The term diabetes mellitus describes a metabolic disorder of multiple aetiology characterized by chronic hypergly-Caemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both.Often symptoms are not severe,or may be absent, and consequently hyperglycaemia of sufficient degree to cause pathological and functional changes may be present for a long time before the diagnosis Is made.In its most severe forms,Ketoacidosis or a non-ketotic hyperosmolar state may develop and lead to stupor, coma and, in absence of effective treatment, death.People with diabetes are at increased risk of cardiovascular, peripheral vascular, and cerebro-vascular disease.Several pathogenetic processes are involved in the development of diabetes