What are the diagnosis and management strategies for Chronic Kidney Disease (CKD)?

Diagnosis and Management of Chronic Kidney Disease

The 2024 KDIGO clinical practice guideline recommends testing people at risk for CKD using both urine albumin measurement and assessment of glomerular filtration rate (GFR) for early detection and management of chronic kidney disease. 1

Diagnosis of CKD

Definition and Criteria

• CKD is defined as persistent abnormality in kidney structure or function for >3 months
• Diagnostic criteria:
  • GFR <60 mL/min/1.73 m² and/or
  • Albuminuria ≥30 mg/24 hours (or albumin-to-creatinine ratio ≥30 mg/g)
  • Persistence for >3 months

Diagnostic Testing

• Initial testing:

  • Serum creatinine with eGFR calculation
  • Urine albumin-to-creatinine ratio (UACR)
  • Urinalysis for hematuria and other markers of kidney damage

• Establishing chronicity:

  • Repeat testing at least once within 3 months to confirm persistence
  • Review of prior laboratory results if available

Risk Assessment and Staging

• CKD is staged based on GFR category (G1-G5) and albuminuria category (A1-A3)
• KDIGO heat map classifies risk of progression:
  • Green (low risk): G1A1, G2A1
  • Yellow (moderately elevated risk): G1A2, G2A2, G3aA1
  • Orange (high risk): G1A3, G2A3, G3aA2, G3bA1
  • Red (very high risk): G3aA3, G3bA2-A3, G4A1-A3, G5A1-A3 2

Management of CKD

Blood Pressure Management

• Target BP:

  • <130/80 mmHg for patients with albuminuria ≥30 mg/24 hours
  • <140/90 mmHg for patients without albuminuria 2

• First-line therapy:

  • ACE inhibitors or ARBs for patients with albuminuria
  • Add dihydropyridine calcium channel blockers and/or diuretics if needed 2

Lifestyle Modifications

• Physical activity:

  • At least 150 minutes of moderate-intensity activity weekly
  • Avoid sedentary behavior 2

• Dietary recommendations:

  • Protein intake: 0.6-0.8 g/kg/day for adults with CKD G3
  • Sodium restriction: <2.3 g/day
  • Plant-dominant, Mediterranean-style diet with increased fruits and vegetables 2, 3

• Weight management:

  • Achieve and maintain optimal BMI (20-25 kg/m²)
  • Weight loss for patients with obesity 2

• Smoking cessation:

  • Complete avoidance of tobacco products
  • Referral to smoking cessation programs 2

Pharmacological Management

• Renin-angiotensin system blockade:

  • ACE inhibitors or ARBs for patients with albuminuria 1, 2

• Novel agents:

  • SGLT2 inhibitors for patients with diabetes and CKD
  • Non-steroidal mineralocorticoid receptor antagonists (finerenone) if albuminuria persists despite ACE inhibitor therapy 2, 3

• Cardiovascular risk reduction:

  • Statin therapy for adults aged ≥50 years with CKD
  • Consider statin/ezetimibe combination for enhanced LDL reduction
  • Low-dose aspirin in patients with established cardiovascular disease or high ASCVD risk 2

Management of CKD Complications

• Anemia management:

  • Evaluate iron status in all patients
  • Administer supplemental iron when serum ferritin <100 mcg/L or transferrin saturation <20%
  • Consider erythropoiesis-stimulating agents (ESAs) when hemoglobin <10 g/dL 4

• Mineral and bone disorder management:

  • Monitor calcium, phosphorus, PTH, and vitamin D levels
  • Treat hyperphosphatemia, secondary hyperparathyroidism, and vitamin D deficiency 5

• Metabolic acidosis:

  • Consider oral bicarbonate supplementation for serum bicarbonate <22 mEq/L 5

Monitoring and Follow-up

• Frequency of monitoring based on risk category:

  • G1-G2 A1: Annual
  • G3a A1 or G1-G2 A2: 1-2 times per year
  • G4-G5 A1-A3 or Any GFR A3: 3-4 times per year 2

• Parameters to monitor:

  • eGFR and albuminuria
  • Blood pressure every 3-6 months
  • Electrolytes, especially potassium
  • Hemoglobin and iron studies
  • Calcium, phosphorus, PTH, and vitamin D 2, 5

Nephrology Referral

• Indications for referral:
  • eGFR <30 mL/min/1.73 m²
  • Albuminuria ≥300 mg/24 hours
  • Rapid decline in eGFR (>5 mL/min/1.73 m²/year)
  • Suspected glomerular disease
  • Resistant hypertension
  • Persistent electrolyte abnormalities 2, 5

Key Considerations and Pitfalls

• Early detection is crucial: CKD is often silent until advanced stages; screening high-risk individuals improves outcomes 1

• Medication safety: Adjust dosages of renally cleared medications and avoid nephrotoxins (NSAIDs, certain antibiotics) 2

• Comprehensive approach: Address all modifiable risk factors simultaneously rather than focusing on a single intervention 6

• Patient education: Engage patients in self-management through education about kidney health, diet, medications, and lifestyle modifications 1

• Avoid diagnostic delays: Don't attribute reduced eGFR solely to age; investigate for underlying causes 1

• Consider disease-specific therapies: Some glomerular and cystic kidney diseases benefit from targeted treatments 6