Steroid-Induced Hyperglycemia

Glucocorticoids can unmask diabetes that was previously compensated for, worsen established diabetes, or cause new hyperglycemia in a person with no prior diabetes history. This is common: roughly 20% to 50% of people without known diabetes develop hyperglycemia during corticosteroid treatment. The central problem is insulin resistance. In skeletal muscle, glucose transport into cells falls because insulin signalling no longer moves glucose transporters effectively to the cell surface. In the liver, insulin becomes less able to suppress glucose production, so hepatic gluconeogenesis rises. Visceral adiposity and, over time, beta-cell stress further weaken the body’s ability to meet the higher insulin demand. This physiology produces a pattern that can be missed by a fasting test. A patient taking prednisone at 0800 may have an acceptable fasting glucose before breakfast, then develop marked hyperglycemia after lunch and dinner. With once-daily morning prednisone or prednisolone, glucose usually rises through the afternoon and peaks in the evening. A normal fasting value does not exclude steroid-induced hyperglycemia. The steroid’s duration shapes the glucose curve: - Hydrocortisone acts for about 8 to 12 hours, so hyperglycemia...