Type 1 Diabetes: Investigation and Treatment
Initial Treatment Approach
For newly diagnosed Type 1 Diabetes in young adults, immediately initiate intensive insulin therapy using either multiple daily injections (MDI) with 3-4 injections per day of basal and prandial insulin, or continuous subcutaneous insulin infusion (CSII/insulin pump), combined with insulin analogs to reduce hypoglycemia risk. 1
Diagnostic Confirmation
Before initiating treatment, confirm the diagnosis of Type 1 DM through:
- Pancreatic autoantibodies testing (GAD, IA-2, ZnT8) to distinguish from Type 2 DM, particularly in young adults with obesity where presentation may overlap 1
- Assessment for diabetic ketoacidosis (DKA) - if present, requires immediate IV insulin until acidosis resolves, then transition to subcutaneous insulin 1
- Baseline HbA1c and fasting glucose measurements to establish severity 1
Initial Insulin Regimen
Starting Dose Calculation
- Begin with 0.5 units/kg/day total daily dose for metabolically stable patients 1
- Split 50/50 between basal and prandial insulin 1
- Higher doses (up to 1.0 units/kg/day) may be needed during acute illness or puberty 1
Insulin Type Selection
Use rapid-acting insulin analogs (lispro, aspart, glulisine) for prandial doses rather than regular human insulin to reduce hypoglycemia risk while achieving equivalent HbA1c reduction 1
Use long-acting insulin analogs (glargine, detemir) for basal coverage administered once daily at bedtime, as they provide more stable glucose control with less hypoglycemia compared to NPH insulin 1, 2, 3, 2
MDI vs. Insulin Pump Decision
Consider automated insulin delivery systems (insulin pump with continuous glucose monitoring) as first-line for all adults with Type 1 DM given superior outcomes in reducing nocturnal hypoglycemia without increasing HbA1c 1
If pump therapy is not feasible due to cost, patient preference, or lack of technical capability:
- Implement MDI with basal insulin once daily (bedtime) plus rapid-acting analog before each meal 1
- Both approaches achieve similar HbA1c reductions (approximately 0.3% difference favoring pumps), but pumps reduce severe hypoglycemia rates 1
Essential Patient Education Components
Immediately educate on carbohydrate counting and insulin dose adjustment - patients must learn to match prandial insulin to carbohydrate intake, premeal glucose levels, and anticipated physical activity 1
Prescribe glucagon for all patients - family members and caregivers must know its location and administration technique; non-reconstitution formulations are preferred 1
Implement continuous glucose monitoring (CGM) early to improve glycemic outcomes, quality of life, and minimize hypoglycemia 1
Glycemic Targets
Target HbA1c <7% for most nonpregnant adults to reduce microvascular and macrovascular complications while balancing hypoglycemia risk 4
Monitor fasting plasma glucose to titrate basal insulin; use both fasting and postprandial glucose to adjust prandial doses 5
Monitoring Requirements
- Self-monitoring blood glucose or CGM multiple times daily - greater frequency correlates with lower HbA1c 4
- HbA1c measurement every 3 months 1
- Reassess insulin regimen and insulin-taking behavior every 3-6 months 1
Common Pitfalls to Avoid
Do not use metformin or other oral agents - Type 1 DM requires insulin as the primary treatment due to absent β-cell function 1, 5
Avoid intramuscular injections especially with long-acting insulins, as this can cause severe hypoglycemia due to rapid absorption 5
Do not inject into lipohypertrophic areas - rotate injection sites properly to prevent lipohypertrophy which distorts insulin absorption 5
Never abruptly discontinue insulin even during illness - develop sick-day management plans to prevent DKA 4
Multidisciplinary Team Approach
Ensure access to diabetes care team including physician, diabetes educator, registered dietitian, and mental health professional for comprehensive diabetes self-management education 1