Diabetic patients develop arteriosclerosis at an early age. Their disease progresses more rapidly than that of nondiabetics, due to the underlying cause of arteriosclerosis of which the origin is still unknown. Much attention has been paid recently to the causative role of glycosilated lipoproteins, free radical reactions and hyperinsulinaemia--insulin resistance. Disturbances of the carbohydrate metabolism are accompanied by disorders in lipid metabolism and in the antioxidant system. While proteins undergo glycosilation, free radicals are being released from inflamed cells and, during the course of glycosilation with subsequent lipid peroxidation. Oxidation of lipids and proteins form the basis of pathological processes that might initiate the development of arteriosclerosis. There are attempts to influence the above processes by scavengers--e.g. vitamins, Ca-antagonists, angiotensin converting enzyme inhibitors and antilipaemic agents.