Role of stress in the etiology and treatment of diabetes mellitus.

Stress has long been suspected as having major effects on metabolic activity. The effects of stress on glucose metabolism are mediated by a variety of "counter-regulatory" hormones that are released in response to stress and that result in elevated blood glucose levels and decreased insulin action. This energy mobilizing effect is of adaptive importance in a healthy organism. However, in diabetes, because of a relative or absolute lack of insulin, stress-induced increases in blood glucose cannot be adequately metabolized. Thus, stress is a potential contributor to chronic hyperglycemia in diabetes, although its exact role is unclear. Although there is some suggestion from retrospective human studies that stress can precipitate type I diabetes, animal studies are contradictory with different stressors either having facilitatory or inhibitory effects upon the development of the disease. Human investigations in patients with established diabetes are equally confusing with some showing that stress can stimulate hyperglycemia, hypoglycemia or have no effect at all on glycemic status. There is more consistent evidence supporting the role of stress in animal models of type II diabetes. However, human studies on the role of stress on the course of established type II diabetes are few. Intervention studies suggest that behavioral or pharmacologic intervention to manage stress may contribute significantly to diabetes treatment, but more long-term research is needed. It is concluded that further research is needed to establish the importance of behavioral factors in the etiology and management of diabetes, and several areas of methodologic improvement are suggested.