Reasons for Racial Disparities in Venous Thromboembolism

描述（由申请人提供）：本申请涉及广泛的挑战领域（4）临床研究和特定的挑战主题，04-HL- 104：对现有数据进行二次分析，以回答重要的临床和预防医学研究问题。根据美国卫生部长2008年的《预防深静脉血栓形成和肺栓塞行动呼吁》，每年有超过30万美国人患有静脉血栓栓塞（VTE），每年可能有超过10万人死亡。非洲裔美国人的静脉血栓栓塞率是欧洲裔美国人的1.5倍;造成这种差异的原因尚不清楚。研究这种发病率差异的原因最大的困难在很大程度上是由于非洲裔美国人在静脉血栓栓塞的研究，特别是在静脉血栓栓塞事件之前测量的风险因素的研究很少。该挑战补助金的目的是确定和验证卒中地理和种族差异原因研究（REGARDS）中的静脉血栓栓塞（VTE）事件，一项前瞻性国家队列研究，调查了美国卒中发病率和风险因素的地理和种族差异，并将数据与血栓栓塞病因学纵向调查（LITE）结合联合收割机为了获得一项前瞻性队列研究，在非洲裔美国人和欧洲裔美国人中有足够的VTE事件，以评价美国VTE发病率的种族差异。LITE研究是一项前瞻性队列研究，涉及来自心血管健康研究（CHS）和社区动脉粥样硬化风险（ARIC）研究的21，680名受试者，其中726例VTE事件（尽管非洲裔美国人中只有224例）。将LITE和REGARDS相结合的统一队列将由51，848人组成，其中17，713人是非洲裔美国人。我们预计总共有1,292起VTE事件，其中492起将发生在非洲裔美国人中。这些队列（REGARDS、CHS、ARIC）中的每一个都记录了广泛的基线人口统计学、人体测量学、社会经济学和病史，基线储存的血液和尿液储存库，以及随访事件信息，包括心血管疾病、住院和死亡。在每个队列中，对风险因素进行了测量和验证，而不是自我报告。通过实现我们的具体目标，我们将能够评估在美国所见的VTE发病率种族差异的风险因素。该项目不仅提供了评估VTE传统风险因素（如癌症，手术，肥胖和医疗条件）的机会，而且还提供了研究营养，体力活动和认知功能等新风险因素的机会。结果将导致一个后续的建议，以获得资金，以评估新的生物标志物的静脉血栓栓塞风险，如因子VIII，血管性血友病因子水平，遗传因素在非洲裔美国人与欧洲裔美国人。通过了解VTE发病率种族差异的原因，我们将能够提出干预措施或进一步的研究，以解决减少这种差异。为该项目组建的团队非常适合进行这项研究。N医生Zakai（该资助的主要研究者）是一名血液学家，曾参与LITE研究和REGARDS研究中的种族差异调查。M博士血液学家Cushman是LITE研究和佛蒙特大学REGARDS中心实验室的研究中心PI。Dr. A.福尔松是明尼苏达大学LITE的总PI。致问候，G博士。生物统计学家霍华德是REGARDS的总PI，也是种族差异方面的专家。Dr. L.麦克卢尔是REGARDS的首席生物统计学家，非常熟悉该队列。Dr. S.贾德是队列研究中的营养评估专家，V.瓦德利博士是认知评估专家。M博士Safford是REGARDS临床结果单元的负责人，也是NHLBI资助的REGARDS辅助研究的PI，该研究评估了心肌梗死的种族差异。非洲裔美国人静脉血栓栓塞（VTE）的发病率约增加30%至60%，原因不明。研究这种差异的主要限制是在大多数大规模流行病学研究中缺乏非洲裔美国人。该挑战补助金的目的是确定和验证卒中地理和种族差异的原因研究（REGARDS）中的VTE事件，一项前瞻性国家队列研究，调查了美国卒中发病率和风险因素的地理和种族差异，并将数据与血栓栓塞病因学纵向调查（LITE）结合联合收割机为了获得一项前瞻性队列研究，在非洲裔美国人和欧洲裔美国人中有足够的VTE事件，以评估美国VTE的种族差异。虽然了解了这种差异的原因，我们可以开始制定公共卫生政策，以解决这种差异。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (4) Clinical Research and specific Challenge Topic, 04-HL- 104: Perform secondary analyses of existing data to answer important clinical and preventive medicine research questions. According to the Surgeon General's 2008 Call to Action to Prevent Deep Venous Thrombosis and Pulmonary Embolism, over 300,000 Americans each year suffer from venous thromboembolism (VTE), with potentially over 100,000 fatalities per year. VTE is approximately 1.5-fold more common in African-Americans as compared to European-Americans; the reasons for this disparity being unclear. The greatest difficulty in studying the reasons for this disparity in incidence is due in great part to a paucity of African-Americans in research studies of VTE to date, especially where risk factors are measured before the VTE event. The purpose of this Challenge Grant is to ascertain and validate venous thromboembolism (VTE) events in the REasons for Geographic and Racial Differences in Stroke Study (REGARDS), a prospective national cohort study investigating geographic and racial disparities in stroke incidence and risk-factors in the United States and combine the data with the Longitudinal Investigation of Thromboembolism Etiology (LITE) in order to obtain a prospective cohort study with sufficient VTE events among African-Americans and European- Americans to evaluate racial disparities in VTE incidence in the United States. The LITE study is a prospective cohort study of 21,680 individuals from the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) study with 726 VTE events (though only 224 among African-Americans). The resulting