What is the initial management for type 1 diabetes?

Initial Management of Type 1 Diabetes

Most people with newly diagnosed type 1 diabetes should be started on multiple daily injections of insulin consisting of basal insulin (long-acting analog) plus rapid-acting insulin analogs before meals, with a typical starting dose of 0.5 units/kg/day divided approximately 50% basal and 50% prandial. 1, 2

Immediate Assessment and Stabilization

• If diabetic ketoacidosis (DKA) is present (pH <7.3, bicarbonate <18 mEq/L, or marked ketosis), initiate continuous intravenous regular insulin until acidosis resolves, then transition to subcutaneous insulin 1, 3
• When transitioning from IV to subcutaneous insulin, administer basal insulin 2-4 hours before stopping the IV infusion to prevent rebound hyperglycemia 1
• If no DKA but random glucose ≥250 mg/dL or A1C ≥8.5%, start insulin immediately while awaiting antibody results 3

Standard Insulin Regimen

Starting Dose Calculation

• Total daily dose: 0.5 units/kg/day for metabolically stable adults 3, 1, 2
• Lower doses (0.2-0.4 units/kg/day) may be appropriate for young children or those in the "honeymoon period" with residual beta-cell function 3
• Higher doses needed if presenting with ketoacidosis or during puberty 3, 4

Insulin Distribution

• 50% as basal insulin (long-acting analog given once daily) 1, 2
• 50% as prandial insulin (rapid-acting analog divided among meals) 1, 2
• Approximately 30-50% basal and remainder prandial is the general range depending on individual factors 3

Preferred Insulin Types

Basal Insulin

• Use long-acting insulin analogs (glargine, detemir, or degludec) rather than NPH insulin 1, 5
• These provide stable 24-hour coverage with lower risk of nocturnal hypoglycemia and less intraindividual variability 5
• Degludec can be administered at any time of day in adults (but same time daily in pediatrics) 4

Prandial Insulin

• Use rapid-acting insulin analogs (aspart, lispro, or glulisine) rather than regular human insulin to reduce hypoglycemia risk 3, 1, 2
• Administer before meals, with timing individualized based on premeal glucose and carbohydrate content 3, 2

Essential Patient Education (Must Begin Immediately)

• Carbohydrate counting and matching prandial insulin doses to carbohydrate intake 3, 2
• Correction dose calculation based on premeal blood glucose levels 2
• Activity adjustment - reducing insulin for anticipated physical activity 3, 2
• Hypoglycemia recognition and management - prescribe glucagon and educate patient and family on administration 3, 2
• Sick-day management protocols 2, 6

Glucose Monitoring

• Continuous glucose monitoring (CGM) should be considered for all patients from the outset, as it improves glycemic control regardless of insulin delivery method 5, 6
• If CGM unavailable, frequent capillary blood glucose monitoring (before meals and bedtime minimum) 6

Advanced Insulin Delivery Options

• Automated insulin delivery (AID) systems should be considered for all adults with type 1 diabetes who can safely use the device, as they improve time in range and reduce hypoglycemia compared to multiple daily injections 3, 2
• Continuous subcutaneous insulin infusion (CSII/pump therapy) offers modest A1C reduction (–0.30%) and reduced severe hypoglycemia compared to multiple daily injections 3
• The choice between multiple daily injections versus pump therapy depends on patient capability, preferences, and cost, but AID systems are preferred when feasible 3

Glycemic Targets

• A1C goal <7% (53 mmol/mol) for most nonpregnant adults 5, 6
• Time in range (70-180 mg/dL) should be maximized while minimizing hypoglycemia 3

Follow-up and Adjustment

• Reassess insulin regimen every 3-6 months and adjust based on glucose data, lifestyle changes, and glycemic goals 3, 2
• Dose adjustments typically made every 3-4 days when titrating 4
• Ensure at least 8 hours between consecutive insulin doses if a dose is missed 4

Critical Pitfalls to Avoid

• Never use basal insulin alone - type 1 diabetes requires both basal and prandial insulin to prevent DKA 4
• Do not delay insulin initiation while awaiting antibody results if clinical presentation suggests type 1 diabetes 3
• Avoid NPH and regular human insulin when analogs are available, as they increase hypoglycemia risk 3, 1, 5
• Do not share insulin pens or needles between patients due to bloodborne pathogen transmission risk 4