What is the recommended glucose monitoring and treatment plan for a non‑diabetic patient with baseline HbA1c 5.9% who is beginning systemic glucocorticoids ≥10 mg prednisone‑equivalent daily?

Management of Steroid-Induced Hyperglycemia in Non-Diabetic Patient with HbA1c 5.9%

For a non-diabetic patient with HbA1c 5.9% starting systemic glucocorticoids ≥10 mg prednisone-equivalent daily, initiate structured blood glucose monitoring every 4-6 hours focusing on afternoon and evening readings, and start NPH insulin in the morning if two blood glucose readings exceed 250 mg/dL (13.9 mmol/L). 1

Glucose Monitoring Strategy

• Check blood glucose every 4-6 hours while on glucocorticoids, with particular attention to afternoon and evening measurements when steroid-induced hyperglycemia peaks (typically 7-9 hours post-administration) 1, 2, 3
• Continue monitoring for 24-48 hours after each glucocorticoid dose, as hyperglycemic effects persist for at least 24 hours 2, 3
• The typical glycemic pattern shows normal or mild fasting hyperglycemia, with increasing hyperglycemia during the afternoon that peaks in the evening 1

Treatment Initiation Threshold

• Begin insulin therapy when two blood glucose readings exceed 250 mg/dL (13.9 mmol/L) 1
• For patients without diabetes receiving once-daily morning intermediate-acting glucocorticoids (prednisone, prednisolone), a single dose of NPH insulin in the morning is the appropriate initial regimen 1
• Administer NPH insulin concomitantly with the morning steroid dose, as NPH peaks at 4-6 hours, matching the steroid's pharmacologic action 1

Insulin Dosing for Non-Diabetic Patients

• Start with NPH insulin at a conservative dose, typically lower than for patients with pre-existing diabetes 1
• Avoid sulfonylureas in this clinical scenario as they are not recommended for steroid-induced hyperglycemia 1
• For correction of initial hyperglycemia, a sliding scale may be required in some patients, though this should supplement—not replace—scheduled insulin 1

Special Considerations for Dexamethasone

• If the patient receives dexamethasone specifically, the management differs slightly: use NPH insulin twice daily (morning and early evening) with a total dose of 0.3 units/kg per day, giving 2/3 in the morning and 1/3 in the early evening 1
• Dexamethasone causes more pronounced and prolonged hyperglycemia than prednisone, requiring more aggressive monitoring 2, 3

Critical Dose Adjustment Principle

• Insulin requirements decline rapidly after glucocorticoid discontinuation—adjust doses accordingly to prevent hypoglycemia 1
• When steroids are tapered or stopped, reduce insulin by 10-20% every 1-2 days when fasting glucose consistently falls below 180 mg/dL 3
• Daily adjustments based on point-of-care glucose testing and anticipated changes in glucocorticoid dosing are critical 1

Risk Stratification Based on HbA1c 5.9%

• An HbA1c of 5.9% places this patient at elevated risk for developing diabetes even without steroids (annual incidence 2.5% for HbA1c 5.6-6.0) 4
• This baseline HbA1c suggests the patient may develop more significant hyperglycemia with glucocorticoids than someone with lower HbA1c 5
• If hyperglycemia persists after glucocorticoid discontinuation, obtain repeat HbA1c and fasting glucose to diagnose new-onset diabetes 1

Warning Signs Requiring Hospital Evaluation

• If capillary blood glucose persistently exceeds 360 mg/dL (20 mmol/L) or the glucose meter reads "HI," the patient should present to the hospital for assessment of potential hyperosmolar hyperglycemic state 1
• This life-threatening condition can develop with severe steroid-induced hyperglycemia and requires immediate intervention 1

Follow-Up After Glucocorticoid Course

• Patients with documented hyperglycemia during glucocorticoid therapy who do not have a prior diabetes diagnosis should have appropriate follow-up testing documented at discharge 1
• Repeat HbA1c 2-3 months after glucocorticoid discontinuation to assess for persistent diabetes 1
• Diagnostic criteria for steroid-induced diabetes converting to type 2 diabetes include persistent hyperglycemia with two abnormal tests (random glucose ≥200 mg/dL on different occasions and/or HbA1c ≥6.5%) 1, 3