EXERCISE, NUTRITION, AND SARCOPENIA IN OLDER ADULTS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 背景：营养摄入和举重运动都能刺激肌肉生长。然而，与年轻人相比，营养摄入(如规律膳食)并不能促进老年人的肌肉生长。 假设：我们假设水上运动训练(结合有氧运动和举重运动)结合规律的膳食摄入量，将最大限度地促进肌肉生长。 具体目标和程序(摘要)： 1)确定哪些与肌肉生长有关的分子标志物在青年和老年志愿者的营养摄入中受到刺激。 2)确定为期12周的水上运动训练计划(同时利用有氧和举重练习)是否会改善肌肉生长，以应对营养摄入。 实验设计(总结)：志愿者将在研究的前一天下午来到GCRC。护士将测量他们的体重、身高、血压，护士将抽血再次检查血细胞计数、凝血和其他一些血液测试，包括电解质(盐)和肝功能。如果这些测试结果不正常，志愿者将不被允许参与研究。还将执行DEXA扫描。 稳定的同位素。在放置导管后，志愿者将通过其中一个手臂导管获得稳定的同位素(输液)。这种输液将持续到研究结束，大约7个小时。一般来说，稳定同位素的物质与构成我们身体的常规物质非常相似，只是它们更重(但不具有放射性)。稳定同位素是一种天然化合物，也存在于你的身体中，数量非常少。对这些同位素进行测试，以确保它们是无菌的(没有可能导致感染和发烧的微生物，如细菌)。然后，我们将能够使用高度复杂的分析仪器，测量血液、呼吸和肌肉中这些物质浓度的微小变化。 肌肉活组织检查。在研究期间，我们将从放置导尿管的同一条腿上取4块肌肉活检。这个过程包括从你的腿上取下一小块肌肉。皮肤被清洗并消毒，下面的皮肤和组织被注射局部麻醉剂(麻药)以消除疼痛。最后一次活组织检查后，伤口将用一针或特殊的皮肤胶(皮肤胶)闭合。 鲜血会吸引人。研究过程中抽取的血液总量约为150毫升(约5盎司或10汤匙)。 营养补充剂。在研究期间，你将在锻炼前一小时或完成举重锻炼后一小时饮用含有糖和蛋白质(氨基酸)的营养补充剂。 (3)水上运动训练(高级志愿者) 24小时食物记录。您将被要求在培训开始时(第1周)、第4周、第8周和最后一周(第12周)，在同一周(两个工作日和一个周末)的三天内，按照我们提供的表格记录您的每日食物摄入量。Inniss博士(研究营养师)将指导您如何填写表格。 水上运动训练。您将在Tideway水上治疗中心(德克萨斯州加尔维斯顿中心大道6444号，加尔维斯顿77551)进行水上运动(在水中进行有氧运动和阻力运动的结合)，由认证教练指导。你将被要求连续12周每周参加三次预定的课程。每次练习都将完全在水中进行，持续时间约为45分钟。 (4)灌输研究(培训后)(高级义工) 在最后一次锻炼后至少48小时，你将被允许进入GCRC，并进行全身DEXA扫描。在隔夜禁食后，您将进行另一项输液研究，如上文(2)输液方案中所述。 意义(摘要)：这些研究将提供有关调节人类肌肉生长的机制，并将被用作开发干预措施的基础，以改善老龄化人口的肌肉生长。

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: Nutritional intake and weight lifting exercise can both stimulate muscle growth. However, nutritional intake (such as regular meal) does not promote as much muscle growth in senior citizens as compared to younger individuals. Hypothesis: We hypothesize that an aquatic exercise training (combining both aerobic and weight lifting exercise) will maximize the muscle growth when combined with regular meal intake. Specific Aims and Procedures (summary): 1) To determine which molecular markers involved in muscle growth are stimulated with nutritional intake in young and older volunteers. 2) To determine if a 12-week aquatic exercise training program (utilizing both aerobic and weight lifting exercises) will improve the muscle growth in response to a nutritional intake. Experimental Design (summary): Volulnteers will come to the GCRC the afternoon before the study. The nurses will measure their weight, height, blood pressure, and the nurses will draw blood to check again blood count, clotting, and some other blood tests including electrolytes (salts) and liver function. Should these tests result abnormal, volunteers will not be allowed to participate to the study. A DEXA scan will also be performed. Stable isotopes. After the catheters are placed, volunteers will be given stable isotopes (infusion) through one of the arm catheters. This infusion will go on until the end of the study, about 7 hours. In general, stable isotopes are of a material very similar to the regular material our body is made of, except that they are heavier (but not radioactive). Stable isotopes are natural compounds also present in very small quantities in your body. The isotopes are tested in order to assure their sterility (absence of microorganisms, such as bacteria, that may give infections and fever). We will then be able, using highly sophisticated analytical instruments, to measure the small changes in the concentration of these substances in your blood, breath, and muscle. Muscle biopsies. During the study we will take 4 muscles biopsies from the same leg in which we placed the catheters. This procedure involves the taking of a small piece of muscle from your leg. The skin is cleaned and made sterile, and the skin and tissue below are injected with local anesthetic (numbing medicine) to eliminate pain After the last biopsy the incision will be closed with one stitch or a special skin glue (Dermabond). Blood draws. The total amount of blood drawn during the study will be approximately 150 ml (approximately 5 ounces or 10 tablespoons). Nutritional Supplement. During the study you will drink a nutritional supplement that contains sugar and protein (amino acids) one hour prior to exercising or one hour after completing the weight lifting exercise. (3) Aquatic Exercise Training (senior volunteers) 24-Hour food record. You will be asked to record your daily food intake in the form provided by us for three days during the same week (two week days and one weekend day) at the start of the training (1st week), during 4th, 8th, and last (12th) week of training. Dr. Inniss (research dietitian) will give you an instruction how to fill out the form. Aquatic Exercise Training. You will perform aquatic exercise (combination of aerobic and resistance exercise in the water) at the TideWay Aquatic Therapy Center (6444 Central City Blvd, Galveston TX 77551) instructed by certified trainers. You will be asked to attend three scheduled classes each week for 12 weeks consecutively. Each exercise session will be performed entirely in the water which lasts approximately for 45 minutes. (4) Infusion Study (Post-training) (senior volunteers) At least 48 hours after the last exercise session, you will be admitted at GCRC and whole body DEXA scan will be performed. After an overnight fast, you will perform another infusion study as described above in (2) Infusion Protocol. Significance (summary): These studies will provide regarding the mechanisms that regulate human muscle growth, and will be utilized as a basis from which to develop interventions for improving muscle growth in aging population.