title: Estimating renal function in morbidly obese patients.
abstract: BACKGROUND
  This paper aims to evaluate, in a clinical context, current creatinine-based formulas commonly used to calculate renal function in morbidly obese patients.
  
  
  METHODS
  A retrospective analysis was performed of the estimates of renal function of 63 obese or morbidly obese patients undergoing gastric bypass surgery. Each patient's glomerular filtration rate (GFR) was calculated using five methods, both before and after surgery, and these approximations were then compared.
  
  
  RESULTS
  Prior to surgery, the values offered by the five formulas for the renal function of this population ranged widely, by over a factor of 2. After surgery, the three weight-based GFR estimation methods indicated that a significant change in GFR had occurred, but the two non-weight-based formulas showed no significant change in estimated GFR.
  
  
  CONCLUSIONS
  At baseline and after significant weight loss, creatinine-based formulas differ twofold in their estimates of renal function of the morbidly obese. An accurate method for calculating these patients' renal function is required to improve patient safety with drug dosing as well as to ensure early detection of renal failure.
authors.affiliation: University of Adelaide, Adelaide, SA 5005, Australia. alexglovell@gmail.com
authors.forename: Alex
authors.initials: A
authors.lastname: Lovell
authors.forename: Philip
authors.initials: P
authors.lastname: Game
authors.forename: Gary
authors.initials: G
authors.lastname: Wittert
authors.forename: Campbell
authors.initials: C
authors.lastname: Thompson
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D015415:Biomarkers / Q000378:metabolism; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D003404:Creatinine / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D005919:Glomerular Filtration Rate; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D009767:Obesity, Morbid / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D057234:Preoperative Period; D051437:Renal Insufficiency / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015431:Weight Loss
chemical_list: D015415:Biomarkers; D003404:Creatinine