Weight may determine how much aspirin is needed to prevent heart attacks

In the journals

Published: November, 2018

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Low-dose aspirin therapy has been shown to help prevent heart attacks, but a study in the Aug. 4, 2018 issue of The Lancet suggests men who weigh more than 154 pounds may need higher doses. Researchers analyzed 10 trials that evaluated daily aspirin therapy for cardiovascular disease prevention in 120,000 men and women. The study participants had no history of heart or vascular disease. The researchers found that low-dose daily aspirin — 75 to 100 mg — was associated with reduced risk for heart attack and stroke among both men and women who weighed less than 154 pounds.

However, there was no significant effect for heavier patients. (About 80% of the men in the study were among this group.) The reason? The researchers speculated that people with more weight also have higher amounts of esterase, an enzyme that reduces how much aspirin is available in the body.

This does not mean than the heavier people cannot benefit from aspirin therapy; it may be that they need higher doses. However, we'll need additional research to determine whether higher doses of aspirin are effective for heavier individuals and to determine the ideal dose. If higher doses are needed, there is a trade-off, as a higher aspirin dose may pose a greater risk of bleeding.

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