Correlation between Myosteatosis and Liver Fibrosis among Patients with Non Alcoholic Fatty Liver Disease: A Cross-Sectional Study

Abstract

Introduction: Non Alcoholic Fatty Liver Disease (NAFLD) is one of the major leading causes of liver diseases, comprising a spectrum of conditions ranging from simple steatosis to cirrhosis. In the era of preventive medicine, it is of utmost importance to recognise the subset of NAFLD patients at high risk of progressing to liver cirrhosis. A newly emerging concept of myosteatosis is now suspected to be an early manifestation of NAFLD disease progression. Aim: To find the correlation between myosteatosis and liver fibrosis among patients with NAFLD. Materials and Methods: This was a cross-sectional study conducted in the Department of Radiodiagnosis and Department of Gastroenterology at Amala Institute of Medical Sciences in Thrissur, Kerala, India, from January 2021 to June 2022. A total of 57 subjects with Magnetic Resonance Imaging-proven (MRI) NAFLD were included in the study. Body weight and height were measured. Liver fat and myosteatosis were measured using the MRI-derived Proton Density Fat Fraction (PDFF) method {Iterative Decomposition of Water and Fat with Echo (IDEAL-IQ sequence)}. Liver fibrosis was assessed using 2D shear wave elastography. The proportion of myosteatosis and liver fibrosis among NAFLD patients was estimated. Partial correlation, controlling for gender, was evaluated using partial Spearman’s rho correlation coefficients. An Reciever Operating Characteristic (ROC) curve was plotted to assess muscle fat fraction in predicting liver fibrosis outcome among patients. Results: Out of the 57 subjects studied, 17 were females and 40 were males. The median Interquartile Range (IQR) age of the subjects was 43.0 (16.5). The median MRI hepatic fat fraction was 10.8. The median muscle PDFF in males was 8.4, and in females, it was 16.9. The median H-PDFF was 18.8. Myosteatosis correlated positively with liver fibrosis (r=0.558; p<0.001). It also negatively correlated with hepatic steatosis (r=-0.321; p=0.02). A statistically significant correlation was not found between liver fat and liver fibrosis. An ROC curve was plotted to predict the liver fibrosis outcome by muscle fat fraction {Area Under Curve (AUC: 0.605; p-value: 0.204)}, which showed a sensitivity of 0.615 and a specificity of 0.389 at a cutoff score of 10.43. Conclusion: Myosteatosis positively correlated with liver fibrosis and negatively with liver steatosis.