Air Pollution and Cognitive Aging Among Older Women

描述（由申请人提供）：认知功能下降是随后痴呆的一个强有力的预测因素，是老年人的一个重要健康问题，其数量将在未来几十年激增。在认知能力下降的潜在风险因素中，可以通过个人和法规来改变的是暴露于环境毒素。特别是，间接证据表明，长期暴露于空气污染中可能与认知能力下降有关。在对狗和人类的尸检研究中，暴露在空气污染中与大脑中类似阿尔茨海默病的变化有关。此外，大量数据描述了暴露于空气污染颗粒（悬浮在空气中的颗粒）与心血管疾病（CVD）之间的关联，而CVD的许多危险因素似乎也与认知能力下降有关。然而，人们对空气污染与认知能力下降的直接关系知之甚少。这种联系可能与妇女特别相关，因为妇女一生中患认知障碍的风险比男子更大，而且似乎特别容易受到空气污染对健康的影响。因此，我们建议进行一项探索性的流行病学研究，探讨空气污染暴露与老年妇女认知能力下降的关系。这项研究是老龄化和环境健康学科的独特合作，将利用护士健康研究（NHS）的现有数据，这是一个自1976年以来跟踪的大型前瞻性女性队列。具体来说，从1995年开始，通过对20,000名年龄最大的参与者（70-81岁）进行有效的电话访谈来评估认知功能，并在每1.5年进行一次连续评估。测试单元评估一般认知状态、言语记忆、执行功能、处理速度和工作记忆。从1999年到2002年，对美国相邻地区暴露于胸部（PM10）和细颗粒物（PM2.5）空气污染的情况进行了估计。对于提议的项目，我们将把这些PM模型扩展到1988年，对于每个女性，我们将估计从1988年到她第一次认知评估的时间间隔内她的平均PM暴露。我们还将研究暴露于交通产生的颗粒，使用大波士顿地区的详细暴露模型和生活在美国邻近地区的女性的更一般的模型。我们将评估长期暴露于3种空气污染物——胸部、细颗粒物和交通颗粒物——是否与老年妇女的认知能力下降有关。利用R21机制，本探索性项目创新性地使用基于地理信息系统（GIS）的空气颗粒暴露模型，并结合电话认知评估，在一大群女性中探索空气污染和认知老化的新领域。该项目将为长期暴露于空气微粒污染与认知老化之间的关系提供重要证据，该项目的数据将刺激进一步的工作，以确认和详细阐述所发现的任何关联，包括评估痴呆风险和评估其他常见空气污染物（如臭氧）。公共卫生相关性：认知功能下降是老年人的一个重要健康问题，并强烈预测个体最终是否会发展为痴呆症。初步证据表明，暴露在空气污染中可能与认知能力下降有关，特别是在老年妇女中，我们的项目，题为“老年妇女的空气污染和认知能力老化”，评估了大量老年妇女的这种关系。由于暴露在空气污染中是认知能力下降的潜在风险因素，可以通过法规和个人行为加以修正，我们的研究结果，以及进一步的验证数据，可能为降低大量高风险人群的认知能力下降风险提供潜在的方向。

DESCRIPTION (provided by applicant): Decline in cognitive function is a strong predictor of subsequent dementia and is an important health issue in older adults, whose numbers will burgeon in coming decades. Among potential risk factors for cognitive decline that can be modified-by both individuals and regulations-are exposures to environmental toxins. In particular, indirect evidence suggests that chronic exposure to air pollution may be associated with cognitive decline. In autopsy studies of dogs and humans, air pollution exposure is associated with Alzheimer-like changes in the brain. Moreover, abundant data describe the association of exposure to particulate air pollution-particles suspended in the air-with cardiovascular disease (CVD), while many risk factors for CVD also appear related to cognitive decline. Yet, little is known about the direct relation of air pollution to cognitive decline. Such an association may be especially pertinent to women, who carry a greater lifetime risk than men of cognitive impairments and who appear to be disproportionately susceptible to the health effects of air pollution. Therefore, we propose to conduct an exploratory epidemiologic study of air pollution exposure in relation to cognitive decline among older women. This study, a unique collaboration of the of aging and environmental health disciplines, will capitalize on available data from the Nurses' Health Study (NHS), a large prospective cohort of women followed since 1976. Specifically, beginning in 1995, cognitive function has been assessed via a validated telephone interview among the 20,000 oldest participants (aged 70-81), with serial assessments occurring every 1.5 years after. The test battery assesses general cognitive status, verbal memory, executive function, processing speed, and working memory. Exposures to thoracic (PM10) and fine (PM2.5) particulate air pollution from 1999-2002 have been estimated for the contiguous United States (US) region. For the proposed project, we will extend these PM models back to 1988, and for each woman, we will estimate her average PM exposures over the interval from 1988 to the time of her first cognitive assessment. We will also examine exposure to traffic-generated particles, using both a detailed model of exposure in greater Boston, MA and a more general model for women living in the contiguous US. We will evaluate whether long-term exposure to each of the 3 air pollutants-thoracic, fine and traffic particles-is related to cognitive decline among older women. Using the R21 mechanism, this exploratory project innovatively uses air particulate exposure models, based on geographic information systems (GIS), with telephone cognitive assessments to explore the new area of air pollution and cognitive aging in a large cohort of women. This project will generate important evidence on the plausibility of a relation between long-term exposure to particulate air pollution and cognitive aging, and the data from this project will stimulate further work to confirm and elaborate any associations found, including evaluations of dementia risk and evaluations of other common air pollutants (e.g., ozone). PUBLIC HEALTH RELEVANCE: Decline in cognitive function is an important health issue in older adults and strongly predicts whether an individual will eventually develop dementia. Preliminary evidence suggests that exposure to air pollution may be related to cognitive decline, particularly among older women, and our project, entitled "Air Pollution and Cognitive Aging among Older Women," evaluates this relation in a large population of older women. Since exposure to air pollution is a potential risk factor for cognitive decline that can be modified-by regulations and individual behaviors-our findings, along with further confirmatory data, may offer potential direction for reducing the risk of cognitive decline among a large high-risk population.