Estimated Glomerular Filtration Rate (eGFR)
eGFR estimates the cumulative volume of fluid filtered through renal glomerular capillaries per unit time, standardized to body surface area using the 2021 CKD-EPI equation.
Standard vs. Optimal Reference RangesmL/min/1.73m²
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Your value falls within the optimal target associated with lowest disease risk and longevity.
> 60 mL/min/1.73m² (Normal: >= 90)
General reference distribution across unselected commercial populations.
> 90 mL/min/1.73m²
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Calculated from serum creatinine and/or cystatin C adjusted for age and biological sex. Reflects functional nephron mass, renal plasma flow, and glomerular capillary hydrostatic pressure.
Differential Diagnosis
Elevated Levels (eGFR High)
- •Glomerular hyperfiltration (early Diabetic Nephropathy)
- •High protein loading and pregnancy
Low Levels (eGFR Low)
- •Chronic Kidney Disease Stages 2 through 5
- •Acute tubular necrosis or prerenal azotemia
- •Dehydration or systemic hypotension
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Maintain standard hydration status prior to venipuncture; acute hypovolemia or hemoconcentration artificially elevates concentrations. Avoid heavy resistance training and high-protein meals (especially cooked red meat) for 24 hours prior if testing serum creatinine. Ensure tourniquet time does not exceed 60 seconds to avoid pseudohyperkalemia or hemoconcentration of electrolyte fractions.
Reflexive Testing Protocol:
- Simultaneous Serum Cystatin C testing to calculate composite CKD-EPI Creatinine-Cystatin C eGFR equation
- Spot Urine Albumin-to-Creatinine Ratio (uACR) to detect subclinical glomerular endothelial leak
- Renal duplex ultrasonography to assess bilateral kidney dimensions, cortical echogenicity, and resistive index
- Fractional Excretion of Sodium (FENa) and Urea (FEUrea) to differentiate prerenal azotemia from intrinsic acute kidney injury
- Serum and urine protein electrophoresis (SPEP/UPEP) if tubular injury or monoclonal gammopathy is suspected
Clinical Citations & Primary Literature (1)
- [1]New Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race - New England Journal of Medicine (2021). PMID: 34554658
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Estimated Glomerular Filtration Rate (eGFR) into overall healthspan optimization.