Higher Mortality in Pediatric Liver Transplant Candidates With Sarcopenia

Abstract

Little is known about the impact of sarcopenia (reduced muscle mass and function) in pediatric chronic liver disease. We compared psoas muscle surface area (PMSA), measured at the 4th lumbar vertebrae, in children listed for liver transplantation (LT) to that of healthy controls and studied the impact of sarcopenia on transplant-associated outcomes. The effect of PMSA (raw value and z score) on survival was studied using multivariable proportional hazards, whereas the impact of PMSA on other transplant-associated outcomes was assessed by multivariable linear or logistic regression. The correlation of PMSA with anthropometric values and markers of disease severity was studied using Spearman's rank-order correlation. Mean PMSA was significantly lower in LT candidates (n = 57, 699.4 ± 591.9 mm² [mean ± SD]) than controls (n = 53, 1052.9 ± 960.7 mm² ; P = 0.02). For LT candidates, there was an increased risk of death (either while on the waiting list or following transplantation) with lower PMSA (hazard ratio [HR], 1.6 per 100 mm² [P = 0.03]; 95% confidence interval [CI], 1.1-2.8), amounting to a 4.9 times higher risk of death for every 1 unit decrease in PMSA z score (HR, 4.9 [P = 0.05], 95% CI, 1.2-34.5), adjusting for age and sex. PMSA did not correlate with posttransplant length of intubation, hospital length of stay, or perioperative complications. PMSA also did not correlate with calculated (r = 0.10, P = 0.60) or appealed Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores (r = 0.10, P = 0.69). Pediatric LT candidates have a significant reduction in muscle compared with controls. LT candidates with lower PMSA experience significant increases in mortality. As such, sarcopenia may provide a novel indicator of disease severity in children with chronic liver disease.