Steroid-Induced Hyperglycemia

Glucocorticoids such as prednisone, methylprednisolone, dexamethasone, and hydrocortisone can unmask diabetes or cause hyperglycemia in someone with no previous diabetes diagnosis. About 20% to 50% of people without known diabetes develop hyperglycemia during corticosteroid therapy. The central problem is insulin resistance. Skeletal muscle and adipose tissue do not move glucose transporters to the cell surface efficiently, so glucose remains in the bloodstream rather than entering cells. At the same time, the liver continues producing glucose through gluconeogenesis and becomes less responsive to insulin's usual signal to reduce hepatic glucose output. With prolonged exposure, visceral fat accumulation, lipid deposition, and endoplasmic-reticulum stress can impair beta-cell function, reducing the pancreas's ability to compensate. This produces a recognizable timing pattern. A patient who receives prednisone with breakfast may have an acceptable fasting glucose the next morning but develop substantial hyperglycemia after lunch and dinner. The plasma steroid concentration peaks approximately 4 to 6 hours after the dose, while its metabolic effect lasts much longer. Steroid duration shapes the glucose curve: - Hydrocortisone acts for roughly 8 to 12 hours. Glucose elevation tends to...