title: Dietary nitrate supplementation improves exercise performance and decreases blood pressure in COPD patients.
abstract: Dietary nitrate (NO3(-)) supplementation via beetroot juice has been shown to increase the exercise capacity of younger and older adults. The purpose of this study was to investigate the effects of acute NO3(-) ingestion on the submaximal constant work rate exercise capacity of COPD patients. Fifteen patients were assigned in a randomized, single-blind, crossover design to receive one of two treatments (beetroot juice then placebo or placebo then beetroot juice). Submaximal constant work rate exercise time at 75% of the patient's maximal work capacity was the primary outcome. Secondary outcomes included plasma NO3(-) and nitrite (NO2(-)) levels, blood pressure, heart rate, oxygen consumption (VO2), dynamic hyperinflation, dyspnea and leg discomfort. Relative to placebo, beetroot ingestion increased plasma NO3(-) by 938% and NO2(-) by 379%. Median (+interquartile range) exercise time was significantly longer (p = 0.031) following the ingestion of beetroot versus placebo (375.0 + 257.0 vs. 346.2 + 148.0 s, respectively). Compared with placebo, beetroot ingestion significantly reduced iso-time (p = 0.001) and end exercise (p = 0.008) diastolic blood pressures by 6.4 and 5.6 mmHg, respectively. Resting systolic blood pressure was significantly reduced (p = 0.019) by 8.2 mmHg for the beetroot versus the placebo trial. No other variables were significantly different between the beetroot and placebo trials. These results indicate that acute dietary NO3(-) supplementation can elevate plasma NO3(-) and NO2(-) concentrations, improve exercise performance, and reduce blood pressure in COPD patients.
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA; Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA. Electronic address: berry@wfu.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Berry
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Justus
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Jordan I
authors.initials: JI
authors.lastname: Hauser
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Ashlee H
authors.initials: AH
authors.lastname: Case
authors.affiliation: Physics Department, Wake Forest University, Winston-Salem, NC 27109, USA; Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Helms
authors.affiliation: Physics Department, Wake Forest University, Winston-Salem, NC 27109, USA; Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Swati
authors.initials: S
authors.lastname: Basu
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Rogers
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Marc T
authors.initials: MT
authors.lastname: Lewis
authors.affiliation: Health and Exercise Science Department, Wake Forest University, Winston-Salem, NC 27109, USA; Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Miller
mesh_terms: D000368:Aged; D027461:Beta vulgaris; D001628:Beverages; D001794:Blood Pressure / Q000187:drug effects*; D019587:Dietary Supplements; D004417:Dyspnea; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D009573:Nitrites / Q000097:blood; D010100:Oxygen / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000178:diet therapy* / Q000503:physiopathology; D016896:Treatment Outcome
chemical_list: D009566:Nitrates; D009573:Nitrites; D010100:Oxygen
keywords: Blood pressure; Chronic obstructive pulmonary disease; Exercise; Nitrate; Nitric oxide; Nitrite