What is the initial approach for a new insulin check in a patient with impaired glucose control?

Initial Approach for New Insulin Therapy in Patients with Impaired Glucose Control

For patients with impaired glucose control requiring insulin initiation, the recommended approach is to start with basal insulin at a dose of 10 units or 0.1-0.2 units/kg body weight per day, with subsequent dose adjustments of 10-15% or 2-4 units once or twice weekly until the fasting blood glucose target is met. 1

Assessment Before Starting Insulin

Before initiating insulin therapy, consider:

• Severity of hyperglycemia (HbA1c level)
• Presence of symptoms (polyuria, polydipsia, weight loss)
• Current medications
• Patient's ability to self-monitor blood glucose
• Risk factors for hypoglycemia

Initial Insulin Selection and Dosing

For Most Patients with Type 2 Diabetes:

1. Start with basal insulin (long-acting) unless the patient is markedly hyperglycemic or symptomatic 1

   • Initial dose: 10 units or 0.1-0.2 units/kg/day 1, 2
   • Options include:
     • Long-acting analogs: insulin glargine or insulin detemir
     • Intermediate-acting: NPH insulin (more affordable but higher risk of nocturnal hypoglycemia) 1

2. Titration protocol:

   • Increase dose by 10-15% or 2-4 units once or twice weekly until fasting glucose target is reached 1
   • Target fasting glucose: 80-130 mg/dL (4.4-7.2 mmol/L) 2

For Patients with Severe Hyperglycemia:

• If HbA1c ≥9.0%, consider starting with combination therapy or insulin directly 1
• If glucose >300-350 mg/dL (16.7-19.4 mmol/L) or HbA1c ≥10-12%, insulin therapy should be strongly considered from the outset 1
• For patients with significant symptoms or catabolic features (weight loss, ketosis), insulin is mandatory 1

Monitoring and Follow-up

1. Blood glucose monitoring:

   • Initially monitor 4 times daily (fasting and 2 hours after meals) 1
   • Use fasting plasma glucose values to titrate basal insulin 3
   • Target postprandial glucose: <180 mg/dL (<10 mmol/L) 2

2. HbA1c monitoring:

   • Reassess within 3 months for achievement of HbA1c target 1
   • Target HbA1c <7% for most adults 2

3. Patient education is critical regarding:

   • Glucose monitoring technique
   • Insulin injection technique and storage
   • Recognition and treatment of hypoglycemia
   • "Sick day" management 1

Advancing Insulin Therapy

If basal insulin alone doesn't achieve target HbA1c despite adequate fasting glucose control:

1. Add prandial (mealtime) insulin when significant postprandial glucose excursions occur (>180 mg/dL) 2

   • Start with one meal (usually the largest meal)
   • Initial dose: 4 units, 0.1 units/kg per meal, or 10% of the basal dose 1, 2
   • Consider reducing basal insulin by the same amount as the starting mealtime dose 1

2. Alternative: Consider premixed insulin for patients who may benefit from simpler dosing 1

   • Contains fixed proportions of basal and prandial insulin
   • Main disadvantage: requires relatively fixed meal schedule and carbohydrate content 1

Concurrent Medications

• Continue metformin when starting insulin (unless contraindicated) as it:

  • Decreases weight gain
  • Lowers insulin dose requirements
  • Reduces hypoglycemia risk compared to insulin alone 1

• Consider discontinuing sulfonylureas, DPP-4 inhibitors, and GLP-1 receptor agonists when more complex insulin regimens beyond basal are used 1

Common Pitfalls to Avoid

1. Delayed intensification of insulin therapy when targets aren't met 2
2. Overbasalization - increasing basal insulin beyond 0.5 units/kg/day without addressing postprandial excursions 2
3. Neglecting patient education on injection technique, which can lead to lipohypertrophy and variable insulin absorption 4
4. Abrupt discontinuation of oral medications when starting insulin, which risks rebound hyperglycemia 3
5. Failure to monitor for hypoglycemia, especially with long-acting insulins given intramuscularly 3

Special Considerations

• Cost concerns: NPH insulin may be more affordable than analog insulins, though it carries higher risk of nocturnal hypoglycemia 1
• Elderly patients or those with renal impairment may require lower initial doses 1
• Needle selection: The shortest needles (4-mm pen and 6-mm syringe needles) are recommended to avoid intramuscular injection 3

By following this structured approach to insulin initiation and titration, clinicians can effectively manage hyperglycemia while minimizing the risks of hypoglycemia and excessive weight gain.