People with one of the type A blood groups are more likely to have a stroke before the age of 60 compared to people with other blood types, studies show.
The blood type describes the rich variety of chemicals shown on the surface of our red blood cells.
Among the most familiar are those called A and B, who can be present together as AB, separately as A or B, or not present at all, such as O.
Even within these basic blood groups, there are subtle variations arising from mutations in responsible genes.
In a study published in 2022, Genomics researchers revealed a clear link between the A1 subgroup gene and an early onset stroke.
Researchers have drawn up data from 48 genetic studies, which include approximately 17,000 stroke people and nearly 600,000 non -stroke controls. All participants were between 18 and 59 years old.
Search throughout the genome revealed two places strongly associated with an earlier risk of stroke. One coincided with the place where the blood type genes were sitting.
A second analysis of specific types of blood type gene is found by people whose genome is encoded for a group A variation, has a 16 percent greater chance of stroke before 60 years of age than a population of other blood groups.
For those with the Gen for group O1, the risk is 12 percent.
However, researchers note that the additional risk of stroke in people with type A blood is small, so there is no need for additional vigilance or screening in this group.
“We still don’t know why the blood type A would bring higher risk,” said senior author and vascular neurologist Stephen Kitner of the University of Maryland.
“But there is probably something to do with blood factors such as platelets and cells that outline blood vessels, as well as other circulating proteins, all of which play a role in the development of blood clots.”
Although the results of the study may seem anxious – the blood type may change the risk of an early stroke – let’s put these results in context.
Each year in the United States, just under 800,000 people experience a stroke. Most of these events – about three out of every four – are found in people 65 years of age or older, with the risks doubled every decade after the age of 55.
Also, the people involved in the study lived in North America, Europe, Japan, Pakistan and Australia, with people of non -European ancestry accounting for only 35 percent of participants. Future studies with a more diverse sample could help clarify the importance of the results.
“We obviously need more subsequent studies to clarify the mechanisms of increased stroke risk,” Kitner said.
Another key finding of the study came from comparing people who had a stroke before the age of 60 with those who had a stroke after the age of 60.
For this, the researchers used a set of data from about 9,300 people over 60 who had a stroke and about 25,000 controls over the age of 60 who had no stroke.
They have found that the increased risk of stroke in the type A blood group becomes insignificant in the late-herd stroke group, suggesting that the strokes that occur at the beginning of life may have a different mechanism compared to those that occur later.
Strokes in younger people are less inclined to cause the accumulation of fat deposits in the arteries (a process called atherosclerosis) and more likely to be caused by factors related to clots, the authors said.
The study also found that people with type B blood were about 11 percent more likely to have a stroke than Needuk’s controls, regardless of their age.
Previous studies suggest that the genome part, which encodes a blood type called “ABO’s locus”, is associated with calcification of the coronary artery, which limits blood flow and heart attack.
The genetic sequence for blood groups A and B is also associated with a slightly higher risk of blood clots in veins called venous thrombosis.
This document has been published in Neurology.
A larger version of this article was published in September 2022.