Melatonin and Nighttime Blood Pressure in African Americans

描述（由申请人提供）：夜间血压升高是心血管疾病（CVD）的重要危险因素。事实上，最近的数据表明，夜间血压升高可能比白天血压升高是心血管疾病的更大危险因素。非洲裔美国人比其他种族/民族更容易出现夜间血压升高，这可能部分解释了为什么非洲裔美国人比美国其他种族/民族有更高的冠心病和中风死亡率，以及更高的肾脏疾病发病率。因此，研究降低非裔美国人夜间血压的方法应被视为一个重要的公共卫生目标。有证据表明，补充褪黑激素可能有助于降低夜间血压。然而，对非裔美国人补充褪黑激素和夜间血压的随机研究尚未进行。本提案的长期目标是研究补充褪黑激素是否有助于降低夜间血压升高的非裔美国人的夜间血压，并探索这种降血压效果可能发生的潜在机制。我们计划开展一项随机、双盲、安慰剂对照、交叉临床试验（n = 40），研究补充褪黑激素对非裔美国人夜间血压的影响。试点试验的具体目的如下：(i)获得关于夜间补充褪黑素4周对夜间血压升高的非裔美国受试者夜间血压的疗效的初步数据；（ii）探索睡眠因素、交感神经驱动和血管松弛作为褪黑激素降低夜间血压的潜在机制；（iii）确定招募和随机分配夜间血压升高的非裔美国人受试者进行褪黑素补充试验的可行性；（iv）评估夜间血压升高的非裔美国成年人连续四周每晚服用褪黑素补充剂是否有任何不良副作用。拟议试验的结果应有助于提供重要的初步数据，可用于指导更大规模、更明确的试验。

DESCRIPTION (provided by applicant): Elevated nighttime blood pressure (BP) is an important risk factor for cardiovascular disease (CVD). Indeed, recent data suggest that elevated nighttime BP may be a stronger risk factor for CVD than elevated daytime BP. African Americans are more likely than other racial/ethnic groups to suffer from elevated nighttime BP, which may partially explain why African Americans are at higher risk of mortality from coronary heart disease and stroke, and have a higher incidence of renal disease, than other racial/ethnic groups in the United States. Thus, investigating methods of reducing nighttime BP in African Americans should be considered an important public health goal. Evidence suggests that melatonin supplementation may help lower nighttime BP. However, randomized studies of melatonin supplementation and nighttime BP in African Americans have not been conducted. The long term goal of this proposal is to examine whether melatonin supplementation helps reduce nighttime BP in African Americans with elevated nighttime BP, and to explore potential mechanisms by which this BP lowering effect might occur. We plan to conduct a pilot randomized, double blind, placebo- controlled, crossover clinical trial (n = 40) examining the effect of melatonin supplementation on nighttime BP in African Americans. The specific aims of the pilot trial are as follows: (i) obtain preliminary data on the efficacy of 4 weeks of nightly melatonin supplementation on nighttime BP in African-American subjects suffering from elevated nighttime BP; (ii) explore sleep factors, sympathetic drive, and vasorelaxation as potential mechanisms by which melatonin may lower nighttime BP; (iii) determine the feasibility of recruiting and randomizing African American subjects with elevated nighttime BP for a melatonin supplementation trial; and (iv) estimate whether melatonin supplementation has any adverse side effects when taken nightly for four weeks in African-American adults with elevated nighttime BP. Results from the proposed trial should help provide important preliminary data that could be used to guide a larger, more definitive trial. PUBLIC HEALTH RELEVANCE: This project is relevant to public health because it will help shed light on whether melatonin supplementation can lower nighttime blood pressure in African Americans who suffer from elevated nighttime blood pressure.