UPI Science News
DALLAS, Sept. 2 (UPI) -- Less may be more when it comes to using aspirin
to prevent stroke in healthy women.
Some aspirin can reduce a woman's risk of ischemic stroke, which is
caused by plaques blocking blood vessels. But researchers at Harvard
Medical School found that taking 15 or more aspirin tablets a week
doubles the risk of hemorrhagic stroke, a more rare but also more
deadly stroke that occurs when a vessel ruptures and bleeds into the
brain.
The study, which the researchers say is the largest of its kind to date
of women, is published in today's issue of Stroke: Journal of the
American Heart Association.
''This is the first large-scale, detailed study of the relationship
between aspirin use and the risk of principal types of stroke,'' says
Dr. JoAnn Manson, lead author of the study and professor of medicine at
Harvard Medical School and Brigham and Women's Hospital in Boston.
Earlier research has shown that aspirin taken regularly by survivors of
stroke or heart attack helps prevent recurrences, but there still is
debate about whether healthy people should routinely take aspirin to
prevent a first heart attack or stroke, Manson says.
She adds that one 81-milligram baby aspirin every other day may be
enough to help prevent ischemic stroke. But she also found that heavy
doses of 325-milligram adult aspirin, for example 15 or more tablets a
week, can double the risk of hemorrhagic stroke. And older women with
high blood pressure who took large doses of aspirin tripled their risk
of hemorrhagic stroke.
''No one should begin taking aspirin regularly to prevent their first
stroke without consulting their physician,'' Manson says. ''Aspirin can
cause gastrointestinal bleeding and it increases the risk of
hemorrhagic stroke.''
The researchers used data collected in the Nurses' Health Study to
examine aspirin use and stroke risk in 79,319 healthy women aged 34 to
59. Participants were monitored for 14 years, from 1980 to 1994. During
that time, there were 295 ischemic and 100 hemorrhagic strokes
recorded.
One in 10 American women aged 45 to 64 has some form of heart disease,
and this increases to one in five women over age 65, according to the
National Heart, Lung and Blood Institute. In addition, 2 million women
have had a stroke, and 93,000 die of stroke each year.
The benefit and risk of aspirin needs to be weighed against the risk of
both first heart attack and stroke, says Dr. Daniel Levy, director of
the Framingham Heart Study, one of the nation's largest studies of
cardiovascular disease that has been going on for more than 50 years.
In addition, patients and doctors need to consider other risk factors
such as uncontrolled hypertension and smoking, he says.
''U.S. deaths from heart disease are five times higher than from stroke,
'' says Levy. ''Aspirin can prevent heart attack. So if people are
using aspirin to prevent their first heart attack, they should be aware
that in higher doses, they may be predisposing themselves to
hemorrhagic stroke. They also may benefit from using lower doses.''
(Written by Lori Valigra in Cambridge, Mass.)
Copyright 1999 by United Press International
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