Basic and Clinical Myology Laboratory, Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia.
Proc Nutr Soc. 2011 Feb;70(1):104-13. doi: 10.1017/S0029665110003927. Epub 2010 Nov 22.
Ageing is accompanied by a progressive loss of skeletal muscle mass and strength, leading to the loss of functional capacity and an increased risk for developing chronic metabolic diseases such as diabetes. The age-related loss of skeletal muscle mass results from a chronic disruption in the balance between muscle protein synthesis and degradation. As basal muscle protein synthesis rates are likely not different between healthy young and elderly human subjects, it was proposed that muscles from older adults lack the ability to regulate the protein synthetic response to anabolic stimuli, such as food intake and physical activity. Indeed, the dose-response relationship between myofibrillar protein synthesis and the availability of essential amino acids and/or resistance exercise intensity is shifted down and to the right in elderly human subjects. This so-called 'anabolic resistance' represents a key factor responsible for the age-related decline in skeletal muscle mass. Interestingly, long-term resistance exercise training is effective as a therapeutic intervention to augment skeletal muscle mass, and improves functional performance in the elderly. The consumption of different types of proteins, i.e. protein hydrolysates, can have different stimulatory effects on muscle protein synthesis in the elderly, which may be due to their higher rate of digestion and absorption. Current research aims to elucidate the interactions between nutrition, exercise and the skeletal muscle adaptive response that will define more effective strategies to maximise the therapeutic benefits of lifestyle interventions in the elderly.
衰老是伴随着骨骼肌质量和力量的逐渐丧失，导致功能能力下降，并增加了患慢性代谢性疾病（如糖尿病）的风险。与年龄相关的骨骼肌质量损失是由于肌肉蛋白合成和降解之间的平衡慢性破坏。由于健康的年轻和老年人体的基础肌肉蛋白合成率可能没有差异，因此有人提出，老年人的肌肉缺乏调节蛋白合成对合成代谢刺激（如食物摄入和体力活动）的能力。事实上，肌原纤维蛋白合成与必需氨基酸的可用性和/或抗阻运动强度之间的剂量反应关系在老年人体中向下和向右转移。这种所谓的“合成代谢抵抗”是导致与年龄相关的骨骼肌质量下降的关键因素。有趣的是，长期抗阻运动训练是一种有效的治疗干预措施，可以增加骨骼肌质量，并改善老年人的功能表现。不同类型的蛋白质（即蛋白质水解物）的摄入可以对老年人的肌肉蛋白合成产生不同的刺激作用，这可能是由于它们更高的消化和吸收速度。目前的研究旨在阐明营养、运动和骨骼肌适应反应之间的相互作用，这些作用将确定更有效的策略，以最大限度地提高老年人生活方式干预的治疗效益。
