Basal Insulin Dose Adjustment for Hyperglycemia
Direct Answer
Increase long-acting insulin by 2-4 units every 3 days based on fasting glucose levels: add 2 units when fasting glucose is 140-179 mg/dL, or 4 units when fasting glucose is ≥180 mg/dL, until reaching target of 80-130 mg/dL. 1
Standard Titration Algorithm
The American Diabetes Association provides a clear, evidence-based approach for adjusting basal insulin 1:
- For fasting glucose 140-179 mg/dL: Increase by 2 units every 3 days 1
- For fasting glucose ≥180 mg/dL: Increase by 4 units every 3 days 1
- Target fasting glucose: 80-130 mg/dL 1
- Alternative approach: Increase by 10-15% of current dose once or twice weekly 1
Weight-Based Titration (Alternative Method)
For hospitalized patients or more aggressive control 2:
- Increase by 0.1 units/kg daily until fasting glucose reaches target 2
- This weight-based approach achieved target glucose in 3.2 days versus 4.8 days with percentage-based titration 2
Critical Threshold: When to Stop Escalating Basal Insulin
When basal insulin exceeds 0.5 units/kg/day, add prandial insulin rather than continuing to increase basal insulin alone. 1 This prevents "overbasalization," which causes:
- Bedtime-to-morning glucose differential ≥50 mg/dL 1
- Increased hypoglycemia risk 1
- High glucose variability 1
At this threshold, blood glucose elevations likely reflect postprandial hyperglycemia requiring mealtime insulin coverage, not inadequate basal insulin 1.
Hypoglycemia Management
If hypoglycemia occurs without clear cause 1:
- Immediately reduce dose by 10-20% 1
- If more than 2 fasting glucose values per week are <80 mg/dL, decrease by 2 units 1
Special Clinical Situations
Glucocorticoid-Induced Hyperglycemia
For patients on steroids requiring higher insulin doses 3:
- Increase prandial and correction insulin by 40-60% or more in addition to basal insulin 3
- Consider adding 0.1-0.3 units/kg/day of glargine to usual regimen 1
- One study demonstrated that initial doses of 0.5 units/kg/day with increases >30% above baseline were needed 4
Hospitalized Patients
For non-critically ill hospitalized patients 3:
- Moderate hyperglycemia (201-300 mg/dL): Start 0.2-0.3 units/kg/day 3
- Severe hyperglycemia (>300 mg/dL): Reduce home dose by 20% or start 0.3 units/kg/day as total daily dose (half basal, half bolus) 3
- For high-risk patients (elderly >65 years, renal failure, poor oral intake): Use lower doses of 0.1-0.25 units/kg/day 1
Monitoring Requirements
- Daily fasting blood glucose monitoring is essential during titration 1
- Reassess every 3 days during active titration 1
- Check HbA1c every 3 months during intensive adjustment 1
Common Pitfalls to Avoid
- Do not wait longer than 3 days between adjustments in stable patients, as this unnecessarily delays achieving glycemic targets 1
- Do not continue escalating basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia—this leads to overbasalization with increased hypoglycemia risk 1
- Do not use correction insulin alone—scheduled basal-bolus regimens are superior to sliding scale monotherapy 3
- Continue metformin when intensifying insulin therapy unless contraindicated 1