How is steroid-induced hyperglycemia managed?

Management of Steroid-Induced Hyperglycemia

For steroid-induced hyperglycemia, initiate NPH insulin at 0.3-0.5 units/kg/day given in the morning to match the afternoon peak hyperglycemic effect of glucocorticoids, with dose adjustments proportional to steroid tapering. 1, 2

Understanding the Hyperglycemic Pattern

Steroid-induced hyperglycemia follows a predictable diurnal pattern that is critical for management:

• Peak hyperglycemia occurs 6-9 hours after morning steroid administration, typically in the afternoon and evening, with glucose levels often normalizing overnight even without treatment 1, 3
• The highest glucose concentrations occur on day 3 of steroid therapy, particularly 2 hours after lunch and dinner 4
• Hyperglycemia develops rapidly, with 94% of patients showing elevated glucose within 48 hours of starting high-dose steroids 5
• The incidence is extremely high: 86% of non-diabetic patients develop at least one glucose reading ≥8 mmol/L (144 mg/dL), and 70% have readings ≥10 mmol/L (180 mg/dL) 5

Monitoring Protocol

Implement four-times-daily glucose monitoring (fasting and 2 hours after each meal) rather than relying on fasting glucose alone, which will miss the peak hyperglycemic effect 1, 2:

• Target glucose range: 5-10 mmol/L (90-180 mg/dL) 1, 2
• Pay particular attention to afternoon and evening readings (2-3 PM and post-dinner), as these capture the peak steroid effect 1, 4
• Monitor every 2-4 hours initially in severe cases or perioperative settings 1

Critical pitfall: Using only fasting glucose to monitor steroid-induced hyperglycemia will underestimate severity and delay intervention 1

Insulin Therapy Algorithm

First-Line Treatment: NPH Insulin

NPH insulin is the preferred agent because its 4-6 hour peak action aligns with the peak hyperglycemic effect of morning glucocorticoid doses 1:

• Starting dose: 0.3-0.5 units/kg/day given in the morning (or 3 hours after steroid administration) 6, 1, 2
• Higher doses (40-60% increase) may be needed for patients on high-dose glucocorticoids (e.g., prednisone ≥50 mg), those with higher baseline HbA1c, or pre-existing diabetes 6, 1, 2
• Lower starting doses (0.2-0.3 units/kg/day) for elderly patients or those with renal impairment 6, 1, 2

Escalation for Severe Hyperglycemia

For more severe cases requiring additional glycemic control 6, 1:

• Add basal-bolus insulin: Once-daily long-acting insulin (glargine/Optisulin) plus rapid-acting insulin (Novorapid) with each meal at 0.3-0.5 units/kg total daily dose, split 50/50 between basal and bolus 6
• Alternative for patients struggling with multiple injections: Mixed insulin (Novomix 30: 30% rapid-acting/70% intermediate protamine insulin) 6
• For high-dose glucocorticoids (e.g., 80 mg): Extraordinary amounts of prandial and correctional insulin may be needed in addition to basal insulin 1

Special Considerations by Steroid Type

For long-acting glucocorticoids (dexamethasone) 1, 2:

• Long-acting basal insulin (glargine) is required to control fasting glucose
• May need combination of basal insulin AND NPH

For multiple daily steroid doses or continuous use 1:

• Long-acting basal insulin becomes more important
• Multiple daily steroid doses increase risk of severe hyperglycemia (>500 mg/dL) 1

Dose Adjustment Strategy

As steroids are tapered, insulin doses must be proportionally decreased to prevent hypoglycemia 6, 1, 2:

• Adjust insulin based on blood glucose patterns, focusing on afternoon/evening readings 1, 2
• Increase NPH by 2 units every 3 days if target glucose not achieved 1
• Critical pitfall: Failing to reduce insulin when steroids are tapered leads to hypoglycemia 1

Role of Oral Agents

Oral antidiabetic agents alone are insufficient for high-dose steroid therapy 1, 2:

• Metformin can be added as an adjunct in patients with preserved renal and hepatic function, with some evidence it alleviates metabolic effects of steroids 6
• Sulfonylureas may be considered for isolated daytime hyperglycemia, though patients must be warned about hypoglycemia risk 6
• For significant hyperglycemia on high-dose steroids (e.g., prednisone 50 mg), insulin therapy is required even if the patient is already on oral agents 2

Perioperative Management

Target glucose: 100-180 mg/dL (5.6-10.0 mmol/L) 1:

• Hold oral glucose-lowering agents on day of surgery 1
• Give half of NPH dose or 75-80% of long-acting insulin dose 1
• Monitor glucose every 2-4 hours while NPO and dose with short/rapid-acting insulin as needed 1

Patient Education

Provide comprehensive education on 6, 2:

• Glucose monitoring technique and frequency
• Symptoms of severe hyperglycemia (polyuria, polydipsia, confusion)
• Emergency threshold: Present to hospital if capillary glucose persistently >20 mmol/L (360 mg/dL) or meter reads "HI" 6
• Hypoglycemia symptoms and management (for those on insulin or sulfonylureas)
• Emphasize that steroid adjustments necessitate diabetes treatment regimen review 6

Life-Threatening Complication

Hyperosmolar hyperglycemic state can develop in very severe cases of steroid-induced hyperglycemia 6, 1, 2:

• This is driven by persistent hyperglycemia leading to profound dehydration and severe hyperosmolality
• Requires immediate hospital presentation for assessment and therapy
• More likely with multiple daily steroid doses 1

Common Pitfalls to Avoid

• Using only fasting glucose for monitoring (misses peak hyperglycemic effect) 1
• Relying solely on sliding-scale correction insulin (associated with poor glycemic control) 1
• Waiting for fasting hyperglycemia before treating (leads to delayed intervention) 1
• Not anticipating the diurnal pattern with peak effects in afternoon/evening 1
• Failing to reduce insulin doses proportionally when steroids are tapered 1