Effect of Dietary Nitrate Supplementation on Exercise Performance in Hypoxic IPF (EDEN-OX3): a double-blind, placebo-controlled, randomised crossover study.

Dietary nitrate (NO₃-) supplementation has been shown to improve vascular function and exercise capacity in chronic obstructive pulmonary disease and in pulmonary hypertension. In a double-blind, placebo-controlled crossover study in 20 patients with idiopathic pulmonary fibrosis who desaturated on exercise, endurance shuttle walk test improved by a median (IQR) difference of 31 s (-9.5 to 100.0; (p=0.043)), following a single dose of 140 mL NO₃- rich beetroot juice, as did brachial artery flow mediated dilatation; +4.25% (95% CI -0.71% to 8.45%; p=0.036), compared with following placebo NO₃- depleted placebo juice. Longer-term studies are needed to see if these acute effects translate into sustained benefit.ISRCTN14888729 Registration date 14 July 2015, https://doi.org/10.1186/ISRCTN14888729.