The Frequency of Aspirin resistance and factors associated with Platetet response to Aspirin in type 2 Diabetic patients

Abstract

The purpose of this study were to investigate whether use of aspirin in patients with type 2 diabetes has desired antiplatelet effects, to determine frequency of aspirin resistance and to identify factors associated with platelet response to aspirin. Platelet response to aspirin. Platelet function of 97 patients with type 2 DM on choronic aspirin therapy and 32 type 2 DM aspirin-free patients who attended the medical outpatient clinic, Ramathibodi hospital, was assessed by optical aggregometry using 1 mmol/l arachidonic acid (AA and 10 umol/l adenosine diphosphate (ADP) as agonists. Aspirin resistance was defined as a maximum aggrgation of >20% with AA and a maximum aggregation of >70% with ADP. Aspirin semiresponders were defined as meeting one, but not both of the above criteria. Serum thromboxane (TX) B2 levels were asayed by enzyme immunoassay (EIA) technique. Of 97 diabetic patiens who were treated with aspirin, 75 were treated with 60 mg/d, 16 were treated with 300 mg/d and 6 patients were treated with 100-150 mg/d. Mean _+ SD. of platelet aggregation induced by AA and ADP in patients with aspirin was significantly lower than those with no aspirin (17.71 _+ 17.99%vs.79.34_+7.34%, p<0.001 and 61.76 _+ 9.16% vs. 72.09%, p<0.001). Median (interquartile range) serum TXB2 level in aspirin group was significantly lower than those in ono-aspirin group (0.189 (0.041-0.373) ng/ml vs 5.526 (3.004-8.318) ng/ml, p<0.001). Patients with 60 mg/d aspirin had significantly higher level of serum TXB2 compared with 300 mg group (0.270(0.08-0.54) vs 0.05 (0.01-0.13), p<0.001), but platelet aggregation was not significantly different. Six (6.19%) of patients were aspirin resistance, 25(25.77%) were aspirin semiresponders and 66 (68.04%) were aspirin sensitive patients. Aspirin resistance was not related to gender, age, blood glucose, total cholesterol, or a history of cardiovascular disease. The results suggest that 60-300 mg/d aspirin can inhibit platelet aggregation in most Thai patients with diabetes and is a reasonable first-line antiplatelet agent in patients with type 2 diabetes.3