Chronic systemic inflammation predicts long-term mortality among patients with fatty liver disease: Data from the National Health and Nutrition Examination Survey 2007-2018

Background Low-grade systemic inflammation (SI) in patients with fatty liver disease (FLD) is an important hallmark of disease onset and progression. This study aims to evaluate the prognostic significance of novel SI markers in FLD. Methods This was a retrospective cohort study. We included adult patients with FLD with complete data and analyzed the association between chronic SI and long-term mortality in patients with FLD. Systemic immune-inflammation index (SII), pan-immune-inflammation value (PIV), and systemic inflammation response index (SIRI) were evaluated based on peripheral blood counts and FLD was determined by the Fatty Liver Index. Results A total of 5497 patients with FLD were included in the final analysis. SII and PIV (but not SIRI) were found to be associated with all-cause and cardiovascular mortality in univariate analysis. Multivariate Cox regression analysis and KM analysis demonstrated that SII and PIV were associated with all-cause mortality, with SII showing a nonlinear correlation in RCS. PIV (but not SII) was associated with the cardiovascular-related survival probability over time. Stratified analysis indicated that the positive correlation between SII and PIV and all-cause mortality was not altered by subgroups. Conclusions SII and PIV are strongly and consistently associated with all-cause mortality in patients with FLD, with PIV potentially showing a closer association with cardiovascular mortality.