DIVERGENCE OF BLOOD PRESSURE BY RACE IN ADOLESCENT GIRLS

描述：(改编自《调查员摘要》)非裔美国人 女性患高血压的比例要高得多， 高血压引起的发病率和死亡率高于 美国白人女性。这种血压的种族差异在很大程度上是 由于非裔美国女性肥胖症的增加。相比之下，年轻的 非洲裔美国女孩和白人美国女孩的肥胖水平相似， 血压。随着肥胖的发展而发生的血流动力学变化 并导致这种血压的种族差异一直不好 特色化的。对青少年的横断面研究表明， 尽管血压水平相似，但非裔美国人的总体血压水平更高 外周阻力，而白人有更高的心输出量。 对成年人的横断面研究表明，肥胖与 心输出量的增加。如果这种与肥胖相关的心脏增加 输出叠加在总周长的基础高程上 在非裔美国女孩中，这些血流动力学因素可能是 造成血压的种族差异的原因 青春期后期，非裔美国女孩的患病率越来越高 以及肥胖的严重程度。 建议的调查是对355名受试者进行前瞻性队列研究。 非裔美国人和315名白人美国女性来自NHLB1生长和 这些女性从18-19岁发展到21-22岁的健康研究 好几年了。这项研究将包括每年对人体测量、血液测量 心输出量和心排血量的超声心动图测定 外围电阻。此外，可能与变化有关的因素 心输出量和总外周阻力，如循环血液 容量(左心室舒张末容量)、心率、左心室 收缩功能、全血粘度、左心室重量和几何构型 将会被测量。这项调查将提供重要的新知识 关于纵向变化和之间的相互关系 潜在的血液动力学因素定义了两者之间的联系 出现肥胖和血压升高。在临床环境中 在肥胖很难预防或治疗的地方，重要的是 了解肥胖导致血液升高的机制 压力。这项队列研究的结果将为 合理而具体的临床干预策略干预病理生理 肥胖导致高血压并使非裔美国人 心血管疾病发病率风险特别高的妇女 和死亡率。

DESCRIPTION: (Adapted from the Investigator's Abstract) African-American women have a substantially higher prevalence of hypertension and suffer greater morbidity and mortality due to blood pressure elevation than White-American women. Much of this ethnic difference in blood pressure is due to increased obesity in African-American women. In contrast, young African-American and White-American girls have similar levels of obesity and blood pressure. The hemodynamic changes that occur with developing obesity and result in this ethnic difference in blood pressure have not been well characterized. Crosssectional studies of adolescents have shown that despite similar blood pressure levels, African-Americans have higher total peripheral resistance while Whites have higher cardiac output. Cross-sectional studies of adults show that obesity is associated with elevation of cardiac output. If such an obesity-related increase in cardiac output is superimposed on the underlying elevation of total peripheral resistance in African-American girls, these hemodynamic factors could be responsible for the developing ethnic divergence in blood pressure seen in late adolescence as African-American girls develop an increasing prevalence and severity of obesity. The proposed investigation is a prospective cohort study of 355 African-American and 315 White-American females from the NHLBl Growth and Health Study as these women progress from age 18-19 years to age 21-22 years. The study will include yearly measurement of anthropometrics, blood pressure, and echocardiographic determination of cardiac output and total peripheral resistance. In addition, factors which may relate to changes in cardiac output and total peripheral resistance, such as circulating blood volume (left ventricular end-diastolic volume), heart rate, left ventricular contractility, whole blood viscosity, and left ventricular mass and geometry will be measured. This investigation will provide important new knowledge regarding the longitudinal changes and interrelationships among the potential hemodynamic factors which define the association between developing obesity and blood pressure elevation. In the clinical setting where obesity is very difficult to prevent or treat, it is important to understand the mechanisms by which obesity results in elevated blood pressure. The results of this cohort study will provide the basis for rational and specific clinical strategies to interrupt the pathophysiologic process by which obesity leads to hypertension and places African-American women at particularly increased risk for cardiovascular disease morbidity and mortality.