Biobehavioral Mechanisms of Blood Pressure Dipping

描述（由申请人提供）：拟议研究的主要目的是进一步了解夜间睡眠期间血压（BP）下降的个体差异的原因和后果。越来越多的证据表明，夜间血压升高作为心血管发病率和死亡率的预后指标上级门诊血压或日间动态血压。钝性血压下降有利于向心性左心室肥厚（LVH）的发展，这是一种心脏几何结构重构，通常在高血压早期很明显。LVH是已知的心血管发病率和死亡率的最强预测因子，而不是年龄增长。 尽管有令人信服的证据表明，钝化BP下降的病理生理后果，其生物行为的决定因素仍有待确定。拟议的研究将在200名正常高血压或1期高血压的男性和女性中评估几种可能的BP下降机制，包括：（i）睡眠质量;（ii）心理社会压力;（iii）交感神经系统（SNS）活动，以及（iv）血管疾病。此外，这项研究将通过补充24小时动态血压监测，同时监测心输出量（CO）和全身血管阻力（SVR），从潜在的血流动力学机制方面描述血压下降的特征。这项研究将重点关注非裔美国人种族和绝经期妇女，因为它们是LVH的既定危险因素。这些因素也与钝化BP浸渍，BP浸渍的生物行为机制，我们建议进行评估。通过定义导致BP下降个体差异的因素，拟议的研究将产生有助于制定有效的生物行为干预措施的信息（例如，药物治疗、睡眠治疗、压力管理训练），旨在优化夜间血压，降低心血管疾病风险。

DESCRIPTION (provided by applicant): The primary objective of the proposed research is to further our understanding of the causes and consequences of individual differences in blood pressure (BP) dipping during nighttime sleep. Growing evidence indicates that elevated nighttime BP is superior to either clinic BP or daytime ambulatory BP as a prognostic indicator of cardiovascular morbidity and mortality. Blunted BP dipping favors the development of concentric left ventricular hypertrophy (LVH), a geometric restructuring of the heart that is often evident early in hypertension. LVH is the strongest known predictor of cardiovascular morbidity and mortality, other than advancing age. Despite compelling evidence for the pathophysiological consequences of blunted BP dipping, its biobehavioral determinants remain to be defined. The proposed study will evaluate several likely mechanisms of blunted BP dipping, including: (i) Sleep Quality; (ii) Psychosocial Stress; (iii) Sympathetic nervous system (SNS) activity, as well as: (iv) Vascular disease, in 200 men and women with high normal BP or Stage 1 hypertension. In addition, this study will characterize BP dipping in terms of the underlying hemodynamic mechanisms by supplementing 24-hour ambulatory BP monitoring with concurrent monitoring of cardiac output (CO) and systemic vascular resistance (SVR).The study will include a focus on African American ethnicity, and on menopause in women, because they are established risk factors for LVH. These factors are also related to blunted BP dipping, and to the biobehavioral mechanisms of BP dipping that we propose to assess. By defining the factors responsible for individual differences in BP dipping, the proposed research will yield information that should facilitate the development of effective biobehavioral interventions (e.g., pharmacological therapy, sleep therapy, stress management training) aimed at optimizing nighttime BP, and reducing cardiovascular disease risk.