Researchers have made an “important and surprising” discovery.
Blood types are important because they determine the type of blood we can be transfused in an emergency. They would also have an influence on our cardiovascular risk, and in particular on our risk of having a young stroke (early stroke).
In a meta-analysis published in the journal Neurology Compiling 48 studies, researchers from the University of Maryland School of Medicine (United States) analyzed the genetic profiles and chromosomes of 17,000 stroke patients and nearly 600,000 healthy controls. having never suffered a stroke. The researchers’ goal was to compare participants’ genetic variants and find potential associations between blood type and stroke risk.
After adjusting parameters such as gender, age or ethnicity, the researchers found that people with blood group A (in France and in the world, this is the most common blood group) had a risk 16% higher to have an early stroke (that is, before age 60) than people with other blood types. Conversely, people with blood group O had a 12% lower risk of having an early stroke compared to people with other blood groups. Rhesus (positive, negative) didn’t seem to matter. For late strokes (after age 60), there also did not appear to be a significant impact of blood type.
At present, “We still don’t know why blood type A may lead to a higher risk of having an early stroke, but it probably has something to do with blood clotting factors like platelets and the cells that line blood vessels as well as other circulating proteins, all of which play a role in the formation of blood clots” said Steven Kittner, co-principal investigator of the study and professor of neurology. Indeed, previous studies suggest that people with blood type A have a slightly higher risk of developing blood clots in the legs, called deep vein thrombosis.
This “important and surprising” discovery could lead to new prevention methods, particularly among young people. Further studies are now needed to clarify the mechanisms of stroke risk, they specify in a press release. However, researchers would like to remind people with blood group A that there is no need to worry or panic, nor to carry out additional examinations or medical tests.