Previous studies have used supplements to increase dietary nitrate intake in clinical populations. Little is known about whether effects can also be induced through vegetable consumption. Therefore, the aim of this study was to assess the impact of dietary nitrate, through nitrate-rich vegetables (NRV) and beetroot juice (BRJ) supplementation, on plasma nitrate and nitrite concentrations, exercise tolerance, muscle oxygenation, and cardiovascular function in patients with peripheral arterial disease. In a randomized crossover design, 18 patients with peripheral arterial disease (age: 73 ± 8 years) followed a nitrate intake protocol (∼6.5 mmol) through the consumption of NRV, BRJ, and nitrate-depleted BRJ (placebo). Blood samples were taken, blood pressure and arterial stiffness were measured in fasted state and 150 min after intervention. Each intervention was followed by a maximal walking exercise test to determine claudication onset time and peak walking time. Gastrocnemius oxygenation was measured by near-infrared spectroscopy. Blood samples were taken and blood pressure was measured 10 min after exercise. Mean plasma nitrate and nitrite concentrations increased (nitrate; Time × Intervention interaction; p < .001), with the highest concentrations after BRJ (494 ± 110 μmol/L) compared with NRV (202 ± 89 μmol/L) and placebo (80 ± 19 μmol/L; p < .001). Mean claudication onset time and peak walking time did not differ between NRV (413 ± 187 s and 745 ± 220 s, respectively), BRJ (392 ± 154 s and 746 ± 176 s), and placebo (403 ± 176 s and 696 ± 222 s) (p = .762 and p = .165, respectively). Gastrocnemius oxygenation, blood pressure, and arterial stiffness were not affected by the intervention. NRV and BRJ intake markedly increase plasma nitrate and nitrite, but this does not translate to improved exercise tolerance, muscle oxygenation, and/or cardiovascular function.

以前的研究已经使用补充剂来增加临床人群的膳食硝酸盐摄入量。关于是否也可以通过食用蔬菜来诱发影响知之甚少。因此，本研究的目的是通过补充富含硝酸盐的蔬菜 (NRV) 和甜菜根汁 (BRJ) 来评估膳食硝酸盐对患者血浆硝酸盐和亚硝酸盐浓度、运动耐量、肌肉氧合和心血管功能的影响患有外周动脉疾病。在一项随机交叉设计中，18 名外周动脉疾病患者（年龄：73 ± 8 岁）通过服用 NRV、BRJ 和硝酸盐耗尽的 BRJ（安慰剂）遵循硝酸盐摄入方案（~6.5 mmol）。取血样，在空腹状态和干预后150分钟测量血压和动脉硬度。每次干预后进行最大步行运动测试，以确定跛行开始时间和步行高峰时间。通过近红外光谱测量腓肠肌氧合。运动后10分钟采集血样并测量血压。平均血浆硝酸盐和亚硝酸盐浓度增加（硝酸盐；时间 × 干预相互作用；p  < .001)，与 NRV (202 ± 89 μmol/L) 和安慰剂 (80 ± 19 μmol/L；p  < .001) 相比，BRJ 后的浓度最高 (494 ± 110 μmol/L)。NRV（分别为 413 ± 187 s 和 745 ± 220 s）、BRJ（392 ± 154 s 和 746 ± 176 s）和安慰剂（403 ± 176 s 和 696 ± 222 秒）（分别为p  = .762 和p  = .165）。腓肠肌氧合、血压和动脉僵硬度不受干预的影响。NRV 和 BRJ 摄入显着增加血浆硝酸盐和亚硝酸盐，但这并不能转化为改善运动耐量、肌肉氧合和/或心血管功能。