Role of Blood Flow and Vascular Function on Exercise Capacity in Cystic Fibrosis
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 19
- 试验地点
- 1
- 主要终点
- Acute Study: Percentage Flow-Mediated Dilation (FMD)
研究概览
简要总结
Cystic fibrosis (CF) has many health consequences. A reduction in the ability to perform exercise in patients with CF is related to greater death rates, steeper decline in lung function, and more frequent lung infections. However, the physiological mechanisms for this reduced exercise capacity are unknown. The investigators laboratory recently published the first evidence of systemic vascular dysfunction in patients with CF. Therefore, it is reasonable to suspect that the blood vessels are involved with exercise intolerance in CF. This study will look at how 1) blood flow and 2) artery function contribute to exercise capacity in CF.
详细描述
The most disturbing aspect of Cystic Fibrosis (CF) is the associated premature death. Low exercise capacity predicts death in patients with CF and is also associated with a steeper decline in lung function and more lung infections. A critical barrier to improving exercise tolerance in patients with CF is the investigators lack of knowledge regarding the different physiological mechanisms which contribute to their lower exercise capacity. We have compelling data to indicate that the blood vessels may contribute to the low exercise capacity in CF. The impact of this proof of concept investigation will test Phosphodiesterase Type 5 inhibitors (PDE5) inhibitors as a potential therapy in CF and will explore blood flow and endothelial function as potential mechanisms which contribute to exercise intolerance in CF. Improvements in exercise capacity will not only contribute to a better quality of live for patients with CF, it will also increase longevity in these patients.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 —（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
Acute Study: Sildenafil first, then Placebo
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
干预措施: Sildenafil (Acute-1 hour) (Drug)
Acute Study: Sildenafil first, then Placebo
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
干预措施: Placebo (Drug)
Acute Study: Placebo first, then Sildenafil
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
干预措施: Sildenafil (Acute-1 hour) (Drug)
Acute Study: Placebo first, then Sildenafil
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
干预措施: Placebo (Drug)
Sub-Chronic Study Sildenafil
Following the acute study, patients will be instructed to take 20 mg of sildenafil, three times a day, for 4 weeks. Endothelial function will be determined within 48 hours following the last dose.
干预措施: Sildenafil (Subchronic-4 weeks) (Drug)
结局指标
主要结局
Acute Study: Percentage Flow-Mediated Dilation (FMD)
时间窗: pre-treatment Baseline and 1 hour post-treatment
FMD determined one hour after ingestion of 50 mg Sildenafil or placebo
Baseline Diameter
时间窗: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Brachial Artery Diameter during FMD (pre-occlusion or "baseline")
Peak Diameter
时间窗: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Peak Brachial Artery Diameter during FMD (post-occlusion)
Absolute Change in Diameter
时间窗: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Absolute change in brachial artery diameter taken from the FMD assessment
FEV1 (% Predicted)
时间窗: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
Forced Expiratory Volume in the first second expressed as a percent predicted.
VO2 Peak (Absolute)
时间窗: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
absolute (L/min) peak oxygen consumption during maximal exercise test
VO2 Peak (Relative)
时间窗: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
relative (mL/kg/min) peak oxygen consumption during maximal exercise test
VO2 Peak (Percent Predicted)
时间窗: pre-treatment Baseline and 1 hour post-treatment, and 4 weeks sub-chronic treatment
Maximal Oxygen consumption expressed as percent predicted taken from maximal exercise test.
VE Peak
时间窗: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak ventilation (L/min) during maximal exercise test
RER Peak
时间窗: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak respiratory exchange ratio during maximal exercise test
次要结局
未报告次要终点
研究者
Ryan Harris
Assistant Professor
Augusta University