Blood Flow and Vascular Function in Cystic Fibrosis (CF-FLOW)

April 23, 2020 updated by: Ryan Harris, Augusta University

Role of Blood Flow and Vascular Function on Exercise Capacity in Cystic Fibrosis

Cystic fibrosis (CF) has many health consequences. A reduction in the ability to perform exercise in patients with CF is related to greater death rates, steeper decline in lung function, and more frequent lung infections. However, the physiological mechanisms for this reduced exercise capacity are unknown. The investigators laboratory recently published the first evidence of systemic vascular dysfunction in patients with CF. Therefore, it is reasonable to suspect that the blood vessels are involved with exercise intolerance in CF. This study will look at how 1) blood flow and 2) artery function contribute to exercise capacity in CF.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The most disturbing aspect of Cystic Fibrosis (CF) is the associated premature death. Low exercise capacity predicts death in patients with CF and is also associated with a steeper decline in lung function and more lung infections. A critical barrier to improving exercise tolerance in patients with CF is the investigators lack of knowledge regarding the different physiological mechanisms which contribute to their lower exercise capacity. We have compelling data to indicate that the blood vessels may contribute to the low exercise capacity in CF. The impact of this proof of concept investigation will test Phosphodiesterase Type 5 inhibitors (PDE5) inhibitors as a potential therapy in CF and will explore blood flow and endothelial function as potential mechanisms which contribute to exercise intolerance in CF. Improvements in exercise capacity will not only contribute to a better quality of live for patients with CF, it will also increase longevity in these patients.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
19

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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
        • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria.

  • Diagnosis of CF and healthy controls
  • Men and women (greater than 18 yrs. old)
  • Resting oxygen saturation (room air) greater than 90%
  • Forced expiratory volume (FEV1) percent predicted greater than 30%
  • Patients with or without CF related diabetes
  • Traditional CF-treatment medications
  • Ability to perform reliable/reproducible pulmonary function tests (PFT)
  • 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 less than 17 years old
  • Body mass less than 20 kg
  • A diagnosis of pulmonary arterial hypertension (PAH)
  • FEV1 less than 30% of predicted
  • Resting oxygen saturation (SpO2) less than 90%
  • Self-reported to be a smoker
  • Current use of any vaso-active medications
  • History of migraine headaches
  • Pregnant or nursing at the time of the investigation
  • A clinical diagnosis of cardiovascular disease, hypertension, or CF related diabetes

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Acute Study: Sildenafil first, then Placebo
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
Drug: Sildenafil (Acute-1 hour)
Vascular function will be assessed 1 hour following oral ingestion of sildenafil (50 mg)
Other Names:
  • Viagra
  • Revatio
Drug: Placebo
Sugar pill designed to mimic the sildenafil treatment
Experimental: Acute Study: Placebo first, then Sildenafil
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
Drug: Sildenafil (Acute-1 hour)
Vascular function will be assessed 1 hour following oral ingestion of sildenafil (50 mg)
Other Names:
  • Viagra
  • Revatio
Drug: Placebo
Sugar pill designed to mimic the sildenafil treatment
Experimental: Sub-Chronic Study Sildenafil
Following the acute study, patients will be instructed to take 20 mg of sildenafil, three times a day, for 4 weeks. Endothelial function will be determined within 48 hours following the last dose.
Drug: Sildenafil (Subchronic-4 weeks)
Vascular function will be assessed 4 weeks following 20 mg three times per day (TID) of sildenafil for four weeks
Other Names:
  • Viagra
  • Revatio

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Acute Study: Percentage Flow-Mediated Dilation (FMD)
Time Frame: pre-treatment Baseline and 1 hour post-treatment
FMD determined one hour after ingestion of 50 mg Sildenafil or placebo
pre-treatment Baseline and 1 hour post-treatment
Baseline Diameter
Time Frame: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Brachial Artery Diameter during FMD (pre-occlusion or "baseline")
pre-treatment Baseline and following 4 weeks sub-chronic treatment
Peak Diameter
Time Frame: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Peak Brachial Artery Diameter during FMD (post-occlusion)
pre-treatment Baseline and following 4 weeks sub-chronic treatment
Absolute Change in Diameter
Time Frame: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Absolute change in brachial artery diameter taken from the FMD assessment
pre-treatment Baseline and following 4 weeks sub-chronic treatment
FEV1 (% Predicted)
Time Frame: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
Forced Expiratory Volume in the first second expressed as a percent predicted.
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Absolute)
Time Frame: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
absolute (L/min) peak oxygen consumption during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Relative)
Time Frame: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
relative (mL/kg/min) peak oxygen consumption during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Percent Predicted)
Time Frame: pre-treatment Baseline and 1 hour post-treatment, and 4 weeks sub-chronic treatment
Maximal Oxygen consumption expressed as percent predicted taken from maximal exercise test.
pre-treatment Baseline and 1 hour post-treatment, and 4 weeks sub-chronic treatment
VE Peak
Time Frame: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak ventilation (L/min) during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
RER Peak
Time Frame: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak respiratory exchange ratio during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Augusta University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ryan Harris, Ph.D., 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

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2018

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2018

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 4, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 6, 2014

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 7, 2014

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 24, 2020

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2020

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • DK100783
  • R21DK100783 (U.S. NIH Grant/Contract)

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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