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，并呈现出 重要的医疗保健问题，特别是对退伍军人来说。退伍军人人群中慢性阻塞性肺疾病的患病率 从33%-43%，高于美国普通人群的患病率。慢性阻塞性肺疾病患者 经验削弱了运动能力。运动能力的这种限制有很大一部分是由于 动态的恶性通货膨胀和呼吸困难。人类表现出行走和运动之间的耦合关系 呼吸。我们的初步数据表明，COPD患者表现出一种异常的偶联模式 与没有慢性阻塞性肺病的人相比，使用一步一呼吸，即使在他们自己选择的速度之外也是如此 走路的步调。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患者的耦合模式，速度增加会导致 呼吸频率、动态过度充气和呼吸困难，从而限制了运动时间。这项提议的目标是 该项目旨在调查在退伍军人COPD患者中，走得更快与在斜坡上行走的效果 关于动力性过度充气和呼吸困难，摄氧量和死腔，以及行走和呼吸 耦合。我们假设在斜坡上行走会改变呼吸和行走的耦合，降低 降低呼吸频率，减少动态恶性充气和伴随的呼吸困难。我们预测，步行 在斜坡上将允许增加氧气摄取和减少死亡空间的患者 慢性阻塞性肺疾病与加速步行速度相比。这些假设将通过三个目标进行检验：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、肺死腔；3)决定步行与呼吸耦合的复杂程度。在这 横断面研究，将招募患有COPD的退伍军人并通过心肺锻炼进行筛查 测试。共有25名符合条件的退伍军人将通过疾病严重程度的分层抽样进行登记。时间 工作时间将根据心肺运动试验计算。它的速度和斜率 对应于70%-80%的峰值工作率将被使用。将进行一项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以下情况相当的摄氧量速度 斜面行走试验。受试者将被要求进行两个实验试验(走得更快与继续走 斜率)在70%-80%的峰值工作率下。动态过度充气、呼吸困难、摄氧量、死亡的测量 空间，在所有步行试验期间将记录耦合。还将收集可能的协变量。我们 预计慢性阻塞性肺疾病患者的动态过度充气和呼吸困难将由于减慢而减少 与较快的水平行走相比，倾斜行走时的步行和较慢的呼吸频率。这是意料之中的 这将受到呼吸和行走耦合比率的复杂性的影响。我们的多学科 团队将提供来自几个学科的综合专业知识，并具有完成目标的唯一资格 建议。这项可行性和可接受性研究的结果将为建立一个严格、有力、全面的 成绩奖励结果研究评估基于斜坡的训练方案的有效性，作为 康复。

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.