it has been suggested that periodontitis is associated with metabolic abnormalities including nonalcoholic fatty liver disease (nAfLD). the fatty liver index (fLi) is a non-invasive surrogate marker and predictor of nAfLD. We aimed to determine whether fLi itself would be associated with periodontitis through a secondary analysis of previously reported nationally representative probability sample data of the Korean population. fLi was calculated from a previously developed algorithm which combines measures of body mass index (BMi), waist circumference, triglyceride, and gamma-glutamyl transferase (GGt). periodontitis was diagnosed based on the community periodontal index (cpi) developed by the World Health Organization. Of 4,272 participants, 26.1% were diagnosed with periodontitis. Higher fLi was associated with a higher prevalence of periodontitis (odds ratio (oR) highest vs. lowest quartile of fLi ,1.63; 95% confidence interval (CI), 1.23-2.16; P = 0.001 for trend) adjusting for confounding factors. in the highest fLi quartile, prevalence of periodontitis was higher in individuals with diabetes (oR highest vs. lowest quartile of fLi , 2.89; 95% CI, 1.01-8.27 for diabetic subgroup; OR highest vs. lowest quartile of fLi , 1.45; 95% CI, 1.07-1.96 for non-diabetic subgroup). In summary, FLI was associated with prevalent periodontitis. Periodontitis is a dental bacteria-induced chronic inflammatory condition characterized by immunologic destruction of supporting structures of teeth 1. Approximately half of the adult U.S. population suffers from periodontitis with data from the 2009 and 2010 National Health and Nutrition Examination Survey 2. Associations between periodontitis and other health problems including obesity, coronary heart disease, stroke, metabolic syndrome, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD) have been already discovered 3-8. Fatty liver index (FLI) is an algorithm that combines measures of body mass index (BMI), waist circumference, triglyceride, and gamma-glutamyl transferase (GGT) 9. FLI is a non-invasive surrogate marker and predictor of NAFLD 8,9. For the definitive diagnosis of NAFLD, the ultrasonic evaluation or liver biopsy is required, while FLI may allow us to identify NAFLD in large-scale epidemiological research. We hypothesize that FLI may be associated with periodontitis prevalence. Therefore, the objective of this study was to assess the relationship between FLI and periodontitis in a large probability sample of the Korean population using data from the 2010 Korea National Health and Nutrition Examination Survey (KNHANES). Since NAFLD accounts for 20-30% and 5-18% of the general population in Western and Asian countries 10 , respectively, it is assumable that a population group with a high prevalence of periodontitis may exist among those not diagnosed with NAFLD but possess high FLI. This hypothesis may be observable in a large population dataset such as KNHANES. Benefitting from the size of the dataset, we stratified the Korean general population according...