The Effects of Acute Dietary Nitrate Supplementation on Constant Work Rate Exercise in Chronic Obstructive Pulmonary Disease (COPD) Patients

The purpose of this study was to investigate the effect of acute nitrate supplementation in the form of beetroot juice on exercise capacity in patients with COPD. Six mild to moderately diseased patients completed four visits and were randomized to one of two treatment groups (beetroot juice, for visit 3, placebo for visit 4; or placebo for visit 3, beetroot juice for visit 4). The primary outcome was exercise time during a constant work rate cycle exercise test at 75% of maximal exercise capacity. Secondarily, plasma nitrate and nitrite levels,VO2, heart rate, blood pressure, inspiratory capacity, dyspnea, and leg discomfort were assessed. Plasma nitrate (p < .001) and nitrite (p = 0.016) levels were significantly elevated (p < .001and p = 0.016, respectively) during the beetroot juice trial as compared to the placebo. There was a trend (p = 0.08) for exercise time to be greater during the beetroot juice trial as compared to the placebo (517. 8 ± 95.5 vs. 407.3 ± 56.5 sec. respectively). Diastolic blood pressure was found to be significantly lower (p = 0.01) during the beetroot juice trial as compared to the placebo (81 ± 4.4 mm Hg vs. 90 ± 3.5 mm Hg, respectively). No other variables were found to be significantly different between the two conditions. In conclusion, acute ingestion of beetroot juice will increase nitrate and nitrite levels and may lead to improvements in submaximal constant work rate cycle exercise performance in mild to moderately diseased COPD patients.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2012

Author dc:creator

• Case, Ashlee

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/37281

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/37281