Aspirin lowers stroke risk in women but not in men

Reported by Susan Aldridge, PhD, medical journalist

A new analysis shows that aspirin's protective effect against stroke is confined to women.
Aspirin thins the blood and so reduces the risk of blood clots. This, in turn, can help protect against heart attack and stroke, which is why many at risk take a daily low-dose aspirin. But researchers at the State University of New York now report on an interesting gender difference in the effects of aspirin.

They looked at trials dealing with the use of aspirin to prevent stroke, which covered over 44,000 men and over 51,000 women. The participants took either low-dose aspirin or a placebo. Among women, aspirin was linked to a 17 per cent overall reduction in stroke risk and a 24 per cent reduction in the risk of ischemic stroke, the type that is caused by a blood clot. For men, there was no reduction in the risk of ischemic stroke. There was, however, a 69 per cent increase in hemorrhagic stroke, the type caused by bleeding into the brain. Women did not have any significant risk of hemorrhagic stroke.

The researchers suggest that biological differences between men and women may account for these differences in response to aspirin. However, these findings need to be confirmed by further controlled trials before any changes in recommendations for aspirin use.

Source
American Heart Association meeting 15th November 2005