Fatty liver index as a predictor of fatal and non-fatal cardiovascular events in Russians: analysis of an epidemiological cohort

Aim. To study the associations of a high fatty liver index (FLI ≥60) with the risk of death and nonfatal cardiovascular events in a Russian epidemiological cohort.

Material and methods. The analysis included data from ESSE-RF2 epidemiological study. FLI was calculated using the Bedogni G et al. equation (2006). A high FLI ≥60 was considered a predictor of liver steatosis. A total of 5381 individuals aged 25-64 years from 4 Russian regions (the Republic of Karelia, Krasnodar Krai, Omsk and Ryazan Oblasts) were included, of which 1672 had FLI ≥60. Fatal endpoints included all-cause (ACD) and cardiovascular death (CVD), while nonfatal endpoints included myocardial infarction (MI), cerebrovascular accident (CVA), heart failure progression (hospitalization), and revascularization. The composite endpoint (CE) included cardiovascular death or a non-fatal endpoint. Statistical analysis was performed using the R language and environment (version 4.2). The significance level for all tested hypotheses was p<0,05.

Results. Kaplan-Meier survival curve analysis showed that the group of patients with a FLI ≥60 had significantly worse survival outcomes compared to the group with an FLI <30, for both death (ACD, p<0,001 and CVD, p=0,004) and CE (p<0,001). In the Cox regression model adjusted for region (M1), FLI ≥60 was significantly associated with ACD (HR 2,61 [95% CI: 1,55-4,41], p=0,001), CVD (HR 4,28 [1,8-10,15], p=0,001), non-fatal CVA (HR 4,89 [1,86-12,84], p=0,001), and CE (HR 3,8 [2,26-6,38], p=0,001). In the model adjusted for region, sex, and age (M2), the association of a high FLI with CVA (p=0,036) and CE (p=0,004) persisted, while in M3 (M2 + lifestyle factors and lipid metabolism disorders) it was only associated with CE (HR 1,93 [1,06-3,51], p=0,031).

Conclusion. In the group of individuals with a FLI ≥60, survival rates were significantly lower than in the group with a FLI <30 for all studied outcomes (ACD, CVD, and CE). In a univariate Cox regression model adjusted for region, a high FLI was associated with non-fatal CVA, ACD, CVD, and CE. However, in a multivariable model (adjusted for region, age, sex, lifestyle factors, and lipid metabolism disorders), a significant association of FLI ≥60 remained only with CE.

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