Muscle fat infiltration assessed by total psoas density on computed tomography predicts mortality in cirrhosis

Background: Ongoing evidence suggests that sarcopenia adversely affects outcomes in cirrhosis. The aim of this study was to evaluate muscle fat infiltration as a component of sarcopenia and its prognostic value in this setting. Methods: In 98 consecutive patients with cirrhosis, muscle density was measured during a computed tomography scan at the level of the fourth to fifth lumbar (L4) vertebrae. Univariate and multivariate Cox regression analysis was used to determine predictors of survival. Results: Body mass index: median 26 (range 17-45.2); model for end-stage liver disease (MELD) score: median 11 (6-29); Child-Pugh (CP) score: median 7 (5-13), CP class: A=49 (50.5%), B=39 (40%), C=10 (9.5%); hepatocellular carcinoma: 14 (14.3%); follow up: median 45 (1-140) months. Median L4 total psoas area (TPA): 2022 (777-3806) mm2; L4 average total psoas density (ATPD): 42.52 (21.26-59.8) HU. ATPD was significantly correlated with age (r=-0.222, P=0.034), creatinine (r=-0.41, P<0.001), albumin (r=0.224, P=0.035), MELD score (r=-0.218, P=0.034), and TPA (r=0.415, P<0.001). Fifty-four patients (55.1%) died during follow up. In the multivariate analysis, higher CP score (hazard ratio [HR] 1.2, 95% confidence interval [CI] 1.04-1.41), advanced age (HR 1.038, 95%CI 1.006-1.07) and lower ATPD (HR 0.967, 95%CI 0.937-0.997) were predictors of mortality. Conclusion: Muscle fat infiltration, as a result of sarcopenia, is a negative predictive factor of survival in cirrhosis, emphasizing the need for early identification of this subgroup of patients.