Diabetes mellitus in older persons.

The relative importance and mechanisms of deficient insulin secretion versus deficient action during aging are still debated. Whatever mechanisms eventually explain the emergence of impaired glucose tolerance during aging, the clinically important extrinsic modifiers of glycemic levels include diet, medications, activity, and chronic illness and stress. Although prospective studies are not available in the elderly, retrospective studies suggest that good blood glucose control reduces the likelihood and severity of stroke, cardiovascular disease, visual impairment, nephropathy, infections, and even cognitive dysfunction. Good control also seems to reduce nocturia, polyuria, and hypovolemia. Therapy of older persons begins with diet, exercise, and oral agents, failing which, insulin is employed. Since many of the newer oral agents carry less risk of hypoglycemia, achieving tighter control in the elderly has become more feasible.