Impact of CT-relevant skeletal muscle parameters on post-liver transplantation survival in patients with hepatocellular carcinoma

The specific CT-related skeletal muscle parameters predictive of postoperative survival in liver transplant (LT) patients with hepatocellular carcinoma (HCC) remain unclear. There is increasing evidence supporting the role of fatty acids and their lipid intermediates in regulating skeletal muscle mass and function, the relationship between lipoprotein subfractions and body composition remains unclear. Adult patients with HCC who underwent LT between January 2015 and September 2022 were retrospectively analyzed. CT parameters, including skeletal muscle index (SMI), psoas muscle index (PMI), skeletal muscle density (SMD), visceral and subcutaneous adipose tissue (VAT and SAT), and the VAT/SAT ratio at the L3 level, and lipid profiles, were assessed prior to LT. Of the 284 LT patients with HCC, 224 underwent CT (L3 level) within 3 months of LT, and 82 (37%) were diagnosed with myosteatosis. Patients with myosteatosis exhibited significantly lower 1- and 3-year survival rates (p = 0.002, p = 0.01), a trend persisting even beyond the Milan criteria (p = 0.004, p = 0.04). After adjusting for covariates, SMD demonstrated a significant negative correlation with post-transplant survival (HR: 0.90, [95% Confidence Interval(CI): 0.83–0.98], C-statistic: 0.78, p = 0.009). Pearson’s correlation analysis revealed a positive correlation between high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1(ApoA1) levels and SMD. Multivariate stepwise regression analysis demonstrated that every 10 Hounsfield unit decrease in SMD was associated with a 0.16 mmol/L decrease in HDL-C and a 0.18 g/L decrease in ApoA1. Routine abdominal CT scans for assessing skeletal muscle density before LT were significantly associated with post-transplant mortality. Furthermore, abnormal HDL-C and ApoA1 levels before LT were associated with myosteatosis.