The decline in vascular function and increase in blood pressure with aging contribute to an increased cardiovascular disease risk. In this randomized placebo-controlled crossover study, we evaluated whether previously reported cardiovascular benefits of plant-derived inorganic nitrate via nitric oxide (NO) translate into improved vascular function and blood pressure-lowering in 15 men and women (age range: 56–71 years) with treated hypertension. We investigated the effects of a single ∼400 mg-dose at 3 hours post-ingestion (3H POST) and the daily consumption of 2 × ∼400 mg of nitrate through nitrate-rich compared with nitrate-depleted (placebo) beetroot juice over 4 weeks (4WK POST). Measurements included nitrate and nitrite in plasma and saliva; endothelial-dependent and -independent forearm blood flow (FBF) responses to acetylcholine (FBF_ACh) and glyceryltrinitrate (FBF_GTN); and clinic-, home- and 24-hour ambulatory blood pressure. Compared to placebo, plasma and salivary nitrate and nitrite increased at 3H and 4WK POST following nitrate treatment (P < 0.01), suggesting a functioning nitrate-nitrite-NO pathway in the participants of this study. There were no differences between treatments in FBF_ACh and FBF_GTN-area under the curve (AUC) ratios [AUC ratios after (3H POST, 4WK POST) compared with before (PRE) the intervention], or 24-hour ambulatory blood pressure or home blood pressure measures (P > 0.05). These findings do not support the hypothesis that an increased intake of dietary nitrate exerts sustained beneficial effects on FBF or blood pressure in hypertensive older adults, providing important information on the efficacy of nitrate-based interventions for healthy vascular aging. This study was registered under ClinicialTrials.gov (NCT04584372).

中文翻译：

---

4 周内增加甜菜根汁中硝酸盐的摄入量会影响硝酸盐代谢，但不会影响患有高血压的老年人的血管功能或血压

随着年龄的增长，血管功能下降和血压升高，导致心血管疾病风险增加。在这项随机安慰剂对照交叉研究中，我们评估了之前报道的植物源性无机硝酸盐通过一氧化氮 (NO) 带来的心血管益处是否会转化为 15 名男性和女性（年龄范围：56-71 岁）的血管功能改善和血压降低。年）并接受治疗的高血压。我们研究了摄入后 3 小时（3H POST）单次 ∼400 mg 剂量的效果，以及每日摄入 2 × ∼400 mg 硝酸盐（通过富含硝酸盐）与缺乏硝酸盐（安慰剂）的甜菜根汁相比，超过 4 小时的效果。周（4 周后）。测量内容包括血浆和唾液中的硝酸盐和亚硝酸盐；内皮依赖性和非依赖性前臂血流 (FBF) 对乙酰胆碱 (FBF _ACh ) 和三硝酸甘油 (FBF _GTN ) 的反应；以及诊所、家庭和 24 小时动态血压。与安慰剂相比，硝酸盐治疗后 3 小时和 4 周后血浆和唾液硝酸盐和亚硝酸盐增加（P < 0.01），表明本研究参与者存在功能性硝酸盐-亚硝酸盐-NO 途径。治疗之间的 FBF _ACh和 FBF _GTN曲线下面积 (AUC) 比率[干预后（3H POST、4WK POST）与干预前 (PRE) 相比的 AUC 比率]、24 小时动态血压或家庭血压测量（P > 0.05）。这些发现并不支持这样的假设：增加膳食硝酸盐的摄入量会对高血压老年人的 FBF 或血压产生持续有益的影响，从而为基于硝酸盐的干预措施对健康血管老化的功效提供了重要信息。该研究已在 ClinicalTrials.gov (NCT04584372) 下注册。