title: Applicability of the Schwartz Equation and the Chronic Kidney Disease in Children Bedside Equation for Estimating Glomerular Filtration Rate in Overweight Children.
abstract: To determine if significant correlations exist between glomerular filtration rate (GFR) prediction equation values, derived by using the original Schwartz equation and the Chronic Kidney Disease in Children (CKiD) bedside equation with a 24-hour urine creatinine clearance (Clcr ) value normalized to a body surface area of 1.73 m(2) in overweight and obese children.
  
  
  
  Prospective analysis (20 patients) and retrospective analysis (43 patients).
  
  
  
  Pediatric inpatient ward and pediatric nephrology clinic at a comprehensive academic medical center.
  
  
  
  Sixty-three pediatric patients (aged 5-17 years), of whom 27 were overweight (body mass index [BMI] at the 85th percentile or higher) and 36 were not overweight (BMI lower than the 85th percentile [controls]) between 2007 and 2012.
  
  
  
  Data from the overweight patients were compared with nonoverweight controls. GFR values were calculated by using the original Schwartz equation and the CKiD bedside equation. Each patient's 24-hour urine Clcr value normalized to a body surface area of 1.73 m(2) served as the index value. A Pearson correlation coefficient model was used to determine association between the 24-hour urine Clcr value (index value) with the Schwartz and CKiD GFR estimations. Significant correlation was found to exist between the Schwartz and CKiD bedside GFR estimations relative to the 24-hour urine Clcr in the control subjects (r = 0.85, p<0.0001, and r = 0.85, p<0.0001, respectively). Significant correlation was also found to exist between the Schwartz and CKiD bedside GFR values with the 24-hour urine Clcr value in overweight subjects (r = 0.86, p<0.0001, and r = 0.86, p<0.0001, respectively). The Schwartz equation estimated average GFR 21.75 ml/minute/1.73 m(2) higher than 24-hour urine Clcr (p<0.0001) in overweight children with a kidney disorder. The CKiD bedside GFR estimations were not significantly different compared with 24-hour urine Clcr values for the overweight group with kidney disorder (p=0.85).
  
  
  
  The Schwartz and CKiD bedside estimations of GFR correlated with 24-hour urine Clcr values in both overweight and nonoverweight children. Compared with the Schwartz equation, which tended to overestimate renal function, the CKiD bedside equation appeared to approximate 24-hour urine Clcr more closely in overweight children with kidney disorder.
authors.affiliation: Department of Pharmacy, Clinical and Administrative Sciences, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Teresa V
authors.initials: TV
authors.lastname: Lewis
authors.affiliation: Department of Pharmacy, Clinical and Administrative Sciences, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Harrison
authors.affiliation: Southwestern Oklahoma State University College of Pharmacy, Weatherford, Oklahoma.
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Gildon
authors.affiliation: Department of Pharmacy, Clinical and Administrative Sciences, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Carter
authors.affiliation: Department of Pediatrics, College of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Turman
mesh_terms: D000293:Adolescent; D001830:Body Surface Area; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests / Q000706:statistics & numerical data*; D008297:Male; D050177:Overweight / Q000652:urine*; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D003404:Creatinine
keywords: CKiD equation; Chronic Kidney Disease in Children bedside equation; Schwartz equation; obesity; pediatrics; renal