Chronic Obstructive Pulmonary Disease
Conditions
Keywords
COPD, beetroot, dietary nitrate, nitric oxide
Brief summary
The acute consumption of dietary nitrate has been shown to improve exercise capacity in athletes, healthy adults and subjects with peripheral vascular disease. Many COPD patients have reduced exercise capacity, The investigators hypothesized that acute nitrate consumption, in the form of beetroot juice, might increase incremental shuttle walk test (ISWT) distance in COPD subjects.
Detailed description
Acute consumption of dietary nitrate (as beetroot juice) has been shown to improve exercise capacity in athletes, healthy adults and subjects with peripheral vascular disease. Many COPD patients have reduced exercise capacity, The investigators hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in COPD subjects compared to a matched, low-nitrate drink. This study is a randomized, double-blind placebo-controlled, crossover trial. Resting blood pressure, phlebotomy and ISWT are performed. Following completion, each subject is randomized to consume beetroot juice or placebo. 3 hours later, the same assessments are repeated by the same people. After a 7d washout, the entire protocol is repeated with the crossover beverage.
Interventions
Following randomisation on day 1, subjects will consume either the nitrate or nitrate-free beverage and then the crossover beverage on day 8.
Following randomisation on day 1, subjects will consume either the nitrate or nitrate-free beverage and then the crossover beverage on day 8.
Sponsors
Study design
Eligibility
Inclusion criteria
* Information consenting out-patients with a previous physician diagnosis of COPD * Clinically stable * Ambulatory
Exclusion criteria
* Subjects who required supplemental oxygen for exercise * Subjects with pulmonary hypertension and angina * Intolerant to beetroot * Insulin dependent diabetes * Thyroid disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Incremental Shuttle Walk Test Distance | day 1, time 0, day 1, time 3h, day 8, time 0, day 8, time 3h | The change between day 1, time 0 and day 1, time 3h will be compared to the changes between day 8, time 0 and day 8, time 3h. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Resting blood pressure | day 1, time 0, day 1, time 3h, day 8, time 0, day 8, time 3h | The change between day 1, time 0 and day 1, time 3h will be compared to the changes between day 8, time 0 and day 8, time 3h. |