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

这项拟议的研究将检查心理压力引起的尿钠排泄和尿钠排泄。 昼夜节律作为一种新的生物学机制，可能是一种异常的昼夜节律的基础 血压(BP)。BP遵循昼夜节律，在白天最高，并下降到 夜间的最低水平(即血压下降)。可以评估24小时内血压的昼夜模式 使用动态血压监测(ABPM)。ABPM血压异常的昼夜模式，由血压降低定义 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，潜在的 机制仍不清楚。通过精神压力任务暴露在急性压力源下通常会增加 尿钠排泄。然而，人与人之间的压力程度有很大的差异- 诱导钠排泄，使一些个体在应激刺激后有钠滞留。它有 假设当白天没有尿钠排泄时，尿钠 排泄物转移到夜间，这伴随着夜间血压的增加。因此， 白天经历心理压力的低应激性钠排泄量的个体 由于不能排泄，尿钠排泄可能从白天转移到夜间 白天的钠盐。这种昼夜尿钠排泄模式的改变可能与 从白天到夜间，BP的降幅较小，导致BP下降的幅度减少。这项研究将是 在实验室环境和自然环境中进行，样本为211个多民族 来自曼哈顿上城的成人社区参与者。在实验室里，尿钠排泄对 精神压力任务将被检查。在自然主义环境中，日模式的测量 钠排泄、动态血压、腕部活动描记和感知压力的生态瞬时评估将是 已执行。我们假设，实验室中应激诱导的较低的钠排泄率将与 自然环境中尿钠排泄率的昼夜比率较低；以及 昼夜尿钠排泄率的比率将与血压下降有关。我们会 还要检查应激后尿钠排泄与昼夜节律之间的关系 钠的排泄模式被更高的生态瞬间应激水平所改变，在 白天。这项研究具有很高的创新性，因为它将检验以前没有提出的理论联系 尿液排泄对实验室压力的反应，生态压力，以及 自然环境中的钠排泄和血压。本研究具有较高的临床意义。 了解心理应激在人类高血压中的作用，并有可能减少 心血管疾病风险与血压昼夜节律异常有关。

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.