High dietary sodium impairs cerebral blood flow regulation in rodents and is associated with increased stroke risk in humans. However, the effects of multiple days of high dietary sodium on cerebral blood flow regulation in humans is unknown. Therefore, the purpose of this study was to determine whether ten days of high dietary sodium impairs cerebral blood flow regulation. Ten participants (3F/7M; age: 30 ± 10 years; blood pressure (BP): 113 ± 8/62 ± 9 mmHg) participated in this randomized, cross-over design study. Participants were placed on 10-day diets that included either low- (1000 mg/d), medium- (2300 mg/d) or high- (7000 mg/d) sodium separated by ≥four weeks. Urinary sodium excretion, beat-to-beat BP (finger photoplethysmography), middle cerebral artery velocity (transcranial Doppler), and end-tidal carbon dioxide (capnography) was measured. Dynamic cerebral autoregulation during a ten-minute baseline was calculated and cerebrovascular reactivity assessed by determining the percent change in middle cerebral artery blood flow velocity to hypercapnia (8% CO₂, 21% oxygen, balance nitrogen) and hypocapnia (via mild hyperventilation). Urinary sodium excretion increased in a stepwise manner (ANOVA P = 0.001) from the low, to medium, to high condition. There were no differences in dynamic cerebral autoregulation between conditions. While there was a trend for a difference during cerebrovascular reactivity to hypercapnia (ANOVA P = 0.06), this trend was abolished when calculating cerebrovascular conductance (ANOVA: P = 0.28). There were no differences in cerebrovascular reactivity (ANOVA P = 0.57) or conductance (ANOVA: P = 0.73) during hypocapnia. These data suggest that ten days of a high sodium diet does not impair cerebral blood flow regulation in healthy adults.

高膳食钠会损害啮齿动物的脑血流调节，并与人类中风风险增加有关。然而，多天的高钠饮食对人类脑血流调节的影响尚不清楚。因此，本研究的目的是确定 10 天的高钠饮食是否会损害脑血流调节。十名参与者（3F/7M；年龄：30 ± 10 岁；血压 (BP)：113 ± 8/62 ± 9 mmHg）参加了这项随机交叉设计研究。参与者接受为期 10 天的饮食，包括低钠（1000 毫克/天）、中钠（2300 毫克/天）或高钠（7000 毫克/天），间隔 ≥ 4 周。尿钠排泄，逐搏血压（手指光电容积描记术），大脑中动脉速度（经颅多普勒），并测量呼气末二氧化碳（二氧化碳图）。计算 10 分钟基线期间的动态脑自动调节，并通过确定大脑中动脉血流速度与高碳酸血症 (8% CO_2，21 % 氧气，平衡氮气）和低碳酸血症（通过轻度过度换气）。尿钠排泄从低、中、高状态逐步增加（ANOVA P  = 0.001）。不同条件下的动态脑自动调节没有差异。虽然在脑血管对高碳酸血症的反应期间存在差异趋势（ANOVA P  = 0.06），但在计算脑血管电导时这种趋势被消除（ANOVA：P  = 0.28）。脑血管反应性 (ANOVA P  = 0.57) 或电导 (ANOVA: P = 0.73) 在低碳酸血症期间。这些数据表明，十天的高钠饮食不会损害健康成年人的脑血流调节。