The impact of airborne particles and ozone on cognition, mobility, and health care spending at older ages: Evidence from a nationally-representative longitudinal cohort

认知功能和活动能力下降在老年人中很常见，这是由于亚临床病理和慢性疾病对多个器官系统的集体影响。随着这些下降从轻微的功能限制发展到更严重的阿尔茨海默病和相关痴呆症和身体残疾阶段，自我护理活动和独立生活可能会受到严重损害。这导致生活质量下降，以及长期服务和支持的医疗保健费用大幅增加。不幸的是，个人一级的预防努力在降低人口残疾流行率方面基本无效，在阿尔茨海默病和相关痴呆症方面仅取得了一定的成功。我们的中心假设是，颗粒物（PM）和臭氧（O3）空气污染可能是环境风险因素，但在很大程度上未被探索，这些风险因素可以在人口水平上得到控制，以尽量减少老年人的认知和行动能力下降。这一假说是基于空气污染物进入血液，转移到大脑，并启动全身病理生理过程，导致亚临床，临床前，然后，慢性疾病的多个器官的证据。这种亚临床和临床疾病的积累最终导致认知和移动障碍、阿尔茨海默病和相关痴呆症和身体残疾的风险增加，以及由于失去独立性而导致的医疗保健费用增加。为了验证我们的假设，我们将使用最先进的国家暴露模型，同时考虑非环境暴露源，为每个健康和退休研究（HRS）受访者预测环境PM和O3的暴露。HRS是一个具有全国代表性的队列，由37，500多名老年人组成，随访时间超过20年，每两年提供一次关于认知功能、阿尔茨海默病和相关痴呆、行动能力、残疾和医疗保健支出的详细数据。具体而言，我们的目标是：1）预防性检查长期接触罚款的关联（PM2.5）和粗颗粒物（PM10-2.5）和O3在环境空气中与老年人的认知和行动能力下降，2）直接估计长期暴露于PM2.5，PM10-2.5和O3在环境空气中与老年人失去独立性的医疗保健费用之间的关联，3）量化美国所有老年人长期暴露于环境PM2.5，PM10-2.5和O3的认知和移动相关的健康和经济负担，以及4）创建和传播环境PM2.5，PM10-2.5的开放获取资源，和O3暴露的HRS和县级和国家的健康和医疗保健成本负担的估计，由于PM和O3的影响，认知，阿尔茨海默氏症和相关的痴呆症，流动性和身体残疾的整个美国。这项研究预计将通过向地方，州和国家层面的政策制定者和利益相关者提供证据来产生巨大的公共卫生影响，这些证据涉及一种新的环境风险因素，可以在人群水平上进行修改，以促进老年人的健康。

Declines in cognitive function and mobility are common in older adults, arising from the collective impacts of subclinical pathologies and chronic disease across multiple organ systems. As these declines progress from minor functional limitations to more severe stages of Alzheimer’s disease and related dementias and physical disabilities, there can be substantial impairments to self-care activities and independent living. This leads to poorer quality of life as well as significantly increased health care costs for long-term services and support. Unfortunately, individual-level prevention efforts have been largely ineffective in reducing the population prevalence of disability and only modestly successful for Alzheimer’s disease and related dementias. Our central hypothesis is that particulate matter (PM) and ozone (O3) air pollution are likely, but largely unexplored, environmental risk factors that could be controlled on the population-level to minimize cognitive and mobility declines in older adults. This hypothesis is based on evidence that air pollutants enter the blood stream, translocate into the brain, and initiate systemic pathophysiological processes that lead to subclinical, preclinical, and then, chronic disease in multiple organs. This accumulation of subclinical and clinical disease ultimately results in an increased risk of cognitive and mobility impairments, Alzheimer’s disease and related dementias and physical disabilities, and health care costs due to lost independence. To test our hypothesis, we will newly predict exposures to ambient PM and O3 for each Health and Retirement Study (HRS) respondent using state-of-the-art national exposure models while also accounting for non-ambient sources of exposure. The HRS is a nationally-representative cohort of over 37,500 older adults followed for more than 20 years with detailed biennial data on cognitive function, Alzheimer’s disease and related dementias, mobility, disability, and health care expenditures. Specifically, we aim to: 1) Prospectively examine associations of long-term exposures to fine (PM2.5) and coarse particulate matter (PM10-2.5) and O3 in ambient air with cognitive and mobility declines in older adults, 2) Directly estimate associations between long-term exposures to PM2.5, PM10-2.5, and O3 in ambient air and health care costs due to lost independence in older adults, 3) Quantify the cognitive and mobility-related health and economic burdens attributable to long-term exposures to ambient PM2.5, PM10-2.5, and O3 among all older adults in the US, and 4) Create and disseminate open-access resources of ambient PM2.5, PM10-2.5, and O3 exposures for the HRS and estimates of county-level and national health and health care cost burdens due to PM and O3’s impacts on cognition, Alzheimer’s disease and related dementias, mobility and physical disabilities for the entire US. This research is expected to have a large public health impact by providing evidence to policy makers and stakeholders at the local, state, and national levels about a novel, environmental risk factor that could be modified at the population-level to promote health in older ages.