What is a recommended insulin regimen for individuals with type 1 diabetes?

Recommended Insulin Regimen for Type 1 Diabetes

Most people with type 1 diabetes should be treated with a basal-bolus regimen consisting of multiple daily injections (MDI) of basal insulin and prandial insulin or continuous subcutaneous insulin infusion (CSII, insulin pump therapy). 1, 2

Basal-Bolus Regimen Components

Basal Insulin

• Long-acting insulin analogs (glargine, degludec) are preferred over NPH insulin due to:
  • Flatter profile with less variability
  • Lower risk of hypoglycemia, especially nocturnal hypoglycemia
  • More stable glucose control 2, 3
• Starting dose: 0.5 units/kg/day for metabolically stable patients 1, 2
• Administration: Once daily at the same time each day 2
• Titration: Increase by 1-2 units every 3-4 days based on fasting glucose levels 2

Prandial (Bolus) Insulin

• Rapid-acting insulin analogs (aspart, lispro, glulisine, faster-acting aspart) are preferred over regular human insulin 1, 2
• Benefits include:
  • Better postprandial glucose control
  • More physiologic insulin delivery
  • Reduced hypoglycemia risk
  • Flexible meal timing 2, 4
• Starting dose: 50% of total daily insulin dose, divided among main meals 2
• Administration: 5-15 minutes before meals 2
• Titration: Based on pre-meal and post-meal glucose levels 2

Insulin Dosing Guidelines

1. Total daily insulin dose:

   • Initial range: 0.4-1.0 units/kg/day 1
   • Typical starting dose: 0.5 units/kg/day for metabolically stable patients 1, 2
   • Higher doses may be required during puberty or following ketoacidosis 1

2. Distribution of insulin:

   • Approximately 50% as basal insulin
   • Approximately 50% as prandial insulin, divided among meals 2

3. Insulin adjustment factors:

   • Carbohydrate intake (carbohydrate counting)
   • Pre-meal blood glucose levels
   • Anticipated physical activity 1, 2

Insulin Delivery Options

Multiple Daily Injections (MDI)

• 3-4 injections per day (basal plus prandial insulin) 1
• Requires comprehensive education on insulin dosing 1, 5
• Benefits: Flexibility, lower cost than pump therapy 4

Continuous Subcutaneous Insulin Infusion (CSII/Pump)

• Provides 24-hour adjustable basal insulin plus patient-activated boluses 5
• Consider for patients with:
  • Frequent or severe hypoglycemia
  • Pronounced dawn phenomenon
  • Not meeting glycemic targets on MDI
  • Personal preference 4
• Meta-analyses show minimal A1C differences between MDI and CSII 1

Special Considerations

Glucose Monitoring

• Self-monitoring of blood glucose at least 4 times daily 2
• Continuous glucose monitoring may improve control regardless of delivery method 4

Hypoglycemia Prevention

• Rapid-acting insulin analogs reduce hypoglycemia risk compared to regular insulin 1
• Long-acting insulin analogs reduce nocturnal hypoglycemia compared to NPH 6, 3

Common Pitfalls to Avoid

1. Never discontinuing basal insulin even during illness or fasting 2
2. Overbasalization - continuing to escalate basal dose without meaningful reduction in fasting glucose 7
3. Insufficient education on carbohydrate counting and insulin adjustment 2
4. Intramuscular injection - insulin should always be administered subcutaneously 2
5. Not rotating injection sites - can lead to lipodystrophy and variable absorption 2

Exercise Considerations

• Reduce prandial insulin doses before exercise to prevent hypoglycemia 2
• Educate patients on insulin adjustment for various activity levels 2

By implementing a basal-bolus insulin regimen with either MDI or CSII and providing comprehensive education on insulin adjustment, most patients with type 1 diabetes can achieve target glycemic control while minimizing the risk of hypoglycemia and other complications.