Age Comparisons of Exercising Muscle O2 Supply in Healthy Adults: Effects of Esmolol Infusion
试验速览
- 阶段
- 早期 1 期
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Tissue Saturation Index (TSI) - Active Leg Muscle
研究概览
简要总结
This study will test the central hypothesis that postmenopausal women will demonstrate increased oxygen extraction in active leg muscle during leg cycling exercise while receiving an infusion of Esmolol, a fast-acting β1 selective antagonist, when compared to premenopausal women
详细描述
This study will test the central hypothesis that postmenopausal women will demonstrate increased oxygen extraction in active leg muscle during leg cycling exercise while receiving an infusion of Esmolol, a fast-acting β1 selective antagonist, when compared to premenopausal women. β1 selective antagonists (or "β1 blockers") are used to lower heart rate and improve O2 supply-to-demand balance in patients with coronary artery disease. By using esmolol to attenuate the central sympathetic response to exercise (increased heart rate and cardiac output) we can examine peripheral mechanisms of O2 delivery. The current project will evaluate how older postmenopausal women adjust active muscle O2 supply to an acute reduction in systemic O2 delivery during large muscle dynamic exercise when compared to younger premenopausal women.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
盲法说明
The participants, investigators, and data analysts (outcomes assessors) will be blinded to the treatment (drug) order. The care providers (research nurse and physician) will be aware of the treatment order for safety reasons i.e., they will be assessing heart rate, blood pressure and symptoms before, during, and after the infusion.
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- Female
- 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
Esmolol Infusion
Drug: Esmolol Hydrochloride Dosage form: Intravenous Infusion Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour.
干预措施: Esmolol infusion (Drug)
Esmolol Infusion
Drug: Esmolol Hydrochloride Dosage form: Intravenous Infusion Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour.
干预措施: Pre exercise baseline (Other)
Esmolol Infusion
Drug: Esmolol Hydrochloride Dosage form: Intravenous Infusion Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour.
干预措施: Isometric handgrip exercise (Other)
Esmolol Infusion
Drug: Esmolol Hydrochloride Dosage form: Intravenous Infusion Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour.
干预措施: Semi-recumbent cycling (Other)
Saline Infusion
Saline infusion volume/rate matched to the calculated dose of esmolol.
干预措施: Saline infusion (Drug)
Saline Infusion
Saline infusion volume/rate matched to the calculated dose of esmolol.
干预措施: Pre exercise baseline (Other)
Saline Infusion
Saline infusion volume/rate matched to the calculated dose of esmolol.
干预措施: Isometric handgrip exercise (Other)
Saline Infusion
Saline infusion volume/rate matched to the calculated dose of esmolol.
干预措施: Semi-recumbent cycling (Other)
结局指标
主要结局
Tissue Saturation Index (TSI) - Active Leg Muscle
时间窗: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.
The primary outcome variable is the change in skeletal muscle oxygenation (∆TSI%) in the active leg muscle from baseline during recumbent cycling using near-infrared spectroscopy. TSI% represent the percentage of oxygenated hemoglobin relative to total hemoglobin in the tissue beneath the NIRS probe. Lower values represent a greater reduction in tissue oxygenation from baseline (greater oxygen extraction and/or reduced oxygen delivery). TSI% = oxy\[heme\] / total\[heme\] x 100
次要结局
- Tissue Saturation Index - Inactive Forearm Muscle(Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.)
- Systolic Blood Pressure(At rest and 3 minutes into moderate exercise and heavy exercise.)
- Heart Rate(Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.)
- Cardiac Output(Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.)
- Diastolic Blood Pressure(At rest and 3 minutes into moderate exercise and heavy exercise.)
- Mean Arterial Pressure(At rest and 3 minutes into moderate exercise and heavy exercise.)
- Stroke Volume(Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.)
- Systemic Vascular Conductance(Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.)
- ∆HHb - Inactive Forearm(Last 60 seconds of Moderate and Heavy Exercise)
研究者
David N. Proctor, PhD
Professor of Kinesiology, Physiology, and Medicine
Penn State University