Dietary Nitrates and Vascular Function in Patients With Peripheral Artery Disease
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 21
- 试验地点
- 2
- 主要终点
- Change in Vasodilator Capacity
研究概览
简要总结
The overarching question addressed in the current project is: Does dietary nitrate supplementation (8 weeks) improve physiological function in patients with peripheral arterial disease (PAD)? The investigators will specifically address whether dietary nitrate supplementation enhances blood vessel function, blood pressure regulation, and exercise capacity. The proposed project uses an array of clearly defined measurements which will allow investigators to quantify blood vessel function (vasodilator responsiveness and arterial stiffness), blood pressure (variability and responsiveness to stress), and functional capacity before and after 8 weeks of dietary supplementation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 50 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Documented peripheral artery disease
- •Ankle-Brachial Index (ABI) < or = to 0.90
排除标准
- •Non-atherosclerotic vascular disease
- •Critical limb ischemia
- •Active ischemic ulceration
- •Recent (within one year) revascularization
- •Symptomatic coronary artery disease (angina pectoris)
- •Heart failure
- •Resting systolic blood pressure > 180 mmHg or diastolic pressure > 100 mmHg
- •Hypotension (resting systolic BP < 90 mmHg)
- •Smoking or history of smoking within past one year
- •Use of phosphodiesterase V inhibitor drugs
- •Women with history of hormone replacement therapy within the past 6 months
研究组 & 干预措施
Placebo capsule
Microcrystalline cellulose (daily) for 8 weeks
干预措施: Placebo (Other)
Sodium Nitrate
Sodium Nitrate (1g/day) for 8 weeks
干预措施: Sodium Nitrate (Dietary Supplement)
结局指标
主要结局
Change in Vasodilator Capacity
时间窗: Pre and post 8 weeks of dietary nitrate supplementation
Forearm and calf blood flow will be measured independently by venous occlusion plethysmography using mercury-in-silastic strain gauges. Plethysmographic measurements will be made at rest and following 5 minutes of ischemia (reactive hyperemia) of the distal limb (forearm and calf). Peak blood flow will be determined as the highest flow recorded during the post deflation period. Total blood flow will be measured as the area under the time-curve after resting flow is subtracted. Vascular conductance will be calculated using blood flow/mean arterial pressure (via finger plethysmograph).
Change in Arterial Stiffness
时间窗: Pre and post 8 weeks of dietary nitrate supplementation
ECG gated arterial waveforms will be obtained via applanation tonometry from the carotid and femoral arteries. The pulse wave velocity (PWV; index of arterial stiffness) will be determined between the carotid and femoral measurement sites (cfPWV). The time (t) between the feet of recorded pressure waves will be determined as the mean of 10 consecutive cardiac cycles. PWV is calculated from the distance (D; meters) between measurement points and the measured time delay (t): PWV = D/Δt (m/s).
Change in Functional Capacity - Distance Walked in 6 Minutes
时间窗: Pre and post 8 weeks of dietary nitrate supplementation
6-minute walk tests will be performed before and after treatment to assess functional capacity. The main comparisons will be changes distance walked in 6 minutes after 8 weeks of dietary nitrate supplementation.
次要结局
未报告次要终点
研究者
Darren P Casey
Assistant Professor
University of Iowa