High heparin released platelet factor 4 in uncomplicated type 1 diabetes mellitus.

The role of platelet activation in diabetic microangiopathy is still controversial. We evaluated the degree of platelet activation in relation to vessel wall damage in three selected, well matched groups of subjects (10 healthy controls; 20 insulin dependent diabetic patients, 10 without microangiopathy and 10 with microangiopathy). We measured beta TG and PF4 plasma levels before and 5, 15 and 90 min after a heparin bolus i.v. (5000 U). beta TG basal levels were increased only in diabetic patients with microangiopathy. Diabetic patients without microangiopathy showed significantly higher levels of heparin released-PF4 (HR-PF4) in comparison with healthy controls. High levels of HR-PF4 seem to be an early marker of in vivo increased platelet activation in uncomplicated diabetes mellitus.