Steroid-Induced Hyperglycemia

Glucocorticoids such as prednisone, methylprednisolone, and dexamethasone can raise blood glucose in people with diabetes and in people with no previous diabetes diagnosis. This is a medication effect, not simply a dietary problem. Insulin normally moves glucose from the bloodstream into skeletal muscle and fat cells while also limiting glucose release from the liver. Glucocorticoids interfere with both actions. Muscle and fat cells become less responsive to insulin, so less glucose enters the cells after meals. At the same time, the liver continues making and releasing glucose even when insulin should suppress that output. With sustained exposure, glucocorticoids can also strain pancreatic beta cells. A patient who previously compensated for mild insulin resistance may no longer make enough insulin to overcome the steroid effect. The medication may therefore uncover previously unrecognized prediabetes or type 2 diabetes. Hyperglycemia occurs in an estimated 20% to 50% of people receiving corticosteroids who had no known history of diabetes. The risk rises with higher doses, longer courses, and repeated courses.