Diabetic neuropathies. Current concepts in prevention and treatment.

Diabetic nerve damage leads to a wide variety of unpleasant problems: painful sensations, muscle weakness, numb feet predisposing to ulcers, impotence, and a series of distressing effects due to autonomic dysfunction. At present, there is no single effective treatment for the many clinical syndromes--each of which may well have a different cause. Improved blood glucose control must remain the first line of treatment, hopefully to improve nerve structure and function but also to raise the pain threshold. A variety of sedatives and analgesics may also help some patients. Inhibition of the enzyme aldose reductase with resultant interference with neural sorbitol and myo-inositol metabolism would seem to have a good theoretical basis in therapy, and detailed results of long term clinical trials of aldose reductase inhibitors such as sorbinil and tolrestat are awaited with interest. Their role in the future could be more important in prevention of nerve damage than in attempting to reverse gross end-stage nerve destruction. In diabetic subjects with loss of pain sensation in the foot due to neuropathy or in the more advanced state of foot ulceration, intensive educational and clinical efforts should be exerted to prevent this distressing and common problem. In the future, a more detailed understanding of the biochemical abnormalities occurring in nerves and their effect on nerve function, structure and vasculature may lead to more satisfactory and logical treatments for this the commonest single complication of diabetes.