Complications of diabetes. Prevalence, detection, current treatment, and prognosis.

The late complications associated with diabetes mellitus affect the eye (retinopathy and cataract), the kidney (diabetic glomerulosclerosis), the nerves (mononeuropathies, distal symmetric polyneuropathy, and autonomic neuropathy), and the large blood vessels (coronary artery, cerebrovascular, and peripheral vascular disease). With the exception of large blood vessel disease, evidence in animals and humans has suggested that the development of diabetes-associated complications is related to metabolic abnormalities associated with hyperglycemia. Although the exact mechanism by which hyperglycemia causes damage in individual tissues is unknown, a number of potentially pathogenic mechanisms have been proposed. These include increased activity of the polyol pathway, disturbance in the metabolism of myo-inositol and its phospholipid derivatives, abnormal permeability of the small blood vessels, and excessive glycosylation of various proteins. With the introduction of potent aldose reductase inhibitors, the role of increased activity of the polyol pathway (and related abnormalities in myo-inositol metabolism) in the pathogenesis of diabetes-associated complications can be clarified.