Dietary Nitrates and Vascular Function in Patients With Peripheral Artery Disease

Peripheral Artery Disease Clinical Trial

Official title:

Dietary Nitrates and Vascular Function in Patients With Peripheral Artery Disease

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01983826
• Other study ID #: 201307745
• Secondary ID: 13GRNT16490002
• Status: Completed
• Phase: N/A
• Start date: November 2013
• Est. completion date: June 30, 2016

Study information

• Verified date: February 2019
• Source: University of Iowa
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 21
• Est. completion date: June 30, 2016
• Est. primary completion date: June 30, 2016
• Accepts healthy volunteers: No
• Gender: All
• Age group: 50 Years to 85 Years

Eligibility

Inclusion Criteria:

• Documented peripheral artery disease

• Ankle-Brachial Index (ABI) < or = to 0.90

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Peripheral Arterial Disease
• Peripheral Artery Disease

Intervention

Dietary Supplement:
• Sodium Nitrate
Sodium Nitrate (1g/day) for 8 weeks

Other:
• Placebo
Microcrystalline cellulose (daily) for 8 weeks

Locations

Country	Name	City	State
United States	University of Iowa	Iowa City	Iowa

Sponsors (2)

Lead Sponsor	Collaborator
University of Iowa	American Heart Association

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Vasodilator Capacity	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).	Pre and post 8 weeks of dietary nitrate supplementation
Primary	Change in Arterial Stiffness	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/?t (m/s).	Pre and post 8 weeks of dietary nitrate supplementation
Primary	Change in Functional Capacity - Distance Walked in 6 Minutes	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.	Pre and post 8 weeks of dietary nitrate supplementation