harmonized cohort combining both LITE and REGARDS will consist of 51,848 individuals, of whom 17,713 are African-Americans. We anticipate a combined total 1,292 incident VTE, 492 of which will be among African-Americans. Each of these cohorts (REGARDS, CHS, ARIC) has extensive baseline demographic, anthropometric, socio- economic, and medical history recorded, a baseline stored blood and urine repository, as well as follow-up events information including cardiovascular diseases, hospitalizations, and death. Risk factors were measured and validated rather than self-reported in each cohort. By accomplishing our specific aims, we will be able to evaluate the risk factors which mediate the racial difference in VTE incidence seen in the United States. This project offers not only the opportunity to evaluate traditional risk factors for VTE, such as cancer, surgery, obesity, and medical conditions, but the opportunity to study novel risk factors such as nutrition, physical activity, and cognitive function. Results will lead to a follow- up proposal to obtain funding to evaluate novel biomarkers of VTE risk such as factor VIII, von Willebrand factor levels, and genetic factors in African-Americans versus European-Americans. By understanding the reasons for the racial disparity in VTE incidence, we will be able to propose interventions or further studies to address reducing this disparity. The team assembled for this project is uniquely suited to do this research. Dr. N. Zakai (the Principal Investigator for this Grant) is a hematologist and has worked on the LITE study and on investigating racial disparities in the REGARDS study. Dr. M. Cushman, a hematologist, is the site PI for the LITE study and the REGARDS central laboratory at the University of Vermont. Dr. A. Folsom is the overall PI of LITE at the University of Minnesota. For REGARDS, Dr. G. Howard, a biostatistician, is the overall PI of REGARDS and an expert in racial disparities. Dr. L. McClure is the lead biostatistician for REGARDS and very familiar with the cohort. Dr. S. Judd is an expert on nutritional assessment in cohort studies, and Dr. V. Wadley is an expert on cognitive assessment. Dr. M. Safford is head of the clinical outcomes unit in REGARDS and PI of the NHLBI- funded REGARDS ancillary study assessing racial disparities in myocardial infarction. African-Americans have an approximately 30% to 60% increased incidence of venous thromboembolism (VTE) for unknown reasons. The main limitation to studying this disparity is the paucity of African-Americans in most large-scale epidemiological studies. The purpose of this Challenge Grant is to ascertain and validate VTE events in the REasons for Geographic and Racial Differences in Stroke Study (REGARDS), a prospective national cohort study investigating geographic and racial disparities in stroke incidence and risk-factors in the United States and combine the data with the Longitudinal Investigation of Thromboembolism Etiology (LITE) in order to obtain a prospective cohort study with sufficient VTE events among African-Americans and European-Americans to evaluate racial disparities in VTE in the United States. Though understanding the reasons for this disparity we can begin to formulate public health policies to address this disparity.