diabetes and aspirin therapy

Last edited 09/2018 and last reviewed 09/2018

  • NICE (1) have stated that:
    • do not offer antiplatelet therapy (aspirin or clopidogrel) for adults with type 2 diabetes without cardiovascular disease


  • evidence of no benefit of aspirin in diabetes
    • a randomised controlled trial investigating the effectiveness of aspirin in preventing cardiovascular disease in diabetic patients with an ankle branchial index <=0.99 did not reveal evidence of benefit (2)
      • a BMJ editorial concluded that:
        • trial evidence shows that aspirin has no benefit for primary prevention of cardiovascular events, even in people at higher risk. Although aspirin is cheap and universally available, practitioners and authors of guidelines need to heed the evidence that aspirin should be prescribed only in patients with established symptomatic cardiovascular disease (3)
      • a meta-analysis has found no benefit for use of aspirin for primary prevention in diabetics (4)
        • meta-analysis included six randomised controlled trials (n=10,117), including POPADAD (3) which compared aspirin with a control (placebo or no aspirin) in people with diabetes and no pre-existing CV disease
        • found aspirin did not statistically significantly reduce the risk of major CV events (relative risk [RR] 0.90; 95%CI 0.81 to 1.00), CV mortality (RR 0.94; 95%CI 0.72 to 1.23), or all-cause mortality (RR 0.93; 95%CI 0.82 to 1.05)
        • no statistically significant increase in the risk of any bleeding or gastrointestinal bleeding with aspirin was identified compared with the control group

  • evidence of benefit of aspirin
    • hypertension and diabetes and aspirin
      • in the hypertensive optimal treatment (HOT) there was evidence of benefit for the use of aspirin in treated hypertensive diabetic patients
        • relative benefit of acetylsalicylic acid on major cardiovascular events and all myocardial infarction was about the same in the groups of patients with diabetes mellitus and IHD as in the whole HOT population (5)
    • the ASCEND study group randomly assigned adults who had diabetes but no evident cardiovascular disease to receive aspirin at a dose of 100 mg daily or matching placebo (6)
      • primary efficacy outcome was the first serious vascular event (i.e., myocardial infarction, stroke or transient ischemic attack, or death from any vascular cause, excluding any confirmed intracranial hemorrhage)
      • primary safety outcome was the first major bleeding event (i.e., intracranial hemorrhage, sight-threatening bleeding event in the eye, gastrointestinal bleeding, or other serious bleeding)
        • during a mean follow-up of 7.4 years, serious vascular events occurred in a significantly lower percentage of participants in the aspirin group than in the placebo group (658 participants [8.5%] vs. 743 [9.6%]; rate ratio, 0.88; 95% confidence interval [CI], 0.79 to 0.97
          • NNT to avoid a serious vascular event equals 91
        • major bleeding events occurred in 314 participants (4.1%) in the aspirin group, as compared with 245 (3.2%) in the placebo group (rate ratio, 1.29; 95% CI, 1.09 to 1.52; P = 0.003), with most of the excess being gastrointestinal bleeding and other extracranial bleeding
        • the study authors note that:
          • "....In contrast to those previous trials, there were high rates of the use of cardioprotective treatments among the participants in ASCEND, with the majority of participants taking statins and blood pressure-lowering therapy. Hence, the present trial provides a direct assessment of the balance of the benefits and hazards of aspirin use in a contemporary context.."
          • "..only approximately one quarter of participants were receiving proton-pump inhibitors (PPIs). It is possible that bleeding rates among aspirin users might be lower if PPIs were routinely used in these persons"
          • "..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.."