Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT06027606 |
Other study ID # |
Pro00126438 |
Secondary ID |
|
Status |
Recruiting |
Phase |
Phase 1
|
First received |
|
Last updated |
|
Start date |
September 1, 2023 |
Est. completion date |
December 2024 |
Study information
Verified date |
May 2024 |
Source |
University of Alberta |
Contact |
Desi P Fuhr, MSc |
Phone |
7804921121 |
Email |
fuhr[@]ualberta.ca |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The goal of this clinical trial is to test the impact inhalers have on blood vessels in young
healthy individuals. The main question it aims to answer is if long term use of asthma
inhalers have any effect on the blood vessels and heart. Participants will be asked to:
- Perform lung function and exercise tests
- Have ultrasound images taken of the artery in their arm
- Use an inhaler for 4 weeks
- Visit the lab for testing on 4-6 different occasions
Researchers will compare two different inhalers (Ventolin and Symbicort) with a placebo to
see if the inhalers have any effect on the blood vessels over the 4 week period.
Description:
Session 1) The first visit is a screening visit where participants will be invited to our
Clinical Sciences Building research lab to conduct pulmonary function testing and
cardiopulmonary exercise testing. A small blood sample will be collected via finger prick to
measure hemoglobin. The cardiopulmonary screening will ensure no underlining health problems
are observed in the participant which would exclude them from the study. This visit will take
~2 hours.
Session 2) The second visit will occur within 1 week of the first visit. On the second visit,
participants will arrive fasted (12 hours) and be asked not to consume caffeine or perform
exercise 8 hours prior to arriving. These restrictions ensure accuracy in our measurement of
vascular reactivity. Measurement of cardiovascular function using heart rate, blood pressure,
flow-mediated dilation, and pulse wave velocity after 10 minutes of supine rest will occur.
Participants will be randomized to one of three study arms: 1) salbutamol (2x200mcg), 2)
budesonide-formoterol (1x400mcg), or 3) placebo (2x0mcg). Upon receiving their group
allocation, an unblinded member of the research team will help the participant in taking the
required dosage, and then the participant will return to 10 minutes of supine rest. Heart
rate, blood pressure, flow-mediated dilation, and pulse wave velocity will then be
re-evaluated by a blinded member of the research team. Session 2 should take approximate ~1.5
hours.
Session 2A) Participants will be asked to sign a second, optional, informed consent form
outlining the additional measures, techniques, and risks that are associated with the
protocol. Participants will rest in the supine position and have an intravenous line inserted
into the cubital fossa of the forearm. A small amount of blood will be pulled for sex hormone
analysis. A 3-lead electrocardiogram will be attached, and finger blood pressure will be
monitored beat-by-beat. Cardiac output will be estimated using cardiac ultrasound, while
brachial blood flow will be estimated using doppler ultrasound. Muscle sympathetic nervous
activity will be measured in the peroneal nerve using microneurography. Lung diffusing
capacity and its components will be evaluated by standardized breath-hold techniques. In
short, participants inhale a very small amount of carbon monoxide and methane and hold their
breath for 6 seconds before rapidly exhaling . This maneuver is completed three times using
21%, 40%, and 60% oxygen concentration to determine diffusing capacity and pulmonary vascular
function. After obtaining baseline measures of all outcomes, a beta-agonist (isoproterenol)
will be injected through the intravenous line at a starting dosage of 0.01 μg∙kg-1∙min-1 for
10 minutes and increase in a stepwise manner at a rate of 0.01 μg∙kg-1∙min-1 every 10 minutes
to a maximal rate of 0.04 μg∙kg-1∙min-1. The incremental dosages creating a dose-response
curve for the variables blood pressure, heart rate, cardiac output, and brachial blood flow
with a reduced curve indicating less β-receptor sensitivity. All values will be obtained
within the last two minutes of the 10-minute dosage. Lung diffusing capacity will be
evaluated following the final dosage of isoproterenol. Upon completion of infusion and data
acquisition, participants will remain resting until blood pressure and heart rate return to
baseline values. This session will be completed within 2 weeks of session 1 and will take ~2
hours.
Intervention: Following either session 2 or 2A if the participant consented to the additional
testing session, participants will then be sent home with their inhaler and dosage regimen
and complete the intervention for 4-weeks, filling out questionnaires to monitor symptoms
each week. Inhalers will be equipped with electronic trackers to calculate the number of
doses the participants have received.
Session 3) Following the 4-week intervention, participants will then replicate session 1 with
a pulmonary function test and exercise test spanning ~2 hours. As completed during the first
session, a small blood sample will be collected via finger prick to measure hemoglobin. This
session will occur within 1-2 days of completing the 4-week intervention.
Session 4) Participants will be asked to arrive fasted (12 hours) and be asked not to consume
caffeine or perform exercise 8 hours prior to arriving. The session will consist of the same
measurements (pulse wave velocity, blood pressure, heart rate, and flow-mediated dilation)
and procedure as Session 2 and spanning ~1.5 hours. This session will occur between 2-4 days
following the intervention.
Session 4A) Those partaking in the additional optional visits would also then complete visit
4A which would be the same protocol as visit 2A and take ~2 hours to complete. This session
will occur 3-6 days following intervention.