Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.
Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.
Clin Nutr. 2018 Dec;37(6 Pt A):1852-1861. doi: 10.1016/j.clnu.2017.10.011. Epub 2017 Oct 31.
BACKGROUND & AIMS: Many COPD patients have a reduced exercise capacity and mechanical efficiency and are at increased cardiometabolic risk. This study aimed to assess acute and 7-days effects of dietary nitrate on mechanical efficiency, exercise performance and cardiac biomarkers in patients with COPD.
This double-blind, randomized cross-over placebo controlled trial included 20 mild-to-moderate COPD patients (66.6 ± 7.5 years) with moderate exercise impairments and decreased mechanical efficiency, normal BMI (26 ± 3 kg/m) but high prevalence of abdominal obesity (83.3%). Subjects were randomly allocated to the treatment order of 7 days sodium nitrate ingestion (∼8 mmol/day) and 7 days placebo (NaCl solution) or vice versa, separated by a washout period. Before (Day-1) and after (Day-7) both intervention periods resting metabolic rate and the metabolic response during submaximal cycle ergometry, cycling endurance time, plasma nitrate and nitrite levels, cardiac plasma biomarkers (e.g. cardiac troponin T, Nt-proBNP and creatinine kinase) and blood pressure were measured. Subsequently, gross, net and delta mechanical efficiency were calculated.
Plasma nitrate and nitrite concentrations increased at Day-1 and Day-7 after sodium nitrate but not after placebo ingestion. Systolic and diastolic blood pressure did not change following nitrate ingestion. Furthermore, no differences were observed in gross, net, and delta mechanical efficiency during submaximal exercise, cycling endurance time and cardiac biomarkers between nitrate and placebo on Day-1 and Day-7. Meta-analysis of all available studies in COPD also showed no beneficial effect of beetroot juice on systolic and diastolic blood pressure.
Acute as well as 7-days sodium nitrate supplementation does not modulate mechanical efficiency, blood pressure or cardiac biomarkers in mild-to-moderate COPD patients.
许多 COPD 患者的运动能力和机械效率降低，且存在较高的心血管代谢风险。本研究旨在评估饮食硝酸盐对 COPD 患者机械效率、运动表现和心脏生物标志物的急性和 7 天影响。
这是一项双盲、随机交叉安慰剂对照试验，纳入了 20 名轻度至中度 COPD 患者（66.6±7.5 岁），这些患者运动能力受损，机械效率降低，BMI 正常（26±3kg/m），但腹部肥胖患病率高（83.3%）。受试者被随机分配到 7 天硝酸钠摄入（~8mmol/天）和 7 天安慰剂（NaCl 溶液）的治疗顺序或相反顺序，洗脱期为 7 天。在干预前（第-1 天）和干预后（第-7 天），测量静息代谢率和亚最大循环测力计的代谢反应、耐力时间、血浆硝酸盐和亚硝酸盐水平、心脏血浆生物标志物（如心脏肌钙蛋白 T、Nt-proBNP 和肌酸激酶）和血压。随后，计算总机械效率、净机械效率和机械效率差值。
第-1 天和第-7 天摄入硝酸钠后，血浆硝酸盐和亚硝酸盐浓度增加，但摄入安慰剂后无变化。摄入硝酸盐后，收缩压和舒张压无变化。此外，在第-1 天和第-7 天，硝酸钠和安慰剂之间，在亚最大运动期间、耐力时间和心脏生物标志物方面，总机械效率、净机械效率和机械效率差值均无差异。COPD 所有可用研究的荟萃分析也表明，甜菜根汁对收缩压和舒张压没有有益影响。
急性和 7 天的硝酸钠补充不会调节轻度至中度 COPD 患者的机械效率、血压或心脏生物标志物。
