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Urinary citrate excretion in healthy children depends on age and gender

Jan K Kirejczyk1, Tadeusz Porowski, Jerzy Konstantynowicz

  • 1Department of Pediatric Surgery, Medical University of Bialystok, Bialystok, Poland.

Pediatric Nephrology (Berlin, Germany)
|April 4, 2014
PubMed

Insights

Urinary citrate excretion in children shows distinct sex differences at puberty, with girls excreting more citrate. Establishing reference values is crucial for assessing hypocitraturia, a risk factor for kidney stones.

Area of Science:

  • Pediatric Nephrology
  • Urology
  • Metabolic Disorders

Background:

  • Hypocitraturia is a significant risk factor for calcium nephrolithiasis.
  • A standardized reference database for pediatric urinary citrate excretion is lacking.
  • Understanding citrate excretion patterns in children is essential for stone prevention.

Purpose of the Study:

  • To establish 24-hour urinary citrate excretion levels in a large pediatric cohort.
  • To identify optimal units for expressing urinary citrate in children.
  • To investigate age- and sex-related variations in urinary citrate.

Main Methods:

  • Analyzed 24-hour urine samples from 2,334 healthy children (ages 2-18).
  • Assessed urinary citrate using an enzymatic method.
  • Expressed citrate levels in various units: absolute values, concentration, citrate/creatinine ratio, per kilogram body weight, per 1.73 m2 body surface area, and calcium/citrate index.

Main Results:

  • Citrate excretion increased with age until puberty, with girls showing significantly higher levels than boys post-puberty.
  • Urinary citrate, adjusted for creatinine and body weight, decreased with age in both sexes.
  • Recommended lower cut-off values for urinary citrate: 180 mg/1.73 m2/24 h for males and 250 mg/1.73 m2/24 h for females.

Conclusions:

  • Significant sex-dependent differences in urinary citrate emerge at puberty.
  • These findings highlight the need for sex-specific reference ranges for pediatric urinary citrate.
  • Further research is needed to determine if these differences impact urolithiasis risk in children.
Abstract

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