title: The Modern Metabolic Stone Evaluation in Children.
abstract: OBJECTIVE
  To evaluate metabolic abnormalities in a contemporary pediatric population after their first stone episode. The incidence of pediatric nephrolithiasis is increasing and therefore the etiologies contributing to today's pediatric stone formation may also be changing.
  
  
  METHODS
  A retrospective review of all consecutive children presenting after their first kidney stone between 2000 and 2014 was performed. We compared demographic data, serum chemistry results, and 24-hour urine results and treatments.
  
  
  RESULTS
  One hundred thirteen children with a mean age of 11 years (5 months to 18 years) who presented with their first kidney stone episode between 2000 and 2014 were evaluated. Sixteen patients (14%) were found to have an underlying genetic or systemic disease. Overall, there was a low rate of serum chemistry abnormalities. The most common abnormalities found within the 24-hour urine evaluation included low urine volume (89%) and hypocitraturia (68%). Hypercalciuria occurred rarely (11%).
  
  
  CONCLUSIONS
  We identified a low rate of underlying genetic or systemic diseases contributing to modern pediatric stone presentation and an increased proportion of idiopathic stones. Our study differs from historical findings by identifying a low rate of hypercalciuria and a high rate of low urine volume and hypocitraturia, suggestive of changing metabolic abnormalities contributing to modern pediatric stone disease.
authors.affiliation: Department of Urology, University of Iowa, Iowa City, IA.
authors.forename: Mark
authors.initials: M
authors.lastname: Bevill
authors.affiliation: Department of Urology, University of Iowa, Iowa City, IA.
authors.forename: Ambika
authors.initials: A
authors.lastname: Kattula
authors.affiliation: Department of Urology, University of Iowa, Iowa City, IA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Cooper
authors.affiliation: Department of Urology, University of Iowa, Iowa City, IA. Electronic address: douglas-storm@uiowa.edu.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Storm
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002118:Calcium / Q000097:blood; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007484:Iowa / Q000453:epidemiology; D007669:Kidney Calculi / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D008297:Male; D008659:Metabolic Diseases / Q000150:complications* / Q000453:epidemiology / Q000378:metabolism; D010758:Phosphorus / Q000097:blood; D011188:Potassium / Q000097:blood; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D012964:Sodium / Q000097:blood; D014527:Uric Acid / Q000097:blood; D016482:Urinalysis
chemical_list: D015415:Biomarkers; D014527:Uric Acid; D010758:Phosphorus; D012964:Sodium; D011188:Potassium; D002118:Calcium