eGFR Calculation for 39-Year-Old Male with Creatinine 100.38 µmol/L
Using the MDRD equation, the estimated glomerular filtration rate (eGFR) for this patient is approximately 85 mL/min/1.73 m², indicating normal kidney function.
Calculation Method
The MDRD equation is the most widely validated and recommended formula for estimating GFR in adults 1, 2. For this calculation:
MDRD Formula:
- eGFR (mL/min/1.73 m²) = 175 × (serum creatinine in mmol/L × 0.0113)^-1.154 × age^-0.203 × (0.742 if female) × (1.212 if Black) 1
Step-by-step calculation:
- Convert creatinine: 100.38 µmol/L ÷ 88.4 = 1.14 mg/dL 2
- Apply MDRD: 175 × (1.14)^-1.154 × (39)^-0.203 × 1.0
- Result: eGFR ≈ 85 mL/min/1.73 m²
Clinical Interpretation
- This eGFR of 85 mL/min/1.73 m² is well above the threshold of 60 mL/min/1.73 m² that defines chronic kidney disease 1
- Normal GFR for men is approximately 130 mL/min/1.73 m² with a mean decline of 0.75 mL/min/year starting in the third or fourth decade 2
- An eGFR ≥60 mL/min/1.73 m² does not meet criteria for CKD in the absence of other kidney damage markers 1, 2
- No medication dose adjustments are required, as these are only necessary when eGFR falls below 60 mL/min/1.73 m² 2
Important Clinical Caveats
- Never use serum creatinine alone to assess kidney function, as it is affected by muscle mass, age, sex, dietary protein intake, creatinine generation, and tubular secretion independent of GFR 2
- The MDRD equation assumes steady-state conditions and may be less accurate in patients with extremes of muscle mass, obesity, recent exercise, infection, fever, or marked hyperglycemia 1, 2
- This calculation assumes the creatinine was measured using a standardized enzymatic method; if the older Jaffé method was used, results may be slightly less accurate 1, 2
- For this young, healthy male with normal kidney function, no specific kidney-related follow-up is indicated based on this eGFR alone 3