In adults with diabetes mellitus but no evident cardiovascular disease, aspirin at a dose of 100 mg daily significantly reduced the risk of serious vascular events by 12% compared to placebo, though it was associated with a 29% increased risk of major bleeding events.
PICO Summary
Population:
Adults aged 40 years or older with diabetes mellitus (any type) and no known cardiovascular disease.
Intervention:
Aspirin 100 mg daily (enteric-coated) daily.
Comparison:
Matching placebo.
Outcome:
- Efficacy: Serious vascular events occurred in 8.5% of the aspirin group vs 9.6% of the placebo group (rate ratio 0.88, 95% CI 0.79-0.97, P=0.01). Most benefits occurred in the first five years of treatment.
- Safety and Tolerability: Major bleeding events occurred in 4.1% of the aspirin group vs 3.2% of the placebo group (rate ratio 1.29, 95% CI 1.09-1.52, P=0.003), primarily gastrointestinal bleeding.
Clinical Summary
Main Finding:
Aspirin use in persons with diabetes and no evident cardiovascular disease prevented serious vascular events but also caused major bleeding events, with the absolute benefits largely counterbalanced by the bleeding hazard.
Clinical Relevance:
These findings are clinically significant as they provide evidence on the balance of benefits and risks of aspirin use for primary prevention in diabetic patients. The authors conclude: “Aspirin use prevented serious vascular events in persons who had diabetes and no evident cardiovascular disease at trial entry, but it also caused major bleeding events. The absolute benefits were largely counterbalanced by the bleeding hazard.”
Study Overview:
- Type of Study: Randomised, double-blind, placebo-controlled trial.
- Sample Size & Population: 15,480 participants with diabetes mellitus but no evident cardiovascular disease; mean age 63, 63% male.
- Intervention Duration & Doses: Mean follow-up of 7.4 years; aspirin 100 mg daily.
- Comparison: Matching placebo.
Outcomes:
- Primary Efficacy Measure: Serious vascular events occurred in 8.5% of the aspirin group vs 9.6% of the placebo group (rate ratio 0.88, 95% CI 0.79-0.97, P=0.01).
- Primary Safety Measure: Major bleeding events occurred in 4.1% of the aspirin group vs 3.2% of the placebo group (rate ratio 1.29, 95% CI 1.09-1.52, P=0.003), with most of the excess being gastrointestinal bleeding and other extracranial bleeding.
- Secondary Measure: No significant difference in gastrointestinal tract cancer incidence (2.0% in both groups).
Considerations:
The trial showed modest net benefits of aspirin in a well-managed population with diabetes already on preventive measures like statins. Further research is needed to refine patient selection criteria for primary prevention. Proton pump inhibitor co-prescription may mitigate bleeding risks. The balance between cardiovascular benefits and bleeding risks should be carefully considered when deciding on aspirin use for primary prevention in patients with diabetes.
Reference:
The ASCEND Study Collaborative Group. (2018). Effects of Aspirin for Primary Prevention in Persons with Diabetes Mellitus. New England Journal of Medicine, 379(16): 1529–15399. DOI: 10.1056/NEJMoa1804988.
Disclosure:
This article on Hormone Insight was created with both human and AI assistance. The human expert editor reviewed the article before publication to ensure accuracy, quality, and clarity.
