Diabetes Management: Evidence-Based Treatment Algorithm
Start with metformin as first-line pharmacologic therapy for type 2 diabetes, combined with comprehensive lifestyle modifications including 150 minutes weekly of moderate-intensity aerobic activity and structured nutrition therapy targeting 5-7% weight loss.
Initial Assessment and Treatment Selection
For Type 2 Diabetes:
- Metformin is the first-line medication when not contraindicated, starting at 500 mg daily and titrating by 500 mg every 1-2 weeks up to 2000 mg daily in divided doses 1, 2
- Metformin is preferred due to its efficacy, safety, low cost, potential cardiovascular benefits, and rare risk of hypoglycemia when used alone 1, 3
Critical Exception - Start Insulin Instead of Metformin When:
- Ketosis or diabetic ketoacidosis is present 1
- Random blood glucose ≥250 mg/dL 1
- HbA1c >8.5% (some sources suggest >9%) 1, 2
- Symptomatic diabetes with polyuria, polydipsia, and weight loss 1, 2
For Type 1 Diabetes:
- Multiple-dose insulin injections (≥3 injections daily) or continuous subcutaneous insulin infusion using insulin analogs 1
- Match prandial insulin to carbohydrate intake, preprandial glucose, and anticipated activity 1
- Consider continuous glucose monitoring to reduce severe hypoglycemia risk 1
Lifestyle Modifications (Universal Foundation)
Physical Activity Requirements:
- At least 150 minutes of moderate-intensity aerobic activity per week 1, 2
- Resistance training at least twice weekly 1, 2
- Reduce sedentary time throughout the day 1
Nutrition Therapy:
- Emphasize nutrient-dense, high-quality foods while decreasing calorie-dense, nutrient-poor foods 1, 2
- For overweight/obese patients: reduce energy intake to promote 5-7% weight loss from starting weight 1
- This modest weight loss improves glycemia, blood pressure, and lipids 1
Treatment Intensification Algorithm
When to Intensify (Add Second Agent):
Second-Line Agent Options:
- SGLT-2 inhibitors 1, 2
- GLP-1 receptor agonists 1, 2
- Thiazolidinediones (e.g., pioglitazone 15-45 mg daily) 1, 4
- DPP-4 inhibitors 1, 2
- Basal insulin 1, 2
- Sulfonylureas 2
Glycemic Targets and Monitoring
HbA1c Goals:
- Target <7% for most adults with diabetes 1, 2
- More stringent targets (such as <6.5%) for selected individuals without hypoglycemia risk 1, 2
- Individualize based on age, comorbidities, and hypoglycemia risk 1
Monitoring Frequency:
Hypoglycemia Management Protocol
Treatment:
- Administer 15-20g of rapid-acting glucose 1, 2
- Confirm blood glucose after 15 minutes 1
- Repeat if hypoglycemia persists (glucose <3.9 mmol/L or <70 mg/dL) 1
Prevention Education:
- Educate on high-risk situations: fasting for procedures, during/after exercise, and during sleep 1, 2
- For hypoglycemia unawareness: temporarily increase glycemic targets to partially reverse this condition 1
- Severe or frequent hypoglycemia requires treatment regimen modification 1
Special Population Considerations
Children and Adolescents with Type 2 Diabetes:
- Start with lifestyle modifications and diabetes education 1
- Metformin for A1C <8.5% without acidosis/ketosis 1
- Insulin therapy for A1C ≥8.5% or with ketosis until acidosis resolves 1
- Consider metabolic surgery for severe obesity with elevated A1C despite lifestyle and pharmacologic intervention 1
Hypertension Management:
- Focus on lifestyle modification including healthy nutrition, physical activity, sleep, and weight management 1
- Start ACE inhibitors or angiotensin receptor blockers for confirmed hypertension 1
Critical Pitfalls to Avoid
- Do not aggressively target near-normal HbA1c in patients with advanced disease where such targets cannot be safely reached 1
- Metformin rarely causes hypoglycemia alone, but risk increases with inadequate food intake, alcohol consumption, or concurrent glucose-lowering medications 3
- Monitor for fluid retention when initiating or increasing doses of thiazolidinediones like pioglitazone 4
- Check liver enzymes before starting pioglitazone and periodically thereafter; do not initiate if ALT >2.5 times upper limit of normal 4