Nitrate-rich vegetables do not lower blood pressure in individuals with mildly elevated blood pressure: a 4-wk randomized controlled crossover trial
Nitrate-rich vegetables do not lower blood pressure in individuals with mildly elevated blood pressure: a 4-wk randomized controlled crossover trial
复制标题
DOI：
10.1093/ajcn/nqy061
复制
发表时间：
2018-06-01
影响因子：
7.1
通讯作者：
Hodgson, Jonathan M.
中科院分区：
文献类型：
--
作者：
Blekkenhorst, Lauren C.;Lewis, Joshua R.;Hodgson, Jonathan M.
背景：越来越多的证据表明，增加摄入富含硝酸盐的蔬菜可能是降低血压的有效方法。目的：我们的主要目的是确定每天食用富含硝酸盐的蔬菜超过4周是否会导致血压降低。设计：招募30名高血压前期或未治疗的1级高血压患者进行随机对照交叉试验，治疗期为4周，洗脱期为4周。参与者按随机顺序完成3个处理：1)增加摄入（类似于200克/天）富含硝酸盐的蔬菜[高硝酸盐（HN）]；2)增加硝酸盐含量低的蔬菜的摄入量（约为200克/天）[低硝酸盐（LN）；与22毫克/天相似]，3)蔬菜没有增加（对照；与6毫克/天相似）。通过使用食物日记和测量血浆硝酸盐和类胡萝卜素来评估依从性。用血浆、唾液、尿液硝酸盐和亚硝酸盐浓度评估硝酸盐代谢。主要终点是通过24小时动态、家庭和气候测量来评估血压。次要结果包括动脉硬度测量。结果：与LN组和对照组相比，HN组血浆硝酸盐和亚硝酸盐浓度升高（P < 0.001）。血浆类胡萝卜素随HN和LN处理的增加而增加（P < 0.01）。HN治疗没有降低收缩压[24小时动态-HN: 127.4 +/- 1.1 mm Hg；LN: 128.6 +/- 1.1 mm Hg；控制：126.2±1.1毫米汞柱(。P = 0.20)；home-HN: 127.4 +/- 0.7 mm Hg；LN: 128.7 +/- 0.7 mm Hg；对照组：128.3±0.7mmHg (P = 0.36)；临床- hn: 128.4 +/- 1.3 mm Hg；LN: 130.3 +/- 1.3 mm Hg；对照组：129.8 +/- 1.3 mm Hg (P = 0.49)]或舒张压（P < 0.05），调整预处理值、治疗时间和治疗顺序后。同样，两组动脉硬度测量也无差异（P < 0.05）。结论：与增加无硝酸盐蔬菜的摄入量和不增加蔬菜摄入量相比，增加富含硝酸盐蔬菜的摄入量并没有降低高血压前期或未治疗的1级高血压患者的血压。该试验在www.anzctr.org.au注册为ACTRN12615000194561。中华临床医学杂志，2018;37(7):894-908。
Background: Emerging evidence suggests that increasing intakes of nitrate-rich vegetables may be an effective approach to reduce blood pressure.Objective: Our primary aim was to determine whether daily consumption of nitrate-rich vegetables over 4 wk would result in lower blood pressure.Design: Thirty participants with prehypertension or untreated grade 1 hypertension were recruited to a randomized controlled crossover trial with 4-wk treatment periods separated by 4-wk washout periods. Participants completed 3 treatments in random order: 1) increased intake (similar to 200 g/d) of nitrate-rich vegetables [high-mtrate (HN); similar to 150 mg mtrate/d], 2) increased intake (similar to 200 g/d) of nitrate-poor vegetables [low-nitrate (LN); similar to 22 mg mtrate/d], and 3) no increase in vegetables (control; similar to 6 mg mtrate/d). Compliance was assessed with the use of food diaries and by measuring plasma nitrate and carotenoids. Nitrate metabolism was assessed with the use of plasma, salivary, and urinary nitrate and nitrite concentrations. The primary outcome was blood pressure assessed by using 24-h ambulatory, home, and clime measurements. Secondary outcomes included measures of arterial stiffness.Results: Plasma nitrate and nitrite concentrations increased with the HN treatment in comparison to the LN and control treatments (P < 0.001). Plasma carotenoids increased with the HN and LN treatments compared with the control (P < 0.01). HN treatment did not reduce systolic blood pressure [24-h ambulatory-HN: 127.4 +/- 1.1 mm Hg; LN: 128.6 +/- 1.1 mm Hg; control: 126.2 +/- 1.1 mm Hg (.P = 0.20); home-HN: 127.4 +/- 0.7 mm Hg; LN: 128.7 +/- 0.7 mm Hg; control: 128.3 +/- 0.7mmHg (P = 0.36); clinic-HN: 128.4 +/- 1.3 mm Hg; LN: 130.3 +/- 1.3 mm Hg; control: 129.8 +/- 1.3 mm Hg (P = 0.49)] or diastolic blood pressure compared with LN and control treatments (P > 0.05) after adjustment for pretreatment values, treatment period, and treatment order. Similarly, no differences were observed between treatments for arterial stiffness measures (P > 0.05).Conclusion: Increased intake of nitrate-rich vegetables did not lower blood pressure in prehypertensive or untreated grade 1 hypertensive individuals when compared with increased intake of nitrate-poor vegetables and no increase in vegetables. This trial was registered at www anzctr.org.au as ACTRN12615000194561. Am J Clin Nutr 2018;107:894-908.