CAFFEINE EFFECTS ON STRESS REACTIVITY

咖啡因是美国消费最广泛的药物，然而，关于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，仍然存在问题。 众所周知，咖啡因会升高血压（BP），研究表明它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（包括高血压和心脏病）的风险。 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，并描述风险最大的个体。 本申请的具体目的是探索高血压患者从停止习惯性咖啡因摄入中获得的潜在心血管健康益处。将检验两个假设。(1)停止咖啡因摄入可使高血压患者的血压显著降低。(2)咖啡因的停止减少神经内分泌应激途径的激活，可以介导血压升高。这项临床干预试验包括血压处于正常高血压或轻度高血压范围内的习惯性咖啡饮用者群体以及目前正在接受治疗已确诊的高血压药物的群体。 受试者将完成为期7天的咖啡因自由摄入或实验性咖啡因戒断，然后进行为期一天的动态监测。咖啡因停止对血压的影响将使用日常活动期间收集的偶然（办公室）和动态测量进行评估。 将在同一环境中通过尿儿茶酚胺和皮质醇排泄的动态测量来研究停药对神经内分泌应激反应途径激活的影响。如果我们知道停止咖啡因可以降低血压，高血压患者可以立即受益。 那些血压正常值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加入咖啡因停止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降低血压，进一步降低长期并发症的风险，并可能减少他们对药物的需求。 虽然咖啡因的停止可能不是每个人都有必要，但它显然有助于高血压患者的血压管理，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.