Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Jun 18, 2022; 12(6): 120-130
Published online Jun 18, 2022. doi: 10.5500/wjt.v12.i6.120
Reduced upper limb lean mass on dual energy X-ray absorptiometry predicts adverse outcomes in male liver transplant recipients
Penelope Hey, Rudolf Hoermann, Paul Gow, Timothy P Hanrahan, Adam G Testro, Ross Apostolov, Marie Sinclair
Penelope Hey, Paul Gow, Timothy P Hanrahan, Adam G Testro, Ross Apostolov, Marie Sinclair, Liver Transplant Unit, Austin Health, Heidelberg 3084, Australia
Penelope Hey, Rudolf Hoermann, Paul Gow, Adam G Testro, Ross Apostolov, Marie Sinclair, Department of Medicine, University of Melbourne, Melbourne 3052, Australia
Author contributions: All authors have contributed to this manuscript and have agreed on the content; Hey P and Sinclair M were involved in the study design; Hey P and Hanrahan TP performed data collection; Hoermann R performed statistical analysis; Hey P, Gow P, Testro AG, Apostolov R and Sinclair M, were involved in data interpretation, drafting and revising the work; and all authors provided approval of the final version to be published.
Institutional review board statement: This study was approved through the Austin Health Human Research Ethics Committee.
Informed consent statement: The informed consent statement was waived.
Conflict-of-interest statement: All authors declare no conflict-of-interest related to this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Penelope Hey, FRACP, MBBS, Research Fellow, Staff Physician, Liver Transplant Unit, Austin Health, 145 Studley Road, Heidelberg 3084, Australia.
Received: January 10, 2022
Peer-review started: January 10, 2022
First decision: April 13, 2022
Revised: April 24, 2022
Accepted: May 22, 2022
Article in press: May 22, 2022
Published online: June 18, 2022
Research background

Pre-transplant sarcopenia defined by reduced skeletal muscle index measured by transverse abdominal computed tomography (CT) is associated with adverse outcomes after liver transplantation. These include increased rates of sepsis, longer hospital length of stay and a possible increase in post-transplant mortality.

Research motivation

CT is not recommended for use solely for the purpose of diagnosing sarcopenia given the high radiation doses. Dual-energy X-ray absorptiometry (DEXA) body composition assessment provides a low radiation and reproducible alternative for measuring muscle mass with prognostic utility in the pre-transplant setting. Upper limb lean mass (LM) has recently been identified as a novel assessment of sarcopenia using DEXA.

Research objectives

This study investigates the use of DEXA body composition assessment in predicting gender-stratified early post-transplant outcomes.

Research methods

This study retrospectively analysed liver transplant recipients who underwent pre-transplant DEXA body composition imaging between 2002 and 2017 at a single-centre. DEXA variables analysed included appendicular LM (APLM), total, upper and lower limb LM and fat mass corrected for height2. Endpoints included post-transplant mortality and graft failure, bacterial infections, acute cellular rejection and intensive care and total hospital length of stay (days).

Research results

Four hundred and sixty-nine patients met inclusion criteria of which 338 were male (72%). Upper limb LM was inversely associated with bacterial infections at 180 d post-transplant in males only. There was a negative correlation between upper limb LM and intensive care and total hospital length of stay in men. In women, neither model for end-stage liver disease (MELD) nor body composition parameters were associated with post-transplant adverse outcomes or increased length of stay. Body composition parameters, MELD and age were not associated with 90-d mortality or graft failure in either gender.

Research conclusions

Upper limb LM measured on DEXA is a novel measure of sarcopenia with better prognostic value compared to APLM in predicting adverse outcomes after liver transplantation. Reduced upper limb LM was a predictor of post-transplant bacterial infection and longer length of stay in men only, but was not associated with increased mortality or graft failure. The lack of association in women requires further investigation.

Research perspectives

Larger multi-centre studies that provide gender-stratified analysis of muscle mass and function serially on the waitlist are required to assess the full impact of pre-transplant sarcopenia on post-transplant outcomes. This will help determine whether prioritizing patients with sarcopenia for transplantation may be an appropriate strategy to minimize waitlist mortality without compromising post-transplant survival.