Fragala Maren S, Kenny Anne M, Kuchel George A
Institute of Exercise Physiology and Wellness, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL, 32816, USA,
Sports Med. 2015 May;45(5):641-58. doi: 10.1007/s40279-015-0305-z.
Aging is often accompanied by declines in physical functioning which impedes older adults' quality of life, sense of independence, and ability to perform daily tasks. Age-related decreases in skeletal muscle quantity, termed sarcopenia, have traditionally been blamed for these physical decrements. However, recent evidence suggests that the quality of muscle tissue may be more functionally relevant than its quantity. 'Muscle quality' has been emerging as a means to elucidate and describe the intricate intramuscular changes associated with muscle performance in the context of aging and sarcopenia. While muscle quality has most commonly been defined in terms of muscle composition or relative strength, at the core, muscle quality really describes muscle's ability to function. Skeletal muscle displays a strong structure-function relationship by which several architectural characteristics factor into its functional capacity. This review describes the structural, physiological, and functional determinants of muscle quality at the tissue and cellular level, while also introducing other novel parameters such as sarcomere spacing and integrity, circulating biomarkers, and the muscle quality index. Muscle qualitative features are described from the perspective of how physical exercise may improve muscle quality in older adults. This broad, multidimensional perspective of muscle quality in the context of aging and sarcopenia offers comprehensive insights for consideration and integration in developing improved prognostic tools for research and clinical care, while also promoting translational approaches to the design of novel targeted intervention strategies designed to maintain function and mobility into late life.
衰老常常伴随着身体机能的下降，这会妨碍老年人的生活质量、独立感以及执行日常任务的能力。与年龄相关的骨骼肌量减少，即肌肉减少症，传统上一直被认为是这些身体机能下降的原因。然而，最近的证据表明，肌肉组织的质量可能比其数量在功能上更具相关性。“肌肉质量”已逐渐成为一种手段，用于阐明和描述在衰老和肌肉减少症背景下与肌肉性能相关的复杂肌肉内变化。虽然肌肉质量最常根据肌肉组成或相对力量来定义，但本质上，肌肉质量真正描述的是肌肉的功能能力。骨骼肌呈现出强大的结构 - 功能关系，通过这种关系，几个结构特征因素影响其功能能力。本综述描述了组织和细胞水平上肌肉质量的结构、生理和功能决定因素，同时还介绍了其他新参数，如肌节间距和完整性、循环生物标志物以及肌肉质量指数。从体育锻炼如何改善老年人肌肉质量的角度描述了肌肉的定性特征。在衰老和肌肉减少症背景下对肌肉质量这种广泛的、多维度的观点，为开发改进的研究和临床护理预后工具时的考虑和整合提供了全面的见解，同时也促进了针对设计旨在维持晚年功能和活动能力的新型靶向干预策略的转化方法。
