Funded in part by GlaxoSmithKline, Astellas Pharma
Acute Dietary Nitrate Supplementation and Exercise Performance in COPD: A Double-Blind, Placebo-Controlled, Randomised Controlled Pilot Study
Curtis KJ, O'Brien KA, Tanner RJ, Polkey JI, Minnion M, Feelisch M, Polkey MI, Edwards LM, Hopkinson NS
PloS one · 44 citations
Review labels
Neutral facts our review recorded about how this study was done. They describe method, never whether we like the result.
How it was studied
- Design
- Randomized controlled trial (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
- Intake measured by
- Not stated
Who paid for it
- Funding
- Industry funded
- Company
- GlaxoSmithKline
- University or hospital
- Royal Brompton and Harefield NHS Foundation Trust
- Government
- National Institute for Health and Care Research
- University or hospital
- Imperial College London
- University or hospital
- King's College London
- Company
- Astellas Pharma
- Government
- Medical Research Council
- Authors
- At least one author declares a financial tie to industry
- Grants
- Medical Research Council (MR/J000620/1); Medical Research Council (G1001536)
Based on 7 listed funder(s) and full-text disclosure statement.
Publication
- Published
- 2015-12-23 · PLoS One · vol. 10 · issue 12 · p. e0144504
- Publisher
- Public Library of Science
- Cited
- 56 citations · more than 93% of similar papers · 3.5× the field average
- Impact
- Top 10% most cited in its field
- References
- 56 works
- Access
- Open access (journal) · CC-BY
- Research areas
- Chronic Obstructive Pulmonary Disease (COPD) Research · Cardiovascular and exercise physiology · Exercise and Physiological Responses
- Keywords
- Placebo, Crossover study, Medicine, Nitrate, Time trial, Dietary Nitrate, COPD, VO2 max, Anesthesia, Internal medicine, Blood pressure, Animal science, Heart rate, Nitrite, Chemistry
- MeSH
- humans, pulmonary disease, chronic obstructive, nitrates, prognosis, exercise therapy, magnetic resonance spectroscopy, follow-up studies, pilot projects, cross-over studies, double-blind method, oxygen consumption, dietary supplements, aged, female, male
9 authors
From GB
- Katrina CurtisRoyal Brompton & Harefield NHS Foundation Trust; Imperial College London
- Katie A. O’BrienKing's College London
- Rebecca TannerRoyal Brompton & Harefield NHS Foundation Trust; Imperial College London
- Juliet I. PolkeyRoyal Brompton & Harefield NHS Foundation Trust; Imperial College London
- Magdalena MinnionSouthampton General Hospital; NIHR Southampton Respiratory Biomedical Research Unit; University of Southampton
- Martin FeelischSouthampton General Hospital; NIHR Southampton Respiratory Biomedical Research Unit; University of Southampton
Abstract
Background
Dietary nitrate supplementation can enhance exercise performance in healthy people, but it is not clear if it is beneficial in COPD. We investigated the hypotheses that acute nitrate dosing would improve exercise performance and reduce the oxygen cost of submaximal exercise in people with COPD.
Methods
We performed a double-blind, placebo-controlled, cross-over single dose study. Subjects were randomised to consume either nitrate-rich beetroot juice (containing 12.9 mmoles nitrate) or placebo (nitrate-depleted beetroot juice) 3 hours prior to endurance cycle ergometry, performed at 70% of maximal workload assessed by a prior incremental exercise test. After a minimum washout period of 7 days the protocol was repeated with the crossover beverage.
Results
21 subjects successfully completed the study (age 68 ± 7 years; BMI 25.2 ± 5.5 kg/m2; FEV1 percentage predicted 50.1 ± 21.6%; peak VO2 18.0 ± 5.9 ml/min/kg). Resting diastolic blood pressure fell significantly with nitrate supplementation compared to placebo (-7 ± 8 mmHg nitrate vs. -1 ± 8 mmHg placebo; p = 0.008). Median endurance time did not differ significantly; nitrate 5.65 (3.90-10.40) minutes vs. placebo 6.40 (4.01-9.67) minutes (p = 0.50). However, isotime oxygen consumption (VO2) was lower following nitrate supplementation (16.6 ± 6.0 ml/min/kg nitrate vs. 17.2 ± 6.0 ml/min/kg placebo; p = 0.043), and consequently nitrate supplementation caused a significant lowering of the amplitude of the VO2-percentage isotime curve.
Conclusions
Acute administration of oral nitrate did not enhance endurance exercise performance; however the observation that beetroot juice caused reduced oxygen consumption at isotime suggests that further investigation of this treatment approach is warranted, perhaps targeting a more hypoxic phenotype.
Trial registration
ISRCTN Registry ISRCTN66099139.
Abstract via Europe PMC. Copyright remains with the authors or publisher (CC BY).
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