Kidney function estimating equations in patients with chronic kidney disease.
Int J Clin Pract. 2011 Apr;65(4):458-64
Authors: Hojs R, Bevc S, Ekart R, Gorenjak M, Puklavec L
Background:? The current guidelines emphasise the need to assess kidney function using predictive equations rather than just serum creatinine. The present study compares serum cystatin C-based equations and serum creatinine-based equations in patients with chronic kidney disease (CKD). Methods:? Seven hundred and sixty-four adult patients with CKD were enrolled. In each patient serum creatinine and serum cystatin C were determined. Their glomerular filtration rate (GFR) was estimated using three serum creatinine-based equations [Cockcroft-Gault (C&G), modification of diet in renal disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI)] and two serum cystatin C-based equations [our own cystatin C formula (GFR?=?90.63?×?cystatin C(-1.192) ) and simple cystatin C formula (GFR?=?100/cystatin C)]. The GFR was measured using (51) CrEDTA clearance. Results:? Statistically significant correlation between (51) CrEDTA clearance with serum creatinine, serum cystatin C and all observed formulas was found. The receiver operating characteristic curve analysis (cut-off for GFR 60?ml/min/1.73?m(2) ) showed that serum cystatin C and both cystatin C formulas had a higher diagnostic accuracy than C&G formula. Bland and Altman analysis for the same cut-off value showed that all formulas except simple cystatin C formula underestimated measured GFR. The accuracy within 30% of estimated (51) CrEDTA clearance values differs according to stages of CKD. Analysis of ability to correctly predict patient's GFR below or above 60?ml/min/1.73?m(2) showed statistically significant higher ability for both cystatin C formulas compared to MDRD formula. Conclusion:? Our results indicate that serum cystatin C-based equations are reliable markers of GFR comparable with creatinine-based formulas.
PMID: 21401834 [PubMed - in process]