Dyspnea on Exertion in Obesity: Effects of Exercise Training and Weight Loss

7.项目摘要/摘要 肥胖在美国是一个流行病问题，是美国人面临的最重要的健康挑战之一 21世纪。肥胖的主要后果是死亡率和发病率的增加。 心脏病、高血压、糖尿病、睡眠呼吸障碍和代谢综合征。许多 肥胖的成年人会出现劳力性呼吸困难，无法锻炼。因此，劳力性呼吸困难在 成年人肥胖不仅是临床上一个重要而多产的问题，而且是预防和治疗肥胖的障碍。 肥胖症及肥胖相关合并症的治疗。尽管大多数患有呼吸困难的肥胖成年人 运动通常被认为是无条件的，我们的初步数据挑战了这一常规 智慧。例如，在有劳累呼吸困难的女性中，我们发现呼吸的氧气成本 (即呼吸功)显著增加，并与劳力性呼吸困难高度相关。因此，它是 目前尚不清楚肥胖的劳力性呼吸困难是否是由于心血管去调理引起的，在这种情况下，锻炼 训练将极大地有益于与肥胖相关的呼吸力学变化，在这种情况下 在可以忍受运动训练之前，积极的减肥措施可能是必要的。整体而言 该应用的目的是调查其他健康的肥胖成年人是否存在劳力性呼吸困难。 可以通过耐力运动训练(即增加心血管调节)来改善，或者通过 体重减轻(即与肥胖相关的呼吸限制的减少，特别是 呼吸)。我们假设，在其他方面健康的肥胖成年人的劳力性呼吸困难不会随着 耐力运动训练既然肥胖成年人有劳力性呼吸困难的情况都没有解除，那就锻炼 单独训练不太可能减少肥胖相关的呼吸限制，特别是 呼吸。相反，我们假设劳力性呼吸困难会随着体重的减轻而改善，因为 减肥应该会减少与肥胖相关的呼吸限制，特别是 呼吸。在本应用程序中，我们将使用两种干预措施来调查我们的建议：1)耐力 运动训练不减肥，2)减肥不耐力运动训练。具体目标： 为了实现总体目标，将检验以下假设：1)耐力运动训练 不会改善患有劳力性呼吸困难的肥胖成年人的劳力性呼吸困难；和2)体重减轻， 尤其是失去胸壁脂肪，将改善有呼吸困难的肥胖成年人的劳力性呼吸困难。 体力消耗。我们的长期目标是研究肥胖成年人劳力性呼吸困难的机制和 提供新的和临床相关的结果，可能会改变介入治疗方法 预防肥胖，治疗肥胖，降低心脏病、高血压和新陈代谢的风险 肥胖患者中的综合征。

7. PROJECT SUMMARY/ABSTRACT Obesity is an epidemic problem in the United States and is among the most important health challenges of the 21st Century. The major consequences of obesity are increased rates of mortality and morbidity from heart disease, hypertension, diabetes, sleep-disordered breathing, and the metabolic syndrome. Many obese adults experience exertional dyspnea and are unable to exercise. Therefore, exertional dyspnea in obese adults is not only an important and prolific clinical concern it is an obstacle to the prevention and treatment of obesity and obesity-related comorbidities. Although most obese adults with dyspnea on exertion are generally considered to be deconditioned, our preliminary data challenge this conventional wisdom. For example, in women with dyspnea on exertion, we have found the oxygen cost of breathing (i.e., work of breathing) to be markedly increased and highly associated with exertional dyspnea. Thus, it is presently unclear if exertional dyspnea in obesity is due to cardiovascular deconditioning, in which exercise training would be dramatically beneficial, or to obesity-related changes in respiratory mechanics, in which aggressive weight loss measures may be necessary before exercise training can be tolerated. The overall objective of this application is to investigate whether exertional dyspnea in otherwise healthy obese adults can be ameliorated by endurance exercise training (i.e., increase in cardiovascular conditioning), or by weight loss (i.e., decrease in obesity related-respiratory limitations, specifically, the oxygen cost of breathing). We hypothesize that exertional dyspnea in otherwise healthy obese adults will not improve with endurance exercise training since obese adults with exertional dyspnea are not deconditioned, and exercise training alone is unlikely to decrease obesity-related respiratory limitations, specifically the oxygen cost of breathing. In contrast, we hypothesize that exertional dyspnea will be ameliorated with weight loss, since weight loss should decrease obesity related-respiratory limitations, in particular, the oxygen cost of breathing. In this application, we will utilize two interventions to investigate our proposals: 1) endurance exercise training without weight loss, and 2) weight loss without endurance exercise training. Specific Aims: To accomplish the overall objective, the following hypotheses will be tested: 1) Endurance exercise training will not ameliorate exertional dyspnea in obese adults with dyspnea on exertion; and 2) Weight loss, especially loss of chest wall fat, will ameliorate exertional dyspnea in obese adults with dyspnea on exertion. Our long-term objective is to investigate the mechanism of exertional dyspnea in obese adults and provide novel and clinically relevant results that could potentially alter interventional approaches for preventing obesity, treating obesity, and reducing the risk of heart disease, hypertension, and the metabolic syndrome in obese patients.