CAFFEINE INFLUENCES ON EXERCISE AND PSYCHOLOGICAL STRESS

咖啡因对运动和心理压力的影响

• 批准号: 3343280
• 负责人: William R Lovallo
• 金额: $ 23.99万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3343280
• 关键词: behavioral medicine; bioenergetics; caffeine; cardiovascular disorder diagnosis; cardiovascular disorder prevention; cardiovascular stress test; disease /disorder proneness /risk; hemodynamics; human subject; hypertension; magnetic resonance imaging; neuroendocrine system; neurotransmitters; noninvasive diagnosis; physiologic stressor; psychological stressor; psychomotor function; stress

Caffeine is considered the most widely used pharmacologic substance in the United States, yet little research has been done on its cardiovascular effects at rest and during psychological and exercise stress. The present proposal describes studies designed to examine how caffeine (3.5 mg/kg, equal to 2-3 cup of coffee) affects cardiovascular function in men at low risk of developing hypertension and those showing early-to-mild hypertension (EH, defined as resting blood pressures of 140-160/90-95). Our research has shown that this dose of caffeine elevates blood pressure at rest by increasing the state for constriction of the peripheral blood vessels. We have also shown that during work on a demanding psychomotor task (unsignalled, simple reaction time with monetary bonuses), caffeine synergistically enhances heart rate, cardiac output, myocardial contractility, and indices of cardiac work. In normotensive men at high risk of developing essential hypertension, caffeine pressor effect in additive with the already elevated blood pressure. As a result, during psychological and aerobic exercise stress, this high risk group shows enhanced levels of blood pressure. At some point during aerobic exercise, 55% of the high risk subjects showed pressures in excess of 230/100 mmHg, considered to be abnormally high during exercise. The proposed studies will extend our work from men at risk to those showing true EH. Study I concerns caffeine's effects on responses to repeated psychomotor challenges separated by brief rests insufficiently long to allow recovery of baseline to occur. Study II tests caffeine's effects on continuous psychomotor and mental challenge with no rests. Study III examines caffeine's potential for producing excessive (greater than or equal to 230/100 mmHg blood pressure responses during graded aerobic bicycle exercise up through maximum exercise. Our use of impedance and nuclear imaging techniques for determining stroke volume and cardiac output permits an extensive characterization of the hemodynamic responses occurring during states of stress under caffeine. This research is of practical significance in providing useful information on caffeine's risk potential in hypertensive men.

咖啡因被认为是最广泛使用的药物 美国有这种物质，但研究还很少 其在休息时和心理状态下对心血管的影响 运动压力。 本提案描述了设计的研究 检查咖啡因（3.5 毫克/公斤，相当于 2-3 杯咖啡）的含量 影响低风险男性的心血管功能 高血压和那些表现出早期至轻度高血压的人（EH， 定义为静息血压140-160/90-95）。 我们的 研究表明，这种剂量的咖啡因可以提高血液水平 通过增加收缩状态来增加静止压力 外周血管。 我们还表明，在工作期间 一项艰巨的精神运动任务（无信号、简单的反应时间 与金钱奖励），咖啡因协同增强心脏 率、心输出量、心肌收缩力和指数 心脏工作。 在血压正常的男性中，患有该病的风险很高 原发性高血压，咖啡因的升压作用 已经升高的血压。 结果，期间 心理和有氧运动压力，这一高危人群 显示血压水平升高。 期间的某个时刻 有氧运动，55%高危人群表现出压力 超过 230/100 mmHg，被认为异常高 运动期间。 拟议的研究将把我们的工作范围从处于危险中的男性扩展到 那些表现出真正的 EH 的人。 研究一涉及咖啡因对 对重复的精神运动挑战的反应，中间有简短的描述 休息时间不够长，无法恢复基线。 研究二测试咖啡因对持续精神运动和 没有休息的精神挑战。 研究三检查咖啡因的 产生过量的潜力（大于或等于 分级有氧运动期间血压反应为 230/100 mmHg 骑自行车通过最大限度的锻炼来锻炼身体。 我们使用阻抗和核成像技术 确定每搏输出量和心输出量可以 血流动力学反应的广泛表征 发生在咖啡因的压力状态下。 这项研究是 提供有用的信息具有实际意义 咖啡因对男性高血压的潜在风险。