Published in:
01-01-2013 | Original Article
Detecting reduced renal function in children: comparison of GFR-models and serum markers
Published in: Pediatric Nephrology | Issue 1/2013
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Background
The aim of this study was to compare the ability of renal indicators [serum creatinine (SCr), cystatin C (SCysC)] and glomerular filtration rate (GFR)-models to discriminate normal and reduced renal function. As a single cut-off level will always lead to false classifications, we propose using two cut-off levels, dividing renal function into normal or reduced, with an intermediate “gray zone” of indeterminable results.
Methods
Glomerular filtration rate was measured by plasma clearance of 51Cr-EDTA (13.7–147.4 mL/min/1.73 m2) in 119 children (age range 2.3–14.9 years). Reduced renal function was defined as a GFR of <82 mL/min/1.73 m2. SCr, SCysC, age-normalized creatinine (SCr-ratio), and eight published GFR-models were compared for their ability to correctly classify renal function as normal or reduced. Cut-off levels were determined so as to give 99 % certainty outside the gray zone.
Results
The multivariable GFR-models by Schwartz et al. (J Am Soc Nephrol 2009; 20:629–637) and Zappitelli et al. (Am J Kidney Dis 2006; 48:221–230) and two models by Andersen et al. [Am J Kidney Dis 2012; 59(1):50–57: body cell mass (BCM)-model and Weight-model] performed significantly better than all other variables (P < 0.01), with the BCM-model performing the best (P < 0.05). The SCr-based Schwartz formula and SCr-ratio both performed better than SCr and SCysC.
Conclusions
Among the 119 children enrolled in this study and the renal indicators tested, the BCM-model had the best diagnostic performance in terms of screening for normal or reduced renal function, and the SCr-ratio was a superior diagnostic tool to both SCr and SCysC.