Urea percentiles in children with chronic renal failure. Data from the ItalKid project

Giovanni Montini, Lorena Pisanello, Sara Testa, Valeria Daccò, Luca Dello Strologo, Emanuela Taioli, Graziella Zacchello, Luigi Avolio, Antonio Ciofani, Aldo Claris-Appiani, Gianluigi Ardissino

Research output: Contribution to journalArticlepeer-review


In chronic renal failure high serum urea levels (sUrea) are correlated with the onset of uremic symptoms. Urea has generally been considered relatively non-toxic, functioning more as a surrogate for other toxic solutes; however, it has been recently reported that it can contribute to uremic toxicity. Clinically sUrea are often difficult to interpret because of the wide range of kidney functions. To obtain a practical and easily accessible tool to evaluate sUrea, we have produced percentile curves for different ranges of chronic renal failure, defined with creatinine clearance (CCr) obtained with the Schwartz formula. Data were obtained from the Italian Pediatric Registry of Chronic Renal Failure (ItalKid); its inclusion criteria are: (1) CCr2, (2) age Cr and sUrea) were available for the construction of the percentile curves. A median of 258 (range 99-380) observations was obtained for each of the eight different categories of CCr (intervals of 10 ml/min per 1.73 m2). The 10th, 25th, 50th, 75th, and 90th percentiles were calculated and a graph was produced. Patients with the highest urea percentiles showed significantly higher plasma levels of phosphorus and parathyroid hormone and significantly lower hemoglobin concentrations and bicarbonate levels. Our percentile curves may help to identify subjects with inappropriate sUrea for a given CCr.

Original languageEnglish
Pages (from-to)261-265
Number of pages5
JournalPediatric Nephrology
Issue number3
Publication statusPublished - Mar 1 2003


  • Chronic renal failure
  • Protein intake
  • Serum urea concentrations
  • Urea percentiles

ASJC Scopus subject areas

  • Nephrology
  • Pediatrics, Perinatology, and Child Health


Dive into the research topics of 'Urea percentiles in children with chronic renal failure. Data from the ItalKid project'. Together they form a unique fingerprint.

Cite this