Treatment for Type 1 Diabetes
Most adults with type 1 diabetes should be treated with continuous subcutaneous insulin infusion (insulin pump) or multiple daily injections of insulin analogs (rapid-acting prandial plus long-acting basal), with automated insulin delivery systems now recommended for all adults. 1
Core Insulin Therapy
Insulin Delivery Methods (in order of preference)
Automated insulin delivery systems (closed-loop systems) should be considered for all adults with type 1 diabetes as they provide superior glycemic control with reduced hypoglycemia risk compared to traditional methods. 1, 2
Continuous subcutaneous insulin infusion (CSII/insulin pump) is preferred for patients not meeting glycemic targets, those with frequent or severe hypoglycemia, or pronounced dawn phenomenon, offering modest A1C reduction of -0.30% and reduced severe hypoglycemia rates. 1, 3
Multiple daily injections (MDI) remain an effective alternative, requiring 4+ injections daily (basal insulin 1-2 times daily plus rapid-acting insulin before each meal). 1, 4
Insulin Type Selection
Rapid-acting insulin analogs (aspart, lispro, or glulisine) are strongly preferred over regular human insulin for all prandial doses to minimize hypoglycemia risk, particularly nocturnal and delayed hypoglycemia. 1, 4, 3
Long-acting basal insulin analogs (glargine or detemir) are preferred over NPH insulin due to reduced peak profile, extended duration of action, lower intraindividual variability, and decreased nocturnal hypoglycemia risk. 5, 3
Inhaled prandial insulin is an FDA-approved alternative to injectable rapid-acting insulin for mealtime coverage. 1
Initial Insulin Dosing
Start with 0.5 units/kg/day total daily dose in metabolically stable patients, divided as 50% basal insulin and 50% prandial insulin (distributed across meals). 1, 2
Total daily insulin requirements typically range from 0.4 to 1.0 units/kg/day, with higher doses required during puberty, pregnancy, and acute illness. 1, 2
For patients presenting with diabetic ketoacidosis, higher weight-based dosing is required initially. 2
Glucose Monitoring
Continuous Glucose Monitoring (CGM)
Early use of continuous glucose monitoring is recommended for all adults with type 1 diabetes to improve glycemic outcomes, quality of life, and minimize hypoglycemia. 1
CGM is particularly beneficial for patients with hypoglycemia unawareness or frequent hypoglycemic episodes. 1, 3
CGM should be integrated with insulin pump therapy when using automated insulin delivery systems. 1, 2
Self-Monitoring of Blood Glucose
Patients on intensive insulin regimens should self-monitor blood glucose before meals and snacks, at bedtime, occasionally after meals, when suspecting low blood glucose, after treating hypoglycemia until normoglycemic, and before exercise and critical tasks like driving. 1
Frequent SMBG (6-10+ times daily) is associated with lower HbA1c levels in clinical trials. 1
Patient Education Requirements
Insulin Dose Adjustment Education
All patients must receive comprehensive education on matching mealtime insulin doses to carbohydrate intake, fat and protein content, premeal blood glucose levels, and anticipated physical activity. 1, 2, 4
Education should include correction dose calculation based on concurrent glycemia, glycemic trends (if CGM available), and sick-day management. 1, 2
Carbohydrate counting is the foundation for prandial insulin dosing; patients who master this should advance to fat and protein gram estimation. 2
Insulin Administration Technique
The shortest needles (4-mm pen and 6-mm syringe needles) are first-line choice as they are safe, effective, less painful, and avoid intramuscular injections. 6
Intramuscular injections must be avoided, especially with long-acting insulins, as severe hypoglycemia may result. 6
Proper injection site rotation is essential to prevent lipohypertrophy, which distorts insulin absorption. 6
Hypoglycemia Management
Glucagon must be prescribed for all individuals taking insulin, with family members, caregivers, and school personnel educated on its location and administration. 1, 2
Glucagon preparations that do not require reconstitution are preferred for ease of use in emergency situations. 1, 2
Adjunctive Therapy
Pramlintide is the only FDA-approved non-insulin adjunctive therapy for type 1 diabetes, though insulin remains the essential primary treatment. 4, 7
Metformin, GLP-1 receptor agonists, and SGLT-2 inhibitors are not FDA-approved for type 1 diabetes and may increase risk of diabetic ketoacidosis. 4
Treatment Plan Monitoring
Insulin treatment plans and insulin-taking behavior should be reevaluated every 3-6 months and adjusted to incorporate specific patient needs and circumstances. 1, 2
Fasting plasma glucose values should be used to titrate basal insulin, while both fasting and postprandial glucose values should be used to titrate mealtime insulin. 6
Glycemic Targets
A glycated hemoglobin (HbA1c) target of <7% (53 mmol/mol) is appropriate for most nonpregnant adults with type 1 diabetes to prevent long-term microvascular and macrovascular complications while minimizing hypoglycemia risk. 3
For children with type 1 diabetes, including preschool children, HbA1c target is <7.5% (58 mmol/mol). 6
Common Pitfalls to Avoid
Never abruptly discontinue oral medications when starting insulin therapy due to risk of rebound hyperglycemia, though this applies primarily to type 2 diabetes patients transitioning to insulin. 6
Avoid using medications not indicated for type 1 diabetes, as this may lead to suboptimal glycemic control, increased diabetic ketoacidosis risk, and delayed appropriate insulin intensification. 4
Do not inject insulin into areas of lipohypertrophy, as this significantly distorts insulin absorption and glycemic control. 6