Polymorphisms of platelet glycoproteins in relation to macrovascular disease in type 2 diabetes mellitus.

We set out to determine the genotype distributions of the PI(A) polymorphism of platelet glycoprotein IIIa, the HPA-3 polymorphism of platelet glycoprotein IIb, and the variable number tandem repeat (VNTR) polymorphism of platelet glycoprotein Ib in subjects with Type 2 diabetes mellitus (Type 2 DM) with (n = 125) and without (n = 90) a clinical history of macrovascular disease. In 215 white European subjects with Type 2 DM, presence of coronary artery disease was determined as a clinical history of angina, myocardial infarction (MI), coronary angioplasty or coronary artery by-pass grafting. Presence of peripheral vascular disease was defined as a clinical history of intermittent claudication with confirmatory vascular ultrasound or angiography, intermittent claudication with undetectable foot pulses and no history of arthralgia or surgery for leg ischaemia, confirmed by reference to medical case notes. Polymorphisms were detected by polymerase chain reaction amplification of DNA. There was no difference in the genotype distributions of subjects with and without macrovascular disease. In subjects with a first MI before the age of 60 years (n = 26), there was a 38% incidence of PI(A2) compared to 29% in subjects free from clinically evident macrovascular disease, but this difference did not reach statistical significance. This study does not support the hypothesis that polymorphisms of platelet glycoproteins, in particular the PI(A) polymorphism of platelet glycoprotein IIIa, play an important role in the pathogenesis of macrovascular disease in subjects with Type 2 DM.