BLOOD PRESSURE EFFECTS OF BEHAVIORAL STRESS / SODIUM LOADING

本研究探讨了生理和心理因素 与血压正常成人的血压升高有关。 的 这项研究的长期目标是开发和完善 高血压的预防性干预，无论是行为还是 饮食，可以针对那些最 易受行为性高血压的协同效应影响， 压力和高钠摄入 约翰霍普金斯大学的医学生 大学医学院戴着动态血压监测仪 在讲座和考试期间， 钠和常规钠摄入量。 考试的压力 与血浆钾降低、 血浆皮质醇和增加血浆钠的趋势。 作为 预期，血压和心率在治疗期间升高， 考试相对于讲座期间，但这些规模 升高不受钠摄入量的影响。 定时尿样 收集，检查与减少 尿排泄率，尽管尿皮质醇和尿 去甲肾上腺素在紧张的检查中倾向于增加。 检查期间尿皮质醇排泄量在 高钠组，而尿去甲肾上腺素排泄倾向于 在高钠组中更低。 尿钠排泄数据如下： 用于识别个体的子集，包括钠潴留 (48%;检查期间尿钠排泄率（Una）降低 相对于讲座）和钠排泄物（52%;增加Una）。 钠潴留者在对照期间显示出较高的钠排泄率 （讲座）条件和较低的钠排泄率在暴露期间 压力源 这些人也显示出较低的夜间钠 在紧张的考试前排泄。 钠潴留显示， 血压对压力的反应更大的趋势 检查，尿去甲肾上腺素水平较高的趋势 检查期间的排泄，以及更高的休息倾向 在检查前30分钟收集的醛固酮水平。这些 发现提示肾上腺皮质激活的重要性， 特别是醛固酮刺激， 挑战作为一个可能的调解员的压力相关的钠潴留。

This study examines the physiological and psychological factors associated with blood pressure elevations in normotensive adults. The long-term goal of this research is the development and refinement of preventative interventions for hypertension, either behavioral or dietary, that can be directed at those individuals who are most vulnerable to the synergistic blood pressure effects of behavioral stress and a high sodium intake. Medical students at Johns Hopkins University School of Medicine wore ambulatory blood pressure monitors during a lecture and during the examination while maintaining the high sodium and regular sodium intake. The stress of taking an examination was associated with a lowering of plasma potassium, an increase in plasma cortisol, and a tendency to increase plasma sodium. As expected, blood pressure and heart rate were elevated during the examination relative to the lecture period, but the magnitude of these elevations was not influenced by sodium intake. Timed urine samples were collected and the examination was associated with a reduction in urinary excretion rate, although both urinary cortisol and urinary norepinephrine tended to increase during the stressful examination. Urinary cortisol excretion during the examination was greater among the high sodium group, whereas urinary norepinephrine excretion tended to be lower in the high sodium group. Urinary sodium excretion data were used to identify subsets of individuals, including sodium retainers (48%; decreased urinary sodium excretion rate (Una) during the exam relative to the lecture) and sodium excreters (52%; increased Una). Sodium retainers showed higher sodium excretion rates during the control (lecture) conditions and lower sodium excretion rates during exposure to the stressor. These individuals also showed lower overnight sodium excretion before the stressful examination. Sodium retainers showed a tendency for greater blood pressure reactivity to the stressful examination, a tendency for higher levels of urinary norepinephrine excretion during the examination, and a tendency for higher resting levels of aldosterone collected 30 minutes before the exam. These findings suggest the importance of adrenocortical activation, particularly aldosterone stimulation, in response to behavioral challenges as a possible mediator of stress-related sodium retention.