title: The Fatty Liver Index has limited utility for the detection and quantification of hepatic steatosis in obese patients.
abstract: OBJECTIVE
  Noninvasive tools for the detection of hepatic steatosis are needed. The Fatty Liver Index (FLI), which includes body mass index (BMI), waist circumference, triglycerides, and γ-glutamyl-transferase, has been proposed as a screening tool for fatty liver. Our objective was to validate the FLI for the detection and quantification of hepatic steatosis in an obese population.
  
  
  METHODS
  Patients with chronic liver disease and BMI ≥ 28 kg/m(2) underwent liver biopsy and FLI determination. FLI performance for diagnosing steatosis compared with biopsy was assessed using areas under receiver operating characteristic curves (AUROCs), and a novel model for the prediction of significant steatosis (≥5 %) was derived.
  
  
  RESULTS
  Among 250 included patients, 65 % were male, and the median BMI was 33 kg/m(2); 48 % had nonalcoholic fatty liver disease, and 77 % had significant (≥5 %) steatosis. The FLI was weakly correlated with the percentage (ρ = 0.25, p = 0.0001) and grade of steatosis (ρ = 0.28, p < 0.00005). The median FLI was higher among patients with significant steatosis (91 vs. 80 with <5 % steatosis; p = 0.0001) and the AUROC for this outcome was 0.67 (95 % CI 0.59-0.76). At an optimal FLI cut-off of 79, the FLI was 81 % sensitive and 49 % specific, and had positive and negative predictive values of 84 and 43 %, respectively. A novel index including triglycerides, glucose, alkaline phosphatase, and BMI outperformed the FLI for predicting significant steatosis [AUROCs 0.78 vs. 0.68; p = 0.009 (n = 247)].
  
  
  CONCLUSIONS
  In obese patients, the FLI is a poor predictor of significant steatosis and has limited utility for steatosis quantification compared with liver histology. A novel index including triglycerides, glucose, alkaline phosphatase, and BMI may be useful, but requires validation.
authors.affiliation: Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, 6D22, Teaching, Research and Wellness Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Borman
authors.affiliation: Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, 6D22, Teaching, Research and Wellness Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
authors.forename: Farah
authors.initials: F
authors.lastname: Ladak
authors.affiliation: Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, 6D22, Teaching, Research and Wellness Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
authors.forename: Pam
authors.initials: P
authors.lastname: Crotty
authors.affiliation: Department of Pathology, Mt. Sinai Hospital, Toronto, ON, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Pollett
authors.affiliation: Department of Pathology, Mt. Sinai Hospital, Toronto, ON, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Kirsch
authors.affiliation: Liver Unit Centre Hospitalier de L'Université de Montréal, Hôpital Saint-Luc, Montréal, QC, Canada.
authors.forename: Gilles
authors.initials: G
authors.lastname: Pomier-Layrargues
authors.affiliation: Multi-Organ Transplant Unit, University of Western Ontario, London, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Beaton
authors.affiliation: Toronto Western Hospital Liver Centre, Toronto, Canada.
authors.forename: Andres
authors.initials: A
authors.lastname: Duarte-Rojo
authors.affiliation: Toronto Liver Centre, Toronto, ON, Canada.
authors.forename: Magdy
authors.initials: M
authors.lastname: Elkashab
authors.affiliation: Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, 6D22, Teaching, Research and Wellness Building, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada. rpmyers@ucalgary.ca.|Liver Unit, University of Calgary, 6D22, Teaching, Research and Wellness Building, 3280 Hospital Drive NW, Calgary, AB, T2 N 4Z6, Canada. rpmyers@ucalgary.ca.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Myers
keywords: Biopsy; Fatty liver; Fibrosis; Noninvasive; Steatosis