AMINO ACID SUPPLEMENTATION AND MUSCLE

氨基酸补充和肌肉

• 批准号: 7605379
• 负责人: ARNY A FERRANDO
• 金额: $ 3.17万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7605379
• 关键词: Admission activity; Aging; Amino Acids; Astronauts; Bed rest; Blood Tests; Body Composition; Burn injury; Caring; Chronic Disease; Computer Retrieval of Information on Scientific Projects Database; Critical Illness; Daily; Diet; Economics; Elderly; Endocrine system; Essential Amino Acids; Exercise; Experimental Designs; Funding; Goals; Grant; Growth; Health Status; Heart; Home environment; Hospitalization; Individual; Injury; Institution; Insulin Resistance; Intervention; Investigation; Length of Stay; Metabolic; Metabolic Control; Morbidity - disease rate; Muscle; Muscle Proteins; Muscle function; Nutritional; Operative Surgical Procedures; Outcome; Patients; Physiological; Physiology; Population; Prevalence; Procedures; Protein Biosynthesis; Proteins; Purpose; Range; Recording of previous events; Recovery; Recovery of Function; Rehabilitation therapy; Research; Research Personnel; Resistance; Resources; Risk; Screening procedure; Source; Speed; Standards of Weights and Measures; Stress; Stress Tests; Supplementation; Testing; Time; TimeLine; Treatment Protocols; United States National Institutes of Health; Visit; Walking; Woman; aging population; day; improved; metabolic abnormality assessment; mortality; nutrition; older men; older patient; prevent; programs; protein metabolism; response; volunteer; wasting

