Lack of correlation between platelet reactivity and glycaemic control in type 2 diabetes mellitus patients treated with aspirin and clopidogrel

The relationship between glycaemic control and platelet reactivity in patients with type 2 diabetes mellitus (DM) on dual antiplatelet therapy is still unclear. A total of 155 consecutive stable angina patients with type 2 DM scheduled for elective percutaneous coronary intervention (PCI) were recruited. All patients were taking aspirin and received a 600-mg loading dose of clopidogrel at least 12 h before intervention. Platelet reactivity was assessed prior to PCI using the VerifyNow (R) device (Accumetrics Inc., San Diego, California). High platelet reactivity on clopidogrel (HPRClopidogrel) was defined as a PRU value >= 240. HPR on aspirin (HPRAspirin) defined as an ARU value >= 550. Poor glycaemic control was defined as a HbA1C value >7 mg/dL. There was no significant difference in either PRU or ARU values in patients with poor glycaemic control compared to those with good glycaemic control (PRU: 230 +/- 92 vs. 228 +/- 110, P = 0.90; ARU: 440 +/- 63 vs. 435 +/- 60, P = 0.61). Patients with and without poor glycaemic control did not show significantly different prevalence of HPRAspirin (8 vs. 6%; P = 0.23) or HPRClopidogrel (46 and 44%; P = 0.80). There was no significant correlation found between HbA1C and either ARU values (r = 0.040, P = 0.71) or PRU values (r = 0.018, P = 0.87). Overall these data suggest that glycaemic control does not appear to influence platelet reactivity in patients with type 2 DM following a loading dose of 600 mg of clopidogrel and aspirin treatment.