Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT04299945 |
| Other study ID # |
H19-02552 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 29, 2020 |
| Est. completion date |
December 31, 2025 |
Study information
| Verified date |
December 2023 |
| Source |
University of British Columbia |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Exercise training as part of a structured pulmonary rehabilitation program is a key factor in
improving quality of life and symptoms in people with interstitial lung disease (ILD).
Optimal methods of exercise training are yet to be explored in ILD. Drinking beetroot juice,
which is rich in nitrate, has been shown to improve exercise performance in a variety of
groups, but its effects in ILD have not been tested. The purpose of this study is to
determine if drinking nitrate-rich beetroot juice can improve exercise performance compared
to drinking nitrate-free beetroot juice in people with ILD.
Description:
PURPOSE:
The primary purpose of this study is to determine the effects of dietary nitrate
supplementation on submaximal cycle exercise performance in patients with fibrotic ILD.
HYPOTHESIS:
Our primary hypothesis is that dietary nitrate supplementation will result in greater
improvement in submaximal cycle exercise endurance time compared with placebo.
JUSTIFICATION:
Fibrotic interstitial lung disease (ILD) is a heterogeneous group of disorders that cause
scarring/fibrosis or inflammation of the lungs, resulting in significant morbidity and high
mortality. Almost all ILDs are characterized by dyspnoea and functional limitation and there
are few effective and/or well-tolerated pharmacotherapies for many ILD subtypes.
Exertional dyspnoea leads to reduced exercise capacity in ILD, and this functional limitation
is further worsened by skeletal muscle weakness and dysfunction. Both dyspnoea and poor
exercise tolerance are strongly associated with quality of life and mortality in ILD and thus
improving dyspnoea and functional capacity are important goals in the management of ILD.
Pulmonary rehabilitation is a structured evidence-based exercise and education intervention
that is recommended for most patients with ILD. Pulmonary rehabilitation improves dyspnoea,
functional capacity, and quality of life in patients with ILD; however, these benefits are
often modest and only temporary. The exercise component of pulmonary rehabilitation is the
predominant mediator of benefit; however, there are no studies that have investigated the
optimal method of exercise training in patients with ILD. Thus, there is a clear need to
identify new strategies that can provide larger and more persistent benefits from pulmonary
rehabilitation.
Nitric oxide (NO) is a physiological signaling molecule that plays a critical role in
vascular control. There is accumulating evidence that dietary nitrate, consumed in the form
of beetroot juice, can increase the bioavailability of NO and subsequently enhance exercise
performance in healthy, elite athlete, as well as diseased populations. These improvements
may be related, but not limited to, enhanced efficiency of locomotion, peripheral locomotor
oxygen delivery, and/or muscle power. The specific effects of dietary nitrate supplementation
in ILD patients has yet to be explored. However, there is great potential for the use of this
dietary supplement to improve exercise tolerance during, and improve patient outcomes from,
pulmonary rehabilitation.
STATISTICAL ANALYSIS:
A p value <0.05 will be considered significant for all analyses. Data analysis will be
performed using Microsoft Excel 2013 (Microsoft Corporation, Redmond, Washington, US) and
Stata v12 (StataCorp, Texas, US).
Primary outcome: The primary outcome of cycle endurance time will be based on the duration
patients were able to exercise during the constant work rate exercise test. A t-test will be
used to compare endurance times between the intervention and placebo conditions.
The investigators have chosen to power this study based on the primary outcome of change in
cycle exercise endurance time. Based on previously collected data in our laboratory in
patients with ILD that show a standard deviation of 289.96 seconds for a 75% constant work
rate cycle exercise test with a conservative between test correlation of 0.90, the
investigators calculated that 15 participants would be needed to detect the minimal
clinically important difference of 105 seconds between conditions assuming a two-sided α of
0.05 and 80% power.
