What are the recommended management strategies for type 1 diabetes, including initial insulin regimens and lifestyle modifications?

Type 1 Diabetes Management: Initial Insulin Regimens and Lifestyle Modifications

All adults with type 1 diabetes should be treated with either multiple daily injections (MDI) of basal and prandial insulin or continuous subcutaneous insulin infusion (CSII), with rapid-acting insulin analogs preferred over regular human insulin to reduce hypoglycemia risk. 1, 2

Initial Insulin Regimen

Starting Dose Calculation

• Begin with 0.5 units/kg/day as the total daily insulin dose in metabolically stable patients 1, 3
• Split this dose approximately 50% as basal insulin and 50% as prandial insulin 1, 3
• Higher doses (up to 1.0 units/kg/day) are required during puberty, pregnancy, or acute illness 1, 2
• Patients presenting with diabetic ketoacidosis require higher weight-based dosing initially 1

Insulin Type Selection

• Use rapid-acting insulin analogs (aspart, lispro, or glulisine) for prandial coverage rather than regular human insulin to minimize hypoglycemia 1, 2, 3
• Use long-acting basal insulin analogs (glargine, detemir, or degludec) for basal coverage, which provide more stable 24-hour coverage with lower nocturnal hypoglycemia risk compared to NPH insulin 3, 4

Administration Schedule

• Administer basal insulin once daily at the same time each day 5
• Give prandial insulin before each meal (typically 3-4 injections daily), with timing based on the insulin formulation's pharmacokinetics and premeal glucose 2, 3
• Rotate injection sites within the same region (abdomen, thigh, or deltoid) to prevent lipodystrophy 5

Advanced Insulin Delivery Options

When to Consider Insulin Pump Therapy

• Automated insulin delivery systems should be considered for all adults with type 1 diabetes to improve glycemic control and reduce hypoglycemia 2
• Prioritize pump therapy for patients with frequent or severe hypoglycemia, hypoglycemia unawareness, or pronounced dawn phenomenon 4
• Both MDI and CSII show similar glycemic outcomes when combined with structured education, though pumps may offer modest additional HbA1c reduction of approximately 0.24% 6

Continuous Glucose Monitoring

• Recommend continuous glucose monitoring (CGM) for all patients, particularly those with hypoglycemia unawareness or frequent hypoglycemic episodes 2
• CGM demonstrates superior reduction in HbA1c (Cohen's d -0.62) and severe hypoglycemia rates compared to self-monitoring of blood glucose 7
• When choosing between adding CGM or pump therapy first, CGM may have greater impact on glycemic variability and severe hypoglycemia than CSII when added to MDI 7

Essential Patient Education Components

Insulin Dose Adjustment Training

• Educate all patients on matching prandial insulin doses to carbohydrate intake, premeal blood glucose levels, and anticipated physical activity 1, 2
• Teach carbohydrate counting as the foundation for prandial insulin dosing 3, 4
• For patients who master carbohydrate counting, advance to fat and protein gram estimation 1
• Include correction dose calculation based on concurrent glycemia and glycemic trends 2

Hypoglycemia Management

• Prescribe glucagon for all patients taking insulin 2
• Train family members and caregivers on glucagon administration techniques 2
• Prefer glucagon preparations that do not require reconstitution for ease of emergency use 2
• Educate patients on recognizing warning signs of hypoglycemia 8

Sick-Day Management

• Provide specific sick-day plans including when to check for ketones and how to adjust insulin 2, 8
• Educate on warning signs of diabetic ketoacidosis 8

Monitoring and Follow-Up

Glycemic Targets

• Target HbA1c <7% (53 mmol/mol) for most nonpregnant adults 4, 8
• Aim for premeal plasma glucose <8.0 mmol/L (approximately 144 mg/dL) 9

Reassessment Schedule

• Reevaluate insulin treatment plans every 3-6 months and adjust as needed 2
• Increase frequency of blood glucose monitoring during any changes to the insulin regimen 5
• Monitor for lipodystrophy at injection sites during routine visits 5

Critical Pitfalls to Avoid

• Never administer basal insulin analogs intravenously or via insulin pump (applies to specific formulations like Lantus) 5
• Do not dilute or mix basal insulin analogs with other insulins 5
• When transitioning from IV to subcutaneous insulin after diabetic ketoacidosis, administer basal insulin 2-4 hours before stopping IV insulin to prevent rebound hyperglycemia 3
• When switching from twice-daily NPH to once-daily basal analog, reduce total dose to 80% of the NPH dose to lower hypoglycemia risk 5
• Recognize that insulin pump therapy carries increased risk of diabetic ketoacidosis compared to MDI 7