Patients with diabetes and CAD have reduced platelet response to aspirin
MedWire News: Study results show that diabetic patients with coronary artery disease (CAD) have higher levels of platelet aggregation and activation when treated with aspirin than nondiabetic CAD patients.
Writing in the journal Thrombosis Research, Stig Mortensen and colleagues from Aahus University Hospital Skejby in Denmark say that "these findings may partly explain the reduced cardiovascular protection from aspirin in diabetic patients."
In total, 85 diabetic and 92 nondiabetic CAD patients taking 75 mg/day non-enteric coated aspirin had platelet aggregation evaluated using arachidonic acid 0.5 and 1.0 mM and platelet activation assessed by soluble (s)P-selectin. CAD was verified in all patients using angiography.
Mortensen and team found that patients with diabetes had significantly higher levels of platelet aggregation (area under the receiver-operating characteristic curve for 0.5 mM - 91 vs 69; 1.0 mM - 159 vs 120) and activation (sP-selectin: 78 vs 66 ng/ml) compared with nondiabetics, despite being treated with the same dose of aspirin and having the same level of compliance.
These results are in agreement with those of previous studies reported by MedWire News suggesting no cardiovascular benefit of taking aspirin for patients with diabetes, despite previous proven benefits in nondiabetics.
"Several mechanisms may explain the reduced response of diabetic platelets to aspirin. Hyperglycemia together with dyslipidemia and insulin resistance in diabetic patients may all affect the response to antiplatelet drugs," say the authors.
"Hyperglycemia may cause a competition between acetylation and glycation of platelet proteins… Diabetics might also have an increased platelet turnover and be hypersensitive to pro-aggregatory agonists causing an increased platelet activation and aggregation," they add.
Mortensen et al suggest: "Randomized clinical trials with diabetic patients should be undertaken to investigate whether antiplatelet therapy can be optimized in order to reduce the risk of cardiovascular events."
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By Helen Albert