Psychological stress, and circadian patterns of sodium excretion and blood pressure

这项研究将检测由心理应激引起的尿钠排泄， 昼夜模式作为一种新的生物学机制，可能是一种异常的昼夜模式的基础， 血压（BP）。血压遵循昼夜节律，在白天最高，福尔斯下降到 夜间最低水平（即BP下降）。可以评估24小时内血压的昼夜模式 动态血压监测（ABPM）ABPM上的血压昼夜模式异常，定义为血压降低 夜间血压下降或升高与心血管疾病（CVD）事件的风险增加有关。 心理压力与血压的异常昼夜模式有关。然而，底层 机制仍然未知。使用精神压力任务暴露于急性压力源通常会增加 尿钠排泄然而，压力的程度在人与人之间存在很大的差异， 诱导钠排泄，使得一些个体在应激激发后具有钠潴留。它有 假设当尿钠排泄不在白天发生时，尿钠 排泄向夜间转移，这伴随着夜间BP的增加。因此，我们认为， 在白天经历心理压力的压力诱导钠排泄较低的个体 由于不能排泄，尿钠排泄可能从白天转移到夜间 钠在白天。尿钠排泄的昼夜模式改变可能与 从白天到夜间血压下降幅度较小，导致血压下降幅度减小。本研究将 在实验室环境和自然环境中进行，有211个多种族样本 来自上曼哈顿的成年社区参与者。在实验室中，尿钠排泄对 将检查精神压力任务。在自然环境中，测量的昼夜模式， 钠排泄、ABPM、腕关节活动记录仪和感知压力的生态瞬时评估将被 执行。我们推测实验室中较低的应激诱导的钠排泄率将与 在自然环境中，尿钠排泄率的昼夜比值较低; 尿钠排泄率的昼夜比与血压下降的减少有关。我们将 还检查了应激后尿钠排泄量与昼夜节律之间的关系。 钠排泄模式被较高的生态瞬时应激水平所改变， 白天。这项研究具有高度的创新性，因为它将测试以前没有提出的理论联系， 在实验室中引起的应激反应、生态应激反应和 自然环境中的钠排泄和血压。本研究对提高临床疗效具有重要意义 了解心理应激在人类高血压中的作用，并有可能降低 CVD风险与血压昼夜模式异常相关。

The proposed study will examine urinary sodium excretion induced by psychological stress and its diurnal pattern as a novel biological mechanism that may underlie an abnormal diurnal pattern of blood pressure (BP). BP follows a diurnal rhythm, for which it is highest during the daytime, and falls to its lowest level during the nighttime (i.e. BP dipping). The diurnal pattern of BP over 24 hours can be assessed using ambulatory BP monitoring (ABPM). An abnormal diurnal pattern of BP on ABPM, defined by reduced BP dipping or elevated nighttime BP, is associated with an increased risk of cardiovascular disease (CVD) events. Psychological stress is associated with an abnormal diurnal pattern of BP. However, the underlying mechanisms remain unknown. An exposure to an acute stressor using a mental stress task normally increases urinary sodium excretion. However, there is substantial between-person variability in the degree of stress- induced sodium excretion, such that some individuals have sodium retention after stress provocation. It has been hypothesized that when urinary sodium excretion does not occur during the daytime, urinary sodium excretion is shifted toward the nighttime, which is accompanied by an increase in nighttime BP. Therefore, individuals with lower stress-induced sodium excretion who experience psychological stress during the daytime may have a shift of urinary sodium excretion from the daytime to nighttime periods due to an inability to excrete sodium during the daytime. This altered diurnal pattern of urinary sodium excretion may be associated with a smaller decline in BP from the daytime to nighttime, leading to reduced BP dipping. The study will be conducted both in the laboratory setting and in the naturalistic environment with a multi-ethnic sample of 211 adult community participants from upper Manhattan. In the laboratory, urinary sodium excretion in response to mental stress tasks will be examined. In the naturalistic environment, measurement of the diurnal pattern of sodium excretion, ABPM, wrist actigraphy, and ecological momentary assessments of perceived stress will be performed. We hypothesize that lower stress-induced sodium excretion rate in the laboratory will be associated with lower daytime-to-nighttime ratio of urinary sodium excretion rate in the naturalistic environment; and lower daytime-to-nighttime ratio of urinary sodium excretion rate will be associated with reduced BP dipping. We will also examine whether the association between urinary sodium excretion after provoked stress and the diurnal pattern of sodium excretion is modified by higher ecological momentary levels of stress, experienced during the daytime. The study is highly innovative as it will test not previously proposed theoretical linkages among urinary excretion in response to stress provoked in the laboratory, ecological stress, and the diurnal patterns of sodium excretion and BP in the naturalistic environment. The study has high clinical significance for improving the understanding of the role of psychological stress in human hypertension, and has the potential for reducing the CVD risk associated with an abnormal diurnal pattern of BP.