HEMODYNAMICS OF CV REACTIVITY IN BLACK OR WHITE YOUTH

原发性高血压（EH）的发病率和死亡率 代表了美国主要的医疗保健成本和关注点。 尽管冠状动脉和脑血管疾病的发病率有所下降， 在过去的几十年里，这种改善的大部分并没有被 在黑人中观察到，特别是在"中风带"地区， 东南部 黑人继续有更大的患病率高血压，它是 更严重。 导致EH演变的因素开始于 童年，因此我们选择了儿童进行研究。 我们的目标是 确定EH演变的标志物和机制， 高风险人群高血压一级预防的策略 人口。 由于血压（BP）是心输出量的乘积， (CO)和总外周血管阻力（TPR），研究必须 旨在评估CO和TPR反应的种族差异， 已知的预测未来BP的挑战。通过使用阻抗 结合心电图和血压测量，本研究旨在 确定黑人与白人在血管收缩方面是否不同， 和/或血管舒张功能。 通过将慢性生活 压力清单，慢性压力和急性压力之间的关系 将确定血液动力学评估。 通过使用纵向 研究设计，本研究将确定 实验室挑战的血流动力学反应，以及 急性CO和TPR对实验室应激源的反应或慢性 生活压力预测未来偶发血压。 这些研究将导致 BP控制系统异常的机理评价， 评估和干预以预防EH的领域，特别是在 美国的高风险黑人。

The morbidity and mortality caused by essential hypertension (EH) represent major health care costs and concerns in the United States. Although there have been reductions in coronary and cerebrovascular diseases over the past few decades, much of this improvement has not been observed among blacks, especially in the "stroke belt" region of the Southeast. Blacks continue to have a greater prevalence of EH, and it is more severe. The factors which lead to the evolution of EH begin in childhood, thus we have chosen children for study. It is our goal to identify both markers for and mechanisms of evolution of EH to allow strategies to be developed for the primary prevention of EH in high-risk populations. Since blood pressure (BP) is the product of cardiac output (CO) and total peripheral vascular resistance (TPR), studies must be designed to evaluate racial differences in CO and TPR responses to challenges known to predict future BP. By the use of impedance cardiography in conjunction with BP measurement, this study seeks to define whether blacks differ from whites with respect to vasoconstrictive and/or vasodilatory function. By the incorporation of a chronic life stress inventory, the relationships between chronic stress and acute hemodynamic assessments will be determined. By use of a longitudinal study design, this investigation will determine the stability of hemodynamic responses to laboratory challenges, and the ability of either acute CO and TPR responses to laboratory stressors or changes in chronic life stress to predict future casual BP. These studies will lead to mechanistic evaluations of BP control system abnormalities to identify areas for assessment and intervention to prevent EH, especially in the high-risk black population of the United States.