40 year male serum creatinine 1.29 mg/dl serum cystatin c 1.13mg/L calculate EGFR
Reading File
Finding Sources
Running Command
Here are the calculated eGFR values for this patient:
eGFR Results — 40-year-old Male
| Parameter | Value |
|---|---|
| Serum Creatinine | 1.29 mg/dL |
| Serum Cystatin C | 1.13 mg/L |
| Age / Sex | 40 years / Male |
eGFR by CKD-EPI Equations
| Equation | eGFR (mL/min/1.73 m²) | CKD Stage |
|---|---|---|
| CKD-EPI Creatinine 2021 (race-free) | 71.9 | G2 — Mildly decreased |
| CKD-EPI Cystatin C 2012 | 71.9 | G2 — Mildly decreased |
| CKD-EPI Creatinine + Cystatin C 2021 (combined) | 66.2 | G2 — Mildly decreased |
Interpretation
- All three equations agree on CKD Stage G2 (eGFR 60–89 mL/min/1.73 m²), indicating mildly decreased kidney function.
- The combined Cr + CysC equation is the most accurate of the three; its result of 66.2 mL/min/1.73 m² is the best single estimate.
- The close concordance between creatinine-based and cystatin C-based eGFR (both ~72) reduces concern for confounding by muscle mass or diet.
- CKD Stage G2 alone is not diagnostic of CKD — diagnosis requires evidence of kidney damage (albuminuria, imaging abnormality, etc.) persisting > 3 months.
Equations Used
- CKD-EPI Cr 2021 (male): 142 × min(Scr/0.9, 1)^−0.302 × max(Scr/0.9, 1)^−1.200 × 0.9938^age
- CKD-EPI CysC 2012 (male): 133 × min(Scys/0.8, 1)^−0.499 × max(Scys/0.8, 1)^−1.328 × 0.9961^age
- CKD-EPI Cr+CysC 2021 (male): 135 × min(Scr/0.9, 1)^−0.144 × max(Scr/0.9, 1)^−0.544 × min(Scys/0.8, 1)^−0.323 × max(Scys/0.8, 1)^−0.778 × 0.9938^age
40 year male serum creatinine 1.29 mg/dl serum cystatin c 1.13mg/L calculate EGFR
Running Command
eGFR Calculation — 40-year-old Male
| Input | Value |
|---|---|
| Age / Sex | 40 years / Male |
| Serum Creatinine | 1.29 mg/dL |
| Serum Cystatin C | 1.13 mg/L |
Results
| Equation | eGFR (mL/min/1.73 m²) | CKD Stage |
|---|---|---|
| CKD-EPI Creatinine 2021 (race-free) | 71.9 | G2 — Mildly decreased |
| CKD-EPI Cystatin C 2012 | 71.9 | G2 — Mildly decreased |
| CKD-EPI Cr + CysC 2021 (combined) | 66.2 | G2 — Mildly decreased |
Step-by-Step Workings
1. CKD-EPI Creatinine 2021 (race-free) — Male
eGFR = 142 × (Scr/0.9)^−1.200 × 0.9938^age (when Scr/κ > 1)
- Scr/κ = 1.29 / 0.9 = 1.433 (>1, so exponent = −1.200)
- = 142 × (1.433)^−1.200 × 0.9938^40
- = 142 × 0.6489 × 0.7798 = 71.9
2. CKD-EPI Cystatin C 2012 — Male
eGFR = 133 × min(Scys/0.8,1)^−0.499 × max(Scys/0.8,1)^−1.328 × 0.9961^age
- Scys/κ = 1.13 / 0.8 = 1.4125 (>1)
- = 133 × 1.000 × (1.4125)^−1.328 × 0.9961^40
- = 133 × 1.000 × 0.6321 × 0.8553 = 71.9
3. CKD-EPI Cr + CysC 2021 Combined — Male (most accurate)
eGFR = 135 × min(Scr/0.9,1)^−0.144 × max(Scr/0.9,1)^−0.544 × min(Scys/0.8,1)^−0.323 × max(Scys/0.8,1)^−0.778 × 0.9938^age
- Cr part = 1.000 × (1.433)^−0.544 = 0.8221
- CysC part = 1.000 × (1.4125)^−0.778 = 0.7644
- Age factor = 0.9938^40 = 0.7798
- = 135 × 0.8221 × 0.7644 × 0.7798 = 66.2
Clinical Interpretation
- All three equations consistently place this patient in CKD Stage G2 (eGFR 60–89).
- The combined Cr+CysC equation is the most accurate single estimate — use 66.2 mL/min/1.73 m² as the best value.
- The excellent concordance between creatinine-based and cystatin C-based eGFR (~72 each) rules out confounders like reduced muscle mass or high-protein diet inflating creatinine-based estimates.
- CKD G2 alone does not diagnose CKD. Kidney damage markers (albuminuria ≥ A2, imaging abnormality, etc.) must also be present and persist >3 months to confirm CKD (KDIGO 2024 guidelines).
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