Subclinical Renal Artery Atherosclerosis, Kidney Function and Hypertension

描述（由申请人提供）： 高血压（HTN）和慢性肾脏病（CKD）是心血管疾病（CVD）的两个高度流行和强烈的风险因素，它们通过常见的风险因素和病理生理学联系在一起。具体地说，肾小球前小动脉的动脉硬化导致相对的肾缺血，随后激活肾素-血管紧张素系统，最终导致血压升高。在本研究中，我们假设局部（即肾动脉）亚临床动脉粥样硬化与肾功能、血压、高血压和心血管事件独立相关。使用来自动脉粥样硬化多种族研究（梅萨）的1970名受试者的主动脉钙子样本，本研究的具体目的是确定：1）肾动脉钙（RAC）是否与肾功能相关，如通过a）肾小球滤过率、B）胱抑素-C和3）尿白蛋白测量的; 2）RAC的基线和前瞻性变化均与约3年随访期间肾功能和CKD事件的变化显著相关; 3）RAC与四种血压（BP）测量相关：a）收缩压，2）舒张压，3）脉压和4）平均动脉压，以及高血压的诊断; 4）RAC与高血压和心血管疾病事件显著相关。如果是这样，我们将确定这种关联是否由肾功能的差异介导。我们将通过询问腹部计算机断层扫描（CT）图像来探索这些目标。将在UCLA的梅萨CT阅读中心对腹部CT图像的RAC、肾脏体积和肾脏密度进行评分。将测定血样中的胱抑素C、肾素和醛固酮。胱抑素-C结果将用作肾功能指标，并与血清肌酐和尿白蛋白的现有数据进行比较。将使用肾素和醛固酮来确定RAC的存在是否与肾素-血管紧张素-醛固酮系统的差异相关。到2007年7月，大约700名受试者将完成随访扫描，以便检验涉及RAC和肾功能前瞻性变化的假设。最后，少数民族群体在梅萨的代表性过高，这将允许测试与种族的相互作用。我们不知道任何其他基于人群的研究足以研究所述目的。

DESCRIPTION (provided by applicant): Hypertension (HTN) and chronic kidney disease (CKD) are two highly prevalent and strong risk factors for cardiovascular disease (CVD) that are linked via common risk factors and pathophysiology. Specifically, arteriosclerosis of the preglomerular arterioles leads to relative renal ischemia and subsequent activation of the rennin-angiotensin system ultimately leading to increases in blood pressure. In this proposal, we hypothesize that local (i.e. renal artery) subclinical atherosclerosis is significantly and independently associated with kidney function, blood pressure, hypertension and incident CVD events. Using the Aortic Calcium subsample of 1970 subjects from the Multi-Ethnic Study of Atherosclerosis (MESA), the specific aims for this study are to determine if: 1) Renal artery calcium (RAC) is associated with kidney function, as measured by a) glomerular filtration rate, b) cystatin-C and 3) urine albumin; 2) Both baseline and prospective changes in RAC are significantly associated with changes in kidney function and incident CKD over approximately 3 years of follow-up; 3) RAC is associated with four blood pressure (BP) measures: a) systolic BP, 2) diastolic BP 3) pulse pressure and 4) mean arterial pressure, as well as the diagnosis of hypertension; 4) RAC is significantly associated with both incident hypertension and cardiovascular disease events. If so, we will determine if this association is mediated by differences in kidney function. We will explore these aims by interrogating images from computed tomography (CT) scans of the abdomen. The abdominal CT images will be scored for RAC, kidney volume and kidney density at the MESA CT reading center at UCLA. Blood samples will be assayed for cystatin-C, renin and aldosterone. The cystatin-C results will be used as a measure of kidney function and compared with existing data on serum creatinine and urine albumin. Renin and aldosterone will be used to determine if the presence of RAC is associated with differences in the rennin-angiotensin-aldosterone system. Approximately 700 of the subjects will have had follow-up scans completed by July 2007 allowing for testing of hypotheses involving prospective changes in RAC and kidney function. Finally, the overrepresentation of ethnic minority groups in MESA will allow for testing of interactions with ethnicity. We are unaware of any other population-based study adequate to study the stated aims.