What is a common starting point for insulin therapy in a patient with diabetes?

Starting Insulin Therapy in Diabetes

For patients with type 2 diabetes, the recommended starting dose of basal insulin is 0.2 units/kg or up to 10 units once daily, while for type 1 diabetes, the typical starting dose is 0.5 units/kg/day with approximately one-third as basal insulin and the remainder as prandial insulin. 1, 2

Type 2 Diabetes Insulin Initiation

When to Start Insulin

• Consider initiating insulin when A1C ≥9% despite oral medications 2
• Insulin therapy should be initiated immediately when blood glucose is ≥300-350 mg/dL (16.7-19.4 mmol/L) or A1C ≥10-12%, especially if symptomatic 2
• Insulin is indicated when patients present with significant hyperglycemia causing ketosis or unintentional weight loss 2

Initial Insulin Regimen for Type 2 Diabetes

• Start with basal insulin at 0.2 units/kg or 10 units once daily 1, 2
• Basal insulin is usually prescribed with metformin and possibly one additional non-insulin agent 2
• Titrate the dose by 2 units twice weekly until fasting blood glucose target is reached 3
• Common basal insulins include glargine, detemir, or degludec, administered at the same time each day 4, 5

Dose Adjustment Algorithm

• Start with 10 units or 0.2 units/kg once daily 1
• Adjust dose based on fasting blood glucose readings 2
• Increase by 2 units every 3-4 days if fasting glucose remains above target 6
• Target fasting glucose: 100-130 mg/dL (or as individually determined) 2

Type 1 Diabetes Insulin Initiation

Initial Insulin Regimen

• Total daily insulin requirement: 0.5 units/kg/day for metabolically stable patients 2
• Distribute as approximately 50% basal and 50% prandial insulin 2
• Most patients should be treated with multiple daily injections (MDI) of both prandial and basal insulin 2
• Rapid-acting insulin analogs should be used to reduce hypoglycemia risk 2

Dosing Specifics

• Basal insulin: Start with 0.2-0.3 units/kg/day 2
• Prandial insulin: Typically 0.3-0.5 units/kg/day divided before meals 2
• Higher weight-based starting doses may be needed for patients with diabetic ketoacidosis 2
• Higher insulin doses are often required during puberty 2

Practical Considerations for All Patients

Injection Technique

• Inject subcutaneously into abdomen, thigh, or deltoid areas 1
• Rotate injection sites within the same region to reduce lipodystrophy risk 1
• Use short needles (4-mm pen needles) to avoid intramuscular injection 2, 6
• Never share insulin pens, syringes, or needles between patients 1

Monitoring and Adjustment

• Increase frequency of blood glucose monitoring when initiating or changing insulin regimens 1
• Use fasting plasma glucose values to titrate basal insulin 6
• Use both fasting and postprandial glucose values to titrate mealtime insulin 6
• Equip patients with an algorithm for self-titration based on self-monitoring of blood glucose 2

Common Pitfalls to Avoid

• Delaying insulin initiation when clearly indicated by severe hyperglycemia 2, 7
• Failing to adequately titrate insulin doses to reach glycemic targets 3
• Not educating patients on proper injection technique, leading to variable absorption 2
• Abruptly discontinuing oral medications when starting insulin therapy 6
• Overlooking the importance of consistent timing for basal insulin administration 2

By following these guidelines, insulin therapy can be safely and effectively initiated to improve glycemic control and reduce the risk of diabetes-related complications.