Insulin Management for Pre-Meal Hyperglycemia on NPH 20 Units
Direct Recommendation
You need to significantly increase your NPH insulin dose and add correction insulin for pre-meal glucose readings of 200-325 mg/dL, as your current 20-unit dose is inadequate for achieving glycemic control.
Understanding Your Current Regimen
Your current setup appears to be:
- NPH 20 units (timing unclear from your question)
- Carbohydrate ratio 1:10 (1 unit per 10 grams of carbohydrate)
- Pre-meal glucose consistently 200-325 mg/dL (indicating poor basal control)
This persistent hyperglycemia signals that your basal insulin dose is too low 1, 2.
Recommended Insulin Adjustments
Basal Insulin (NPH) Dosing
Increase your NPH dose by 2 units every 3 days until your fasting and pre-meal glucose readings reach 90-150 mg/dL 3, 1. Based on your current readings of 200-325 mg/dL, you likely need 30-40 units of NPH to achieve adequate basal coverage 1, 2.
Timing matters critically:
- If you're taking steroids, administer NPH in the morning to match the peak hyperglycemic effect 1, 2
- If you're NOT on steroids, bedtime NPH provides superior glycemic control compared to morning dosing 4
- For twice-daily NPH, split as 2/3 morning and 1/3 evening 5, 6
Correction (Sliding Scale) Insulin
Add rapid-acting insulin for pre-meal corrections using this simplified approach 3:
- For glucose 250-350 mg/dL: Give 2 units of rapid-acting insulin
- For glucose >350 mg/dL: Give 4 units of rapid-acting insulin
This correction insulin is in addition to your carbohydrate coverage 3.
Carbohydrate Ratio
Your 1:10 ratio is appropriate for most patients on moderate insulin doses 2, 6. However, if you're on high-dose steroids or have significant insulin resistance (obesity, infections), you may need to tighten this to 1:8 or 1:6 1, 2.
Monitoring and Titration Protocol
Blood Glucose Targets
Adjustment Algorithm
- If ≥50% of fasting readings are above goal over one week: Increase NPH by 2 units 3, 1
- If >2 readings per week are <80 mg/dL: Decrease NPH by 2 units 3
- Adjust every 3 days until target achieved 1, 2
Critical Context-Specific Considerations
If You're on Steroids (Prednisone/Dexamethasone)
Morning NPH is mandatory because steroids cause afternoon/evening hyperglycemia 1, 2. You may need 40-60% higher insulin doses than standard recommendations 1, 2. For high-dose steroids (e.g., dexamethasone 40 mg), total daily insulin requirements can reach 1.5 units/kg/day 1.
When tapering steroids: Reduce NPH by 10-20% immediately to prevent hypoglycemia 1, 5.
If You're NOT on Steroids
Bedtime NPH provides better fasting glucose control than morning dosing in Type 2 diabetes 4. Consider switching your 20 units to bedtime administration before increasing the dose 4, 7.
For Older Adults or Frail Patients
The American Diabetes Association recommends more liberal targets (90-150 mg/dL pre-meal) and emphasizes avoiding hypoglycemia over tight control 3. Your current readings of 200-325 mg/dL still warrant dose increases, but proceed cautiously with 2-unit increments every 3 days 3.
Common Pitfalls to Avoid
- Do NOT use rapid-acting insulin at bedtime for corrections—this causes nocturnal hypoglycemia 3
- Do NOT continue the sliding scale indefinitely—once your basal dose is optimized, you should rarely need corrections 3
- Do NOT split NPH equally if using twice-daily dosing—always use 2/3 morning and 1/3 evening 5, 6
- Do NOT delay dose increases—waiting longer than 3 days between adjustments prolongs poor control 1, 2
When to Consider Alternative Approaches
If you develop frequent hypoglycemia despite dose adjustments, switch from NPH to a long-acting basal analog (glargine, detemir, degludec) for more stable coverage 3, 5.
If your HbA1c remains elevated despite optimized basal insulin, add non-insulin agents (metformin, GLP-1 agonists, SGLT2 inhibitors) before further intensifying insulin 3.