Doctoral Dissertation Reserch: The Spatial Ecology of Chronic Kidney Disease in Nicaragua

本博士论文研究项目的目的是从空间流行病学的角度调查尼加拉瓜CKD发展的因素。肾功能不全或慢性肾脏病（CKD）在发达国家长期存在，主要归因于高血压和糖尿病。然而，公共卫生领域的一个最新问题是在欠发达国家报告了异常高的CKD发病率，这些国家对该病的病因学了解非常有限。尼加拉瓜西北部地区是CKD的头号死亡原因，该地区沿着中美洲太平洋海岸，该地区的发病率普遍高于预期。从观察到的表型和受影响的人群来看，环境暴露被怀疑是该地区的主要促成因素。研究人群的样本来自莱昂州正在进行的地理参考健康和人口监测系统。 每个人的数据包括CKD发病率、人口统计学变量、生活方式因素和居住家庭的特征。这些信息将被整合到研究区域的地理数据库中，以首先确定该地区CKD发病率的较高浓度或“集群”。将利用卫星图像和通过实地调查收集的数据，按土地覆盖类型对研究区域进行分类。在将所有数据纳入地理信息系统后，将使用多层次分析对每个确定的聚类进行调查，以评估人口一级的影响是否是空间聚类的原因。那些不是由于人口的基本特征将进一步探讨有关的位置，环境和周围的空间特征，使用病例对照方法和基于距离的回归模型。据推测，接近火山土壤，使用农药的农业用地，以及受污染的水源都将与CKD的发病率有关。 该项目将为了解CKD及其在尼加拉瓜的发展提供信息。这一点特别重要，因为发展中国家的CKD病因尚未得到充分了解，而且贫穷国家的治疗和护理有限。因此，这项研究可用于协助尼加拉瓜和其他发展中国家预防CKD的努力。该项目采取的方法是生态的，因为它不仅考虑到个人层面的特征，而且考虑到CKD患者生活的环境背景。作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

The purpose of this doctoral dissertation research project is to investigate the factors contributing to the development of CKD in Nicaragua from a spatial epidemiological perspective. Renal insufficiency, or Chronic Kidney Disease (CKD), has long been present in developed countries and it is primarily attributed to hypertension and diabetes. A recent issue in public health, however, is the reporting of abnormally high CKD rates in less-developed countries where knowledge regarding the etiology of the disease is very limited. The northwestern district of Nicaragua, where CKD is the number one cause of death, presents one such setting along the Pacific coast of Central America, a region with generally higher-than-expected rates. From the phenotypes observed and the populations affected, environmental exposure is suspected as the main contributing factor in this area. The study population is sampled from an ongoing geographically-referenced health and demographic surveillance system in the state of Leon. Data on each individual include CKD incidence, demographic variables, lifestyle factors, and characteristics of the household of residence. This information will be integrated into a geographic database of the study area to first identify higher concentrations, or "clusters" of CKD incidence in the region. The study area will be classified by land-cover type using satellite imagery and data collected through field surveys. Upon integration of all data within a geographic information system, each identified cluster will be investigated using multi-level analyses to assess whether population-level effects are the cause of spatial clusters. Those not due to the underlying characteristics of the population will be further explored in relation to location, environment, and surrounding spatial features using case-control methods and distance-based regression models. It is hypothesized that proximity to volcanic soils, agricultural land where pesticides are used, and contaminated water sources will all be related to CKD incidence. This project will inform understanding of CKD and its development in Nicaragua. This is of particular importance because the cause of CKD in the developing world is not well understood and because treatment and care is limited in poor countries. This study can therefore be used to assist efforts in prevention of CKD in Nicaragua and other developing countries. The approach taken in this project is ecological, as it takes into consideration not only individual-level characteristics, but also the environmental context in which the people with CKD live. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.