School of Medicine, The University of Queensland, Brisbane, Queensland, Australia; Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Queensland, Australia; Translational Research Institute, Brisbane, Australia.
Centre for Research on Exercise, Physical Activity and Health (CRExPAH), School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, Australia.
Clin Nutr ESPEN. 2021 Aug;44:287-296. doi: 10.1016/j.clnesp.2021.05.029. Epub 2021 Jun 11.
Loss of skeletal muscle mass is a well-recognised complication of cirrhosis. Bedside methods to assess skeletal muscle mass including anthropometrics and bioelectrical impedance analysis (BIA) are negatively impacted by fluid overload in advanced cirrhosis and thus there is a need to identify alternatives. There is a paucity of data on the accuracy of commonly used radiological methods such as dual X-ray absorptiometry (DXA) to assess appendicular lean mass (ALM), and computed tomography (CT) skeletal muscle area in patients with cirrhosis. The aim of this study was to evaluate the relationships and agreement of several skeletal muscle mass estimation methods compared to a reference model in patients with cirrhosis.
A cross-sectional, single centre study was performed by prospectively recruiting patients with cirrhosis referred to the Queensland Liver Transplant Service. Patients underwent assessment of skeletal muscle mass using bedside techniques (mid-upper arm muscle circumference (MUAMC), bioelectrical impedance spectroscopy (BIS), ultrasound muscle thickness (USMT)) and radiological methods (DXA ALM, CT skeletal muscle area). These were compared to a reference measurement of body cell mass derived from a multi-compartment model using isotope dilution tests and DXA.
Forty-two patients (age 56 years, interquartile range 48-60, 86% male) were recruited. Bedside skeletal muscle mass estimation techniques were strongly correlated to the body cell mass reference, with BIS estimation having the strongest correlation coefficients (r = 0.78-0.79; P < 0.01). A novel technique measuring USMT offered no advantage over traditional bedside techniques. Of the radiological methods, DXA ALM had the strongest correlation coefficient (r = 0.781; P < 0.01). Weaker correlation coefficients were observed in patients with ascites, except when using the MUAMC. Bland-Altman analysis of BIS body composition estimates demonstrated significant systematic biases and large limits of agreement compared to reference values.
These results confirm the difficulties in assessing skeletal muscle mass in patients with cirrhosis, particularly in those with ascites. DXA ALM and BIS measurements provided the best correlation to body cell mass. We suggest DXA ALM for estimation of skeletal muscle mass in patients with cirrhosis as there are established thresholds for skeletal muscle mass depletion, and an accurate assessment of bone mass and density can also be provided. The use of USMT over other bedside skeletal muscle mass estimates was not supported by our results. Further studies evaluating novel bedside skeletal muscle mass estimation techniques in cirrhosis patients are required.
骨骼肌量减少是肝硬化的一种公认并发症。评估骨骼肌量的床边方法包括人体测量学和生物电阻抗分析（BIA），但在晚期肝硬化中会受到液体超负荷的负面影响，因此需要寻找替代方法。目前，关于双能 X 射线吸收法（DXA）等常用影像学方法评估肝硬化患者四肢瘦体重（ALM）和计算机断层扫描（CT）骨骼肌面积的准确性数据较少。本研究旨在评估几种骨骼肌量评估方法与肝硬化患者参考模型的相关性和一致性。
通过前瞻性招募昆士兰肝移植服务中心转介的肝硬化患者进行横断面、单中心研究。患者接受床边技术（中上臂肌围（MUAMC）、生物电阻抗光谱（BIS）、超声肌肉厚度（USMT））和影像学方法（DXA 四肢瘦体重、CT 骨骼肌面积）评估骨骼肌量。将这些方法与使用同位素稀释试验和 DXA 得出的多腔室模型参考的体细胞质量进行比较。
共纳入 42 例患者（年龄 56 岁，四分位间距 48-60，86%为男性）。床边骨骼肌量评估技术与体细胞质量参考值密切相关，其中 BIS 评估的相关性最强（r=0.78-0.79；P<0.01）。测量 USMT 的新技术与传统床边技术相比没有优势。在影像学方法中，DXA ALM 的相关性最强（r=0.781；P<0.01）。腹水患者的相关性系数较弱，MUAMC 除外。与参考值相比，BIS 身体成分估计的 Bland-Altman 分析显示出显著的系统偏差和较大的一致性界限。
这些结果证实了评估肝硬化患者骨骼肌量的困难，特别是腹水患者。DXA ALM 和 BIS 测量与体细胞质量相关性最好。我们建议在肝硬化患者中使用 DXA ALM 评估骨骼肌量，因为有骨骼肌量减少的既定阈值，并且还可以提供准确的骨量和密度评估。我们的结果不支持 USMT 优于其他床边骨骼肌量评估方法。需要进一步研究评估肝硬化患者新型床边骨骼肌量评估技术。
