Objective: To evaluate the benefits of aspirin in people with diabetes mellitus for the primary prevention of cardiovascular disease.
Research design/methods: We searched MEDLINE and Cochrane database for randomized, controlled trials of aspirin in people with diabetes and no cardiovascular disease. Relative risks were determined using random-effects meta-analysis.
Main outcome measures: Risk reduction of aspirin compared with control groups for major cardiovascular events.
Results: Six trials consisting of 7374 patients with diabetes showed no benefits of aspirin compared with non-aspirin users with regard to overall mortality, risk reduction (relative risk (RR) = 0.96, 95% CI 0.78 - 1.18, p = 0.71), major cardiovascular events (RR = 0.90, 95% CI 0.78 - 1.05, p = 0.17) and myocardial infarction (RR = 0.95, 95% CI 0.76 - 1.18, p = 0.63). Risk of major bleeding in the aspirin compared with the non-aspirin group was not significant (RR = 2.49, 95% CI 0.70 - 8.84, p = 0.16).
Conclusions: Aspirin therapy did not reduce the risk of cardiovascular events. Existing trials were limited by small patient numbers and low cardiovascular event rates. The use of aspirin cannot be routinely recommended for primary prevention of cardiovascular events in diabetes.