title: The effect of bariatric surgery on renal function.
abstract: BACKGROUND
  Obesity is associated with albuminuria and impaired renal function. We previously reported on 38 nondiabetics with improved albuminuria after Roux-en-Y gastric bypass (RYGB).
  
  
  METHODS
  Our objectives were to evaluate changes in renal function, urinary albumin-to-creatinine ratio (UACR), and glomerular filtration rate (GFR) in a larger cohort of patients with normal or mildly impaired renal function, undergoing RYGB or sleeve gastrectomy at 1 year postop. This was a retrospective study. Inclusions: patients with preoperative and 1 year postoperative serum and urine albumin and creatinine and weight (kg).
  
  
  METHODS
  preop chronic kidney disease (CKD)≥Stage 3 or macroalbuminuria (UACR≥300 mg/g).
  
  
  METHODS
  changes in UACR and estimated GFR (eGFR) at 1 year. The setting was in a public hospital in New York City, 2004-2011.
  
  
  RESULTS
  158 patients met inclusion criteria; 91.8% female; mean age 40.8 years; 84.2% white Hispanic, 14.6 % black. Hypertension was present in 43.0%, diabetes mellitus in 28.5%. UACR was 21.5±3.2 mg/g, decreasing to 10.2±1.2 mg/g at 1 year (P<.0001). Microalbuminuria was present in 22/158 patients (14%) preop, resolving in 82% at 1 year; pre- versus 1 year postop eGFR, 97.5±2.2 versus 87.1±2.0 mL/min (P<.0001). Hyperfiltration was present in 8.2% preop, decreasing to 4.4% 1 year postop.
  
  
  CONCLUSIONS
  In this mainly female minority population, UACR decreased within the normal range, while eGFR decreased from normal to the range for Stage 2 CKD at 1 year postop. Microalbuminuria resolved in most affected and hyperfiltration resolved in nearly half of those affected. This study is limited by its retrospective nature. Prospective studies should be performed.
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York; Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York. Electronic address: tjr2122@cumc.columbia.edu.
authors.forename: Tirissa J
authors.initials: TJ
authors.lastname: Reid
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York.
authors.forename: Saqib
authors.initials: S
authors.lastname: Saeed
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York.
authors.forename: Shiranda
authors.initials: S
authors.lastname: McCoy
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York.
authors.forename: Adebola A
authors.initials: AA
authors.lastname: Osewa
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York.
authors.forename: Amrita
authors.initials: A
authors.lastname: Persaud
authors.affiliation: Department of Surgery, Harlem Hospital, New York, New York; Department of Surgery, Columbia University, College of Physicians and Surgeons, New York, New York.
authors.forename: Leaque
authors.initials: L
authors.lastname: Ahmed
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000209:etiology; D050110:Bariatric Surgery; D003404:Creatinine / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000150:complications / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D008297:Male; D009765:Obesity / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000503:physiopathology; D012189:Retrospective Studies
chemical_list: D003404:Creatinine
keywords: Bariatric surgery; Glomerular filtration rate; Hyperfiltration; Microalbuminuria; Minority; Renal function; Urinary albumin creatinine ratio