Insulin Correction Scale for Prednisone-Induced Hyperglycemia in Type 2 Diabetes
For patients with type 2 diabetes experiencing prednisone-induced hyperglycemia, a basal-bolus insulin regimen with higher afternoon and evening coverage is strongly recommended to match the specific pattern of steroid-induced glucose elevation.1, 2
Understanding Prednisone's Effect on Glucose Metabolism
- Prednisone causes a distinctive pattern of hyperglycemia that peaks from midday to midnight, with relatively normal fasting glucose levels in the morning 1
- Short-term, medium-dose prednisone treatment (20mg/day) induces postprandial hyperglycemia primarily through:
- Initial suppression of insulin secretion
- Followed by decreased insulin action
- Effects typically dissipate overnight 1
Recommended Insulin Regimen for Prednisone-Induced Hyperglycemia
Initial Insulin Dosing
- Starting total daily insulin requirement: 0.5 units/kg body weight for insulin-naïve patients 3
- For patients already on insulin: increase current daily dose by approximately 30% 3
- Distribution of insulin doses should match the pattern of steroid-induced hyperglycemia:
Insulin Type Selection
Option 1 (Preferred for prednisone therapy): NPH insulin in the morning with rapid-acting insulin (aspart, lispro, glulisine) before meals 3
Option 2: Basal insulin (glargine, detemir) with rapid-acting insulin before meals 2
- Basal dose: 50% of total daily dose
- Mealtime rapid-acting insulin: 50% of total daily dose, with higher proportions at lunch and dinner 2
Blood Glucose Monitoring
- Monitor blood glucose 4 times daily (before meals and at bedtime) 2
- Target blood glucose range: 140-180 mg/dL for most hospitalized patients 2
- More stringent targets (110-140 mg/dL) may be appropriate for selected patients if achievable without significant hypoglycemia 2
Correction Scale Guidelines
Standard Correction Scale (Starting Point)
- For blood glucose 140-180 mg/dL: Add 2 units rapid-acting insulin
- For blood glucose 181-220 mg/dL: Add 4 units rapid-acting insulin
- For blood glucose 221-260 mg/dL: Add 6 units rapid-acting insulin
- For blood glucose 261-300 mg/dL: Add 8 units rapid-acting insulin
- For blood glucose >300 mg/dL: Add 10 units rapid-acting insulin and notify provider 2
Time-Based Adjustment for Prednisone Effect
- Morning (before noon): Use standard correction scale
- Afternoon/Evening (noon to midnight): Use 1.5-2× the standard correction dose
- Overnight (midnight to morning): Use 0.5-1× the standard correction dose 1, 3
Monitoring and Dose Adjustments
- Adjust insulin doses daily based on blood glucose patterns 2
- Increase insulin doses if blood glucose consistently exceeds target range
- Be vigilant for overnight hypoglycemia as prednisone effects wane 1, 3
- If prednisone dose is reduced, insulin doses should be proportionally decreased to prevent hypoglycemia 3
Special Considerations
- Avoid sliding scale insulin as the sole treatment strategy 2
- For patients with kidney disease (eGFR <30 ml/min/1.73m²), insulin is the preferred treatment for glycemic control 2
- Consider consulting endocrinology for complex cases, especially when initiating insulin in steroid-induced hyperglycemia 2
- Recognize that insulin requirements will likely decrease as prednisone is tapered 3
Common Pitfalls to Avoid
- Using a fixed insulin regimen throughout the day fails to address the afternoon/evening hyperglycemic pattern of prednisone 1
- Overtreatment with long-acting insulin can lead to overnight hypoglycemia as prednisone effects diminish 1, 3
- Undertreatment of midday to evening hyperglycemia can lead to sustained hyperglycemia and adverse outcomes 2, 1
- Relying solely on oral agents is often insufficient for managing significant prednisone-induced hyperglycemia 2