What stage of chronic kidney disease (CKD) is a patient with a creatinine level of 1.52 and a glomerular filtration rate (GFR) of 61?

CKD Stage 3a: Moderate Kidney Disease

A GFR of 61 mL/min/1.73 m² with a creatinine of 1.52 mg/dL indicates Stage 3a chronic kidney disease (CKD), defined as moderately decreased kidney function with GFR 45-59 mL/min/1.73 m².

CKD Staging Classification

According to the K/DOQI and KDIGO guidelines, CKD is classified into five stages based on GFR levels 1:

• Stage 1: GFR ≥90 mL/min/1.73 m² (with evidence of kidney damage)
• Stage 2: GFR 60-89 mL/min/1.73 m² (with evidence of kidney damage)
• Stage 3a: GFR 45-59 mL/min/1.73 m² 2
• Stage 3b: GFR 30-44 mL/min/1.73 m² 2
• Stage 4: GFR 15-29 mL/min/1.73 m² 2
• Stage 5: GFR <15 mL/min/1.73 m² or dialysis 2

With a GFR of 61 mL/min/1.73 m², this patient falls into Stage 3a CKD, representing moderate kidney dysfunction. 1

Critical Diagnostic Clarification

A crucial point: after GFR decreases to less than 60 mL/min/1.73 m², the patient is classified as having CKD regardless of evidence of kidney damage 1. However, at GFR 60-89 mL/min/1.73 m² (Stage 2), evidence of kidney damage such as proteinuria or structural abnormalities must be present to diagnose CKD 1.

Since this patient's GFR is 61 mL/min/1.73 m², they are technically just above the Stage 3 threshold. If this measurement is confirmed on repeat testing and persists for ≥3 months, this represents Stage 2 CKD only if markers of kidney damage (albuminuria, proteinuria, imaging abnormalities) are present 1.

Essential Next Steps

Confirm the Diagnosis

Measure urinary albumin-to-creatinine ratio (UACR) immediately on a random spot urine sample 3. This is essential because:

• GFR 60-89 mL/min/1.73 m² requires evidence of kidney damage to confirm CKD Stage 2 1
• UACR provides independent prognostic information for cardiovascular events and CKD progression 3
• Albuminuria categories determine treatment intensity: A1 (<30 mg/g), A2 (30-299 mg/g), A3 (≥300 mg/g) 1, 2

Verify Chronicity

Repeat serum creatinine and eGFR within 2-4 weeks to distinguish CKD from acute kidney injury, as CKD requires kidney dysfunction persisting >3 months 3. Review any historical creatinine or eGFR measurements to establish chronicity 3.

Calculate Accurate eGFR

Do not rely on serum creatinine alone, as it results in gross and unpredictable overestimates of kidney function 1. Use the CKD-EPI equation (preferred) or MDRD equation, which account for age, sex, race, and body size 1, 4, 5. The creatinine-cystatin C combined equation provides the best accuracy (P30 = 94.9%) but is not necessary for routine monitoring 5, 6.

Clinical Action Plan for Stage 3a CKD

Once confirmed, the following interventions are indicated 1:

Blood Pressure Management

• Target blood pressure <130/80 mmHg 3
• Initiate ACE inhibitor or ARB if UACR 30-299 mg/g with hypertension 3
• Strongly recommend ACE inhibitor or ARB if UACR ≥300 mg/g regardless of blood pressure 3

Cardiovascular Risk Reduction

• Initiate statin therapy, as CKD patients have 5-10 times higher cardiovascular mortality risk 3

Screen for CKD Complications

At Stage 3a, begin screening for 1, 3:

• Anemia (hemoglobin)
• Metabolic acidosis (serum bicarbonate)
• Mineral bone disease (calcium, phosphate, PTH, vitamin D)
• Hyperkalemia (potassium monitoring)

Monitoring Frequency

• If UACR <30 mg/g: Monitor eGFR and UACR annually 3
• If UACR 30-300 mg/g: Monitor 2 times per year 3
• If UACR >300 mg/g: Monitor 3-4 times per year and refer to nephrology 3

Common Pitfalls to Avoid

Do not use serum creatinine alone to assess kidney function, as patients can maintain seemingly normal creatinine levels (e.g., 1.3 mg/dL) despite declining GFR 1. In this case, a creatinine of 1.52 mg/dL with GFR 61 mL/min/1.73 m² demonstrates this principle—the creatinine appears only mildly elevated, but kidney function is already moderately reduced.

Do not skip albuminuria testing, as eGFR and UACR provide independent prognostic information 3. A patient with GFR 61 mL/min/1.73 m² and UACR >300 mg/g has dramatically different cardiovascular and progression risk compared to one with UACR <30 mg/g 1, 2.

Do not discontinue ACE inhibitors or ARBs for minor increases in serum creatinine (<30%) in the absence of volume depletion 3.