Starting Dose of Long-Acting Insulin for HbA1c 11.3%
For a patient with HbA1c 11.3%, start basal insulin at 0.2 units/kg/day (or 10 units if weight-based dosing yields a lower value), administered once daily at the same time each day. 1, 2
Rationale for Starting Dose
Severe hyperglycemia (HbA1c >10%) requires more aggressive initial dosing than the standard 10 units or 0.1 units/kg/day used for mild hyperglycemia. 1
The American Diabetes Association recommends 0.1-0.2 units/kg/day for insulin-naive type 2 diabetes patients, with the higher end of this range (0.2 units/kg/day) appropriate for patients with marked hyperglycemia like this case. 1, 2
For patients with HbA1c ≥10-12% with symptomatic or catabolic features (polyuria, polydipsia, weight loss), consider starting basal-bolus insulin immediately rather than basal insulin alone, with total daily dose of 0.3-0.5 units/kg/day split 50% basal and 50% prandial. 3, 1
Titration Protocol
Increase basal insulin by 4 units every 3 days if fasting glucose ≥180 mg/dL, or by 2 units every 3 days if fasting glucose is 140-179 mg/dL, until fasting blood glucose reaches 80-130 mg/dL. 3, 1
Daily fasting blood glucose monitoring is essential during titration to guide dose adjustments and prevent hypoglycemia. 1
If hypoglycemia occurs, reduce the dose by 10-20% immediately and reassess the cause. 3, 1
Critical Threshold: When to Add Prandial Insulin
When basal insulin exceeds 0.5 units/kg/day and fasting glucose is controlled but HbA1c remains elevated, add prandial insulin rather than continuing to escalate basal insulin alone. 3, 1
Start prandial insulin with 4 units of rapid-acting insulin before the largest meal (or 10% of basal dose), increasing by 1-2 units twice weekly based on postprandial glucose readings. 3, 1
Clinical signals of overbasalization include bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia, and high glucose variability—all indicating the need for prandial insulin rather than more basal insulin. 3, 1
Foundation Therapy
Continue metformin unless contraindicated (GFR <30 mL/min), as it provides complementary glucose-lowering effects and reduces total insulin requirements. 3, 4
Discontinue sulfonylureas when moving beyond basal-only insulin to reduce hypoglycemia risk. 3
Alternative Consideration for Very High HbA1c
At HbA1c 11.3%, consider adding a GLP-1 receptor agonist to basal insulin, which can provide 2-2.5% HbA1c reduction with weight loss benefits rather than weight gain. 3, 5
GLP-1 receptor agonists have shown equal or superior HbA1c reduction compared to insulin glargine in patients with baseline HbA1c >9%, with the advantage of weight loss rather than weight gain. 5
Common Pitfalls to Avoid
Do not delay insulin intensification while trying additional oral agents at this HbA1c level—prolonged severe hyperglycemia (>9%) increases complication risk. 3
Do not rely solely on sliding scale insulin without optimizing basal insulin first, as this approach is ineffective for long-term management. 3
Baseline HbA1c is the strongest predictor of HbA1c reduction—each 1% increase in baseline HbA1c provides a 0.7-0.8% greater fall with insulin therapy. 6