Risk of overestimation of kidney function using GFR-estimating equations in patients with low inulin clearance
Journal of Clinical Laboratory Analysis, 08/03/2012
Nakata J et al. – Although glomerular filtration rate GFR)–estimating equations are useful for estimating GFR accurately, they pose a risk of overestimation of kidney function in patients with decreased GFRor a poor physique.Methods
- Seventy–two Japanese patients were enrolled in this study.
- Cin was measured by the continuous infusion method.
- Serum creatinine (s–Cr), cystatin C, uric acid (UA), and hemoglobin (Hb) were measured.
- The Japanese formula of estimated GFR (eGFR) was as follows: eGFR (ml/min/1.73m2) = 194 × s–Cr–1.094 × Age–0.287 × 0.739 (if female).
- The endogenous creatinine clearance test was also performed.
- Levels of Cin were highly correlated with those of endogenous creatinine clearance (Ccr) (R2 = 0.7585) and eGFR (R2 = 0.5659).
- However, patients with lower Cin showed unexpectedly elevated levels of endogenous Ccr and eGFR.