EXERCISE EFFECTS ON PROTEIN NUTRITION IN RENAL FAILURE

运动对肾衰竭患者蛋白质营养的影响

基本信息

批准号：
2748534
负责人：
MARIA A FIATARONE
金额：
$ 12.67万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-08-01 至 2000-07-31
项目状态：
已结题

项目摘要

Nutritional status has a complex relationship to health and functional status in the elderly. Older persons are at high risk for morbidity from malnutrition due to a combination of age-related physiological changes as well as the development of acute and chronic illnesses. Marginal protein nutritional status, in particular, is of concern in the elderly, as it may contribute to detrimental changes in body composition and organ function with advancing age, as well as increasing susceptibility to acute illness. Plans are to study the nutritional status of elderly patients with chronic renal failure who are newly prescribed a low protein diet as a means to slow progression of their renal disease, as an ideal model of chronic marginal protein nutrition. In addition, plans are to investigate the efficacy and mechanism of resistance training as an anabolic stimulus which may counteract the catabolic effects of protein undernutrition. The hypotheses which will be tested are: (1) Free living elderly individuals with early stage chronic renal failure following a low protein diet of about 0.6 g per kg body weight per day will demonstrate significant losses in body cell mass and muscle cross-sectional area, which are associated with decreased muscle function, insulin-like growth factor (IGF-1), and whole -body protein turnover as assessed by leucine kinetics. (2) A progressive resistance exercise training program will attenuate these declines in body cell mass, muscle cross-sectional area and function seen in diet-only controls. (3) The mechanism by which progressive resistance exercise training will improve nitrogen economy will be via an increase in whole-body protein turnover as assessed by rates of leucine flux and leucine oxidation, in association with elevation of plasma levels of IGF-1, and the expression of IGF-1 in skeletal muscle. The design of this study is a randomized controlled trial of 30 subjects over the age of 50 with early to moderate stage chronic renal failure. Subjects will be randomized to receive a low protein diet of 0.6 g/kg body weight/day plus stretching exercises or the same diet plus whole-body resistance training 3 days/ week for 12 weeks. The effects of the diet and exercise interventions on lean tissue mass will be measured by whole- body potassium, computerized tomography scans of the thigh muscles, and skeletal muscle fiber cross-sectional area. Whole body protein turnover will be assessed by leucine kinetics. The functional outcomes of changes in nitrogen economy will be assessed via dynamic muscle strength, leg power output, and the contraction-relaxation characteristics of the adductor pollicis muscle.

营养状况与健康和功能性有复杂的关系老年人的身份。老年人的发病率很高由于年龄相关的生理变化而引起的营养不良以及急性和慢性病的发展。边缘蛋白特别是，营养状况在老年人中引起了关注，因为导致身体成分和器官功能的有害变化随着年龄的增长，并增加了对急性疾病的敏感性。计划是研究老年慢性患者的营养状况肾衰竭新处方低蛋白质饮食作为一种手段肾脏疾病的缓慢进展，是慢性的理想模型边缘蛋白营养。此外，计划是调查抗性训练作为合成代谢刺激的功效和机制这可能抵消蛋白质不足的分解代谢作用。将要测试的假设是：（1）自由活着的老年人低蛋白质后具有早期慢性肾衰竭的个体每天每公斤体重约0.6 g的饮食将证明人体细胞质量和肌肉横截面区域的重大损失，与肌肉功能降低，胰岛素样生长有关因子（IGF -1）和全体蛋白质更新，如亮氨酸评估动力学。（2）进行性抵抗运动训练计划将减弱这些人体细胞质量下降，肌肉横截面区域在饮食中只能对照中看到的功能。（3）进行性抵抗运动训练将改善氮经济将通过增加全身蛋白质周转率的增加。亮氨酸通量和亮氨酸氧化的速率与升高有关 IGF-1的血浆水平以及骨骼肌中IGF-1的表达。这项研究的设计是30名受试者的随机对照试验在50岁以上，早期至中度阶段的慢性肾衰竭。受试者将被随机接受0.6 g/kg身体的低蛋白质饮食体重/一天加伸展运动或相同的饮食以及全身阻力训练3天/周，持续12周。饮食的影响在瘦肉组织质量上进行的运动干预将由整个人体钾，计算机断层扫描大腿肌肉和骨骼肌纤维横截面区域。全身蛋白质更新将由亮氨酸动力学评估。变化的功能结果在氮经济中，将通过动态肌肉力量，腿部进行评估功率输出，以及收缩 - 放松特征的特征加和粉的肌肉。