Dietary Nitrates and Vascular Function in Patients With Peripheral Artery Disease

NCT01983826 | Completed Results

• 2 other identifiers: 20130774513GRNT16490002
• Study Type: interventional
• Target: 21
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Peripheral Artery Disease

Keywords

nitrates; blood flow; vascular function; exercise

Outcome Measures

Primary Outcomes (3)

• 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

• 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/Δt (m/s).

  Pre and post 8 weeks of dietary nitrate supplementation

• 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

Study Arms (2)

Sodium Nitrate

EXPERIMENTAL

Sodium Nitrate (1g/day) for 8 weeks

Dietary Supplement: Sodium Nitrate

Placebo capsule

PLACEBO COMPARATOR

Microcrystalline cellulose (daily) for 8 weeks

Other: Placebo

Interventions

Sodium Nitrate DIETARY_SUPPLEMENT

Sodium Nitrate (1g/day) for 8 weeks

Sodium Nitrate

Placebo OTHER

Microcrystalline cellulose (daily) for 8 weeks

Placebo capsule

Eligibility Criteria

• Age: 50 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Documented peripheral artery disease
• Ankle-Brachial Index (ABI) \< or = to 0.90

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Iowa: lead
• American Heart Association: collaborator

Study Sites (1)

University of Iowa

Iowa City, Iowa, 52242, United States

Location

Related Publications (1)

• Hughes WE, Treichler DP, Ueda K, Bock JM, Casey DP. Sodium nitrate supplementation improves blood pressure reactivity in patients with peripheral artery disease. Nutr Metab Cardiovasc Dis. 2022 Mar;32(3):710-714. doi: 10.1016/j.numecd.2021.12.002. Epub 2021 Dec 8.

  PMID: 35090799 DERIVED

MeSH Terms

Conditions

Peripheral Arterial Disease; Motor Activity

Interventions

sodium nitrate

Condition Hierarchy (Ancestors)

Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases; Cardiovascular Diseases; Peripheral Vascular Diseases; Behavior

Results Point of Contact

• Title: Dr. Darren P. Casey
• Organization: University of Iowa

darren-casey@uiowa.edu

Study Officials

• Darren P Casey, Ph.D.

  University of Iowa

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: October 28, 2013
• First Posted: November 14, 2013
• Study Start: November 1, 2013
• Primary Completion: June 30, 2016
• Study Completion: June 30, 2016
• Last Updated: June 3, 2019
• Results First Posted: June 3, 2019

Record last verified: 2019-02

Locations

US (1)