title: Comparative analysis of nephrolithiasis in otherwise healthy versus medically complex gastrostomy fed children.
abstract: OBJECTIVE
  The purpose was to compare nephrolithiasis in healthy versus medically complex gastrostomy fed children.
  
  
  METHODS
  Children with nephrolithiasis with and without gastrostomy were identified by database searches from 1999 to 2009. Gastrostomy fed stone formers (GSF) were compared to an age-matched cohort of non-gastrostomy-fed stone formers (NGSF) for demographic and clinical data.
  
  
  RESULTS
  16 neurologically impaired GSF (10M:6F), mean age 10.4 years (range 1.7-17.5 years), were compared to 32 matched neurologically intact NGSF. Compared to NGSF, GSF had significantly higher urine pH (6.93 vs 6.23, p = 0.001) and larger stones (14.5 vs 6.9 mm, p = 0.02) more commonly composed of calcium phosphate (7/11, 64% vs 3/28, 11%, p = 0.002). 15/16 (94%) of GSF were immobile while 0% of NGSF were immobile. GSF had lower l-spine bone density Z-scores (-3.02 vs -1, p = 0.002) but an equal rate of hypercalciuria (2/7, 29% vs 7/24, 29%, p = NS). Contributing lithogenic factors in 8/16 (50%) GSF included urinary tract infection (UTI) (5), lithogenic medications (2), and xanthinuria (1).
  
  
  CONCLUSIONS
  Stone disease in GSF is multifactorial, and half of our study group had an identifiable risk factor for nephrolithiasis. A recurring pattern of alkaline urine and calcium phosphate stone formation was evident. GSF did not have higher rates of hypercalciuria despite chronic immobilization and markedly lower bone density. An awareness of the potential risk factors identified is mandatory for this vulnerable population.
authors.affiliation: Department of Urology, University of Texas Southwestern Medical Center, Children's Medical Center, Dallas, TX 75390-9110, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Smith
authors.forename: Seerath
authors.initials: S
authors.lastname: Basravi
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Schlomer
authors.forename: Nicol C
authors.initials: NC
authors.lastname: Bush
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Brown
authors.forename: Aaron
authors.initials: A
authors.lastname: Gingrich
authors.forename: Linda A
authors.initials: LA
authors.lastname: Baker
mesh_terms: D000293:Adolescent; D015519:Bone Density; D002130:Calcium Phosphates / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D005774:Gastrostomy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007669:Kidney Calculi / Q000737:chemistry / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D056844:Renal Colic / Q000175:diagnosis; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000453:epidemiology; D014556:Urine / Q000737:chemistry
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate