What is the recommended insulin regimen for type 1 diabetes mellitus (DM) management?

Insulin Regimen for Type 1 Diabetes Management

Most people with type 1 diabetes should be treated with multiple daily injections (MDI) of prandial and basal insulin or continuous subcutaneous insulin infusion (CSII/insulin pump) therapy to optimize glycemic control and reduce mortality risk. 1

Recommended Insulin Regimen Structure

Multiple Daily Injections (MDI)

• Basal insulin: 50% of total daily insulin requirement

  • Long-acting insulin analogs (glargine, degludec) preferred over NPH due to lower hypoglycemia risk 1
  • Typically administered once or twice daily

• Prandial insulin: 50% of total daily insulin requirement

  • Rapid-acting insulin analogs (aspart, lispro) preferred over regular human insulin 1
  • Administered before meals (0-15 minutes prior)

Insulin Dosing

• Initial total daily insulin dose: 0.4-1.0 units/kg/day 1
• Typical starting dose for metabolically stable patients: 0.5 units/kg/day 1
• Higher doses may be required during:
  • Puberty
  • Pregnancy
  • Medical illness 1

Advanced Management Strategies

Insulin Dose Adjustment

• Prandial insulin doses should be matched to:
  • Carbohydrate intake (carbohydrate counting)
  • Pre-meal blood glucose levels
  • Anticipated physical activity 1
• For patients who have mastered carbohydrate counting, education on fat and protein gram estimation can further improve control 1

Alternative Delivery Methods

• Continuous subcutaneous insulin infusion (CSII/insulin pump) should be considered for:
  • Patients with frequent hypoglycemia on MDI
  • Those with pronounced dawn phenomenon
  • Patients not meeting glycemic targets on MDI 2
  • Patients with nocturnal hypoglycemia (sensor-augmented pump with threshold suspend feature) 1

Special Considerations

Hypoglycemia Prevention

• Use rapid-acting insulin analogs to reduce hypoglycemia risk 1
• Consider sensor-augmented insulin pump therapy with threshold suspend feature for patients with nocturnal hypoglycemia 1
• Newer longer-acting basal analogs (U-300 glargine or degludec) may confer lower hypoglycemia risk compared to U-100 glargine 1

Insulin Injection Technique

• Inject into subcutaneous tissue, not intramuscularly 1
• Recommended injection sites: abdomen, thigh, buttock, and upper arm 1
• Proper site rotation is essential to prevent lipohypertrophy 3
• Use shortest needles available (4-mm pen, 6-mm syringe) 3

Monitoring and Adjustment

• Continuous glucose monitoring (CGM) is strongly recommended for all patients with type 1 diabetes 4
• Evaluate insulin treatment plan every 3-6 months 4
• Adjust basal insulin based on fasting glucose values
• Adjust prandial insulin based on both fasting and postprandial glucose values 3

Common Pitfalls to Avoid

1. Sole use of sliding scale insulin is strongly discouraged 1
2. Abrupt discontinuation of insulin therapy can lead to diabetic ketoacidosis
3. Intramuscular injections can cause unpredictable absorption and hypoglycemia 1
4. Inadequate education on carbohydrate counting and dose adjustment
5. Failure to adjust insulin for physical activity can lead to hypoglycemia 4

The evidence clearly shows that intensive insulin management with either MDI or CSII, combined with active patient participation in diabetes self-management, leads to improved outcomes and reduced risk of long-term complications in type 1 diabetes 1.