What is the treatment for type 1 diabetes?

Treatment of Type 1 Diabetes

All individuals with type 1 diabetes require intensive insulin therapy delivered via either multiple daily injections (MDI) of prandial and basal insulin or continuous subcutaneous insulin infusion (CSII), using rapid-acting insulin analogs to minimize hypoglycemia risk. 1

Core Insulin Regimen

Insulin Delivery Methods

• Start with MDI or CSII as first-line therapy - both approaches provide superior glycemic control and reduce long-term microvascular and macrovascular complications compared to conventional regimens 1
• MDI consists of rapid-acting insulin analogs before each meal combined with once or twice-daily long-acting basal insulin 1, 2
• CSII (insulin pump) offers a modest additional benefit over MDI, with approximately 0.3 percentage point lower HbA1c and reduced severe hypoglycemia rates 1
• Consider CSII preferentially for patients experiencing frequent hypoglycemia, significant glycemic variability, or those unable to achieve targets with MDI 2

Insulin Types and Dosing

• Use rapid-acting insulin analogs (aspart, lispro, or glulisine) rather than regular human insulin - these reduce hypoglycemia risk while achieving equivalent HbA1c control 1
• Rapid-acting analogs have onset in 0.25-0.5 hours, peak at 1-3 hours, and duration of 3-5 hours 1
• Long-acting basal analogs (glargine, detemir, or degludec) provide 12-24+ hours of coverage with minimal peak effect 1
• Starting total daily insulin dose: 0.4-1.0 units/kg body weight, with 0.5 units/kg typical for metabolically stable patients 1
• Split approximately 50% as basal insulin and 50% as prandial insulin 2

Insulin Dose Adjustment

• Match prandial insulin to carbohydrate intake, premeal glucose levels, and anticipated physical activity 1
• Patients who master carbohydrate counting should advance to estimating fat and protein content, as these also affect postprandial glucose 1
• Administer rapid-acting insulin 0-15 minutes before meals 3
• Higher doses (up to 1.5 units/kg/day) are often required during puberty due to growth hormone and sex hormone effects 2

Glycemic Targets and Monitoring

HbA1c Goals

• Target HbA1c <7.5% for children and adolescents with type 1 diabetes 1, 2
• For adults, aim for HbA1c <7% when achievable without problematic hypoglycemia 1
• Measure HbA1c every 3 months to assess overall glycemic control 1, 2

Critical evidence: The DCCT demonstrated that intensive insulin therapy achieving HbA1c around 7% reduced microvascular complications by 50% over 6 years, with persistent benefits for decades including 57% reduction in cardiovascular events and modest reduction in all-cause mortality 1, 2

Continuous Glucose Monitoring (CGM)

• Integrate CGM metrics beyond HbA1c, including time in target range (70-180 mg/dL) and frequency of hypoglycemia 1
• CGM combined with CSII provides the best outcomes for motivated patients with active participation 1
• Hybrid closed-loop systems that automatically adjust basal insulin based on CGM values are now available and represent the cutting edge of diabetes technology 1

Exercise Management

• Ensure pre-exercise glucose is 90-250 mg/dL (5-13 mmol/L) before starting physical activity 2
• Prevent exercise-induced hypoglycemia by: reducing prandial insulin for the pre-exercise meal by 10-50%, increasing carbohydrate intake, and/or reducing basal insulin by 20% after exercise 2
• Postpone intense activity if glucose ≥350 mg/dL with moderate-to-large urine ketones or β-hydroxybutyrate >1.5 mmol/L 2
• Recommend 60 minutes of moderate-to-vigorous aerobic activity daily for children, with vigorous muscle-strengthening at least 3 days per week 2

Adjunctive Therapies

Pramlintide

• Consider pramlintide (injectable amylin analog) as adjunct to mealtime insulin for patients not achieving glucose goals despite optimized insulin therapy 1
• Pramlintide delays gastric emptying, blunts glucagon secretion, and enhances satiety 1
• Reduce prandial insulin doses by 50% when initiating pramlintide to minimize severe hypoglycemia risk 1

Pancreas and Islet Transplantation

• Reserve pancreas transplantation for patients also requiring renal transplantation or those with recurrent ketoacidosis/severe hypoglycemia despite intensive management, as it requires lifelong immunosuppression 1
• Islet transplantation remains investigational 1

Common Pitfalls and Caveats

Diagnostic Considerations

• In overweight/obese adolescents, distinguish type 1 from type 2 diabetes by measuring islet autoantibodies and C-peptide, as 10% of apparent type 2 cases have islet autoimmunity 1
• Consider monogenic diabetes (MODY) in antibody-negative youth, as 1.2-4% of pediatric diabetes is monogenic and frequently misdiagnosed as type 1 diabetes 1
• Neonatal diabetes diagnosed in the first 6 months of life requires genetic testing, as treatment may differ significantly from type 1 diabetes 1

Injection Technique

• Use the shortest needles (4-mm pen or 6-mm syringe needles) as first-line to reduce pain and avoid intramuscular injection 3
• Avoid injecting into areas of lipohypertrophy, as this distorts insulin absorption; rotate injection sites properly 3
• While needle reuse is not recommended by manufacturers and associates with lipohypertrophy, patients who reuse needles should not be subjected to alarming claims of excessive morbidity 3

Monitoring and Screening

• Screen for thyroid autoantibodies at diabetes diagnosis, then measure TSH after metabolic control is established and recheck every 1-2 years 4
• Screen for other autoimmune conditions common in type 1 diabetes, including celiac disease 4