Association of iron status with non-alcoholic fatty liver disease and liver fibrosis in US adults: a cross-sectional study from NHANES 2017–2018

Abstract

Aims: Non-alcoholic fatty liver disease (NAFLD) is a widely prevalent hepatic disorder resulting in a high risk of adverse prognosis, and its presence has been considered a cause or an outcome of metabolic syndrome. But the relative factors and mechanism of NAFLD are still unclear. The aim of this study is to explore the association between iron status indicators and NAFLD as well as liver fibrosis. Methods: This study evaluated whether serum iron status indicators are independently related to the risk of NAFLD. The independent variable was each one of the iron status indicators (iron intake, ferritin, iron, unsaturated iron binding force (UIBC), total iron binding capacity (TIBC), transferrin saturation, transferrin receptor, hemoglobin, and mean cell hemoglobin), and the dependent variables were NAFLD and advanced liver fibrosis. A multivariable logistic regression analysis and subgroup analysis were performed to evaluate the association between iron status indicators and NAFLD as well as liver fibrosis. Results: A total of 3727 patients were included. After adjusting for other covariates in multiple logistic regression models, the serum ferritin, UIBC, TIBC, and hemoglobin had a significant positive association with the NAFLD (odds ratio [OR] = 1.16, 95% confidence interval [CI]: 1.09, 1.23; 1.31, 95% CI: 1.06, 1.62; 1.82, 95% CI: 1.23, 2.67; 2.67, 95% CI: 1.48, 4.82, separately), and the risk of NAFLD diagnosed by VCTE or ALT/AST further increased in the fourth quartile group of serum ferritin (diagnosed by VCTE OR = 1.93, 95% CI: 1.49, 2.50; diagnosed by ALT/AST OR = 5.76, 95% CI: 3.96, 8.38). Moreover, the main positive correlation between serum ferritin and NAFLD was found in females, participants aged >41 years, with no diabetes. Conclusion: Our results indicated that iron status indicators were closely associated with the occurrence of advanced liver fibrosis, which may indicate that iron status indicators could be potential biomarkers of NAFLD and advanced liver fibrosis.