Pathogenesis of angiopathy in diabetes.

Hyperglycaemia as a common feature of diabetes mellitus is a cause of different pathogenic mechanisms influencing endothelial function. Oxidative stress is one of the main causative factors inducing endothelial dysfunction and changes in plasma protein or platelet function. In type 2 diabetes mellitus, a combination of hyperglycaemia together with dyslipidaemia, obesity and other factors may accelerate the process of glycoxidation and lipid oxidation, causing an early impairment of the vessel wall or properties of circulating blood. This induces hypercoagulability characterised by impaired fibrinolysis and hyperaggregability. The initial functional changes are later substituted by morphologically impaired structure of the blood capillaries (microangiopathy) or arteries (macroangiopathy). The latter represent advanced atherosclerosis when typical plaques are formed. Failure of protective scavenger mechanisms is one possible explanation of vessel wall pathology in diabetes.