title: Pediatric urolithiasis--does body mass index influence stone presentation and treatment?
abstract: OBJECTIVE
  Pediatric obesity is a major public health concern in the United States. We investigated the association of body mass index with presentation and outcome in children with urolithiasis.
  
  
  METHODS
  We identified all patients 2 to 18 years old at our institution with a radiographically confirmed first renal or ureteral stone between January 2003 and June 2008. Data abstracted included demographics, stone characteristics, treatment and metabolic evaluation. Patients were stratified into 3 body mass index categories, including lower (10th percentile or less for age), normal (10th to 85th percentile) and upper (85th percentile or greater) percentile body weight.
  
  
  RESULTS
  Of the children 62 boys (55.4%) and 50 girls (44.6%) were evaluable. Mean age at diagnosis was 11.8 years. Body mass index stratification showed lower percentile body weight in 11 patients (9.8%), normal percentile body weight in 55 (49.1%) and upper percentile body weight in 46 (41.1%). Mean stone diameter was 5.0 mm. Of the stones 31 (27.7%) were in the kidney or ureteropelvic junction and 81 (72.3%) were in the ureter. Surgery was done in 87 patients (78.9%) and stone clearance was accomplished by 1 (69.0%) or 2 (31.0%) procedures in all. Lower percentile body weight patients presented earlier than normal and upper percentile body weight patients (9.0 vs 12.2 and 12.0 years, respectively, p = 0.04). Neither stone size nor the number of procedures required for stone clearance differed significantly by body mass index.
  
  
  CONCLUSIONS
  Upper percentile body weight was not associated with earlier stone development, larger stones or the need for multiple surgical procedures. In lower percentile body weight patients symptomatic renal stones developed significantly earlier than in normal or upper percentile body weight patients. Stone size and the surgical intervention rate were similar regardless of body mass index. Further research may identify potential factors predisposing children with lower percentile body weight to early stone development.
authors: Division of Pediatric Urology, Department of Urology, University of Tennessee Memphis-LeBonheur Children's Medical Center, Memphis, Tennessee 38123, USA. kkieran@utmem.edu
authors: Kathleen
authors: K
authors: Kieran
authors: Dana W
authors: DW
authors: Giel
authors: Brent J
authors: BJ
authors: Morris
authors: Jim Y
authors: JY
authors: Wan
authors: Chrisla D
authors: CD
authors: Tidwell
authors: Andrew
authors: A
authors: Giem
authors: Gerald R
authors: GR
authors: Jerkins
authors: Mark A
authors: MA
authors: Williams
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D008297:Male; D009765:Obesity / Q000150:complications; D014514:Ureteral Calculi / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*