Decrease in Psoas Muscle Mass and Density Following Liver Transplantation Is Greatest in Patients With the Highest Muscle Quantity and Density Pre-Transplant.

Sarcopenia is a known predictor of morbidity and mortality after liver transplantation (LT); it has been assessed with computed tomography (CT) derived Psoas Area Index (PAI) and mean Hounsfield units (mHU). While literature is abundant regarding the adverse outcomes of liver transplant in sarcopenic patients, a paucity of data exists describing the change in psoas muscle area and density from pre- to post-liver transplant. One hundred and four adult liver transplant recipients had pre- and post-transplant CT scans analyzed with respect to PAI and mHU. Mean PAI pre-transplant was 7.94 and 6.99 cm2/m2 post-transplant (12% loss). Mean mHU pre-transplant was 35.47 and 33.00 post-transplant (7% reduction). However, stratified by pre-transplant quartiles, PAI reduction was -15%, -12%, and -6% for the upper, mid-two, and lower quartiles, respectively (p value = 0.0028). The mHU stratification was -15%, -8%, and  + 12% for the upper, mid-two, and lower quartiles, respectively (p value = 0.0004). No relationship was noted between PAI and mHU. PAI and mHU decreased following liver transplantation; however, the most pronounced decrease in muscle mass and density was in patients with the highest starting muscle mass and density. However, muscle mass (PAI) and composition (mHU) appear to be affected by multiple factors.