Initiating Basal Insulin in Uncontrolled Type 2 Diabetes

Rationale for Insulin Initiation

The American Diabetes Association recommends insulin when HbA1c remains elevated after triple oral therapy, as insulin is more effective than adding a fourth oral agent, for patients with HbA1c ≥8.0% despite triple therapy, indicating progressive beta-cell failure and warrants insulin initiation 3, 4, 5, 6, 1
With HbA1c 8.9%, this patient is approaching the threshold (≥10%) where insulin becomes strongly preferred over other options 1

Begin with 10 units of basal insulin once daily, administered at bedtime, using a long-acting insulin analog (glargine or detemir preferred over NPH) for more consistent glucose control with less nocturnal hypoglycemia risk 1, 2, 6
Detemir typically requires higher doses than glargine to achieve equivalent glycemic control 2

Titrate weekly by 2-3 units based on fasting blood glucose readings, targeting fasting glucose: 4.0-5.5 mmol/L (72-99 mg/dL) or 4.4-7.0 mmol/L per Chinese guidelines 1, 3
Patients should check fasting glucose daily during titration 1

Metformin 1000 mg twice daily should remain part of the regimen unless contraindicated, as it enhances insulin sensitivity and limits weight gain when combined with insulin 3, 6, 7, 2

Stop the DPP-4 inhibitor (sitagliptin/linagliptin) as the American Diabetes Association recommends discontinuing DPP-4 inhibitors when initiating insulin 1

Ensure the patient receives education on glucose monitoring technique and frequency, daily fasting checks minimum during titration 1, 2
Educate on insulin injection technique, proper subcutaneous administration, site rotation 1, 2
Teach insulin storage, refrigeration of unopened vials, room temperature for in-use pens 1
Educate on hypoglycemia recognition and treatment, symptoms, use of 15g fast-acting carbohydrates, glucagon if available 1, 2
Provide self-adjustment protocols, when and how to increase insulin dose based on glucose patterns 2
Teach "sick day" management rules, never stop insulin, increase monitoring frequency 1

Do not use sliding scale insulin alone as primary therapy, basal insulin is superior for glycemic control 2
Do not delay insulin initiation, this patient has already failed triple therapy and further delay risks metabolic decompensation 2
Do not stop metformin unless eGFR <30 mL/min/1.73 m² or other contraindications exist 2
Do not continue sulfonylureas if you were using them, they significantly increase hypoglycemia risk when combined with insulin 1

Schedule follow-up within 1-2 weeks to assess response and adjust insulin dose 1
Recheck HbA1c in 3 months, if target not achieved with optimized basal insulin, consider adding prandial (mealtime) insulin 1, 2
Consider referral to diabetes educator if available for comprehensive insulin training 1
If basal insulin alone (titrated to 0.5 units/kg/day or higher) fails to achieve HbA1c <7%, progression to basal-bolus regimen (adding rapid-acting insulin before meals) becomes necessary 5, 2

With proper basal insulin initiation and titration, expect HbA1c reduction of 1.5-2.5% from baseline when added to oral agents 5
Expect fasting glucose normalization within 2-4 weeks of optimal dosing 2
Expect minimal hypoglycemia risk with basal insulin alone (2-4% incidence) compared to sulfonylureas (24%)
Expect some weight gain (typically 2-4 kg), though less than with sulfonylureas and mitigated by continuing empagliflozin 5