Type 2 Diabetes Mellitus in Patients with a Prior History of Corticosteroid-induced Hyperglycemia

also been observed in healthy subjects. (3) Prednisone, prednisolone, and methylprednisolone are intermediate-acting corticosteroids with a peak effect four to six hours after administration. (1)(2) After just one dose, postprandial blood glucose may be affected without much effect on fasting blood glucose. (1) However, after repeated doses, these intermediate-acting corticosteroids can cause persistent hyperglycemia. (1) Dexamethasone, a long-acting corticosteroid, is associated with hyperglycemia that may persist for longer than 24 hours. (1) High doses of corticosteroids, defined as more than 30 mg of prednisone equivalent per day, lead to more adverse effects, such as hyperglycemia. (5) Likewise, many adverse effects, including glucose intolerance, are related to the cumulative corticosteroid dose and longer duration of corticosteroid use. A prospective, observational study of 35 patients without pre- existing diabetes, taking high-dose corticosteroids for 6 to 12 weeks, found 40.6% of patients to have elevated fasting or postprandial blood glucose at eight weeks (fasting blood glucose >126 mg/dL). (6) Both higher cumulative corticosteroid doses and continuous corticosteroid administration were associated with a higher incidence of impaired fasting glucose. A case-control study found a slight association between oral glucocorticoid prescriptions and diagnoses of diabetes. (7) The majority of the patients in this study received low daily doses of glucocorticoids. (7) It is presently unknown whether short-term administration of high-dose corticosteroids is associated with the subsequent development of type 2 diabetes, defined as hemoglobin A1c (HbA1c) ≥ 6.5% (48 mmol/mol). (8-9) In addition, no studies have evaluated whether the development of hyperglycemia during the time of short-term, high-dose corticosteroid administration is predictive of type 2 diabetes in the future.