Muscle Mass, Quality, and Composition Changes During Atrophy and Sarcopenia
Muscle Mass, Quality, and Composition Changes During Atrophy and Sarcopenia
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DOI：
10.1007/978-981-13-1435-3_3
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发表时间：
2018-01-01
期刊：
影响因子：
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通讯作者：
Yamada, Yosuke
中科院分区：
文献类型：
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作者：
Yamada, Yosuke
人一生中，骨骼肌质量和肌肉力量在20 ~ 40岁达到高峰，然后随着年龄的增长而下降。肌肉力量或功率的下降率是SMM的2 ~ 4倍。因此，标准化的肌肉力量（肌肉力量除以SMM）也在老化中降低。它取决于骨骼肌组织和神经肌肉系统中因子的数量。在人体研究中，如果不进行解剖，就无法直接测量SMM，因此所有方法都是评估SMM的间接方法，甚至是计算机断层扫描或磁共振成像。双能X线吸收法、超声检查、人体测量和生物电阻抗分析（BIA）被用作估计SMM的次要间接方法。近年来的研究表明，随着年龄的增长和/或身体机能的下降，肌肉组成发生变化，特别是肌细胞质量（MCM）与SMM的比率下降，细胞外水（ECW）和细胞外空间的相对扩张。利用节段性生物电阻抗谱或多频生物电阻抗分析技术测定的细胞内水（ICW）和细胞内水（ECW）是反映肢体MCM/SMM比值的良好生物标志物。BIS和其他用于评估肌肉质量、质量和组成的最先进技术对于充分了解生物体中的肌肉萎缩是有用的。
Skeletal muscle mass (SMM) and muscle strengh reach their peak in 20s to 40s of age in human life and then decrease with advancing age. The decrease rate of muscle strength or power was twice to four times as large as that of the SMM. Thus, the normalized muscle force (muscle strength divided by SMM) also decreases in aging. It depends on the number of factors in skeletal muscle tissues and neuromuscular system. In human study, SMM cannot be measured directly without dissection so that all of the methodologies are indirect methods to assess SMM, even computing tomography or magnetic resonance imaging. Dual-energy X-ray absorptiometry, ultrasonography, anthropometry, and bioelectrical impedance analysis (BIA) are used as secondary indirect methods to estimate SMM. Recent researches show muscle composition changes in aging, and in particular, the ratio of muscle cell mass (MCM) against SMM decrease and relative expansion of extracellular water (ECW) and extracellular space is observed with advancing age and/or decrease of physical function. The intracellular water (ICW) and ECW estimated by segmental bioelectrical impedance spectroscopy or multifrequency BIA are good biomarkers of the ratio of MCM against SMM in limbs. The BIS and other state-of-the-art technology for assessment of muscle mass, quality, and composition are useful to fully understand the muscle atrophy in a living organism.