Type 1 Diabetes Management with Insulin Therapy

Introduction to Insulin Requirements

Type 1 diabetes management requires both basal and bolus insulin to effectively control blood glucose levels, with approximately 50% of daily insulin as basal and 50% as prandial insulin, as recommended by the American Diabetes Association 1, 2
Most individuals with type 1 diabetes should be treated with multiple daily injections of prandial insulin and basal insulin or continuous subcutaneous insulin infusion, according to the American Diabetes Association guidelines 2

Typical multidose regimens for patients with type 1 diabetes combine premeal use of shorter-acting insulins with a longer-acting formulation, as suggested by the American Diabetes Association 1, 3
The long-acting basal dose is titrated to regulate overnight and fasting glucose levels, with a typical starting dose of 0.5 units/kg/day, as recommended by the American Diabetes Association/JDRF Type 1 Diabetes Sourcebook 1, 3
Postprandial glucose excursions require rapid-acting insulin administered before meals, with total daily insulin requirements typically ranging from 0.4 to 1.0 units/kg/day, according to the American Diabetes Association guidelines 1, 3

The American Diabetes Association/JDRF Type 1 Diabetes Sourcebook recommends against using only long-acting insulin, as it would fail to control postprandial glucose excursions, leading to persistent hyperglycemia after meals 1
Patients with type 1 diabetes are at high risk for diabetic ketoacidosis if they do not receive prandial insulin coverage, as demonstrated by the Diabetes Control and Complications Trial (DCCT) 1, 3
The DCCT also showed that intensive therapy with multiple daily injections reduced A1C and was associated with improved long-term outcomes, including 50% reductions in microvascular complications 1, 3

Long-acting insulins like glargine or detemir are indicated for once- or twice-daily subcutaneous administration for patients with type 1 diabetes, but specifically as part of a regimen that includes mealtime insulin, as recommended by the American Diabetes Association 4, 5
Long-acting insulin analogs may be preferred over NPH insulin due to lower risk of hypoglycemia, particularly nocturnal hypoglycemia, according to the American College of Physicians 6, 7

Long-acting insulin analogs should be considered for patients who have frequent severe hypoglycemia with human insulin, though this is still in combination with rapid-acting insulin, as suggested by the American College of Physicians 6, 7
Patients should always carry rapid-acting insulin to accommodate flexible meal and snack times or in case additional doses are needed, as recommended by the American Academy of Family Physicians 4, 5