eGFR of 119.77: Interpretation and Clinical Significance
An eGFR of 119.77 mL/min/1.73 m² indicates normal to hyperfiltration kidney function, but paradoxically may be associated with increased mortality risk and warrants evaluation for underlying conditions, particularly if accompanied by proteinuria. 1
Understanding This eGFR Value
Your eGFR of 119.77 mL/min/1.73 m² falls well above the normal range threshold of 90 mL/min/1.73 m², representing what appears to be excellent kidney filtration capacity. 2 However, this seemingly optimal value requires careful clinical interpretation rather than automatic reassurance.
The Hyperfiltration Paradox
Elevated eGFR values (≥105 mL/min/1.73 m²) are associated with a 3.7-fold increased risk of all-cause mortality compared to the optimal reference range of 60-74.9 mL/min/1.73 m². 1 This counterintuitive finding suggests that very high eGFR may reflect:
- Hyperfiltration states such as early diabetic nephropathy, where the kidneys are working excessively hard before eventual decline 1
- Measurement limitations at low serum creatinine levels, where eGFR formulas may overestimate true kidney function 1, 3
- Underlying systemic conditions driving increased renal blood flow 1
Critical Next Steps
1. Check for Proteinuria Immediately
The presence and severity of proteinuria dramatically amplifies risk at all eGFR levels, including elevated values. 1 Obtain a urine albumin-to-creatinine ratio, as proteinuria with hyperfiltration represents a particularly high-risk combination for adverse outcomes. 2, 1
2. Evaluate for Diabetes
If you have diabetes or prediabetes, this elevated eGFR may represent early hyperfiltration—a precursor to diabetic kidney disease. 1 In this context:
- Optimize glycemic control immediately 2
- Consider SGLT2 inhibitor therapy if eGFR remains ≥30 mL/min/1.73 m² and diabetes is present 2
- Initiate ACE inhibitor or ARB if proteinuria develops (>30 mg/g creatinine) 2
3. Assess Body Surface Area Adjustment
If your body surface area differs significantly from 1.73 m², the eGFR should be adjusted for accurate medication dosing decisions. 4 Very large or small individuals may have misleadingly high or low eGFR values when using the standardized 1.73 m² normalization. 4
4. Consider Measurement Accuracy
eGFR equations have inherent limitations, particularly at extremes of kidney function. 3 Your value may not accurately reflect true GFR due to:
- Low muscle mass leading to low creatinine and falsely elevated eGFR 3, 5
- Recent dietary protein intake or hydration status affecting creatinine levels 3
- Equation limitations at low serum creatinine concentrations 1, 3
Monitoring Strategy
Establish baseline monitoring with annual eGFR and urine albumin-to-creatinine ratio measurements. 2 This creates a trajectory to detect:
- Progression from hyperfiltration to declining function 2
- Development of proteinuria 2
- Changes requiring intervention 2
Common Pitfalls to Avoid
- Don't assume high eGFR always means healthy kidneys—it may signal early disease or measurement artifact 1, 3
- Don't ignore this value if proteinuria is present—the combination substantially increases cardiovascular and mortality risk 1
- Don't use this eGFR for medication dosing without BSA adjustment if you are significantly larger or smaller than average 4
- Don't rely on serum creatinine alone—it may appear normal (<1.2 mg/dL in women, <1.4 mg/dL in men) even with significant kidney dysfunction 6
When to Seek Specialist Evaluation
Referral to nephrology should be considered if: 2