Dietary nitrate supplementation to enhance exercise capacity in hypoxic COPD: EDEN-OX, a double-blind, placebo-controlled, randomised cross-over study

Study answer

What this study found

Acute NR-BRJ supplementation increased endurance time on ESWT by a median 62 s vs placebo (NR-BRJ 194.6 s vs PL-BRJ 159.1 s; p<0.0001). Endothelial function improved with NR-BRJ: +4.1% vs -5.0% with placebo (p=0.0003). SpO2 AUC higher with NR-BRJ (estimated treatment effect 43.69; 95% CI 29.09-58.28; p<0.0001). HR AUC showed no significant difference. FE NO increased with NR-BRJ (area under the curve higher; p=0.0011). Plasma NO3- and NO2- rose substantially after NR-BRJ vs placebo (NO3- change ~550 µM; NO2- ~0.248 µM; p=0.0003 and p=0.0011 respectively). No significant changes in oxidative…

Study & population

Single-centre, double-blind, placebo-controlled, randomized cross-over trial; adults with COPD requiring long-term oxygen therapy (LTOT); 20 participants completed.

Intervention

NR-BRJ: 140 mL nitrate-rich beetroot juice containing 12.9 mmol NO3-, ingested orally 3 hours before endurance shuttle walk test; placebo BRJ: 140 mL nitrate-depleted beetroot juice; single-dose per session; two dosing events per participant (NR-BRJ and PL-BRJ).

Key limitation

Small, single-centre, acute-dose study in a COPD phenotype with hypoxaemia requiring LTOT; short follow-up; incomplete data for some measures; generalizability to broader COPD populations or longer-term use unknown.

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Original abstract