Insulin Initiation for Poorly Controlled Diabetes with HbA1c of 12%
For a patient with diabetes and HbA1c of 12%, basal insulin should be initiated at 10 units or 0.1-0.2 units/kg/day, with consideration for adding mealtime insulin due to the severely elevated HbA1c level. 1
Initial Insulin Selection and Dosing
- For patients with HbA1c ≥10-12%, especially with symptoms or catabolic features, basal insulin plus mealtime insulin is the preferred initial regimen 1
- Start basal insulin (glargine, detemir, NPH, or degludec) at 10 units daily or 0.1-0.2 units/kg/day, depending on the degree of hyperglycemia 1
- When initiating insulin therapy, timely dose titration is important to achieve glycemic targets 1
- Basal insulin is typically used with metformin and perhaps one additional noninsulin agent 1
Insulin Type Selection
- Long-acting basal insulins (glargine, detemir) provide more stable glycemic control with less hypoglycemia compared to NPH insulin 2, 3
- Both insulin glargine and insulin detemir are equally effective in lowering HbA1c with comparable risk of hypoglycemia 3, 4
- Insulin detemir may require higher doses compared to glargine (0.27 ± 0.16 units/kg/day vs. 0.22 ± 0.15 units/kg/day) 4
Titration Algorithm
- Equip patients with an algorithm for self-titration of insulin doses based on self-monitoring of blood glucose (SMBG) to improve glycemic control 1
- Adjust basal insulin dose by 2 units every 3 days until fasting blood glucose reaches target (<130 mg/dL) without hypoglycemia 5, 6
- For patient-managed titration: increase insulin dose by 2 units every 3 days if blood glucose remains above target and no hypoglycemia occurs 1, 7
- For physician-managed titration: adjust insulin dose by 0-2,4, or 6-8 units based on mean fasting plasma glucose over previous 3 days 7
Adding Mealtime Insulin
- When HbA1c is 12%, consider starting with both basal and mealtime insulin due to severe hyperglycemia 1
- If starting with basal insulin alone and HbA1c remains above target after basal insulin has been optimized, add mealtime insulin to control postprandial glucose excursions 1
- For mealtime insulin, rapid-acting insulin analogs (lispro, aspart, or glulisine) are preferred due to their faster action 1
- Start mealtime insulin at 4 units per meal or 10% of the basal dose, and titrate by 1-2 units or 10-15% twice weekly based on postprandial glucose readings 6
Monitoring and Adjustments
- Monitor fasting blood glucose daily to guide basal insulin titration 1, 6
- Adjust both basal and prandial insulins based on SMBG levels 1
- If hypoglycemia occurs, determine the cause and reduce the corresponding insulin dose by 10-20% 6
- Comprehensive education regarding SMBG, diet, exercise, and hypoglycemia management is critical for patients using insulin 1
Special Considerations
- For patients with HbA1c ≥9%, consider starting at a higher insulin dose or with combination injectable therapy 1, 5
- When blood glucose levels are ≥300-350 mg/dL and/or HbA1c is 10-12%, especially with symptoms, basal insulin plus mealtime insulin is the preferred initial regimen 1
- Sulfonylureas, DPP-4 inhibitors, and GLP-1 receptor agonists are usually withdrawn when more complex insulin regimens are used 1
- Thiazolidinediones or SGLT2 inhibitors may be continued to improve glucose control and reduce total daily insulin dose 1