Cystic Fibrosis and Endothelial Function: At Rest and During Exercise

June 18, 2019 updated by: Ryan Harris, Augusta University

Influence of Cystic Fibrosis on Vascular Endothelial Function at Rest and During Exercise

Perhaps one of the most disturbing aspects of Cystic Fibrosis (CF) is the associated premature death. Oxidative stress has been observed in patients with CF and exercise intolerance has been shown to predict mortality in patients with CF, regardless of how healthy their lungs are. A critical barrier to improving the quality of life and longevity in patients with CF is our lack of knowledge regarding the different reasons why patients with CF cannot exercise to the level of their peers. We have collected preliminary data to support our central hypothesis that oxidative stress contributes to the impairment in blood vessel function at rest and during exercise which ultimately oxygen transport and delivery resulting in exercise intolerance. Exercise is therapeutic medicine for patients with CF and this investigation represents a major breakthrough in the approach to begin understanding the physiological mechanisms which contribute to exercise intolerance in these patients.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The overall goals of this proposal are to provide mechanistic evidence that oxidative stress contributes to 1) endothelial dysfunction and 2) exercise intolerance in patients with CF. This study consists of two separate sub-studies, or protocols. Protocol 1: AOC tested the effect of an antioxidant cocktail (AOC) on endothelial function at rest and during exercise in CF patients. Protocol 2: BH4 tested the effect of tetrahydrobiopterin (BH4) on endothelial function at rest and during exercise in CF patients.

Study Type

Interventional

Enrollment (Actual)

64

Phase

  • Phase 2

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

  • United States
    • Georgia
      • Augusta, Georgia, United States, 30912
        • Georgia Prevention Institute/ Laboratory of Integrative and Exercise Physiology

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

7 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Diagnosis of CF and healthy controls
  • Men and women (> 18 yrs. old)
  • Boys and girls (7 -17 yrs. old)
  • FEV1 percent predicted > 30%
  • Resting oxygen saturation (room air) >90%
  • Patients with or without CFRD
  • Traditional CF-treatment medications
  • Ability to perform reliable/reproducible PFTs
  • Clinically stable for 2 weeks (no exacerbations or need for antibiotic treatment within 2 weeks of testing or major change in medical status)

Exclusion Criteria:

  • Children 6 yrs. old and younger
  • FEV1 percent predicted < 30%
  • Resting oxygen saturation (room air) < 90%
  • Clinical diagnosis of heart disease
  • Pulmonary artery hypertension
  • Febrile illness within two weeks of visit
  • Current smokers
  • Currently pregnant or nursing
  • Individuals on vaso-active medications (i.e. nitrates, beta blockers, ACE inhibitors, etc.)
  • Inability to swallow pills
  • Patients with B. Cepacia (only ~3% of our CF center patient population)

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: Other
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Protocol 1: AOC
measurements at baseline and 2 hours following the antioxidant cocktail that is comprised of over the counter vitamins (vitamin C 1000mg, vitamin E 600 IU, and alpha lipoic acid 600 mg) that will be given in two doses, 30 minutes apart.
Dietary supplement: Antioxidant Cocktail
Vitamin C (1000 mg) , Vitamin E (600 IU) , and alpha-lipoic acid (600 mg). all BID
Experimental: Protocol 2: BH4 (5mg)
measurements at baseline and 3 hours following the single dose of 5mg/kg Kuvan® or sapropterin dihydrochloride which is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4).BH4 has been shown in past studies to increase NO bioavailability.
Drug: BH4 5mg
Kuvan® or sapropterin dihydrochloride is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4). Subjects received an oral dose of 5 mg/kg of Kuvan® (Biomarin Pharmaceuticals Inc.)
Other Names:
  • Kuvan
  • Tetrahydrobiopterin
Experimental: Protocol 2: BH4 (20mg)
measurements at baseline and 3 hours following the single dose of 20mg/kg Kuvan® or sapropterin dihydrochloride which is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4).BH4 has been shown in past studies to increase NO bioavailability.
Drug: BH4 20mg
Kuvan® or sapropterin dihydrochloride is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4). Subjects received an oral dose of 20 mg/kg of Kuvan® (Biomarin Pharmaceuticals Inc.)
Other Names:
  • Kuvan
  • Tetrahydrobiopterin
No Intervention: Healthy Controls
baseline measurements were done with no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage Flow-Mediated Dilation (FMD)
Time Frame: pre-treatment Baseline and 2-3 hours post-treatment
Brachial artery FMD induced by reactive hyperemia assessed vascular endothelial function at baseline and several hours after treatment.
pre-treatment Baseline and 2-3 hours post-treatment

Collaborators and Investigators

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

Sponsor

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.

Helpful Links

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

August 1, 2011

Primary Completion (Actual)

June 21, 2016

Study Completion (Actual)

June 21, 2016

Study Registration Dates

First Submitted

October 16, 2012

First Submitted That Met QC Criteria

January 18, 2013

First Posted (Estimate)

January 21, 2013

Study Record Updates

Last Update Posted (Actual)

June 20, 2019

Last Update Submitted That Met QC Criteria

June 18, 2019

Last Verified

June 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CFD Study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

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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