National Heart and Lung Institute, Royal Brompton Campus, Imperial College London, London, UK.
Respiratory Therapy Department, College of Medical Rehabilitation Sciences, Taibah University, Madinah, Saudi Arabia.
Eur Respir J. 2024 Feb 1;63(2). doi: 10.1183/13993003.02353-2022. Print 2024 Feb.
Short-term studies suggest that dietary nitrate (NO ) supplementation may improve the cardiovascular risk profile, lowering blood pressure (BP) and enhancing endothelial function. It is not clear if these beneficial effects are sustained and whether they apply in people with COPD, who have a worse cardiovascular profile than those without COPD. Nitrate-rich beetroot juice (NR-BRJ) is a convenient dietary source of nitrate.
The ON-BC trial was a randomised, double-blind, placebo-controlled parallel group study in stable COPD patients with home systolic BP (SBP) measurement ≥130 mmHg. Participants were randomly allocated (1:1) using computer-generated, block randomisation to either 70 mL NR-BRJ (400 mg NO ) (n=40) or an otherwise identical nitrate-depleted placebo juice (0 mg NO ) (n=41), once daily for 12 weeks. The primary end-point was between-group change in home SBP measurement. Secondary outcomes included change in 6-min walk distance (6MWD) and measures of endothelial function (reactive hyperaemia index (RHI) and augmentation index normalised to a heart rate of 75 beats·min (AIx75)) using an EndoPAT device. Plasma nitrate and platelet function were also measured.
Compared with placebo, active treatment lowered SBP (Hodges-Lehmann treatment effect -4.5 (95% CI -5.9- -3.0) mmHg), and improved 6MWD (30.0 (95% CI 15.7-44.2) m; p<0.001), RHI (0.34 (95% CI 0.03-0.63); p=0.03) and AIx75 (-7.61% (95% CI -14.3- -0.95%); p=0.026).
In people with COPD, prolonged dietary nitrate supplementation in the form of beetroot juice produces a sustained reduction in BP, associated with an improvement in endothelial function and exercise capacity.
短期研究表明，饮食中的硝酸盐（NO ）补充可能改善心血管风险状况，降低血压（BP）并增强内皮功能。目前尚不清楚这些有益效果是否持续存在，以及它们是否适用于 COPD 患者，这些患者的心血管状况比没有 COPD 的患者更差。富含硝酸盐的甜菜根汁（NR-BRJ）是一种方便的硝酸盐饮食来源。
ON-BC 试验是一项在稳定的 COPD 患者中进行的随机、双盲、安慰剂对照的平行组研究，这些患者的家庭收缩压（SBP）测量值≥130mmHg。参与者使用计算机生成的、分块随机化方法以 1:1 的比例随机分配到 NR-BRJ（400mgNO ）（n=40）或硝酸盐含量相同的安慰剂（0mgNO ）（n=41）组中，每天一次，持续 12 周。主要终点是家庭 SBP 测量值的组间变化。次要结局包括使用 EndoPAT 设备测量的 6 分钟步行距离（6MWD）和内皮功能的变化（反应性充血指数（RHI）和归一化至 75 次心跳的增强指数（AIx75））。还测量了血浆硝酸盐和血小板功能。
与安慰剂相比，活性治疗降低了 SBP（Hodges-Lehmann 治疗效果-4.5（95%CI-5.9-3.0）mmHg），并改善了 6MWD（30.0（95%CI15.7-44.2）m;p<0.001），RHI（0.34（95%CI0.03-0.63）;p=0.03）和 AIx75（-7.61%（95%CI-14.3-0.95%）;p=0.026）。
在 COPD 患者中，以甜菜根汁形式长期补充饮食硝酸盐可持续降低血压，同时改善内皮功能和运动能力。
