Ferrando Arny A, Paddon-Jones Douglas, Wolfe Robert R
Department of Surgery, University of Texas Medical Branch, Shrine Hospital for Children, Galveston, Texas 77550, USA.
Curr Opin Clin Nutr Metab Care. 2006 Jul;9(4):410-5. doi: 10.1097/01.mco.0000232901.59168.e9.
The loss of skeletal muscle with injury or critical illness can be dramatic. This review emphasizes the importance of skeletal muscle as a metabolic reserve. Changes in protein metabolism with bed rest alone and during physiological stress are discussed. Nutritional and hormonal interventions that ameliorate the loss of skeletal muscle are highlighted.
The loss of skeletal muscle that occurs with inactivity alone can be prevented by nutritional supplementation with an essential amino acid formula. Bed rest with accompanying hypercortisolemia produces a threefold greater loss of skeletal muscle than bed rest alone. Essential amino acids stimulate muscle anabolism during acute hypercortisolemia; however, their effects during chronic hypercortisolemia must be explored.
Skeletal muscle loss with trauma or critical illness is due in great part to the interaction of bed rest (muscular inactivity) and stress (hypercortisolemia). Younger individuals respond to nutritional and pharmacological interventions during bed rest alone. Given a lower relative lean mass in the elderly and the importance of skeletal muscle as a metabolic reserve during stress, it is understandable that clinical outcomes are worse in older patients. Countermeasures to the loss of skeletal muscle, especially in the stressed patient, must be developed.
损伤或危重病期间骨骼肌的丢失可能很显著。本综述强调骨骼肌作为代谢储备的重要性。讨论了仅卧床休息以及生理应激期间蛋白质代谢的变化。着重介绍了改善骨骼肌丢失的营养和激素干预措施。
仅通过不活动导致的骨骼肌丢失可通过补充必需氨基酸配方营养物来预防。伴有高皮质醇血症的卧床休息比单纯卧床休息导致的骨骼肌丢失多三倍。在急性高皮质醇血症期间，必需氨基酸可刺激肌肉合成代谢；然而，必须探究其在慢性高皮质醇血症期间的作用。
创伤或危重病期间骨骼肌的丢失在很大程度上归因于卧床休息（肌肉不活动）和应激（高皮质醇血症）的相互作用。仅卧床休息期间，较年轻个体对营养和药物干预有反应。鉴于老年人相对瘦体重较低以及骨骼肌在应激期间作为代谢储备的重要性，老年患者临床结局较差是可以理解的。必须制定针对骨骼肌丢失的对策，尤其是针对应激患者。
