Association of Fatty Liver Index with Incident Diabetes Risk in Patients Initiating Statin-Therapy: A 6-Year Retrospective Study

Background: Statins are associated with new-onset type 2 diabetes (T2D), mainly in patients with metabolic syndrome (MetS). The fatty liver index (FLI) is used as a prognostic score for the diagnosis of non-alcoholic fatty liver disease (NAFLD), which is common in patients with MetS. We aimed to investigate the association of FLI with new-onset T2D in patients initiating statin therapy. Methods: A retrospective observational study including 1241 individuals with dyslipidemia and followed up for >= 3 years. Patients with T2D and those receiving lipid-lowering treatment at the baseline visit were excluded. Models with clinical and laboratory parameters were used to assess the association of FLI with incident T2D. Results: Among the 882 eligible subjects, 11% developed T2D during the follow-up (6 years; IQR: 4-10 years). After adjusting for sex, age and MetS parameters, a multivariate analysis revealed that age (HR:1.05; 95%CI: 1.01-1.09, p < 0.05), fasting plasma glucose (HR: 1.09; 95%CI: 1.06-1.13, p < 0.001) and FLI (HR: 1.02; 95%CI: 1.01-1.04, p < 0.01) were independently associated with T2D risk. The subjects with probable NAFLD (FLI >= 60) had a three-fold increased T2D risk compared with the subjects with FLI < 60 (HR: 3.14; 95%CI: 1.50-6.59, p = 0.001). A ROC curve analysis showed that FLI had a significant, although poor, predictive value for assessing T2D risk (C-Statistic: 0.67; 95%CI: 0.58-0.77, p = 0.001). Higher FLI values were associated with reduced T2D-free survival (log-rank = 15.46, p < 0.001). Conclusions: FLI is significantly and independently associated with new-onset T2D risk in patients initiating statin therapy.