Effects of Obesity in the Aged

项目摘要/摘要 70%的老年人(60岁以上)超重或肥胖，许多人无法或不愿锻炼 由于运动不耐受和/或劳累时呼吸困难(DOE)。我们已经确认了大量的肥胖-- 可能影响肥胖成年人运动耐量和DOE的相关效应。我们还确认了 非肥胖老年人的许多与年龄相关的呼吸限制。然而，目前还不清楚肥胖是否- 相关和衰老相关的影响共同降低运动耐量，引发DOE，或有助于 老年肥胖成年人的呼吸道症状。我们认为，老年人肥胖的许多相关影响 成人肥胖是低肺容量呼吸的结果，即功能残气量减少 (FRC)和运动时呼气末肺活量(EELV)。胸壁脂肪增多 产生低FRC和EELV水平，其中呼吸限制，如呼气流速限制(EFL)和 由于与年龄相关的最大呼吸困难的下降，更有可能发生呼吸困难的感觉增强 低肺容量时的呼气流量。我们的总体假设是呼吸受限、运动 老年肥胖者的耐受性、DOE和呼吸道症状是由于机械负荷 胸腔和低肺容量呼吸。我们建议使用外部镶嵌玻璃来检验这一假设 (即，一个覆盖在胸腔上的塑料外壳)，以机械地卸载胸壁。这将减少 从而增加休息时的FRC和运动时的EELV，并潜在地减少 锻炼时的呼吸。此应用程序的总体目标是调查以下各项的影响 老年肥胖者与老年肥胖者相比，肥胖对肺功能、运动耐量和DOE的影响 没有肥胖的成年人，使用一种新的探头在休息和运动中机械地卸载胸腔 锻炼身体。我们将使用1)持续负压和2)辅助双相硫化物 通风以减少老年肥胖者的肥胖相关影响。我们的方法将是检查 老年肥胖者机械卸载前后的呼吸功能、运动耐量和DOE 男性和女性(65-75岁)，包括有呼吸道症状的人，与老年人相比 没有肥胖症。具体目标：我们将检验以下假设：目标1)肥胖将会减少 呼吸功能，但在有呼吸道症状的老年肥胖成年人中程度更高；目标2) 肥胖会降低运动耐量，但不会降低心肺健康，老年肥胖者除外 有呼吸道症状的成年人，两者都可能减少；目标3)肥胖会增加DOE，但 在有呼吸道症状的老年肥胖成年人中作用更大；以及Aim 4)机械 胸腔卸载将改善老年人的呼吸功能、运动耐量和DOE 成年人肥胖，但更大程度上是有呼吸道症状的老年肥胖成年人。这些结果 将对患有DOE的老年肥胖成年人的护理产生广泛和直接的临床影响。

PROJECT SUMMARY/ABSTRACT Seventy% of older adults (60+ yr) are overweight or obese and many are unable or unwilling to exercise due to exercise intolerance and/or dyspnea on exertion (DOE). We have identified numerous obesity- related effects that could influence exercise tolerance and DOE in obese adults. We have also identified many age-related ventilatory constraints in nonobese older adults. However, it is unclear whether obesity- related and aging-related effects combine to reduce exercise tolerance, provoke DOE, or contribute to respiratory symptoms in older obese adults. We propose that many of the obesity-related effects in older obese adults are the result of low lung volume breathing, i.e., a reduction in functional residual capacity (FRC) at rest and end-expiratory lung volume (EELV) during exercise. Increased fat on the chest wall produces low FRC and EELV levels, where breathing limitations like expiratory flow limitation (EFL) and enhanced perception of dyspnea are more likely to occur due to the age-related decline in maximal expiratory flow at low lung volumes. Our overall hypothesis is that respiratory limitations, exercise intolerance, DOE, and respiratory symptoms in older obese adults are due to mechanical loading of the thorax and low lung volume breathing. We propose to test this hypothesis with the use an external cuirass (i.e., a plastic shell over the thorax) to mechanically unload the chest wall. This will decrease the load on the thorax thereby increasing FRC at rest and EELV during exercise, and potentially decrease the work of breathing during exercise. The overall objective of this application is to investigate the effects of obesity on lung function, exercise tolerance, and DOE in older obese adults as compared with older adults without obesity, using a novel probe for mechanically unloading the thorax at rest and during exercise. We will use 1) continuous negative cuirass pressure, and 2) assisted biphasic cuirass ventilation to decrease obesity-related effects in older obese adults. Our approach will be to examine respiratory function, exercise tolerance, and DOE with and without mechanical unloading in older obese men and women (65-75 yr), including those with respiratory symptoms, as compared with older adults without obesity. Specific Aims: We will test the following hypotheses: Aim 1) Obesity will decrease respiratory function but to a greater extent in older obese adults with respiratory symptoms; Aim 2) Obesity will decrease exercise tolerance but not cardiorespiratory fitness, except in older obese adults with respiratory symptoms where both may be reduced; Aim 3) Obesity will increase DOE but to a greater extent in older obese adults with respiratory symptoms; and Aim 4) Mechanical unloading of the thorax will improve respiratory function, exercise tolerance, and DOE in older obese adults, but to a greater extent in older obese adults with respiratory symptoms. These results will have broad and immediate clinical impact on the care of older obese adults with DOE.