Acute and chronic complications of diabetes mellitus in older patients.

The chronic complications of diabetes are thought to be caused by an interaction between hyperglycemia or other metabolic consequences of insulin deficiency and other poorly defined independent genetic or environmental factors. Several important biochemical sequelae to hyperglycemia are discussed. Macrovascular disease appears to be primarily age-related in diabetic patients. The clinical course, manifestations, and management of diabetic complications are significantly altered when they appear against a background of the degenerative changes of aging, greatly complicating diagnosis and management. In elderly patients, the acute complications of diabetes--ketoacidosis and hyperosmolar dehydration--often occur in the context of chronic complications that greatly compound their management and increase their morbidity and mortality.