Experts are now recommending that low-dose aspirin therapy to prevent heart attacks be used somewhat more conservatively - that men younger than 50 and women younger than 60, who have diabetes but no other major risk factors, probably not use aspirin.
The new recommendations are based on an analysis of nine studies, which found that the risks of some side effects such as stomach bleeding, and to a much less extent bleeding strokes, have to be better balanced against the potential benefits of using aspirin.
The findings are agreed upon by a panel of experts and endorsed by the American Diabetes Association, the American Heart Association and the American College of Cardiology Foundation. They were just published online as a position statement in the journal Diabetes Care.
"The larger theme here is that use of low-dose aspirin to prevent heart attacks in people who have not already experienced one is probably not as efficacious as we used to believe it was," said Craig Williams, an associate professor in the College of Pharmacy at Oregon State University, and one of the experts on the recent review panel.
"With any medication, you have to balance the benefits against possible side effects or risks," Williams said. "But even a baby aspirin has some degree of risk, even though it's very low, so we have to be able to show clear benefits that outweigh that risk. In the case of young adults with diabetes but no other significant risk factors, it's not clear that the benefits are adequate to merit use of aspirin."
Aspirin first came to attention for its clear value in acute situations, or people experiencing a heart attack and immediately taking an aspirin. Later it was believed that regular low-doses of aspirin, which act as an anti-coagulant or blood thinner, may have value for people who have risk factors for heart disease, such as high blood pressure, smoking, a family history of cardiovascular disease, or other relevant health issues.
Diabetics also face higher risk of heart disease as they age, and it had been recommended by many doctors that diabetics use low-dose aspirin therapy along with their other medications. The newest recommendations suggest that aspirin be used only by diabetics who have other risk factors and are older - men older than 50 and women older than 60. A recent update to the U.S. Preventive Services Task Force is still recommending aspirin use for older adults who are not diabetics - ages 45-79 for men, 55-79 for women - and who have other risk factors.
"The newest studies just weren't showing adequate benefits for some younger diabetics," Williams said.
At least part of the issue, Williams said, is that widespread use of drugs to control blood pressure and reduce cholesterol has lessened the additional benefits of aspirin. For people who have high blood pressure or elevated cholesterol and are not taking appropriate medications to address those problems, aspirin use might be more justified, Williams said. However, generic statin medications for cholesterol and various hypertension treatments are now available at minimal costs, he said, and have to be considered as part of the optimal approach.
Williams said there is no evidence that higher doses of aspirin beyond the range of 75-162 milligrams per day have any added value in preventing heart attacks. An adequate level of protection is generally achieved with what's considered a "baby aspirin," usually sold in the U.S. as a pill of 81 milligrams, or one-fourth the strength of a typical 325 milligram single aspirin pill.
Additional studies in patients with diabetes are being conducted to further demonstrate exactly who would best benefit from aspirin therapy, Williams said.
Global gap in diabetes prevalence and treatment has widened since 1990