Nitric Oxide Bioavailability in Chronic Obstructive Pulmonary Disease (COPD)

November 9, 2017 updated by: Ryan Harris, Augusta University

Regulation of Nitric Oxide Bioavailability in Chronic Obstructive Pulmonary Disease: A Mechanistic Approach

More patients with chronic obstructive pulmonary disease (COPD) die from cardiovascular disease than direct pulmonary complications. Inflammation and oxidative stress, characteristic in COPD, are likely contributors to the reduction in nitric oxide (NO) bioavailability and vascular endothelial dysfunction in COPD patients; however, this has yet to be determined. Thus, the overall objective of this proposal is to identify the role of NO bioavailability in contributing to vascular endothelial dysfunction in patients with COPD and to provide insight into the molecular mechanisms involved. Our central hypothesis is that inflammation and oxidative stress, both independently, contribute to the reduction in NO bioavailability and vascular endothelial dysfunction in patients with COPD.

Study Overview

Detailed Description

Flow-Mediated Dilation (FMD) - Subjects will lie in the supine position for 20 minutes to obtain hemodynamic steady state. A blood pressure cuff (Hokanson) will be placed around the forearm (distal to the Doppler transducer) and rapidly inflated to 250 mmHg for 5 minutes (circulatory arrest). Simultaneous ultrasound images of the vessel (B-mode) and Doppler waveforms will be collected 10 seconds prior to and for 2 minutes following deflation of the cuff. All B-mode images will be analyzed using automated edge detection software (Medical Imaging Applications), while intensity weighted velocity spectra segments will be saved to the GE Logiq 7 hard drive for off-line blood velocity waveform analysis. P.I. has utilized the traditional method of brachial artery flow-mediated dilation (FMD) induced by reactive hyperemia to assess vascular endothelial function in populations ranging from young healthy adults to older adults with pathological conditions.

Spygmocor - Pulse Wave Velocity (PWV) - A Spygmocor® device will be used at baseline and following each protocol to assess PWV. PWV analysis provides a non-invasive assessment of arterial stiffness. Increased arterial stiffness is known to be associated with cardiovascular disease. The participant is required to lie in a resting position for approximately 30-45 minutes. The research assistant will place ECG electrode sensors at the carotid, femoral, radial and distal artery locations. A highly sensitive pen-like device, called a tonometer, is then gently applied to record the velocity of the blood flow between each of the points.

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Georgia
      • Augusta, Georgia, United States, 30912
        • Augusta University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with COPD (GOLD stages II-IV) and matched healthy controls
  • Caucasian or African American
  • Both men and women
  • Current and former smokers

Exclusion Criteria:

  • GOLD Stage I
  • Clinical diagnosis of heart disease, hypertension, or metabolic disease
  • Vasoactive medications (i.e. nitrates, beta-blockers, ACE inhibitors, Viagra, etc.)
  • Pulmonary hypertension
  • Hypothyroidism
  • Hyper-homocysteinemia
  • Interstitial lung disease
  • Phenylketonuria
  • Pregnancy
  • Sleep apnea
  • Anemia
  • Raynod's phenomenon
  • Gangrene of the digits
  • History of low platelets or coagulopathies
  • Aspirin sensitivity or allergy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: PREVENTION
  • Allocation: RANDOMIZED
  • Interventional Model: CROSSOVER
  • Masking: DOUBLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: COPD Patients

Patients with COPD

AOC protocol: Brachial artery flow-mediated dilation, direct assessment of oxidative stress via EPR spectroscopy (O2-) and biomarkers of oxidative stress (8-isoprostane, LH, SOD) will be assessed at baseline and 2 hours following ingestion of a single oral antioxidant cocktail (1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid.) Antioxidant Cocktail: 1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid

BH4 protocol: Brachial artery flow-mediated dilation (FMD), markers of inflammation, and markers of oxidative stress will be assessed at baseline and following an increase in nitric oxide bioavailability after administering a single dose = 5 mg/kg of Tetrahydrobiopterin (BH4)

single dose = 5 mg/kg
Other Names:
  • Kuvan (Sapropterin Dihydrochloride)
1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid
EXPERIMENTAL: Controls

Healthy age- and sex- matched controls

AOC protocol: Brachial artery flow-mediated dilation, direct assessment of oxidative stress via EPR spectroscopy (O2-) and biomarkers of oxidative stress (8-isoprostane, LH, SOD) will be assessed at baseline and 2 hours following ingestion of a single oral antioxidant cocktail (1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid.) Antioxidant Cocktail: 1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid

BH4 protocol: Brachial artery flow-mediated dilation (FMD), markers of inflammation, and markers of oxidative stress will be assessed at baseline and following an increase in nitric oxide bioavailability after administering a single dose = 5 mg/kg of Tetrahydrobiopterin (BH4)

single dose = 5 mg/kg
Other Names:
  • Kuvan (Sapropterin Dihydrochloride)
1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Flow-Mediated Dilation (FMD)
Time Frame: Post FMD was taken approximately 110 min after baseline
Brachial artery FMD induced by reactive hyperemia will be used to assess vascular endothelial function at baseline and several hours after each experimental intervention.
Post FMD was taken approximately 110 min after baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pulse Wave Velocity
Time Frame: Post PWV was taken approximately 90 min after baseline
A measure of vascular stiffness at baseline and several hours after each experimental intervention.
Post PWV was taken approximately 90 min after baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Ryan A Harris, PhD, Augusta University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2010

Primary Completion (ACTUAL)

June 1, 2015

Study Completion (ACTUAL)

June 1, 2015

Study Registration Dates

First Submitted

July 19, 2011

First Submitted That Met QC Criteria

July 20, 2011

First Posted (ESTIMATE)

July 21, 2011

Study Record Updates

Last Update Posted (ACTUAL)

December 11, 2017

Last Update Submitted That Met QC Criteria

November 9, 2017

Last Verified

November 1, 2017

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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