Your Blood Type Affects Your Risk of Early Stroke, Scientists Find

According to study, those with one of the type A blood groups are more likely than those with other blood types to get a stroke before the age of 60.

The wide range of substances that are visible on the surface of our red blood cells are described by blood types. The names A and B, which can be present together as AB, separately as A or B, or not at all as O, are among the most well-known.

Subtle differences caused by gene mutations can be seen even among these primary blood types.

A1 subgroup gene and early onset stroke have been linked in a study that was released last year by genomics experts.

Researchers gathered information from 48 genetic studies, which comprised approximately 600,000 non-stroke controls and around 17,000 patients who had had strokes. Ages of all participants ranged from 18 to 59.

Two regions highly connected with an early risk of stroke were found by a genome-wide search. One matched the location of the blood type genes.

Persons whose genomes encoded for a variation of the A group had a 16 percent increased risk of having a stroke before the age of 60 compared with a population of people with other blood types, according to a second investigation of particular blood-type genes.

Those who carried the gene for group O1 had a 12 percent decreased risk.

The elevated risk of stroke among those with type A blood, according to the researchers, is minimal, thus there is no need for further screening or monitoring in this population.

Steven Kittner, a vascular neurologist at the University of Maryland and a senior author on the study, stated, "We still don't know why blood type A would impart a greater risk."

However, it most certainly has something to do with circulating proteins, platelets, and cells that coat blood arteries, all of which are involved in the formation of blood clots.

Let's put the research findings—that a person's blood type may affect their chance of developing an early stroke—into perspective.

Just nearly 800,000 people in the US have a stroke every year. About three out of every four of these incidents involve adults 65 years of age or older, with chances rising every ten years following that.

Additionally, the study's participants were from North America, Europe, Japan, Pakistan, and Australia, with just 35% of them having non-European ancestry. Future research with a more varied sample may be able to shed further light on the results' importance.

According to Kittner, "We obviously need further follow-up research to elucidate the reasons of increased stroke risk."

Comparing individuals who experienced a stroke before the age of 60 to those who experienced a stroke after the age of 60 led to another important study conclusion.

The researchers utilized a dataset of around 9,300 over-60s who had strokes and roughly 25,000 over-60s controls who didn't have strokes for this.

They discovered that the type A blood group's higher risk of stroke diminished in the late-onset stroke group, indicating that strokes that develop early in life could have a different mechanism from those that happen later.

Atherosclerosis, or the buildup of fatty deposits in the arteries, is less likely to cause strokes in younger individuals and is more likely to be brought on by variables related to clot formation, according to the authors.

The study also discovered that regardless of age, those with type B blood were around 11% more likely to get a stroke than non-stroke controls.

Previous research suggests that coronary artery calcification, which inhibits blood flow, and heart attacks are linked to the "ABO locus," a region of the genome that codes for blood type.

The genetic makeup of blood types A and B has also been linked to a marginally increased risk of venous thrombosis, or blood clots in veins.

This paper was published in Neurology.