Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, Victoria University , Melbourne, Victoria , Australia.
Western Health, Melbourne, Victoria , Australia.
Am J Physiol Heart Circ Physiol. 2018 Feb 1;314(2):H195-H212. doi: 10.1152/ajpheart.00414.2017. Epub 2017 Nov 3.
Oral consumption of inorganic nitrate, which is abundant in green leafy vegetables and roots, has been shown to increase circulating plasma nitrite concentration, which can be converted to nitric oxide in low oxygen conditions. The associated beneficial physiological effects include a reduction in blood pressure, modification of platelet aggregation, and increases in limb blood flow. There have been numerous studies of nitrate supplementation in healthy recreational and competitive athletes; however, the ergogenic benefits are currently unclear due to a variety of factors including small sample sizes, different dosing regimens, variable nitrate conversion rates, the heterogeneity of participants' initial fitness levels, and the types of exercise tests used. In clinical populations, the study results seem more promising, particularly in patients with cardiovascular diseases who typically present with disruptions in the ability to transport oxygen from the atmosphere to working tissues and reduced exercise tolerance. Many of these disease-related, physiological maladaptations, including endothelial dysfunction, increased reactive oxygen species, reduced tissue perfusion, and muscle mitochondrial dysfunction, have been previously identified as potential targets for nitric oxide restorative effects. This review is the first of its kind to outline the current evidence for inorganic nitrate supplementation as a therapeutic intervention to restore exercise tolerance and improve quality of life in patients with cardiovascular diseases. We summarize the factors that appear to limit or maximize its effectiveness and present a case for why it may be more effective in patients with cardiovascular disease than as ergogenic aid in healthy populations.
口服无机硝酸盐，其在绿叶蔬菜和根茎类蔬菜中含量丰富，已被证明可增加循环血浆中亚硝酸盐浓度，而在低氧条件下，亚硝酸盐可转化为一氧化氮。相关的有益生理效应包括降低血压、改变血小板聚集以及增加肢体血流量。已有大量关于硝酸盐补充剂在健康的业余和竞技运动员中应用的研究；然而，由于多种因素，其促进表现的益处目前尚不清楚，这些因素包括样本量小、不同的给药方案、硝酸盐转化率的变化、参与者初始健康水平的异质性以及所使用的运动测试类型。在临床人群中，研究结果似乎更有希望，特别是在心血管疾病患者中，这些患者通常存在从大气中输送氧气到工作组织的能力受损以及运动耐量降低的情况。许多与疾病相关的生理适应不良，包括内皮功能障碍、活性氧增加、组织灌注减少和肌肉线粒体功能障碍，以前被认为是一氧化氮恢复作用的潜在靶点。这是此类综述中首次概述了无机硝酸盐补充剂作为一种治疗干预措施，以恢复心血管疾病患者的运动耐量和提高生活质量的现有证据。我们总结了似乎限制或最大化其有效性的因素，并提出了一个理由，即与作为健康人群的运动表现增强剂相比，它在心血管疾病患者中可能更有效。
