Can a patient not have Chronic Kidney Disease (CKD) without impaired renal function?

Why CKD Requires Evidence of Kidney Damage When GFR is Normal or Mildly Reduced

A patient cannot be diagnosed with CKD based solely on a normal or mildly reduced GFR (≥60 mL/min/1.73 m²) without additional evidence of kidney damage persisting for at least 3 months. 1

CKD Diagnostic Criteria

CKD requires both a duration criterion AND either functional or structural abnormalities:

Duration Requirement

• Abnormalities must persist for ≥3 months to distinguish CKD from acute kidney disease (AKD) or acute kidney injury (AKI) 1

Functional or Structural Criteria (at least one must be present)

Option 1: Reduced GFR alone is sufficient

• GFR <60 mL/min/1.73 m² for ≥3 months, with or without other evidence of kidney damage 1
• This threshold is diagnostic because complications of CKD begin to rise significantly below this level 2

Option 2: Evidence of kidney damage WITH normal/mildly reduced GFR

• When GFR is ≥60 mL/min/1.73 m², you must have additional markers of kidney damage 1, 3:
  • Albuminuria (UACR ≥30 mg/g or ≥3 mg/mmol) 1, 4
  • Hematuria or pyuria 1
  • Urinary tract obstruction 1
  • Pathological findings on kidney biopsy 1
  • Radiological evidence of kidney disease (abnormal ultrasound, etc.) 1
  • Other structural or functional abnormalities 1

Why This Two-Pronged Approach Matters

The critical distinction: A decreased GFR <60 mL/min/1.73 m² is **by itself diagnostic** of CKD when persisting >3 months, but an eGFR ≥60 mL/min/1.73 m² requires an additional criterion to diagnose CKD 3, 5

Common Clinical Pitfall

Many clinicians mistakenly diagnose CKD in patients with:

• GFR ≥60 mL/min/1.73 m²
• No albuminuria
• No other markers of kidney damage

This is incorrect and can have serious consequences including insurance problems and inappropriate labeling 1, 3

Stages 1 and 2 CKD Specifically Require Damage Markers

• Stage 1: GFR ≥90 mL/min/1.73 m² with evidence of kidney damage 2
• Stage 2: GFR 60-89 mL/min/1.73 m² with evidence of kidney damage 2
• Without damage markers, these patients do not have CKD despite the GFR values 3

Clinical Examples

Has CKD:

• Patient with GFR 55 mL/min/1.73 m² for 4 months (no other criteria needed) 1
• Patient with GFR 75 mL/min/1.73 m² with persistent albuminuria (UACR 50 mg/g) for 4 months 4, 2
• Patient with GFR 95 mL/min/1.73 m² with biopsy-proven glomerulonephritis for 4 months 1

Does NOT have CKD:

• Patient with GFR 70 mL/min/1.73 m² with normal urinalysis and no other abnormalities 3
• Patient with single elevated UACR that doesn't persist on repeat testing 1, 6
• Patient with GFR 85 mL/min/1.73 m² with no proteinuria, hematuria, or imaging abnormalities 3

Verification Steps Before Diagnosing CKD

When GFR is ≥60 mL/min/1.73 m²:

1. Confirm persistence: Repeat measurements over ≥3 months 1, 6
2. Document kidney damage: Obtain UACR, urinalysis, and consider renal imaging 4, 6
3. Rule out transient causes: Exclude fever, exercise, body position effects on albuminuria 1
4. Verify with repeat testing: 37-59% of single abnormal albuminuria measurements may not persist 1

The rationale for requiring evidence of kidney damage at higher GFR levels is that GFR alone at these levels does not predict adverse outcomes (progression to kidney failure, cardiovascular disease, mortality) without accompanying structural or functional abnormalities 3, 5