title: Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared With Normal-weight Stone Formers?
abstract: OBJECTIVE
  To determine if 24-hour urinary parameters in children with nephrolithiasis across 4 institutions were influenced by body mass index (BMI).
  
  
  METHODS
  The 24-hour urinary parameters obtained from children with nephrolithiasis between 2000 and 2013 were stratified by BMI percentile ≥85th and <85th (overweight and obese patients vs healthy weight, respectively). A total of 206 children were included in the study. Exclusion criteria included patients with a history of spina bifida, neurogenic bladder, and cerebral palsy, and patients on medical treatment before the first 24-hour urine collection.
  
  
  RESULTS
  Overweight and obese patients consisted of 35.4% of the cohort (n = 73). Metabolic abnormalities were present in 130 children (63.1%). The most common abnormality present in the <85th percentile was hypercalciuria (32.3%), and in the ≥85th percentile, hyperoxaluria (37.0%). Univariable and multivariable analyses revealed that overweight and obese children were more likely to have low urinary volume and elevated uric acid compared to normal-weight children.
  
  
  CONCLUSIONS
  Although there is a link between stone formation and BMI in adults, no definitive conclusions have been proven in the pediatric literature. Our study indicates that stone-forming children who are overweight or obese have low urinary volume and elevated uric acid compared to normal-weight stone-forming children.
authors.affiliation: Department of Urology, University of California San Diego, San Diego, CA. Electronic address: ginacambareri@gmail.com.
authors.forename: Gina M
authors.initials: GM
authors.lastname: Cambareri
authors.affiliation: Division of Pediatric Urology, University of Tennessee Health Science Center/Le Bonheur Children's Hospital, Memphis, TN.
authors.forename: Dana W
authors.initials: DW
authors.lastname: Giel
authors.affiliation: Department of Urology, Oregon Health Sciences University, Portland, OR.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Bayne
authors.affiliation: Department of Urology, University of Virginia, Charlottesville, VA.
authors.forename: Sean
authors.initials: S
authors.lastname: Corbett
authors.affiliation: Division of Pediatric Urology, University of Tennessee Health Science Center/Le Bonheur Children's Hospital, Memphis, TN.
authors.forename: Elleson
authors.initials: E
authors.lastname: Schurtz
authors.affiliation: Department of Urology, Children's Hospital of Michigan, Detroit, MI.
authors.forename: Larisa
authors.initials: L
authors.lastname: Kovacevic
authors.affiliation: Department of Urology, University of Virginia, Charlottesville, VA.
authors.forename: Troy
authors.initials: T
authors.lastname: Sukhu
authors.affiliation: Department of Urology, University of California San Diego, San Diego, CA.
authors.forename: Michael
authors.initials: M
authors.lastname: Yap
authors.affiliation: University of California San Diego Department of Urology, Rady Children's Specialists of San Diego, San Diego, CA.
authors.forename: George
authors.initials: G
authors.lastname: Chiang
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D015992:Body Mass Index; D002648:Child; D003404:Creatinine / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000378:metabolism* / Q000652:urine; D008297:Male; D008659:Metabolic Diseases / Q000150:complications* / Q000652:urine; D009765:Obesity / Q000150:complications* / Q000378:metabolism; D050177:Overweight / Q000150:complications* / Q000652:urine; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014527:Uric Acid / Q000652:urine*; D016482:Urinalysis
chemical_list: D015415:Biomarkers; D014527:Uric Acid; D003404:Creatinine