MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, National Institute for Health Research Biomedical Research Centre, University of Nottingham, Royal Derby Hospital, Derby, UK.
Curr Opin Clin Nutr Metab Care. 2017 Nov;20(6):433-439. doi: 10.1097/MCO.0000000000000413.
In addition to being essential for movement, skeletal muscles act as both a store and source of key macronutrients. As such, muscle is an important tissue for whole body homeostasis, undergoing muscle wasting in times of starvation, disease, and stress, for example, to provide energy substrates for other tissues. Yet, muscle wasting is also associated with disability, comorbidities, and mortality. As nutrition is so crucial to maintaining muscle homeostasis 'in health', it has been postulated that muscle wasting in cachexia syndromes may be alleviated by nutritional interventions. This review will highlight recent work in this area in relation to muscle kinetics, the acute metabolic (e.g. dietary protein), and longer-term effects of dietary interventions.
Whole body and skeletal muscle protein synthesis invariably exhibit deranged kinetics (favouring catabolism) in wasting states; further, many of these conditions harbour blunted anabolic responses to protein nutrition compared with healthy controls. These derangements underlie muscle wasting. Recent trials of essential amino acid and protein-based nutrition have shown some potential for therapeutic benefit.
Nutritional modulation, particularly of dietary amino acids, may have benefits to prevent or attenuate disease-induced muscle wasting. Nonetheless, there remains a lack of recent studies exploring these key concepts to make conclusive recommendations.
除了对运动至关重要外，骨骼肌还是关键营养素的储存库和来源。因此，肌肉是维持全身稳态的重要组织，在饥饿、疾病和压力等情况下会发生肌肉减少症，以向其他组织提供能量底物。然而，肌肉减少症也与残疾、合并症和死亡率有关。由于营养对维持肌肉稳态“健康”如此重要，因此有人假设营养干预可能可以缓解恶病质综合征中的肌肉减少症。这篇综述将重点介绍该领域最近在肌肉动力学、急性代谢（例如膳食蛋白质）以及膳食干预的长期影响方面的工作。
在消耗状态下，全身和骨骼肌蛋白质合成的动力学普遍失调（有利于分解代谢）；此外，与健康对照组相比，许多这些情况对蛋白质营养的合成代谢反应迟钝。这些紊乱是肌肉减少症的基础。最近的必需氨基酸和蛋白质为基础的营养试验显示出了一定的治疗益处。
营养调节，特别是膳食氨基酸的调节，可能有助于预防或减轻疾病引起的肌肉减少症。尽管如此，仍然缺乏探索这些关键概念的最新研究来做出明确的建议。
