What is the treatment approach for diabetes mellitus?

Treatment Approach for Diabetes Mellitus

The treatment of diabetes mellitus should follow a stepwise approach with metformin as first-line therapy for type 2 diabetes, while type 1 diabetes requires immediate insulin therapy with multiple daily injections or continuous subcutaneous insulin infusion. 1

Type 1 Diabetes Management

Initial Treatment

• Insulin therapy is mandatory for all patients with type 1 diabetes 1
• Treatment options include:
  • Multiple daily insulin (MDI) injections (3-4 injections per day of basal and prandial insulin)
  • Continuous subcutaneous insulin infusion (CSII) via insulin pump
  • Most patients should use insulin analogs to reduce hypoglycemia risk 1

Insulin Regimen Components

• Basal insulin: 30-50% of total daily insulin requirements
• Prandial insulin: Remaining portion given before meals
• Starting dose: Typically 0.4-1.0 units/kg/day (may be higher during puberty, menses, and illness) 1
• Insulin analogs are preferred over human insulins to minimize hypoglycemia 1

Monitoring and Adjustment

• Early use of continuous glucose monitoring is recommended to improve outcomes 1
• Patients should be educated on matching prandial insulin doses to:
  • Carbohydrate intake
  • Premeal blood glucose levels
  • Anticipated physical activity 1
• For patients using carbohydrate counting, education on the impact of protein and fat on glycemic excursions should be incorporated 1

Type 2 Diabetes Management

First-Line Therapy

• Metformin should be initiated at diagnosis unless contraindicated 1, 2
• Start at low dose with gradual titration to minimize gastrointestinal side effects 1
• Medication plan should be reevaluated every 3-6 months and adjusted as needed 1

Treatment Selection Based on Comorbidities

• For patients with heart failure: SGLT2 inhibitor is recommended regardless of ejection fraction 1, 2
• For patients with CKD (eGFR 20-60 mL/min/1.73m²): SGLT2 inhibitor to minimize CKD progression 1, 2
• For patients with advanced CKD (eGFR <30 mL/min/1.73m²): GLP-1 RA preferred for glycemic management 1, 2

Intensification of Therapy

• Early combination therapy can be considered to shorten time to goal attainment 1
• If A1C target not achieved with metformin:
  • Add SGLT2 inhibitor if patient has or is at risk for cardiovascular or kidney disease 2
  • Add GLP-1 RA for patients needing greater glucose lowering and weight management 1, 3

Insulin Initiation in Type 2 Diabetes

• Consider insulin regardless of background therapy if:
  • Evidence of ongoing catabolism (unexpected weight loss)
  • Symptoms of hyperglycemia are present
  • A1C >10% or blood glucose ≥300 mg/dL 1, 2
• GLP-1 RA is preferred to insulin when possible 1
• If insulin is used, combination with GLP-1 RA is recommended for:
  • Greater glycemic effectiveness
  • Beneficial effects on weight
  • Lower hypoglycemia risk 1

Lifestyle Management for All Diabetes Patients

Nutrition

• No single ideal macronutrient distribution exists for all people with diabetes 2
• Choose carbohydrates from vegetables, fruits, whole grains, legumes, and dairy products 2
• For overweight/obese individuals, aim for minimum weight loss of 5% 2

Physical Activity

• Regular physical activity can reduce A1C by 0.4-1.0% and improve cardiovascular risk factors 3

Education

• Provide diabetes self-management education at diagnosis, annually, with changes in health status, and during transitions of care 2

Common Pitfalls and Caveats

1. Medication Inertia: Failure to intensify therapy when glycemic targets are not met leads to prolonged hyperglycemia and increased risk of complications 1

2. Hypoglycemia Risk: Particularly with insulin and sulfonylureas; use insulin analogs when possible to reduce this risk 1

3. Metformin Side Effects: Gastrointestinal issues are common; start at low dose and titrate gradually 4

4. Insulin Administration Technique: Improper injection technique can lead to lipohypertrophy and erratic glucose control; proper site rotation is essential 5

5. Overreliance on A1C: While important, A1C should be complemented with blood glucose monitoring, especially in patients prone to glycemic variability 5

6. Neglecting Cardiovascular Risk: Diabetes treatment should address not only glycemic control but also cardiovascular risk factors including hypertension and dyslipidemia 2, 3