[Glucocorticoid-induced insulin resistance and diabetes mellitus. Receptor-, postreceptor mechanisms, local cortisol action, and new aspects of antidiabetic therapy].

BACKGROUND: Glucocorticoids are frequently prescribed drugs. Nearly half of the patients treated with glucocorticoids over a longer period develop a deranged glucose metabolism. In about 50%, these disturbances persist despite reduction or even withdrawal of the drug. PATHOPHYSIOLOGY: Glucocorticoids antagonize the insulin-mediated inhibition of hepatic glucose release, decrease glucose utilisation in muscle, and reduce the binding affinity of insulin receptors. Therefore, glucocorticoid-induced diabetes mellitus is equivalent to unmasked type 2 diabetes. New studies presume that an increased endogenous production of glucocorticoids particularly in adipocytes could play a role in type 2 diabetes as well. THERAPY: Patients with glucocorticoid-induced diabetes bear, comparable to patients with other types of diabetes, a considerable risk of arteriosclerotic and cardiovascular diseases and should therefore receive an intensified treatment. Therapy of glucocorticoid-induced diabetes basically corresponds to that of type 2 diabetes. Applicable are oral antidiabetic drugs, particularly metformin and the glitazones as insulin sensitizers both requiring consideration of contraindications, or treatment with insulin.