Improving exercise capacity in chronic obstructive pulmonary disease patients through uphill walking

慢性阻塞性肺疾病（COPD）是发病率和死亡率的主要原因， 重要的医疗保健问题，特别是对退伍军人。退伍军人人群COPD患病率范围 从33%-43%，高于美国的一般人群的患病率。copd患者 运动能力下降。这种运动能力的限制很大一部分是由于 动态过度充气和呼吸困难。人类展示了行走和 呼吸了我们的初步数据表明，COPD患者表现出异常的耦合模式 与那些没有COPD的人相比，使用一个步幅进行一次呼吸，即使在他们自己选择的速度之外， 步行速度。目前的肺康复依赖于通过加速运动来增加运动强度。 走路根据COPD患者的偶联模式，增加速度会导致 呼吸频率、动态过度充气和呼吸困难，从而限制运动时间。这一提议的目的是 一个项目是调查慢性阻塞性肺疾病（COPD）退伍军人患者，在斜坡上走得更快与走得更快的效果 对动态过度充气和呼吸困难、氧摄取和死腔以及行走和呼吸的影响 偶合器.我们假设，在斜坡上行走会改变呼吸和行走的耦合，降低 呼吸频率，并减少动态过度充气和相关的呼吸困难。我们预测步行 在斜坡上将允许增加氧摄取和减少死腔患者 COPD与加速行走速度相比。这些假设将通过三个目标进行测试：1） 确定动态过度充气和呼吸困难的差异; 2）比较呼吸频率、氧气 摄取和肺死腔; 3）确定行走和呼吸耦合比率的复杂性。在这 在一项横断面研究中，将招募患有COPD的退伍军人，并使用心肺运动进行筛选 test.通过疾病严重程度分层抽样，共招募25名合格退伍军人。的时间 将根据心肺运动试验计算工作过程速率。速度和坡度， 对应于峰值工作率的70%-80%。将进行额外的恒定工作速率测试 使用水平跑步机的速度增加来确定与水平跑步机相比的促进氧摄取的速度。 斜坡行走测试受试者将被要求进行两项实验性试验（更快地行走vs. a斜率）在70%-80%的峰值工作速率下。测量动态过度充气、呼吸困难、氧摄取、死亡 空间和耦合将在所有行走试验期间记录。还将收集可能的协变量。我们 预计COPD患者的动态过度充气和呼吸困难将减少， 步行和较慢的呼吸率在斜坡步行相比，更快的水平步行。预计 这将受到呼吸和行走耦合比的复杂性的影响。我们的多学科 团队将提供来自多个学科的综合专业知识，并具有独特的资格来完成目标 提出了这项可行性和可接受性研究的结果将为一项严格、有力、全面的 优秀奖成果研究，评估斜坡训练方案的有效性， 康复活动.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality and presents an important healthcare problem, especially for Veterans. Prevalence of COPD in the Veteran population ranges from 33%-43%, a higher prevalence than among the general population of the United States. COPD patients experience diminished exercise capacity. A significant portion of this limitation in exercise capacity is due to dynamic hyperinflation and dyspnea. Humans demonstrate a coupled relationship between walking and breathing. Our preliminary data indicates that patients with COPD demonstrate an abnormal coupling pattern compared to those without COPD, using one stride for one breath, even at speeds outside of their self-selected walking pace. Current pulmonary rehabilitation relies on increasing intensity of exercise through accelerated walking. Based on coupling patterns in patients with COPD, increasing speed leads to an increase in respiratory rate, dynamic hyperinflation, and dyspnea, thus limiting exercise time. The goal of this proposed project is to investigate, in Veteran COPD patients, the effect of walking faster vs. walking on a slope on dynamic hyperinflation and dyspnea, oxygen uptake and dead space, and walking and breathing coupling. We hypothesize that walking on a slope will alter breathing and walking coupling, lower respiratory rates, and reduce dynamic hyperinflation and associated dyspnea. We predict that walking on a slope will permit an increase in oxygen uptake and a decrease in dead space in patients with COPD as compared to accelerated walking speeds. These hypotheses will be tested through three aims: 1) Identify differences in dynamic hyperinflation and dyspnea; 2) Compare differences in respiratory rate, oxygen uptake, and lung dead space; 3) Determine the complexity of walking and breathing coupling ratios. In this cross-sectional study, Veterans with COPD will be recruited and screened using a cardiopulmonary exercise test. A total of 25 eligible Veterans will be enrolled through stratified sampling of disease severity. The time course of work rate will be calculated from the cardiopulmonary exercise test. The speed and slope that corresponds to 70%-80% of peak work rate will be used. An additional constant work rate test will be given using increases in speed with a level treadmill to determine the speed that elicits oxygen uptake comparable to the sloped walking test. Subjects will be asked to perform two experimental trials (walking faster vs. walking on a slope) at 70%-80% peak work rate. Measures of dynamic hyperinflation, dyspnea, oxygen uptake, dead space, and coupling will be recorded during all walking trials. Possible covariates will also be collected. We anticipate that dynamic hyperinflation and dyspnea will be reduced in patients with COPD due to slower walking and slower respiratory rates during sloped walking as compared to faster level walking. It is expected that this will be influenced by the complexity in breathing and walking coupling ratios. Our multidisciplinary team will provide combined expertise from several disciplines and is uniquely qualified to complete the aims proposed. Results from this feasibility and acceptability study will set the stage for a rigorous, well-powered, full Merit award outcome study evaluating the effectiveness of a slope-based training regimen as part of rehabilitation.