white European, Black, and Hispanic. Blood pressure measurements were taken for all participants at the outset, establishing a baseline before a lengthy observation period commenced (University of Michigan researchers, JAMA Network Open).
During follow-up, investigators tracked strokes across three categories: ischemic stroke, caused by thrombosis and clot formation; hemorrhagic stroke, including intracerebral hemorrhage; and subarachnoid hemorrhage, which involves bleeding into the space between the meninges. This comprehensive approach allowed researchers to compare how blood pressure levels correlated with each stroke type over time (University of Michigan researchers, JAMA Network Open).
The results indicated that an average systolic blood pressure about 10 millimeters mercury higher than normal in adulthood was associated with a roughly 20% greater risk of ischemic stroke and a roughly 31% greater risk of hemorrhagic stroke. Importantly, the elevated risk associated with higher systolic pressure appeared more pronounced among Black and Hispanic participants compared with white European participants (University of Michigan researchers, JAMA Network Open).
For context, systolic blood pressure—the higher number in a reading—measures the pressure in arteries when the heart contracts and pumps blood outward. The diastolic pressure, the lower number, reflects the pressure in the arteries when the heart rests between beats. The study’s emphasis on systolic pressure underscores its potential role as a modifiable risk factor for stroke across diverse populations (University of Michigan researchers, JAMA Network Open).
These findings align with a broader body of evidence linking elevated blood pressure to vascular events and cognitive concerns over time. They also emphasize the importance of regular blood pressure monitoring, especially for adults who may not yet have a diagnosed hypertension. Clinicians may consider these results when evaluating stroke risk and in making decisions about prevention strategies, including lifestyle changes and, when appropriate, medical treatment (University of Michigan researchers, JAMA Network Open).
In explaining the implications, researchers noted that while lowering systolic blood pressure can reduce the absolute risk of stroke, the effect may vary by race and ethnicity, underscoring the need for culturally sensitive risk assessment and prevention efforts. Public health messages that encourage regular blood pressure checks, healthy diets, physical activity, and weight management can play a key role in reducing stroke burden across communities (University of Michigan researchers, JAMA Network Open).
Overall, the study contributes to the growing understanding that even modest increases in systolic blood pressure can translate into meaningful differences in stroke risk. The authors advocate for ongoing efforts to identify individuals at higher risk and to tailor prevention strategies that address the unique needs of diverse populations, with the aim of lowering the incidence of both ischemic and hemorrhagic strokes in the United States and Canada (University of Michigan researchers, JAMA Network Open).