Comprehensive Diabetes Management
Foundation: Lifestyle Modifications First
All patients with diabetes must begin with comprehensive lifestyle interventions focusing on nutrition therapy and physical activity, as these form the cornerstone of management regardless of pharmacologic therapy. 1, 2
Nutrition Therapy
- Emphasize nutrient-dense, high-quality foods while decreasing calorie-dense, nutrient-poor foods 1, 2
- Reduce intake of saturated fat, trans fat, and cholesterol while increasing ω-3 fatty acids, viscous fiber, and plant stanols or sterols 3
- For overweight or obese patients with type 2 diabetes, reducing energy intake promotes weight loss of 5-7% of starting weight, which improves glycemia, blood pressure, and lipids 1, 2
- Limit sodium intake to 2,400 mg daily (or 6,000 mg sodium chloride) for patients with comorbidities 1
Physical Activity Requirements
- Prescribe at least 150 minutes of moderate-intensity aerobic activity per week 1, 2
- Add resistance training at least twice per week 1, 2
- Reduce sedentary time throughout the day 1
Pharmacologic Management for Type 2 Diabetes
First-Line Therapy: Metformin
Metformin should be initiated at or soon after diagnosis if not contraindicated, starting at 500 mg daily and increasing by 500 mg every 1-2 weeks up to an ideal maximum dose of 2000 mg daily in divided doses. 1, 2, 4
- Metformin is preferred due to efficacy, safety, low cost, and potential cardiovascular benefits 2
- Metformin rarely causes hypoglycemia by itself, though risk increases with inadequate food intake, alcohol consumption, or concurrent blood sugar-lowering medications 4
When to Use Insulin Instead of Metformin First
Initiate insulin therapy as first-line treatment (bypassing metformin) in patients with: 1, 2
- Ketosis or diabetic ketoacidosis
- Random blood glucose ≥250 mg/dL
- HbA1c >9% (>75 mmol/mol) per the American College of Clinical Endocrinologists, or >8.5% per the American College of Physicians 1, 2
- Severe hyperglycemia with catabolism
- Symptomatic diabetes with polyuria, polydipsia, and weight loss
Treatment Intensification Algorithm
When metformin monotherapy at maximum tolerated dose fails to achieve or maintain HbA1c target over 3 months, add a second agent: 1, 2
- SGLT-2 inhibitors
- GLP-1 receptor agonists
- Sulfonylureas
- Thiazolidinediones
- DPP-4 inhibitors
- Basal insulin
The choice depends on patient-specific factors including cardiovascular disease, renal function, hypoglycemia risk, and cost considerations.
Type 1 Diabetes Management
Most patients with type 1 diabetes require multiple-dose insulin injections (≥3 injections per day) or continuous subcutaneous insulin infusion using insulin analogs to reduce hypoglycemia risk. 2
Rapid-Acting Insulin (e.g., Insulin Aspart)
- Inject subcutaneously within 5-10 minutes before a meal into the abdominal area, thigh, buttocks, or upper arm 5
- Rotate injection sites within the same region to reduce lipodystrophy and localized cutaneous amyloidosis risk 5
- Match prandial insulin doses to carbohydrate intake, preprandial blood glucose levels, and anticipated activity 2
Long-Acting Insulin (e.g., Insulin Detemir)
- Dosage adjustments may be necessary with changes in physical activity, meal patterns, renal or hepatic function, or during acute illness 6
- When switching from other intermediate or long-acting insulins, prescribe on a unit-to-unit basis initially, but adjust dose and timing to reduce hypoglycemia risk 6
Glycemic Targets and Monitoring
Target HbA1c <7% for most adults with diabetes, with more stringent targets (such as <6.5%) for selected individuals without significant hypoglycemia risk. 1, 2
- Monitor HbA1c every 3 months until target is reached, then at least twice yearly 1, 2
- Increase frequency of blood glucose monitoring during any insulin regimen changes 1, 2
- Self-monitoring of blood glucose is essential for preventing and managing hypoglycemia 2
Hypoglycemia Management
Treat hypoglycemia (plasma glucose <3.9 mmol/L) with 15-20g of rapid-acting glucose, confirm blood glucose after 15 minutes, and repeat if hypoglycemia persists. 2
High-Risk Situations for Hypoglycemia
- Fasting for tests or procedures 1
- During or after exercise 1
- During sleep 1
- In patients with renal or hepatic impairment 1, 6
- In patients taking beta-blockers or other sympatholytic medications that mask hypoglycemia symptoms 6
Critical Pitfall
Repeated insulin injections into areas of lipodystrophy or localized cutaneous amyloidosis cause hyperglycemia; sudden change to an unaffected injection site can cause severe hypoglycemia. 5 Advise patients who have repeatedly injected into affected areas to change injection sites and closely monitor for hypoglycemia 5.
Cardiovascular Risk Management
Blood Pressure Control
Target blood pressure <140/90 mm Hg for patients with diabetes and hypertension. 3
- Lifestyle therapy includes weight loss, reduced-sodium diet, moderate alcohol intake, and increased physical activity 3
- Pharmacologic therapy should include either an ACE inhibitor or ARB (but not both) 3
- Monitor serum creatinine/eGFR and potassium levels when using ACE inhibitors, ARBs, or diuretics 3
- Critical contraindication: ACE inhibitors and ARBs are contraindicated during pregnancy due to fetal damage risk 3
Lipid Management
Statin therapy is recommended for most persons with diabetes aged 40 years or older in addition to intensive lifestyle therapy. 3
- Obtain lipid profile at diabetes diagnosis, initial evaluation, and every 5 years thereafter 3
- For patients with recent acute coronary syndrome and LDL cholesterol ≥1.3 mmol/L (≥50 mg/dL), consider adding ezetimibe to moderate-intensity statin therapy 3
- Avoid combination therapy with statin and niacin—this increases stroke risk without cardiovascular benefit 3
Antiplatelet Therapy
- Aspirin 75-162 mg daily is recommended for primary prevention in patients with 10-year cardiovascular risk >10% 3
- Do not use aspirin for primary prevention in patients with 10-year risk <5% 3
- For secondary prevention in patients with documented aspirin allergy, use clopidogrel 75 mg daily 3
Special Populations
Children and Adolescents with Type 2 Diabetes
- Begin with lifestyle modifications and diabetes education 2
- Initiate metformin for HbA1c <8.5% without acidosis or ketosis 2
- Start insulin therapy for HbA1c ≥8.5% or with ketosis until acidosis resolves 2
Elderly Patients
- Energy requirements are lower than for younger adults 1
- Exercise caution when prescribing weight-loss diets 1
- Avoid aggressive targeting of near-normal HbA1c levels in patients with advanced disease where targets cannot be safely reached 2
Critical Medication Safety Issues
Never Share Insulin Pens or Needles
Insulin pens must never be shared between patients even if the needle is changed, as this poses risk for blood-borne pathogen transmission. 5
Avoid Medication Errors
- Always check insulin labels before each injection to prevent accidental mix-ups between insulin products 5
- Do not mix insulin detemir with other insulin preparations—mixing can alter the action profile 6
- Do not mix insulin aspart with other insulins 5