Dietary nitrate supplementation improves exercise performance and decreases blood pressure in COPD patients

Nitric Oxide. 2015 Aug 1;48:22-30. doi: 10.1016/j.niox.2014.10.007. Epub 2014 Oct 27.

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.

Keywords: Blood pressure; Chronic obstructive pulmonary disease; Exercise; Nitrate; Nitric oxide; Nitrite.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Beta vulgaris
  • Beverages
  • Blood Pressure / drug effects*
  • Dietary Supplements
  • Dyspnea
  • Exercise / physiology*
  • Female
  • Heart Rate / drug effects
  • Humans
  • Male
  • Middle Aged
  • Nitrates / administration & dosage
  • Nitrates / blood
  • Nitrates / therapeutic use*
  • Nitrites / blood
  • Oxygen / blood
  • Pulmonary Disease, Chronic Obstructive / diet therapy*
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Treatment Outcome

Substances

  • Nitrates
  • Nitrites
  • Oxygen