Adjunct vitamin D therapy as a means to reduce the disparity in subclinical targe

描述(由申请人提供)：已知在心血管疾病及其相关结果中存在巨大差异。这在很大程度上可以追溯到高血压及其随之而来的与压力相关的后果，特别是靶器官心脏损害。后者过早地出现在非裔美国人中，而且不成比例，降低了生活的质量和数量。在市中心患有高血压的非裔美国人中，靶器官心脏损伤的风险尤其高，特别是那些利用急诊科进行慢性血压管理的人。与心血管疾病一样，维生素D缺乏对非裔美国人的影响不成比例。维生素D被认为是心血管差异的重要调节剂，它通过直接(和通过甲状旁腺激素间接)心肌(肥大、纤维化)和血管(增加抵抗力、顺应性丧失)作用。维生素D缺乏者的维生素D补充被认为是减轻非裔美国人心血管疾病负担的机制，特别是如果在不可逆转的损害发生之前就开始补充维生素D，但这还有待前瞻性临床试验的测试。因此，这项建议旨在研究维生素D与亚临床靶器官心脏损害(如心脏磁共振成像所确定的)之间的关系，在一组无心脏病病史的非裔美国人缺乏维生素D的高血压患者中进行研究。具体地说，我们试图通过一项安慰剂对照的随机设计，在一年内确定辅助维生素D治疗对左室肥厚(主要目的)、心肌纤维化和中心血管功能(次要目的)的影响。两个研究部门的降压治疗都将标准化，我们的重点将是招募到我们的安全网机构中血压控制不佳的患者-这是一个高风险、高回报的群体，他们将从确定一种廉价的干预措施中受益匪浅，这种干预措施可以有效地减少高血压的不利影响。

DESCRIPTION (provided by applicant): Tremendous disparities are known to exist in cardiovascular disease and its related outcomes. Much of this can be traced to poorly controlled hypertension and its attendant, pressure-related consequences, especially target-organ cardiac damage. The latter, which occurs prematurely and disproportionately in African- Americans, reduces both quality and quantity of life. The risk of target-organ cardiac damage is particularly high among inner-city African-Americans with hypertension, particularly those who utilize the emergency department for chronic blood pressure management. Like cardiovascular disease, vitamin D deficiency disproportionately affects African-Americans. Vitamin D is thought to be an important modifier of cardiovascular disparities through its direct (and, via parathyroid hormone, indirect) myocardial (hypertrophy, fibrosis) and vascular (increased resistance, loss of compliance) effects. Vitamin D repletion in those who are deficient has been postulated as mechanism to reduce the cardiovascular disease burden experienced by African- Americans, especially if initiated early before irreversible damage has occurred, but this has yet to be tested in a prospective clinical trial. Accordingly, this proposal was designed to investigate the relationship between vitamin D and subclinical target-organ cardiac damage (as identified on cardiac magnetic resonance imaging) in a cohort of African-American, vitamin D deficient hypertensive patients without prior history of heart disease. Specifically, we seek to ascertain the effect of adjunct vitamin D therapy on left ventricular hypertrophy (primary aim), myocardial fibrosis and central vascular function (secondary aims) at one-year using a placebo controlled, randomized design. Antihypertensive treatment in both study arms will be standardized and our focus will be recruitment of patients who present to our safety-net institution with poorly controlled blood pressure - a high-risk, high-reward subset who would stand to benefit tremendously from identification of an inexpensive intervention, which could effectively reduce the adverse impact of hypertension.