Gaby
Research from the University of Maryland (USA) has revealed that people with blood type B are more likely to suffer a stroke before the age of 60 than those with other blood types. People with type B blood were 16 percent more likely to experience an early stroke than others.
By contrast, those with blood type O or type A had a 12 percent lower risk of an early stroke.
Each blood type is defined by chemical markers on the surface of red blood cells. Small differences in those markers arise from mutations in the genes that determine them.
What Did the Researchers Discover?
In this new study, scientists analyzed data from 48 previous genetic studies, involving around 17,000 stroke patients and approximately 600,000 control participants without strokes. The participants ranged in age from 18 to 59, as reported by Science Alert.
A genome-wide search identified two genetic regions closely associated with the risk of early stroke. One of these matched the area where blood-group genes are located.
Analysis of blood-group genes showed that people with the genetic variant for blood type B had a 16 percent higher risk of stroke before age 60 than people with other blood types. By contrast, those with the gene for blood type A had a 12 percent lower risk.
The researchers also found that people with blood type B had roughly an 11 percent higher likelihood of stroke regardless of age.
“We still don’t know why blood type B predicts the highest risk,” said lead author Stephen Kittner, a vascular neurologist.
“But it’s likely related to factors involved in blood clotting, such as platelets and the cells that line blood vessels, as well as proteins that help form clots,” he suggested.
Study participants lived in North America, Europe, Japan, Pakistan, and Australia, with non-European individuals making up 35 percent of the sample. The researchers say studies with a more diverse sample are needed. Kittner believes additional research would help “clarify the mechanisms behind the increased risk of stroke.”
The results of the study were published in the journal Neurology.
For reference, about 15 million people worldwide have a stroke each year. Stroke is the second leading cause of death after ischemic heart disease. Risk factors include high blood pressure, smoking, blood clotting disorders, obesity, and a lack of physical activity, and genetics often play a role. New statistics show 25 percent of stroke survivors are under 45. Stroke most commonly affects men over 55 and women over 65. Doctors say a healthy lifestyle and preventive measures could help avoid stroke in about 80 percent of cases.
