title: Neutrophil Gelatinase-Associated Lipocalin as a Biomarker of Acute Kidney Injury in Patients with Morbid Obesity Who Underwent Bariatric Surgery.
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL) has been identified as a biomarker of acute kidney injury (AKI) that could contribute to early diagnosis and effective management of AKI. The purpose of this study was to evaluate NGAL as a predictive marker of AKI in patients with clinically severe obesity (BMI >50) who underwent biliopancreatic diversion surgery.
  
  
  METHODS
  We prospectively studied 23 patients with clinically severe obesity who underwent biliopancreatic bypass surgery. NGAL was measured using chemiluminescent microparticle immunoassay in three urine samples collected from each patient before surgery (first sample), 2-6 h after surgery (second sample) and on the first postoperative day (third sample).
  
  
  RESULTS
  Renal function was evaluated using serum creatinine values, which were 0.91 ± 0.26 mg/dl before surgery, 0.87 ± 0.31 mg/dl immediately after surgery and 0.92 ± 0.62 mg/dl on the fifth postoperative day. During the immediate postoperative period, AKI was observed in 2 patients, one of whom required renal replacement therapy with hemodialysis. In both patients, urine NGAL increased within the first postoperative hours before the values of serum creatinine increased.
  
  
  CONCLUSIONS
  Urine NGAL in patients with clinically severe obesity, which was surgically treated, might be a potential biomarker of early AKI detection. Further research is required in order to confirm these results observed in a small number of patients who developed postoperative AKI and make recommendations for predictive NGAL values in patients who underwent bariatric surgery.
authors.affiliation: Department of Internal Medicine-Nephrology, University Hospital of Patras, Rio, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Koukoulaki
authors.affiliation: Department of Surgery, University Hospital of Patras, Rio, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Spyropoulos
authors.affiliation: Department of Internal Medicine-Nephrology, University Hospital of Patras, Rio, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Hondrogiannis
authors.affiliation: Department of Internal Medicine-Nephrology, University Hospital of Patras, Rio, Greece.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papachristou
authors.affiliation: Department of Internal Medicine-Nephrology, University Hospital of Patras, Rio, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Mitsi
authors.affiliation: Department of Surgery, University Hospital of Patras, Rio, Greece.
authors.forename: Fotios
authors.initials: F
authors.lastname: Kalfarentzos
authors.affiliation: Department of Internal Medicine-Nephrology, University Hospital of Patras, Rio, Greece.
authors.forename: Dimitrios S
authors.initials: DS
authors.lastname: Goumenos
keywords: Acute kidney injury; Biliopancreatic diversion or bypass surgery ; Biomarkers; Neutrophil gelatinase-associated lipocalin;  Severe obesity