Melatonin and Nighttime Blood Pressure in African Americans

项目总结/摘要 夜间血压（BP）升高是心血管疾病（CVD）的重要危险因素。的确， 最近的数据表明，夜间血压升高可能是比白天血压升高更强的心血管疾病危险因素 BP.非裔美国人比其他种族/族裔群体更容易患夜间血压升高， 这可能部分解释了为什么非裔美国人死于冠心病的风险更高 和中风，并有较高的发病率肾脏疾病，比其他种族/族裔群体在美国。 因此，研究降低非裔美国人夜间血压的方法应该被认为是一个重要的问题。 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，在非裔美国人中补充褪黑激素和夜间血压的随机研究并没有 进行了。这项建议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，并探索潜在的机制， 这种降压效果可能会发生。我们计划进行一项随机双盲安慰剂试验- 对照、交叉临床试验（n = 40），检查补充褪黑激素对夜间血压的影响 在非裔美国人中。试点试验的具体目标如下：（一）获得关于 4周每晚补充褪黑激素对非裔美国人夜间血压的影响 患有夜间血压升高;（ii）探索睡眠因素，交感神经驱动和血管舒张， 褪黑激素可能降低夜间血压的潜在机制;（iii）确定招募的可行性 随机选择夜间血压升高的非裔美国人进行褪黑激素补充试验; 以及（iv）估计每天晚上服用褪黑激素补充剂是否有任何不良副作用， 在夜间血压升高的非裔美国成年人中，拟议中的试验结果应该会有所帮助 提供了重要的初步数据，可用于指导更大，更明确的试验。

PROJECT SUMMARY/ABSTRACT 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.