Effects of Deployment Exposures on Cardiopulmonary and Autonomic Function

描述（由申请人提供）： 项目概要/摘要：有证据表明，部署到“持久行动”、“伊拉克自由行动”和“新黎明行动”（OEF/OIF/OND）的退伍军人暴露于高水平的颗粒物（PM），超过了环境、职业和军事暴露指南。PM暴露被认为是心血管疾病发病率和死亡率的危险因素，并可增加气道疾病的风险和加重气道疾病。经审查的流行病学资料表明，持久自由行动/伊图里武装部队/维持和平行动退伍军人中新报告的呼吸道症状流行率很高，严重影响了他们的部署任务，包括体力活动能力。 尽管有这些回顾性数据和有限的空气采样报告，但缺乏前瞻性研究。我们的试点研究将采用综合方法，与从未部署到该地区的退伍军人相比，评估OEF/OIF/OND退伍军人的心肺和自主神经功能。 为了评价心肺功能，每名退伍军人将接受运动挑战，包括运动前和运动后（运动后5、10、15、20和30分钟）的肺量测定。运动将以跑步机为基础，参与者将尝试在目标通气量和心率下保持6 - 8分钟的运动。对于肺量测定测试， 要求退伍军人在每个时间点进行最大用力呼气动作。还将在不同的日期重复肺量测定，以包括相同的最大用力呼气动作，但将在使用支气管扩张剂前后进行评估。 由于我们预期交感迷走神经平衡改变，我们将评估几个指数的心率变异性在起搏呼吸。此外，我们将量化脑血流量、血压、心率和通气量，以响应Valsalva动作和姿势变化（即从坐到站）。这种综合评估将提供自主神经系统调节心血管功能的指示，这取决于精确的反射调节。这些评估可以提供有关认可症状背后的病理生理机制的见解，并可以提供减轻肺部和心血管疾病等长期不良后果的干预点。 从该试点项目中获得的数据将对心肺功能障碍的程度和严重程度产生重要的见解-这些数据随后可用于指导康复。此外，自主神经测试的结果将在以下方面具有相似的功效： 检测亚临床或明显生理变化的存在。通过早期识别，可以实施治疗方案（例如运动疗法，药物）以增强自主神经功能，目的是帮助缓解症状并降低慢性病风险。 公共卫生相关性： 项目叙述：在部署到持久行动、伊拉克自由行动和新黎明行动（OEF/OIF/OND）后，退伍军人报告呼吸问题、运动困难和其他症状。这些症状可能与部署暴露有关，例如区域灰尘和沙子，燃烧垃圾产生的烟雾和当地工业。研究报告了糟糕的空气质量，但很少有人知道暴露于这种污染的空气可能对退伍军人的短期和长期健康的影响。我们将确定与部署相关的暴露是否影响了这些退伍军人的呼吸和神经系统功能-这些数据随后可用于指导康复。最终，我们的长期目标是早期识别和循证治疗，以防止OEF/OIF/OND退伍军人群体中慢性呼吸系统疾病的发展。

DESCRIPTION (provided by applicant): Project Summary/Abstract: Evidence is clear that Veterans deployed to Operations Enduring and Iraqi Freedom and Operation New Dawn (OEF/OIF/OND) have been exposed to high levels of particulate matter (PM) that exceeded environmental, occupational and military exposure guidelines. PM exposure is acknowledged as a risk factor for cardiovascular morbidity and mortality, and can increase the risk of and exacerbate airway disease. The reviewed epidemiology indicates a high prevalence of newly reported respiratory symptoms in OEF/OIF/OND Veterans that has significantly affected their deployment duties, including their physical exertion capability. Despite these retrospective data and limited air sampling reports, prospective studies are absent. Our pilot study will take an integrative approach to evaluate cardiorespiratory and autonomic function in OEF/OIF/OND Veterans as compared to Veterans never deployed to the region. To evaluate cardiopulmonary function, each Veteran will undergo an exercise challenge which consists of spirometry before and then serially after exercise (5, 10, 15, 20, and 30 min post-exercise). Exercise will be treadmill-based and participants will try to maintain 6 - 8 minutes of exercise at a target ventilation and heart rate. For spirometric testing, Veterans will be asked to perform a maximal forced expiratory maneuver at each time point. Spirometry will also be repeated on separate day to include the same maximal forced expiratory maneuver, but will be assessed before and after a bronchodilator. As we anticipate altered sympathovagal balance, we will evaluate several indices of heart rate variability during paced breathing. In addition, we will quantify cerebral blood flow, blood pressure, heart rate and ventilation in response to a Valsalva maneuver and postural change (i.e. sit-to-stand). This integrative assessment will provide an indication of how well the autonomic system regulates cardiovascular function, which is dependent on precise reflex regulation. These assessments may provide insight on the pathophysiological mechanisms that underlie endorsed symptoms, and may provide intervention points for attenuating long-term adverse outcomes such as pulmonary and cardiovascular disease. Data derived from this pilot project will yield important insight on the extent and severity of cardiorespiratory impairment - data that may then be used to guide rehabilitation. In addition, results from autonomic testing will be of similar efficacy in detecting the presence of subclinical or overt physiological changes. Through early identification, treatment options (e.g. exercise therapy, pharmaceutical) may be implemented to enhance autonomic function, with the goal of helping to alleviate symptoms and reduce chronic disease risk. PUBLIC HEALTH RELEVANCE: Project Narrative: Following deployment to Operations Enduring and Iraqi Freedom and Operation New Dawn (OEF/OIF/OND), Veterans report breathing problems, difficulty exercising and other symptoms. These symptoms are likely related to deployment exposures, such as regional dust and sand, smoke from burning trash, and local industry. Studies have reported poor air quality, but very little is known about the effect that exposure to this polluted air may have on Veterans' short- and long-term health. We will determine whether deployment-related exposures have affected respiratory and nervous system function in these Veterans - data that may then be used to guide rehabilitation. Ultimately, our long-term goal is early identification and evidence-based therapy to prevent the development of chronic respiratory conditions in this group of OEF/OIF/OND Veterans.