CAFFEINE EFFECTS ON STRESS REACTIVITY

咖啡因是美国消费最广泛的药物，但习惯性消费对健康的长期影响，特别是对心血管疾病的影响，仍然存在疑问。众所周知，咖啡因会升高血压，研究表明，咖啡因可以增强心血管和神经内分泌应激反应。这两种影响都可能增加患心血管疾病的风险，包括高血压和心脏病。该项目的长期目标是调查咖啡因的影响，确定其对心血管健康和疾病的影响，并确定风险最高的个人的特征。这项应用的具体目的是探索高血压患者从停止习惯性摄入咖啡因中可能获得的潜在心血管健康益处。我们将检验两个假设。(1)停用咖啡因可显著降低高血压患者的临床血压。(2)停用咖啡因可降低调节血压升高的神经内分泌应激通路的激活。这项临床干预试验包括血压在高、正常或轻度高血压范围内的习惯喝咖啡的人，以及那些目前正在接受高血压药物治疗的人。受试者将完成7天的临时咖啡因摄入或实验性咖啡因戒除，然后进行一天的动态监测。停止咖啡因对血压的影响将通过在正常一天的活动中收集的临时(办公室)和动态测量来评估。停药对神经内分泌应激反应通路激活的影响将在同一环境下尿儿茶酚胺和皮质醇排泄的动态测量中进行研究。如果我们了解到停止咖啡因可以降低血压，高血压患者可能会立即受益。那些正常血压偏高或轻度高血压的人可以通过在饮食和生活方式管理计划中增加咖啡因戒断来避免或推迟抗高血压药物的需要。已经接受药物治疗的高血压患者可能会通过停止咖啡因来进一步降低血压，进一步降低他们长期并发症的风险，或许还会减少他们对药物的需求。虽然不是每个人都有必要停用咖啡因，但它显然有助于高血压患者的血压控制，从而降低心脏病、中风和肾脏疾病的风险，这些疾病都是这种疾病的后果。

Caffeine is the most widely consumed drug in the U.S., yet questions remain about the long-term health consequences of habitual consumption, especially with regard to cardiovascular diseases. Caffeine is known to raise blood pressure (BP), and research shows that it can potentiate cardiovascular and neuroendocrine stress reactivity. Both effects could increase the risks of developing cardiovascular diseases including hypertension and heart disease. The long-term objectives of this project are to investigate caffeine's effects, determine their implications for cardiovascular health and disease, and characterize the individuals who are most at risk. The specific aim of this application is to explore the potential cardiovascular health benefits that hypertensive individuals could obtain from the cessation of habitual caffeine consumption. Two hypotheses will be tested. (1) Caffeine cessation results in clinically significant reductions in BP in hypertensive individuals. (2) Caffeine cessation reduces activation of the neuroendocrine stress pathways that can mediate BP elevations. This clinical intervention trial includes groups of habitual coffee drinkers who have blood pressures in the high normal or mild hypertensive range and those who are currently receiving medication for established hypertension. Subjects will complete 7-day periods of ad lib caffeine consumption or experimental caffeine abstinence followed by a day of ambulatory monitoring. The effects of caffeine cessation on BP will be evaluated using both casual (office) and ambulatory measurements collected during the activities of the normal day. The effects of cessation on activation of neuroendocrine stress response pathways will be investigated in ambulatory measures of urinary catecholamine and cortisol excretion in the same environment. Hypertensive individuals could receive an immediate benefit if we learn that caffeine cessation reduces blood pressure. Those with high normal BP or mild hypertension might avoid or postpone the need for anti-hypertensive medications by adding caffeine cessation to a program of dietary and lifestyle management. Hypertensive patients already receiving pharmacological treatment might lower BP even more by caffeine cessation, further reducing their risk of long-term complications and perhaps reducing their need for medication. Although caffeine cessation may not be necessary for everyone, it may clearly contribute to BP management in hypertensive individuals and thereby reduce the risks for heart disease, stroke, and kidney disease that are the consequences of this disease.