Higher serum vitamin A is associated with a worsened progression of non-alcoholic fatty liver disease in adults: a prospective study

Abstract

Background: The association between serum vitamin A and non-alcoholic fatty liver disease (NAFLD) remains uncertain due to inconsistent results and scarce longitudinal data. We examined the prospective associations between serum vitamin A and the evolution of the NAFLD severity score as well as the potential mediating effects in middle-aged and older Chinese adults. Method: A total of 2658 adults (between 40–75 years of age) were included in the analysis. We determined the serum concentrations of vitamin A at the onset of the study (the baseline), and the degree of NAFLD after years 3 and 6. Results: Subjects were classified into stable, progressed, and improved groups according to the changes in their severity score (0–3) of NAFLD between two visits. Analyses of covariance showed that the serum VA concentrations were positively associated with NAFLD progression (all p-trend < 0.05). After adjusting for potential confounders, the mean differences in the serum vitamin A were 7.7% lower in the improved group than those in the progressed group among the total population. Path analyses showed that vitamin A was positively associated with the serum retinol-binding protein 4, triglycerides, insulin resistance, and body mass index (standardized β 0.065–0.304, all p < 0.001), and all of these factors positively correlated with the prevalence and progression of NAFLD (standardized β 0.045–0.384, all p < 0.01). Conclusions: A higher serum vitamin A concentration was associated with NAFLD progression, which might be mediated by increases in the serum retinol-binding protein 4, triglycerides, insulin resistance, and body mass index.