Climate Change and Health: Assessing the Risk of Preterm Delivery

描述(由申请人提供)：美国国立卫生研究院(NIH)和国家环境卫生与科学研究所(NIEHS)最近发布了一份白皮书，强调需要研究气候变化对人类健康的影响，特别是对包括孕妇在内的脆弱人群的影响。早产是导致婴儿死亡和发病的主要原因，也是我国和世界其他地区面临的最大公共卫生挑战之一。然而，病因在很大程度上仍不清楚。对空气污染和季节趋势的研究支持了PTD等不良生育结果之间的关系，从而支持了更多研究来阐明这种关系的必要性。孕妇在热暴露期间患PTD的风险可能会增加，因为她们更有可能脱水，这可能会导致子宫血流减少，脑下垂体分泌的抗利尿激素和催产素增加，从而引产。这项拟议的研究检验了一个创新的假说和一个以前未知的PTD危险因素，这是从文献中新出现的。具体地说，这项拟议研究的目标是检查气候变化对PTD风险的影响，并将是旨在临床环境下解决这种联系的首批此类研究之一。为了实现拟议的目标，我们将利用Kaiser Permanente North California(KPNC)的成员进行病例交叉研究，KPNC是一个集成的医疗保健提供系统，每年提供超过33,000次服务。病例交叉是一种研究设计，特别适合研究短期高温与PTD风险之间的联系，因为它具有通过研究设计消除潜在的可测量和未测量的混杂因素的优势。拟议的研究将使用1995年1月至2009年12月期间发生的KPNC电子医疗记录(EMR)的数据，其中包括分娩时居住的信息。加州灌溉和管理系统和美国环境保护局将提供产妇住宅表观温度的数据，这是一种综合衡量温度和相对湿度的指标。将通过KPNC的EMR确定大约50万名新生儿，其中约10%预计是早产儿。分析将按季节以及产妇种族/民族、产妇年龄和社会经济地位进行分层。这项研究的发现将有助于对这种关系的初步理解。一旦确定了PTD风险增加与表观温度之间的关系，就可以实施公共卫生干预措施，以减少高温暴露对孕妇的影响，同时针对风险最高的人群。预防措施可能包括喝更多的液体和电解质，呆在室内空调环境中，以及在温暖的季节与他人在一起，特别是在热浪期间。 公共卫生相关性：对空气污染和季节的研究已经发现与早产(PTD)有关，因此，环境温度高也可能与早产有关，需要进行研究。这项拟议的项目将研究1995至2009年间在北加州凯撒永久医院分娩的女性在温暖季节的温度与PTD风险之间的关系。一旦确定了PTD风险增加与表观温度之间的关系，就可以实施公共卫生干预措施，以减少高温暴露对孕妇的影响，特别是那些风险最高的孕妇。

DESCRIPTION (provided by applicant): The National Institutes of Health (NIH) and National Institute of Environmental Health and Science (NIEHS) have recently published a White Paper emphasizing the need to study the impact of climate change on human health, specifically among vulnerable populations including pregnant women. Pre-term delivery (PTD) is the leading cause of infant mortality and morbidity and among the top public health challenges facing our nation as well as the rest of the world. Yet the etiology remains largely unknown. Studies of air pollution and seasonal trends have supported a relationship between adverse birth outcomes, such as PTD, thus supporting the need for more research to elucidate this relationship. Pregnant women may be at increased risk of PTD during periods of heat exposure, since they are more likely to be dehydrated, which could result in decreased uterine blood flow and increased pituitary secretion of anti-diuretic hormone and oxytocin to induce labor. The proposed study examines an innovative hypothesis and a previously unknown risk factor for PTD that has newly emerged from the literature. Specifically, the objective of the proposed study is to examine the impact of climate change on the risk of PTD, and will be among the first such studies designed to address this association in a clinical setting. To achieve the proposed aims, we will conduct a case-crossover study utilizing members of Kaiser Permanente Northern California (KPNC), an integrated health care delivery system with more than 33,000 deliveries each year. The case-crossover is a study design uniquely suited for examining the association between short-term high ambient temperature and the risk of PTD, as it has the advantage of eliminating potential measured and unmeasured confounders inherently by study design. The proposed study will use data on deliveries that occurred between January 1995 and December 2009 from KPNCs electronic medical records (EMR), which includes information on residence at the time of deliveries. Data on maternal residential apparent temperature, a measure of both temperature and relative humidity combined, will be provided by the California Irrigation and Management System and the US Environmental Protection Agency. A cohort of approximately half a million births will be identified through KPNC's EMR, and approximately ten percent of these births are expected to be preterm. The analyses will be stratified by season, and also by maternal race/ethnic group, maternal age, and socioeconomic status. Findings from this study will contribute to the nascent understanding of this relationship. Once the relationship between increased risk of PTD and apparent temperature has been established, public health interventions can be implemented to reduce the impact of increasing heat exposure on pregnant women, while targeting those who are at greatest risk. Precautions may include drinking more fluids and electrolytes, staying indoors in air conditioned environments, and being with others during the warm season, especially during heat waves. PUBLIC HEALTH RELEVANCE: Studies of air pollution and season have found relationships with preterm delivery (PTD) thus, high ambient temperature and PTD could also be associated, and needs to be studied. The proposed project will examine the association between temperature during the warm season and risk of PTD in women who delivered at a hospital in Kaiser Permanente Northern California between 1995 and 2009. Once the relationship between increased risk of PTD and apparent temperature has been established, public health interventions can be implemented to reduce the impact of heat exposure on pregnant women, especially those who are at greatest risk.