Psoas Muscle Trajectory and Survival After Liver Transplantation for Steatotic Liver Disease in Severe Obesity

BACKGROUND: Sarcopenia after liver transplantation is poorly characterized in recipients with metabolic dysfunction-associated steatotic liver disease (MASLD) and severe obesity. We evaluated longitudinal changes in psoas muscle index (PMI) after transplantation and examined whether PMI trajectory was associated with post-transplant survival. METHODS: who underwent orthotopic liver transplantation between January 2015 and June 2023. PMI was measured on computed tomography at the L3 level before transplantation and at 6 months, 1 year, 3 years, and 5 years when available. Longitudinal change was assessed using linear mixed-effects models adjusted for survival status. Survival analyses included Kaplan-Meier estimation and univariate logistic regression. RESULTS: Seventy-three recipients were included; mean age was 59.3 years, 50.7% were women, median body mass index was 38.1 kg/m2, and mean Model for End-Stage Liver Disease score was 23.6. PMI declined significantly from baseline to 6 months (β = - 0.60, 95% confidence interval [CI] - 0.98 to - 0.22; p = 0.002) and 1 year (β = - 0.46, 95% CI - 0.83 to - 0.09; p = 0.015), with persistent reduction at 3 years. Survivors showed modest early decline followed by relative stabilization, whereas non-survivors demonstrated steeper decline. However, pre-transplant PMI, 6-month PMI, and early PMI change were not significantly associated with mortality. CONCLUSIONS: In liver transplant recipients with MASLD and severe obesity, muscle loss worsens during the first post-transplant year and may persist thereafter. These findings raise questions regarding optimal timing of nutritional and physical rehabilitation and justify larger studies to determine the prognostic significance of post-transplant muscle trajectories.