National Heart and Lung Institute, Royal Brompton Campus, Imperial College London, London, UK.
Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, UK.
Thorax. 2020 Jul;75(7):547-555. doi: 10.1136/thoraxjnl-2019-214278. Epub 2020 May 6.
Dietary nitrate supplementation has been proposed as a strategy to improve exercise performance, both in healthy individuals and in people with COPD. We aimed to assess whether it could enhance the effect of pulmonary rehabilitation (PR) in COPD.
This double-blind, placebo-controlled, parallel group, randomised controlled study performed at four UK centres, enrolled adults with Global Initiative for Chronic Obstructive Lung Disease grade II-IV COPD and Medical Research Council dyspnoea score 3-5 or functional limitation to undertake a twice weekly 8-week PR programme. They were randomly assigned (1:1) to either 140 mL of nitrate-rich beetroot juice (BRJ) (12.9 mmol nitrate), or placebo nitrate-deplete BRJ, consumed 3 hours prior to undertaking each PR session. Allocation used computer-generated block randomisation.
The primary outcome was change in incremental shuttle walk test (ISWT) distance. Secondary outcomes included quality of life, physical activity level, endothelial function via flow-mediated dilatation, fat-free mass index and blood pressure parameters.
165 participants were recruited, 78 randomised to nitrate-rich BRJ and 87 randomised to placebo. Exercise capacity increased more with active treatment (n=57) than placebo (n=65); median (IQR) change in ISWT distance +60 m (10, 85) vs +30 m (0, 70), estimated treatment effect 30 m (95% CI 10 to 40); p=0.027. Active treatment also impacted on systolic blood pressure: treatment group -5.0 mm Hg (-5.0, -3.0) versus control +6.0 mm Hg (-1.0, 15.5), estimated treatment effect -7 mm Hg (95% CI 7 to -20) (p<0.0005). No significant serious adverse events or side effects were reported.
Dietary nitrate supplementation appears to be a well-tolerated and effective strategy to augment the benefits of PR in COPD.
ISRCTN27860457.
膳食硝酸盐补充已被提议作为一种提高健康个体和 COPD 患者运动表现的策略。我们旨在评估其是否可以增强 COPD 患者肺康复（PR）的效果。
这是一项在英国四家中心进行的双盲、安慰剂对照、平行组、随机对照研究，纳入了全球慢性阻塞性肺疾病倡议（GOLD）II-IV 级 COPD 且改良英国医学研究理事会呼吸困难量表（mMRC）评分为 3-5 级或功能受限的成年人，他们接受每周两次、为期 8 周的 PR 计划。他们被随机（1:1）分配至饮用富含硝酸盐的甜菜根汁（BRJ）（12.9mmol 硝酸盐）或安慰剂硝酸盐缺乏的 BRJ，在每次 PR 治疗前 3 小时饮用。采用计算机生成的分组随机化。
主要结局是递增式 shuttle 步行测试（ISWT）距离的变化。次要结局包括生活质量、身体活动水平、血流介导的扩张（FMD）内皮功能、去脂体重指数和血压参数。
共招募了 165 名参与者，78 名随机分配至富含硝酸盐的 BRJ 组，87 名随机分配至安慰剂组。与安慰剂组（n=65）相比，活性治疗组（n=57）的运动能力增加更多；ISWT 距离的中位数（IQR）变化为+60m（10，85）比+30m（0，70），估计治疗效果为 30m（95%CI 10 至 40）；p=0.027。活性治疗还影响收缩压：治疗组为-5.0mmHg（-5.0，-3.0），而对照组为+6.0mmHg（-1.0，15.5），估计治疗效果为-7mmHg（95%CI 7 至 -20）（p<0.0005）。未报告任何严重不良事件或不良反应。
膳食硝酸盐补充似乎是一种耐受良好且有效的策略，可以增强 COPD 患者 PR 的效果。
ISRCTN27860457。
