The Influence of Visceral Adiposity on Overall Survival: Exploring "Obesity Paradox" Among Hepatocellular Carcinoma Patients Who Receiving Immunotherapy

Purpose: The impact of visceral adiposity on overall survival (OS) in hepatocellular carcinoma (HCC) receiving immunotherapy was unclear. We aimed to determine how visceral adiposity affected OS and explore the interrelationships between visceral adiposity, body mass index (BMI), and other body compositions. Patients and Methods: Data from three centers were retrospectively analyzed. Skeletal muscle index (SMI), skeletal muscle density (SMD), visceral adipose tissue index (VATI), and subcutaneous adipose tissue index (SATI) were used to define each body composition. The BMI subgroups included the underweight, the normal weight, and the obesity. The Log rank test compared survival curves calculated by the Kaplan -Meier method. The relationships between body compositions and BMI with OS were examined using Cox proportional risk regression models. Results: A total of 305 patients who met the criteria were included. Patients with low VATI had significantly worse OS ( P = 0.001). The protections of VATI ( P = 0.011) on OS were independent of covariates. However, after additional adjustment of SMI, the effect of VATI on OS disappeared ( P = 0.146), but the effect of SMD on OS did not ( P = 0.021). BMI has a significant U-shaped relationship with OS, and the effect of BMI on OS equally disappeared after additional adjustment by SMI. Conclusion: This study first demonstrated that high VATI and mid -level BMI were protective for the survival of patients with HCC receiving immunotherapy. Skeletal muscle status (including SMI and SMD) may be the better predictor for outcomes of patients with HCC receiving immunotherapy.