Nonalcoholic fatty liver disease (NAFLD) is common in insulin-resistant subjects1 and affects 20% to 30% of the adult population and more than 50% of overweight and obese individuals.2 NAFLD is associated with an increased risk of developing advanced fibrosis and cirrhosis3 and incident type 2 diabetes.4 Because of its association with metabolic syndrome and type 2 diabetes, it has been hypothesized that NAFLD may also be associated with increased rates of cardiovascular disease (CVD)5; in particular, patients with NAFLD have elevated levels of plasma biomarkers of inflammation, endothelial dysfunction, markers of subclinical cardiovascular risk, and a higher prevalence of clinically manifesting CVD.6 Some studies have also reported a higher incidence of major outcomes,7-10 such as nonfatal CVD events,7 deaths due to CVD,8, 9 revascularization procedures,9 and all-cause mortality.10 The data were obtained from community-based cohorts,7, 10 nested case-control studies,8, 9 the general population,7, 10 or patients with type 2 diabetes8, 9; NAFLD was established with abdominal ultrasonography,7, 10 liver biopsy,8, 9 or γ-glutamyltransferase (GGT) levels.10 These studies had a maximum follow-up of 7.3 years.
The fatty liver index (FLI) is a surrogate marker of a fatty liver. It was validated in a large group of subjects with or without suspected liver disease11 and was associated with coronary heart disease and early atherosclerosis in a cross-sectional study.12
The aim of this study was to assess the relationship between FLI and hepatic-related, all-cause, CVD, and cancer mortality rates in the Cremona study, a 1990-1991 population survey designed to establish the prevalence of diabetes in Lombardy, Italy.13, 14 In this cohort, the vital status and the time of death were ascertained through Regional Health Registry files, and the causes of death were classified with the International Classification of Diseases. The follow-up was 15 years, which is the shortest time needed to explore the effects of metabolic risk factors (diabetes status, insulin resistance, body fatness, and metabolic syndrome) on mortality.15, 16