ORLANDO, Fla. (AP) — Your blood type might affect your risk for stroke. People with AB and women with B were a little more likely to suffer one than people with O blood — the most common type, a study found.
The research can't prove such a link. But it fits with other work tying A, B and AB to more risk of blood clots in the legs and heart attacks. Blood type O also has been tied to an increased risk of bleeding, which implies less chance of clots, the cause of most strokes.
"There's increasing evidence that blood type might influence risk of chronic disease," said one of the study leaders, Dr. JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital.
"It's not at the level where we want to alarm people and we want to make that clear. But it's one more element of risk that people would want to know about," and it could give them one more reason to keep blood pressure and cholesterol in line, she said.
The study, led by Brigham's Dr. Lu Qi, was presented Wednesday at an American Heart Association conference. It involved 90,000 men and women in two observational health studies that have gone on for more than 20 years.
Looking at the 2,901 strokes that have occurred and taking into account other things that can cause them, such as high blood pressure, researchers found:
—Men and women with AB had a 26 percent increased risk of stroke compared to those with type O.
—Women but not men with B blood had a 15 percent greater risk compared to those with O.
What's the explanation?
Blood type depends on proteins on the surface of red blood cells. A pattern of immune system responses forms early in life based on them. Certain blood types may make red cells more likely to clump together and stick to the lining of blood vessels, setting the stage for a blood clot, Manson said.
"You can't change it, and we don't know if it's the blood type per se or other genes that track with it" that actually confers risk, said Dr. Larry Goldstein, director of Duke University's stroke center.
"There are other things that are more important" than blood type for stroke risk, such as smoking, drinking too much and exercising too little, he said.
About 45 percent of whites, 51 percent of blacks, 57 percent of Hispanics and 40 percent of Asians have blood type O, according to the American Red Cross. Such people are called "universal donors" because their blood can safely be used for transfusions to any other blood type.
AB blood type is the least common type, present in 4 percent of whites and blacks, 2 percent of Hispanics and 7 percent of Asians.
B is second least common overall, in 11 percent of whites, 19 percent of blacks, 10 percent of Hispanics and 25 percent of Asians.
A is in 40 percent of whites, 26 percent of blacks, 31 percent of Hispanics and 28 percent of Asians.
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혈액형中 AB형 뇌졸중 위험 가장높아
사람은 혈액형에 따라 뇌졸중 위험에 차이가 있다는 사실이 밝혀졌다.
미국 하버드 대학 의과대학 보건대학원 연구팀은 사람의 혈액형을 ABO 방식으로 구분할 때 AB형의 남녀가 뇌졸중 발생률이 가장 높은 것으로 조사됐다고 밝힌 것으로 AP통신과 헬스데이 뉴스가 16일(현지시간) 보도했다.
연구팀은 간호사와 의료 요원 약 9만 명의 20-26년간 조사자료를 분석한 결과 A B형은 남녀 모두 0형보다 뇌졸중 발생률이 평균 26%, B형은 여성만이 15% 높은 것으로 나타났다고 밝혔다.
A형은 남녀 모두 O형보다 뇌졸중 위험이 더 크지 않았다.
이 조사결과는 그러나 혈액형과 뇌졸중 사이에 인과관계가 존재함을 증명하는 것은 아니다.
연구팀의 일원인 조앤 맨슨(JoAnn Manson) 박사는 혈액형이 만성질환 위험에 영 향을 미칠 수 있다는 증거가 점차 드러나고 있기는 하지만 사람들을 놀라게 할만한 수준은 아니라면서 그러나 이 결과가 해당 혈액형을 가진 사람들에게 혈압과 혈중 콜레스테롤 수치를 잘 관리해야 할 또 하나의 이유는 될 수 있다고 말했다.
이에 대해 듀크 대학 뇌졸중센터실장이자 미국심장학회(AHA) 대변인인 래리 골 드스타인 박사는 특정 혈액형이 뇌졸중 위험을 높일 수 있는 이유는 아무도 모른다 고 말하고 어떤 유전적 인자와 연관이 있을지 모른다고 논평했다.
미국적십자사에 따르면 4가지 혈액형 중에서 0형인 사람이 백인 45%, 흑인 51%, 히스패닉계 57%, 아시아계 40%로 가장 많고 AB형은 백ㆍ흑인 각 4%, 히스패닉계 2%, 아시아계 7%로 가장 적다.