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background: Muscle wasting and weakness are common due prolonged inactivity and bedrest. Unfortunately, bedrest is a common occurrence post surgery, serious injury, or chronic illness. The loss of lean body mass (LBM) with inactivity is associated with longer recovery time and a great decrease in overall health status. Due to the greater prevalence of surgeries and serious illnesses in the aging population, the elderly are at an increased risk for morbidity and mortality. Our previous investigations in younger individuals demonstrated that minimal resistance exercise and nutritional supplementation with essential amino acids can maintain LBM and preserve or diminish the loss of muscle function. Therefore, the goal of this project is to examine the effects of essential amino acids alone or in combination with resistance or walking exercise on muscle protein metabolism, LBM and muscle function in older individuals. Hypothesis: The purpose of the study is to determine how the elderly's muscle and hormonal system respond to 10 days of bedrest. The study will also determine if amino acid (protein) supplementation and exercise can reduce muscle loss and maintain muscle function during 10 days of bedrest. Specific Aims and Procedures (summary): The importance of maintaining muscle mass and function after forced inactivity, such as illness, is clear. Information obtained from these studies will allow for a better understanding of the mechanisms involved in muscle protein metabolism in the elderly. This project will test two proven strategies that should reduce the loss of muscle mass and function in the elderly undergoing bedrest. Further, this project will investigate these strategies in terms of rehabilitation from inactivity and return to normal function. This project will help explain the metabolic mechanisms involved in response to exercise and nutrition. This information will be valuable for determining the optimal nutritional and exercise strategies to minimize the loss of muscle mass and function during hospitalization. These strategies are not only important for healthy individuals, but for those populations that will benefit from muscle growth, e.g., elderly, burn patients, astronauts, and those rehabilitating from serious injury or critical illness. Experimental Design (summary): We propose to study three groups of older men and women (65-80 years) before, during, and after 10 days of bedrest: 1) a group who will receive three supplements per day of EAA alone (EAA), 2) a group that will receive the same EAA supplementation plus three sessions of resistance exercise throughout bedrest (EAA+RE), and 3) a group who will receive EAA supplementation plus the standard-of-care daily walking exercise (EAA+WE). We will examine the hypotheses that the combination of EAA and these exercise regimens will be more effective in preserving muscle protein synthesis, LBM, and muscle function than either intervention alone. Further, we propose that combination of these interventions will expedite recovery from bedrest. Finally, we propose that these interventions, or combination of interventions, will be effective in maintaining muscle protein synthesis, muscle mass, and function in the elderly. Bedrest Study Timeline Study Visit Procedures Duration Screening visit one Blood tests, history, and physical 1-2 hr Screening visit two Heart station stress test 2-3 hr Study Days 1-4 (non-bedrest) Admission to GCRC Diet stabilization Strength testing Body composition testing Subjects at GCRC Study Day 5 1st Metabolic Study Study Days 6-8 Controlled metabolic diet Study Days 9-18 10 days' bedrest Study Day 18 2nd Metabolic Study Study Days 19-21 (non-bedrest) Strength testing Body composition testing PT and rehab sessions Bedrest ends on Day 19 Study Day 21 Discharge from GCRC - home Study Days 22-82 Rehabilitation program (up to 60 days) 60 min, 3 days/wk Significance (summary): Taken together, these findings demonstrate that the elderly have a higher likelihood of morbidity and mortality related to prolonged hospitalization and inactivity. There are several factors that contribute to the resulting loss of muscle mass and function: 1. For a given surgical procedure or injury, elderly patients require a longer period of hospitalization. 2. The elderly have an existing degree of insulin resistance that is exacerbated during physiological stress. 3. The elderly have less lean body and muscle mass than the young; therefore, a given loss of LBM has a greater impact on survivability, recovery, and function. 4. The elderly patient tends to be undernourished and this relates to length of hospital stay and outcome. Despite the proclaimed standard of care that attempts to get patients up and moving as quickly as possible after injury or surgery, the "reality" of care is that this does not often occur. Bedrest may not be prescribed for many maladies, but is inherent in the treatment of elderly patients. Attempts to adhere to the standard of care are thwarted by numerous factors, ranging from the inherent compromises of the aging physiology to economic and logistical issues. Given the dangers and risks of inactivity and bedrest on the elderly, it is vital that interventions be implemented to overcome these effects. We anticipate that the two interventions that were found, in our previous studies, to ameliorate the loss of LBM and muscle function in younger, bedrested volunteers will be effective at doing the same in the elderly. If this proves to be true, these interventions can be used to prevent or minimize loss of LBM and muscle function during periods of inactivity, which will improve and speed recovery thus having an enormous, positive impact for elderly individuals.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 背景：由于长时间不活动和卧床休息，肌肉萎缩和无力是常见的。不幸的是，卧床休息是手术、严重受伤或慢性疾病后常见的情况。不活动导致的去脂体重 (LBM) 损失与较长的恢复时间和整体健康状况的大幅下降有关。由于老龄化人口中手术和严重疾病的发生率更高，老年人的发病和死亡风险增加。我们之前对年轻人的研究表明，最小的阻力运动和补充必需氨基酸的营养可以维持 LBM 并保持或减少肌肉功能的丧失。因此，该项目的目标是检查必需氨基酸单独或与阻力或步行运动相结合对老年人肌肉蛋白质代谢、LBM 和肌肉功能的影响。 假设：该研究的目的是确定老年人的肌肉和荷尔蒙系统对卧床休息 10 天有何反应。该研究还将确定氨基酸（蛋白质）补充和运动是否可以减少卧床休息 10 天期间的肌肉损失并维持肌肉功能。 具体目标和程序（摘要）：在被迫不活动（例如生病）后保持肌肉质量和功能的重要性是显而易见的。从这些研究中获得的信息将有助于更好地了解老年人肌肉蛋白质代谢的机制。该项目将测试两种行之有效的策略，以减少卧床老年人的肌肉质量和功能损失。此外，该项目还将研究这些从不活动中康复和恢复正常功能方面的策略。该项目将有助于解释运动和营养反应所涉及的代谢机制。这些信息对于确定最佳营养和运动策略非常有价值，以尽量减少住院期间肌肉质量和功能的损失。这些策略不仅对健康个体很重要，而且对那些将从肌肉生长中受益的人群也很重要，例如老年人、烧伤患者、宇航员以及从严重受伤或危重疾病中康复的人群。 实验设计（摘要）：我们建议对三组老年男性和女性（65-80 岁）在卧床休息 10 天之前、期间和之后进行研究：1) 一组每天仅接受 3 次 EAA 补充剂 (EAA)，2) 一组接受相同的 EAA 补充剂加上整个卧床期间的 3 次阻力运动 (EAA+RE)，3) 一组接受 EAA 补充剂加上标准护理每日步行锻炼 （EAA+我们）。我们将检验以下假设：EAA 与这些运动方案相结合，比单独使用任何一种干预措施更能有效地保护肌肉蛋白质合成、LBM 和肌肉功能。此外，我们建议结合这些干预措施将加速卧床恢复。最后，我们建议这些干预措施或干预措施的组合将有效维持老年人的肌肉蛋白质合成、肌肉质量和功能。 卧床休息研究时间表 考察访问程序持续时间 筛查访视 1 次 血液检查、病史和体检 1-2 小时 筛选访问两次 心脏站压力测试 2-3 小时 学习第 1-4 天 （非卧床休息）进入 GCRC 饮食稳定 强度测试 GCRC 身体成分测试对象 研究第 5 天第一次代谢研究 研究第 6-8 天 控制代谢饮食 研究第 9-18 天 卧床休息 10 天 研究第 18 天第二次代谢研究 学习日 19-21 （非卧床）强度测试 身体成分测试 PT 和康复课程 卧床休息于第 19 天结束 研究第 21 天 GCRC 出院 - 家 学习天数 22-82 康复计划（最长 60 天）60 分钟，每周 3 天 意义（摘要）：总而言之，这些研究结果表明，老年人因长期住院和不活动而发病和死亡的可能性更高。 有几个因素会导致肌肉质量和功能的丧失： 1. 对于特定的手术或损伤，老年患者需要较长的住院时间。 2.老年人存在一定程度的胰岛素抵抗，在生理应激时会加剧。 3、老年人的瘦身量和肌肉量比年轻人少；因此，LBM 的特定损失对生存能力、恢复和功能具有更大的影响。 4. 老年患者容易营养不良，这与住院时间和结果有关。 尽管宣称的护理标准试图让患者在受伤或手术后尽快起床并活动，但护理的“现实”是这种情况并不经常发生。 对于许多疾病来说，卧床休息可能并不适用，但却是老年患者治疗中固有的。 遵守护理标准的尝试受到许多因素的阻碍，从衰老生理的固有妥协到经济和后勤问题。 鉴于老年人不活动和卧床的危险和风险，采取干预措施来克服这些影响至关重要。 我们预计，在我们之前的研究中发现的两种干预措施，可以改善卧床休息的年轻志愿者的 LBM 和肌肉功能丧失，也能有效地对老年人起到同样的作用。 如果事实证明这是真的，这些干预措施可用于预防或尽量减少不活动期间的 LBM 和肌肉功能损失，这将改善并加速康复，从而对老年人产生巨大的积极影响。