High fatty liver index is an independent predictor of ischemic heart disease during a 10-year period in a Japanese population

Aim Fatty liver index (FLI), which is calculated by using body mass index, waist circumference and levels of gamma-glutamyl transferase and triglycerides, is a validated surrogate marker of nonalcoholic fatty liver disease. We retrospectively investigated the relationship between FLI and the development of ischemic heart disease (IHD) during a 10-year period. Methods Among subjects who received annual health checkups (n = 28 990), a total of 18 851 subjects (men/women: 11 659/7192) were enrolled after exclusion of subjects with missing data and those with IHD at baseline. Results FLI at baseline was significantly higher in men than in women. During the 10-year period, 450 men (3.9%) and 123 women (1.7%) had new onset of IHD determined by a self-reported questionnaire survey. Multivariable Cox proportional hazard models with a restricted cubic spline showed that hazard risk (HR) for the development of IHD increased with a higher FLI at baseline after adjustment of age, sex, current smoking habit, family history of IHD and diagnosis of diabetes mellitus, hypertension, dyslipidemia and chronic kidney disease at baseline. There was no significant interaction between FLI and sex for the adjusted HR. When divided by tertiles of FLI at baseline (T1 similar to T3), the adjusted risk for development of IHD in the T3 group (HR [95% confidence interval]: 1.34 [1.05-1.71]) was significantly higher than that in the T1 group as the reference. The addition of FLI into traditional risk factors for IHD significantly improved the discriminatory capability. Conclusions A high level of FLI is an independent predictor of new onset of IHD during a 10-year period.