Sport and Physical Activity Research Centre, Department of Sport and Physical Activity, Sheffield Hallam University, Sheffield, UK.
Lifestyle, Exercise and Nutrition Improvement (LENI) Research Group, Department of Nursing and Midwifery, Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield, UK.
Eur J Clin Nutr. 2022 Oct;76(10):1380-1386. doi: 10.1038/s41430-022-01115-4. Epub 2022 Mar 29.
BACKGROUND/OBJECTIVES: To compare the effects of supplemental inorganic nitrate (NO) on microvascular endothelial function and blood pressure in younger vs. older participants.
SUBJECTS/METHODS: 25 individuals participated in a double-blind, randomised, placebo-controlled crossover pilot study. Participants were stratified by age (18-35 and ≥55 years) and consumed a single dose beetroot juice (providing 6.4 mmol NO) or NO-depleted beetroot juice. Blood pressure, microvascular function (via Laser Doppler Flowmetry; LDF) and urinary NO were assessed, and the effects of NO supplementation on cardiovascular parameters were compared between participants and conditions using mixed-design ANOVA.
Treatments and methods were well tolerated, and no adverse events were reported. Urinary NO increased 3 h following ingestion in both groups, (P = 0.02). Levels remained elevated at 24 h post consumption in younger participants only (P = 0.02). Beetroot juice had no effect on blood pressure in either group nor on microcirculatory endothelial function.
Beetroot juice had no effect on blood pressure or microvascular endothelial function in young and older individuals. Dosage and timing regimens for supplemental beetroot juice should be avenues for further inquiry.
背景/目的：比较补充无机硝酸盐（NO）对年轻和老年参与者微血管内皮功能和血压的影响。
受试者/方法：25 名参与者参加了一项双盲、随机、安慰剂对照交叉先导研究。参与者按年龄（18-35 岁和≥55 岁）分层，并摄入单次剂量的甜菜根汁（提供 6.4mmol 的 NO）或缺乏 NO 的甜菜根汁。评估血压、微血管功能（通过激光多普勒流量测定法；LDF）和尿中的 NO，并使用混合设计 ANOVA 比较 NO 补充对心血管参数的影响在参与者和条件之间。
治疗和方法均耐受良好，无不良事件报告。两组在摄入后 3 小时内尿中的 NO 增加（P=0.02）。只有年轻组在摄入后 24 小时内仍保持升高（P=0.02）。甜菜根汁对两组的血压或微血管内皮功能均无影响。
甜菜根汁对年轻和老年个体的血压或微血管内皮功能均无影响。补充甜菜根汁的剂量和时间方案应进一步研究。
