Background: Non-alcoholic fatty liver disease (NAFLD) is considered as the most common chronic liver disease, which can contribute to some clinical conditions varying from simple steatosis to hepatic cirrhosis. Consequently, the early diagnosis of NAFLD is vital. The present study aimed at investigating the ability of FLI (fatty liver index) in predicting NAFLD. Methods: A total of 212 individuals over the age of 18 years (103 males and 109 females) were recruited from those admitted to a gastrointestinal clinic in Mashhad, northeastern Iran. Anthropometric parameters were measured and blood samples were collected. Hepatic steatosis and fibrosis were identified by FibroScan. FLI from body mass index, waist circumference (WC), triglyceride, and gamma glutamyltransferase data were calculated. Logistic regression was applied to establish a relationship among FLI, hepatic steatosis, and fibrosis. The sensitivity and specificity of FLI and its optimal cut-off point were detected by receiver operating characteristic analysis. Results: The mean age of the participants was 39. 26  14. 18 years. FLI was significantly associated with NAFLD (OR = 1. 062, 95%CI: 1. 042-1. 082, P < 0. 001) and hepatic fibrosis (OR = 1. 022, 95%CI: 1. 011-1. 032, P < 0. 001). The AUC of FLI was 0. 85 (95%CI = 0. 79-0. 9) in the diagnosis of NAFLD, and its optimal cut-off point was 26. 2 (sensitivity = 0. 83, specificity = 0. 7). Also, the optimal cut-off point of FLI was 30. 4 in males (sensitivity = 0. 82, specificity = 0. 71) and 20. 7 in females (sensitivity = 0. 89, specificity = 0. 66). Conclusions: fatty liver index (FLI) is a suitable and simple predictor for liver steatosis. However, performance of FLI in predicting NAFLD is not more effective than WC. Although FLI is a predictor for liver steatosis, it has a positive association with liver fibrosis and can perhaps predict liver fibrosis too.

Introduction: This study was conducted to determine the discriminatory performance of fatty liver index (FLI) for nonalcoholic fatty liver disease (NAFLD).Methods: The data of 5052 subjects aged over 18 years were analyzed. FLI was calculated based on data of body mass index (BMI), waist circumference (WC), triglyceride (TG) and gamma glutamyl transferase (GGT).Logistic regression analysis was conducted to determine the association between FLI and NAFLD.The discriminatory performance of FLI in the diagnosis of NAFLD was evaluated by receiver operating characteristic (ROC) analysis. Area under the curves (AUCs) and related confidence intervals were estimated. Optimal cutoff points of FLI in the diagnosis of NAFLD were determined based on the maximum values of youden index.Results: The mean age of men and women were 44.8・} 16.8 and 43.78± 15.43, respectively (p-value =0.0216). The prevalence of NAFLD was 40.1 % in men and 44.2% in women (p-value<0.0017). FLI was strongly associated with NAFLD, so that one unit increase in FLI increased the chance of developing NAFLD 5.8% (OR=1.058, [95%CI= (1.054-1.063)], p-value<0.0001).Although FLI revealed a good performance in the diagnosis of NAFLD (AUC=0.8656 (95% CI=0.8548-0.8764), its performance had not significant difference with WC (AUC=0.8533, 0.95% CI=0.8419-0.8646).According sex the performance of FLI was not different between men (AUC=0.8648 [0.95% CI=0.8505- 0.8791]) and women (AUC=0.8682- [0.95% CI=0.8513- 0.8851]) while based on age the highest performance was related to the age group of 18-39 (AUC=0.8930 [0.95% CI=0.8766- 0.9093]).The optimal cutoff points of FLI were 46.9 in men (sensitivity=0.8242, specificity=0.7687, Youden index=0.5929) and 53.8 in women (sensitivity= 0.8233, specificity=0.7655, Youden index=0.5888).Conclusion: FLI had an acceptable discriminatorypower in the diagnosis of NAFLD, however WC as a more simple and accessible index revealed similar performance.