Title: Use of insulin NPH in patients with steroid-induced hyperglycemia
Authors: McCleary D, Van Slyke B, Schaefer M, Calder T
Learning Objective: Evaluate the effects of insulin NPH on hyperglycemia management outcomes and safety considerations.
Self-Assessment Question: Which insulin strategy best aligns with the glucose-raising pattern of glucocorticoids in steroid-induced hyperglycemia?
Background/Objective: Glucocorticoids are widely used for their immunosuppressive and anti-inflammatory effects but often cause hyperglycemia. This study evaluates the effectiveness of NPH insulin versus non‑NPH regimens in managing steroid‑induced hyperglycemia.
Methods: A two‑month retrospective chart review will be conducted from November 1, 2025, to December 31, 2025, for patients started on glucocorticoid therapy who meet inclusion criteria. These patients, identified through an automated report, will serve as the intervention‑free control period. A subsequent two‑month prospective phase from January 1, 2026, to February 28, 2026, will evaluate the insulin NPH intervention. Included patients must be initiated on glucocorticoid therapy exceeding 10 mg prednisone equivalents per dose, have two or more blood glucose readings above 180 mg/dL in the first 24 hours of therapy or a history of diabetes, and be ≥18 years old. Exclusion criteria include hypoglycemia during the current admission, treatment for DKA or HHS, or age <18. The primary outcome is the rate of blood glucose readings >180 mg/dL while on glucocorticoids. The safety outcome is the rate of hypoglycemia events.
Results: A total of 42 patients met inclusion criteria, including 24 in the retrospective control group and 18 in the prospective insulin NPH group. Baseline characteristics were comparable between groups. There was no statistically significant difference in the rate of hyperglycemia between patients managed without insulin NPH and those receiving insulin NPH (43% vs 43%; P = 0.99). Among patients with ≥2 blood glucose readings >180 mg/dL within the first 24 hours of glucocorticoid initiation, the mean rate of hyperglycemia was 52% in the non–insulin NPH group and 43% in the insulin NPH group (P = 0.39). One hypoglycemia event occurred in the non–insulin NPH group compared with four events in the insulin NPH group.
Conclusion: Insulin NPH use for steroid‑induced hyperglycemia did not result in a statistically significant reduction in hyperglycemia compared with non–insulin NPH therapies. However, the pharmacodynamic profile of insulin NPH closely aligns with glucocorticoid‑related glucose elevations. Optimized dosing strategies, standardized protocols, and larger studies are needed to better define its role in managing steroid‑associated hyperglycemia.
