How often should I monitor renal function in patients with established diabetic nephropathy?

For patients with established diabetic nephropathy, the frequency of renal function monitoring, including estimated Glomerular Filtration Rate (eGFR) and albumin:creatinine ratio (ACR), should be agreed upon with the individual ¹,²,⁵.

The minimum frequency of monitoring checks per year is guided by the patient's eGFR and ACR categories, as follows ¹,²:

• eGFR Category G1 (90 ml/min/1.73 m² or over):
  • ACR A1 (less than 3 mg/mmol): 0 to 1 check per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 1 check per year ¹,².
  • ACR A3 (over 30 mg/mmol): 1 or more checks per year ¹,².
• eGFR Category G2 (60 to 89 ml/min/1.73 m²):
  • ACR A1 (less than 3 mg/mmol): 0 to 1 check per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 1 check per year ¹,².
  • ACR A3 (over 30 mg/mmol): 1 or more checks per year ¹,².
• eGFR Category G3a (45 to 59 ml/min/1.73 m²):
  • ACR A1 (less than 3 mg/mmol): 1 check per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 1 check per year ¹,².
  • ACR A3 (over 30 mg/mmol): 2 checks per year ¹,².
• eGFR Category G3b (30 to 44 ml/min/1.73 m²):
  • ACR A1 (less than 3 mg/mmol): 1 to 2 checks per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 2 checks per year ¹,².
  • ACR A3 (over 30 mg/mmol): 2 or more checks per year ¹,².
• eGFR Category G4 (15 to 29 ml/min/1.73 m²):
  • ACR A1 (less than 3 mg/mmol): 2 checks per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 2 checks per year ¹,².
  • ACR A3 (over 30 mg/mmol): 3 checks per year ¹,².
• eGFR Category G5 (under 15 ml/min/1.73 m²):
  • ACR A1 (less than 3 mg/mmol): 4 checks per year ¹,².
  • ACR A2 (3 to 30 mg/mmol): 4 or more checks per year ¹,².
  • ACR A3 (over 30 mg/mmol): 4 or more checks per year ¹,².

It is important to tailor the monitoring frequency based on several factors, including the underlying cause of CKD (such as diabetic nephropathy), the rate of decline in eGFR or increase in ACR, other risk factors, and changes to their treatment ¹,². More frequent monitoring may be necessary for individuals with changing clinical status, intercurrent illness (e.g., acute kidney injury), or when receiving therapeutic interventions ¹,². Regular monitoring of renal function is arranged for people with chronic diseases, including diabetes, with the frequency based on the person's individual risk, clinical context, and clinical judgement ³,⁴. For the initial detection and ongoing monitoring of proteinuria in adults with diabetes (type 1 or type 2), urine ACR should be measured ⁵.