无机硝酸盐和维生素 C 联合补充对年轻和老年健康成年人血压和血管功能的影响：一项随机、双盲、交叉试验。

Effects of inorganic nitrate and vitamin C co-supplementation on blood pressure and vascular function in younger and older healthy adults: A randomised double-blind crossover trial.

机构信息

Department of Internal Medicine, College of Medicine, Mustansiriyah University, Baghdad, Iraq; Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, William Leech Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom.

Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, William Leech Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom.

出版信息

Clin Nutr. 2020 Mar;39(3):708-717. doi: 10.1016/j.clnu.2019.03.006. Epub 2019 Mar 20.

DOI:10.1016/j.clnu.2019.03.006

PMID:30930132

Abstract

BACKGROUND

Vitamin C and inorganic nitrate have been linked to enhanced nitric oxide (NO) production and reduced oxidative stress. Vitamin C may also enhance the conversion of nitrite into NO.

AIMS

We investigated the potential acute effects of vitamin C and inorganic nitrate co-supplementation on blood pressure (BP) and peripheral vascular function. The secondary aim was to investigate whether age modified the effects of vitamin C and inorganic nitrate on these vascular outcomes.

METHODS

Ten younger (age 18-40 y) and ten older (age 55-70 y) healthy participants were enrolled in a randomised double-blind crossover clinical trial. Participants ingested a solution of potassium nitrate (7 mg/kg body weight) and/or vitamin C (20 mg/kg body weight) or their placebos. Acute changes in resting BP and vascular function (post-occlusion reactive hyperemia [PORH], peripheral pulse wave velocity [PWV]) were monitored over a 3-h period.

RESULTS

Vitamin C supplementation reduced PWV significantly (vitamin C: -0.70 ± 0.31 m/s; vitamin C placebo: +0.43 ± 0.30 m/s; P = 0.007). There were significant interactions between age and vitamin C for systolic, diastolic, and mean arterial BP (P = 0.02, P = 0.03, P = 0.02, respectively), with systolic, diastolic and mean BP decreasing in older participants and diastolic BP increasing in younger participants following vitamin C administration. Nitrate supplementation did not influence BP (systolic: P = 0.81; diastolic: P = 0.24; mean BP: P = 0.87) or vascular function (PORH: P = 0.05; PWV: P = 0.44) significantly in both younger and older participants. However, combined supplementation with nitrate and vitamin C reduced mean arterial BP (-2.6 mmHg, P = 0.03) and decreased PWV in older participants (PWV: -2.0 m/s, P = 0.02).

CONCLUSIONS

The co-administration of a single dose of inorganic nitrate and vitamin C lowered diastolic BP and improved PVW in older participants. Vitamin C supplementation improved PWV in both age groups but decreased systolic and mean BP in older participants only.

CLINICAL TRIAL REGISTRATION

Current Controlled Trials (ISRCTN98942199).

摘要

背景

维生素 C 和无机硝酸盐已被证明可增强一氧化氮（NO）的产生并减少氧化应激。维生素 C 还可能增强亚硝酸盐向 NO 的转化。

目的

我们研究了维生素 C 和无机硝酸盐联合补充对血压（BP）和外周血管功能的潜在急性影响。次要目的是研究年龄是否会改变维生素 C 和无机硝酸盐对这些血管结果的影响。

方法

10 名年轻（18-40 岁）和 10 名年长（55-70 岁）健康参与者被纳入一项随机双盲交叉临床试验。参与者摄入了硝酸钾（7mg/kg 体重）和/或维生素 C（20mg/kg 体重）或安慰剂溶液。在 3 小时内监测静息血压和血管功能（后闭塞性再充血[PORH]、外周脉搏波速度[PWV]）的急性变化。

结果

维生素 C 补充显著降低了 PWV（维生素 C：-0.70±0.31m/s；维生素 C 安慰剂：+0.43±0.30m/s；P=0.007）。年龄与维生素 C 之间存在显著的交互作用，影响收缩压、舒张压和平均动脉压（P=0.02、P=0.03、P=0.02，分别），补充维生素 C 后，年长参与者的收缩压、舒张压和平均动脉压降低，而年轻参与者的舒张压升高。硝酸盐补充对年轻和年长参与者的血压（收缩压：P=0.81；舒张压：P=0.24；平均动脉压：P=0.87）或血管功能（PORH：P=0.05；PWV：P=0.44）均无显著影响。然而，硝酸盐和维生素 C 联合补充可降低年长参与者的平均动脉压（-2.6mmHg，P=0.03）和降低 PWV（PWV：-2.0m/s，P=0.02）。