title: An association between kidney stone composition and urinary metabolic disturbances in children.
abstract: OBJECTIVE
  To determine kidney stone composition in children and to correlate stone fractions with urinary pH and metabolic urinary risk factors.
  
  
  METHODS
  We studied 135 pediatric patients with upper urinary tract lithiasis in whom excreted or extracted stones were available for analyses. Composition of stones was analyzed. A 24-hour urine assessment included volume, pH and daily excretions of calcium, oxalate, uric acid, cystine, creatinine, phosphate, magnesium and citrate.
  
  
  RESULTS
  Calcium oxalate was the major component of 73% stones, followed by struvite (13%) and calcium phosphate (9%). Uric acid was present in almost half of stones, but in rudimentary amounts. The calcium oxalate content in calculi showed a strong relationship with calciuria, and moderate association with oxaluria, magnesuria and acidification of urine. The percent content of struvite presented reverse and lower correlations with regard to the above parameters. Calcium phosphate stone proportion had low associations with urinary risk factors.
  
  
  CONCLUSIONS
  Calciuria, oxaluria, magnesuria and low urine pH exerted the biggest influence on calcium oxalate content in pediatric renal stones. Relationships of urinary risk factors with calculi calcium phosphate content were of unclear significance. Urinary citrate excretion did not significantly correlate with kidney stone composition in children.
authors: Department of Pediatric Surgery, Medical University of Bialystok, Poland. Electronic address: kkirejczyk@wp.pl.
authors: Jan K
authors: JK
authors: Kirejczyk
authors: Department of Pediatric Nephrology, Medical University of Bialystok, Poland.
authors: Tadeusz
authors: T
authors: Porowski
authors: Department of Pediatric Nephrology, Medical University of Bialystok, Poland.
authors: Renata
authors: R
authors: Filonowicz
authors: Department of Pediatric Nephrology, Medical University of Bialystok, Poland.
authors: Anna
authors: A
authors: Kazberuk
authors: Department of Pediatric Nephrology, Medical University of Bialystok, Poland.
authors: Marta
authors: M
authors: Stefanowicz
authors: Department of Pediatric Nephrology, Medical University of Bialystok, Poland.
authors: Anna
authors: A
authors: Wasilewska
authors: Department of Pediatric Surgery, Medical University of Bialystok, Poland.
authors: Wojciech
authors: W
authors: Debek
mesh_terms: D000293:Adolescent; D002129:Calcium Oxalate / Q000032:analysis; D002130:Calcium Phosphates / Q000032:analysis; D002648:Child; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007669:Kidney Calculi / Q000737:chemistry*; D017616:Magnesium Compounds / Q000032:analysis; D008297:Male; D010710:Phosphates / Q000032:analysis; D012307:Risk Factors; D000069877:Struvite
chemical_list: D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; D002129:Calcium Oxalate; C020243:calcium phosphate; D000069877:Struvite
keywords: Children; Metabolic examination; Stone composition; Urolithiasis