Glycemic Profile of Intravenous Dexamethasone-Induced Hyperglycemia Using Continuous Glucose Monitoring

Patient: Female, 70-year-old Final Diagnosis: Diabetes mellitus type 2 • pancreatic adenocarcinoma Symptoms: Hyperglycemia Medication: Insulin • Dexamethasone Clinical Procedure: Continuous glucose monitoring (CGM) Specialty: Endocrinology • Diabetes and Metabolism OBJECTIVE: Unusual clinical course BACKGROUND: Intravenous (IV) dexamethasone is widely used in critical illness, chemotherapy, or severe COVID-19. Although glucocorticoid-induced hyperglycemia (GCIH) is well-known, there is no report describing the glycemic profile following a single dose of IV dexamethasone as captured on continuous glucose monitoring (CGM) in a patient with diabetes treated with insulin. CASE REPORT: A 70-year-old woman with diabetes and pancreatic adenocarcinoma was treated with chemotherapy containing dexamethasone every other week. CGM data of 23 cycles revealed a reproducible triphasic glycemic pattern consisting of a constant hyperglycemia period, followed by a transient improvement, and ending with another hyperglycemic plateau. Given this recurrent pattern, basal insulin and correction insulin were adjusted with subsequent GCIH attenuation. CONCLUSIONS: This is the first report of CGM glycemic profile following recurring doses of IV dexamethasone in a patient with diabetes treated with basal-bolus insulin. The understanding of triphasic glycemic pattern allows optimal glycemic management.