Comparison of the Cardiovascular, Metabolic and Respiratory Effects of Nebivolol and Carvedilol at High Altitude in Healthy Subjects.
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 27
- 试验地点
- 1
- 主要终点
- Peak Exercise Oxygen Consumption
研究概览
简要总结
Exposure of healthy subjects to high altitude hypoxia elicits changes in cardiovascular, respiratory and metabolic features as weel as in exercise performance similar, for some aspects, to those observed in chronic heart failure. Exposure to high altitude hypoxia represents a suitable model to assess different treatments proposed for this pathological condition. Our aim was to evaluate the impact of two different third-generation beta-blockers used in heart failure (carvedilol and nebivolol) on cardiovascular, respiratory, metabolic profile and on exercise performance at high altitude.
详细描述
Methods. Study Subjects. Adults, males and females, non smoking healthy volunteers, sea-level residents not engaged in regular endurance exercise training, taking no medications will be recruited. As there are no studies comparing the effects of beta-blockers on exercise performance at high altitude, the sample size set for each treatment arm was defined on the basis of the sample size of previous investigations showing significant changes in exercise performance in normal subjects taking no medications.
Study design. Time 0. Screening, enrollement and randomization. Subjects meeting the inclusion/exclusion criteria will undergo at sea-level, general laboratory investigations and physical examination. Eligible subjects will be double blindly randomized to either placebo (one tablet twice daily), carvedilol (one 25 mg tablets twice daily), or to nebivolol (one 5 mg tablet in the morning and one placebo tablet in the evening).
Time 1. Before starting the medications, at sea level after an overnight fast, subject will undergo: blood pressure and heart rate measurement, 24 hour ambulatory blood pressure monitoring, Doppler heart ultrasound, cardiopulmonary exercise test, resting energy expenditure measurement.
Time 2. After three weeks of allocated treatment, at sea-level, after an overnight fast, subjects will undergo: blood pressure and heart rate measurement, 24 hour ambulatory blood pressure monitoring, Doppler heart ultrasound, cardiopulmonary exercise test, resting energy expenditure measurement.
Time 3. Under treatment within the first two days of high altitude exposure (Regina Margherita hut, Monte Rosa, altitude 4559 m), subjects will undergo after an overnight fast to blood pressure and heart rate measurement, 24 hour ambulatory blood pressure monitoring, Doppler heart ultrasound, cardiopulmonary exercise test, resting energy expenditure measurement, acute mountain sickness quantification by the Lake Louise Score.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
placebo
Placebo tablets. One tablet twice daily.
干预措施: placebo (Drug)
2: Carvedilol
Carvedilol 25 mg tablets. One tablet twice daily.
干预措施: Carvedilol (Drug)
3: Nebivolol
Nebivolol 5 mg tablets. One nebivolo tablet daily. One placebo tablet daily.
干预措施: Nebivolol (Drug)
结局指标
主要结局
Peak Exercise Oxygen Consumption
时间窗: Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.
Oxygen consumption at peak of exercise
Delta Peak Exercise Oxygen Consumption Time 1 Versus Time 3
时间窗: Time 1: sea level, baseline, no treatment. Time 3: within the first two days of high altitude exposure, under treatment.
Difference in peak exercise oxygen consumption between Time 1 and Time 3 (Time 3 - Time 1)
Peak Exercise Minute Ventilation
时间窗: Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.
Minute ventilation at peak of exercise. Minute ventilation = tidal volume (ml) multiplied by the respiratory rate (breaths/min)
Delta Peak Exercise Minute Ventilation Time 1 Versus Time 3.
时间窗: Time 1: sea level, baseline, no treatment. Time 3: within the first two days of high altitude exposure, under treatment.
Difference in peak exercise minute ventilation between Time 1 and Time 3 (Time 3 - Time 1. Minute ventilation = tidal volume (ml) multiplied by the respiratory rate (breaths/min).
次要结局
- Peak Exercise Oxygen Saturation(Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.)
- Systolic Pulmonary Artery Pressure.(Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.)
- Resting Energy Expenditure(Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.)
- Sitting Blood Pressure and Heart Rate(Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.)
- Mean 24 Hour/Daytime/Night-time Blood Pressure and Heart Rate(Time 1: sea level, baseline, no treatment. Time 2: sea level, after three weeks of allocated treatment. Time 3: within the first two days of high altitude exposure, under treatment.)