What does an Epidermal Growth Factor Receptor (EGFR) measurement greater than 60 indicate?

Understanding eGFR >60: Normal or Mildly Decreased Kidney Function

An estimated Glomerular Filtration Rate (eGFR) greater than 60 mL/min/1.73 m² indicates normal or mildly decreased kidney function and does not meet the threshold for chronic kidney disease (CKD) unless other markers of kidney damage are present. 1

What eGFR Measures and Classification

eGFR is a key measure of kidney function that estimates how well your kidneys filter waste from your blood. According to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, kidney function is classified as follows:

• eGFR ≥90 mL/min/1.73 m²: Normal kidney function (Stage G1 if other markers of kidney damage exist)
• eGFR 60-89 mL/min/1.73 m²: Mildly decreased function (Stage G2 if other markers of kidney damage exist)
• eGFR <60 mL/min/1.73 m²: Moderately to severely decreased function (Stages G3a-G5)

Clinical Significance of eGFR >60

When a patient has an eGFR >60 mL/min/1.73 m²:

• Their kidneys are filtering waste at a normal or near-normal rate
• They do not meet the eGFR criterion for CKD diagnosis
• CKD diagnosis would require additional markers of kidney damage such as:
  • Albuminuria (protein in urine)
  • Abnormalities in imaging tests
  • Pathological abnormalities
  • Structural abnormalities

Important Considerations

Albuminuria Assessment

• Assessment of albuminuria is equally important for complete kidney health evaluation, as eGFR alone does not tell the complete story 1
• KDIGO guidelines recommend using urine albumin-to-creatinine ratio (ACR) as the preferred initial test for proteinuria 2

Factors That Can Affect eGFR Readings

• Hydration status
• Medication use
• Recent exercise
• Infection or fever
• Congestive heart failure
• Marked hyperglycemia
• Menstruation
• Hypertension 1

Age-Related Changes

• eGFR naturally declines with age beginning in the third or fourth decade of life
• Typical decline is 1-2 mL/min per year after age 60 1

Monitoring Recommendations

For individuals with eGFR >60 mL/min/1.73 m²:

• Annual monitoring is generally sufficient if no other risk factors or markers of kidney damage are present
• Healthcare providers should check for albuminuria to complete the kidney health assessment 1
• If eGFR is between 45-59 mL/min/1.73 m² without markers of kidney damage, measuring cystatin C may be helpful to confirm CKD diagnosis 2

Maintaining Kidney Health

To preserve kidney function:

• Control blood pressure
• Manage diabetes if present
• Maintain a healthy weight
• Stay hydrated
• Avoid nephrotoxic medications when possible 1

Common Pitfalls to Avoid

1. Misinterpreting isolated eGFR values: A single eGFR reading may not be reliable; confirmation with repeat testing is often necessary
2. Overlooking albuminuria: Even with normal eGFR, the presence of albuminuria indicates kidney damage
3. Ignoring eGFR variability: eGFR can fluctuate based on various factors; trends over time are more meaningful than single measurements
4. Confusing eGFR with EGFR: eGFR (estimated Glomerular Filtration Rate) should not be confused with EGFR (Epidermal Growth Factor Receptor), which is a completely different entity related to cancer biology and targeted therapies

Remember that kidney function assessment requires consideration of both eGFR and albuminuria status for proper classification and management.