Diabetes Management: Evidence-Based Treatment Algorithm
Start all patients with type 2 diabetes on metformin as first-line pharmacologic therapy (unless contraindicated), combined with comprehensive lifestyle modifications including at least 150 minutes of weekly moderate-intensity exercise and structured nutrition therapy targeting 5-7% weight loss. 1
Initial Assessment and Treatment Selection
When to Start with Insulin Instead of Metformin
Bypass metformin and initiate insulin immediately if any of the following are present: 1, 2
- Ketosis or diabetic ketoacidosis
- Random blood glucose ≥250 mg/dL
- HbA1c >8.5% (some sources suggest >9%)
- Symptomatic hyperglycemia with polyuria, polydipsia, and weight loss
- Severe hyperglycemia with catabolism
Standard First-Line Approach (No Contraindications)
Metformin dosing protocol: 1, 2
- Start at 500 mg daily
- Increase by 500 mg every 1-2 weeks
- Target maximum dose: 2000 mg daily in divided doses
- Metformin is preferred due to efficacy, safety, low cost, and potential cardiovascular benefits
Lifestyle Modifications (Mandatory for All Patients)
Physical Activity Prescription 1, 2
- Aerobic activity: Minimum 150 minutes of moderate-intensity exercise per week
- Resistance training: At least twice weekly
- Sedentary time: Actively reduce throughout the day
Nutrition Therapy 1, 2
- Emphasize nutrient-dense, high-quality foods
- Decrease calorie-dense, nutrient-poor foods
- For overweight/obese patients: Reduce energy intake while maintaining healthy eating patterns
- Target weight loss: 5-7% of starting weight provides clinical benefits including improved glycemia, blood pressure, and lipids
Treatment Intensification Algorithm
When to Add Second Agent 1, 2
If HbA1c target not achieved after 3 months on maximum tolerated metformin dose, add one of the following:
- SGLT-2 inhibitors
- GLP-1 receptor agonists
- Thiazolidinediones
- DPP-4 inhibitors
- Basal insulin
- Sulfonylureas
Note: The choice among these agents should be guided by patient-specific factors including cardiovascular disease, kidney disease, heart failure, and hypoglycemia risk. 1
Glycemic Targets and Monitoring
HbA1c Goals 1, 2
- Standard target: <7% for most adults
- More stringent target: <6.5% for selected individuals (younger, newly diagnosed, no cardiovascular disease)
- Less stringent targets: For patients with advanced disease, limited life expectancy, or high hypoglycemia risk
Monitoring Frequency 1, 2
- Every 3 months until HbA1c target is reached
- At least twice yearly once target is maintained
Type 1 Diabetes Management
Most patients require multiple-dose insulin injections (≥3 injections daily) or continuous subcutaneous insulin infusion: 1
- Use insulin analogs to reduce hypoglycemia risk
- Match prandial insulin to carbohydrate intake, preprandial glucose, and anticipated activity
- Consider continuous glucose monitoring systems to significantly reduce severe hypoglycemia risk
Hypoglycemia Management Protocol
Acute Treatment 1, 2
- Administer 15-20g of rapid-acting glucose
- Recheck blood glucose after 15 minutes
- Repeat if hypoglycemia persists (glucose <3.9 mmol/L or <70 mg/dL)
High-Risk Situations 2
- Fasting for tests or procedures
- During or after exercise
- During sleep
Special Consideration 1
For patients with hypoglycemia unawareness: Temporarily increase glycemic targets to partially reverse this condition and reduce future risk
Special Populations
Children and Adolescents with Type 2 Diabetes 1
- Initial therapy: Lifestyle modifications plus metformin for A1C <8.5% without acidosis/ketosis
- If A1C ≥8.5% or ketosis present: Initiate insulin until acidosis resolves
- Severe obesity with elevated A1C despite treatment: Consider metabolic surgery
Hypertension Management 1
- Focus on lifestyle modification first
- For confirmed hypertension: Start ACE inhibitors or angiotensin receptor blockers
Critical Pitfalls to Avoid
Do not aggressively target near-normal HbA1c levels in patients with: 1
- Advanced disease
- Limited life expectancy
- High hypoglycemia risk
- Inability to safely reach such targets
Metformin rarely causes hypoglycemia alone, but risk increases with: 3
- Inadequate food intake
- Alcohol consumption
- Concurrent use of other glucose-lowering medications