Reduced levels of protein C in diabetic subjects: A hyperglycemia-induced phenomenon

Protein C biological activity and plasma concentration were evaluated in 30 diabetic patients and in 30 healthy subjects. They were found to be significantly reduced and inversely correlated with glycemia levels in diabetics. A good direct correlation between protein C activity and its plasma concentration was found in both diabetic and normal subjects. Induced hyperglycemia in diabetic and normal subjects reduced both protein C activity and concentration; moreover, heparin administration, started concomitantly with induced-hyperglycemia, was able to prevent protein C reduction in both normal and diabetic subjects. The effect of heparin administration suggests that protein C reduction is mediated through accelerated thrombin formation, due to hyperglycemia.