What is the recommended insulin regimen for diabetes management?

Recommended Insulin Regimens for Diabetes Management

For optimal management of diabetes, a basal-bolus insulin regimen is recommended for most patients, with specific dosing tailored to the type of diabetes, glycemic patterns, and individual patient factors.

Type 1 Diabetes Insulin Regimen

• Most patients with type 1 diabetes should be treated with multiple daily injections (MDI) of both prandial and basal insulin or with continuous subcutaneous insulin infusion (CSII) 1
• Rapid-acting insulin analogs (insulin lispro, aspart, or glulisine) should be used before meals to reduce hypoglycemia risk compared to regular human insulin 1
• The starting total daily insulin dose typically ranges from 0.4 to 1.0 units/kg of body weight, with 0.5 units/kg being common for metabolically stable patients 1
• The total daily dose should be divided with approximately 50% as basal insulin and 50% as prandial insulin 1
• Patients should be educated on matching prandial insulin doses to carbohydrate intake, premeal blood glucose levels, and anticipated physical activity 1

Insulin Options for Type 1 Diabetes

• Basal insulin options: Long-acting analogs (insulin glargine, detemir, or degludec) are preferred over NPH insulin due to less overnight hypoglycemia 1
• Prandial insulin options: Rapid-acting analogs administered 0-15 minutes before meals provide better postprandial glucose control than human regular insulin 1
• For patients who have successfully used insulin pumps (CSII), continued access should be maintained even after age 65 1

Type 2 Diabetes Insulin Regimen

• For insulin-naive patients with type 2 diabetes, basal insulin is typically added first when oral medications are insufficient 1
• Basal insulin may be initiated at 10 units or 0.1-0.2 units/kg of body weight per day 1, 2
• When initiating basal insulin, metformin should generally be continued, while other oral agents may be discontinued to avoid unnecessarily complex regimens 1

Progression of Insulin Therapy in Type 2 Diabetes

• When basal insulin has been optimized but HbA1c remains above target, consider adding:
  • A GLP-1 receptor agonist, or
  • Prandial insulin (1-3 injections of rapid-acting insulin before meals), or
  • Switching to twice-daily premixed insulin 1
• For patients with severely elevated glucose (>300-350 mg/dL) or HbA1c >10%, consider starting with basal plus mealtime insulin as the initial regimen 1
• When bolus insulin is needed, insulin analogs are preferred due to their faster action 1

Insulin Administration Guidelines

• Basal insulin (glargine, detemir) should be administered once or twice daily according to the specific product 2, 3
• Rapid-acting insulin should be administered immediately before meals 1
• Insulin doses should be adjusted based on self-monitoring of blood glucose (SMBG) results 1
• Fasting plasma glucose values should guide basal insulin titration, while both fasting and postprandial glucose values should guide mealtime insulin adjustments 4

Special Considerations

• Premixed insulin products (70/30 aspart mix or 75/25 or 50/50 lispro mix) may be considered for patients who need a simpler regimen but have suboptimal pharmacodynamic profiles for covering postprandial glucose excursions 1
• Inhaled insulin is available for prandial use but has a limited dosing range and is contraindicated in patients with chronic lung disease 1
• For hospitalized patients, a basal-bolus approach shows better glycemic control than sliding scale insulin alone, but carries a higher risk of hypoglycemia 1

Common Pitfalls and Caveats

• Sliding scale insulin alone is insufficient for most patients with diabetes and should not be used in patients with type 1 diabetes 1
• Premixed insulin therapy (human insulin 70/30) has been associated with high rates of hypoglycemia in hospitalized patients and is not recommended in this setting 1
• When transitioning from IV to subcutaneous insulin in hospitalized patients, calculate the daily dose based on the average hourly infusion rate over the previous 12 hours 1
• Insulin therapy should not be delayed in patients not achieving glycemic goals, as this can lead to worsening hyperglycemia and complications 1
• Proper patient education regarding glucose monitoring, insulin injection technique, insulin storage, and hypoglycemia recognition/treatment is essential for safe and effective insulin therapy 1