Stroke is a leading cause of disability and death in the United States, affecting more than 795,000 Americans every year. But what if doctors were better able to predict who is likely to have a stroke, providing greater opportunity for prevention? Researchers have uncovered four biomarkers that could help do just that.
In a study published in the journalNeurology, researchers found that individuals who had higher levels of four inflammatory biomarkers in their blood were at greater risk forstroke than those with lower levels.
Study co-author Dr. Ashkan Shoamanesh, of McMaster University in Canada, and colleagues say that – while further research is needed to determine whether these biomarkers could be used in clinical practice – their findings could pave the way for better prevention and treatment of stroke.
Stroke occurs when the flow of oxygen-rich blood to the brain is reduced, causing brain cell death.
According to the Centers for Disease Control and Prevention (CDC), in the U.S., strokekills more than 130,000 Americans every year – accounting for 1 in every 20 deaths.
High blood pressure, high cholesterol, and smoking are among the major risk factors for stroke, and tools such as the Framingham Stroke Risk Profile take these factors into account when being used to assess a person’s stroke risk.
Now, Dr. Shoamanesh and team suggest adding four new biomarkers to stroke risk assessments could improve prediction capability.
Up to 33 percent greater stroke risk with high biomarker levels
To reach their findings, the researchers analyzed data from the Framingham Heart Study Offspring Cohort, which included 3,224 subjects of an average age of 61 years with no history of stroke.
Blood samples were taken from the participants at study baseline and assessed for the presence of 15 inflammatory biomarkers. The team notes that inflammatory cascades are believed to play a role in ischemic stroke, whereby a vessel supplying blood to the brain becomes blocked.
Over an average follow-up period of 9 years, 98 participants experienced stroke, the researchers report.
Looking at subjects’ blood samples, the team found that high levels of four biomarkers were associated with greater stroke risk during the 9-year follow-up:
- ln-tumor necrosis factor receptor 2; a 33 percent increased stroke risk
- Homocysteine; a 32 percent increased risk
- In-C reactive protein; a 28 percent increased risk
- Vascular endothelial growth factor; a 25 percent increased risk.
Dr. Shoamanesh notes that these findings are purely observational, so they are unable to conclude that high levels of these biomarkers cause stroke.
What is more, he points out that biomarker levels were only measured once in the study, and there were a number of possible confounding factors that were not accounted for, such as presence of infections and chronic diseases.
Additionally, the study only included individuals of European ancestry, so the results may not be generalizable to other populations.
Still, the researchers are encouraged by their findings, and they suggest that including the four biomarkers in the Framingham Stroke Risk Profile could better pinpoint patients who are likely to experience stroke.
“Identifying people who are at risk for stroke can help us determine who would benefit most from existing or new therapies to prevent stroke.
Future research could also investigate whether lowering the levels of these biomarkers or blocking their action could be a way to prevent strokes. However, our study does not provide evidence that these markers are validated well enough to be implemented in clinical practice.”
Dr. Ashkan Shoamanesh
Written by Honor Whiteman