Chronic Kidney Disease Management

GFR Classification and Referral Guidelines

• The GFR is classified into categories, including G1 (normal or high), G2 (mildly decreased), G3a (mildly to moderately decreased), G3b (moderately to severely decreased), G4 (severely decreased), and G5 (kidney failure), with corresponding ranges of ≥90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m², respectively, as supported by the KDIGO guidelines 1, 2, 3, 4, 5
• For patients with eGFR <30 mL/min/1.73 m², referral for evaluation for renal replacement therapy is warranted, according to the Diabetes/Metabolism Research and Reviews and supported by the American Diabetes Association 1, 6
• The following GFR categories are used to classify CKD:

1, 3, 4, 5

GFR Decline and CKD Progression

• Rapid GFR decline (>3 mL/min/1.73 m² per year) is a high-risk phenotype that predicts progression to impaired kidney function, as supported by the KDIGO guidelines 1, 2, 7
• 20-40% of patients with diabetes develop diabetic kidney disease, which typically develops after 10 years in type 1 diabetes but may be present at diagnosis of type 2 diabetes, and is a significant concern as CKD markedly increases cardiovascular risk in people with diabetes, according to the American Diabetes Association 6, 8
• Annual screening for urinary albumin and eGFR assessment is recommended for all patients with type 2 diabetes, with more frequent monitoring for those with eGFR 30-60 mL/min/1.73 m² and/or urinary albumin ≥300 mg/g creatinine, as supported by the American Diabetes Association and the KDIGO guidelines 8, 6
• Assessment of albuminuria is recommended to evaluate for early kidney damage, according to the Diabetes Care guidelines and supported by the KDIGO guidelines 6, 8
• Presence of albuminuria (>30 mg/g creatinine) alongside reduced eGFR significantly increases risk for progression, as supported by the American Diabetes Association 8

CKD Management and Treatment

• For patients aged ≥65 years with diabetes, the European Society of Cardiology (ESC) and European Society of Hypertension (ESH) guidelines support a blood pressure target between 130/70 and 139/79 mm Hg, recognizing the physiological changes in older adults 9
• For patients with diabetes and CKD, optimize glucose control, blood pressure, and consider SGLT2 inhibitors to reduce CKD progression, as supported by the American Diabetes Association and the KDIGO guidelines 8, 6
• Normal GFR varies by age, sex, and body size, with reference ranges for young adult males being 120-130 mL/min/1.73 m² and for young adult females being 90-120 mL/min/1.73 m², and naturally declines with age at an average rate of approximately 0.75-0.8 mL/min/year after age 40, as supported by the KDIGO guidelines 10, 5
• The MDRD Study Equation is more accurate for GFR <90 mL/min/1.73 m², while the CKD-EPI Equation is more accurate for GFR >60 mL/min/1.73 m² and better predicts adverse outcomes, as supported by the KDIGO guidelines 10, 5
• Serum creatinine alone is an unreliable indicator of kidney function, as GFR must decline to approximately half the normal level before serum creatinine rises above the upper limit of normal, as supported by the KDIGO guidelines 5, 11