CKD Stage 3a
With a GFR of 54 mL/min/1.73 m² and creatinine of 1.14 mg/dL, this patient has Stage 3a chronic kidney disease (CKD). 1
CKD Staging Framework
The KDIGO 2024 guidelines define CKD stages based on estimated glomerular filtration rate (eGFR), with Stage 3 subdivided into two categories 1:
- Stage 3a: eGFR 45-59 mL/min/1.73 m²
- Stage 3b: eGFR 30-44 mL/min/1.73 m²
Your patient's eGFR of 54 mL/min/1.73 m² falls squarely within the Stage 3a range.
Important Context About the Creatinine Value
The creatinine of 1.14 mg/dL appears deceptively "normal" by traditional laboratory reference ranges, but this is a common pitfall in CKD diagnosis. Research demonstrates that 80.6% of older adults with Stage 3 CKD have creatinine values ≤1.5 mg/dL, and 38.6% have values ≤1.2 mg/dL 2. This is why eGFR calculation is essential—serum creatinine alone significantly underestimates CKD prevalence, particularly in older adults, women, and those with lower muscle mass 2, 3.
Clinical Implications of Stage 3a CKD
At this stage, the patient requires:
- Albuminuria assessment (urine albumin-to-creatinine ratio) to complete CKD staging and guide treatment decisions 1
- Monitoring every 2-4 weeks if starting renin-angiotensin system inhibitors (RASi), checking blood pressure, serum creatinine, and potassium 1
- Consideration for SGLT2 inhibitor therapy if albuminuria ≥200 mg/g, heart failure, or type 2 diabetes is present (eGFR ≥20 required for initiation) 1
Confirmatory Testing Consideration
For patients with eGFR 45-59 mL/min/1.73 m² without albuminuria or other markers of kidney damage, the 2013 KDIGO guidelines suggest measuring cystatin C to confirm the CKD diagnosis 4. This is particularly relevant because approximately one-third of patients in this eGFR range may have normal cystatin C-based eGFR, potentially avoiding the label of CKD and its associated implications 4.