Malta Daniela, Esfandiari Sam, Goldraich Livia A, Allard Johane P, Newton Gary E
School of Nutrition, Toronto Metropolitan University, 350 Victoria St., Toronto, ON M5B 2K3, Canada.
Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
Nutrients. 2024 Dec 27;17(1):45. doi: 10.3390/nu17010045.
There is compelling evidence of an inverse association between potassium intake and blood pressure (BP). A potential mechanism for this effect may be dietary potassium-mediated augmentation of endothelium-dependent relaxation. To date, studies have investigated potassium intake supplementation over several weeks in healthy volunteers with variable results on vascular function. There is no assessment of the acute vascular effects of potassium supplementation achieved by the ingestion of potassium-rich food in a hypertensive population.
The purpose of this study was to investigate the effect of a high potassium meal on postprandial endothelial function as measured by flow-mediated dilatation (FMD).
We performed an investigator-blinded randomized crossover trial in 33 treated hypertensive individuals. Participants consumed both a high (2400 mg) and low (543 mg) K meal, separated by a one-week washout period. The primary endpoint was endothelial function as assessed by FMD pre-meal and postprandially at 60 and 120 min. Meals were compared at each time point using the Hills-Armitage approach.
33 individuals were included in the study (48% male, mean age 68). In the fasting state (Baseline), and at 60 min postprandial, radial artery FMD was not significantly different between the participants after consumption of either meal (baseline: high K 4.2 ± 2% versus Low K 2.6 ± 3%, = 0.93; 60 min: high K 3.8 ± 4% versus Low K 4.1 ± 3%, = 0.69). However, at 120 min, FMD tended to be higher in participants after the high K meal (5.2 ± 4.1%) than after the low K meal (3.9 ± 4.1%) ( = 0.07). There were no differences in participants' radial artery diameter and blood flow between meals.
This study does not support our hypothesis that a single high K meal improves vascular function in individuals with treated hypertension. This does not contradict the clinical evidence relating greater K intake with lower BP, but suggests that mechanistic investigations of increased K intake through diet alone and its impact on endothelial function as a mediator to reducing BP are complex and not simply due to single nutrient-mediated improvement in vascular function.
有确凿证据表明钾摄入量与血压（BP）呈负相关。这种效应的一个潜在机制可能是膳食钾介导的内皮依赖性舒张增强。迄今为止，研究在健康志愿者中对钾摄入量补充数周进行了调查，对血管功能的影响结果不一。尚无关于高血压人群通过摄入富含钾的食物实现钾补充的急性血管效应的评估。
本研究的目的是通过血流介导的扩张（FMD）来研究高钾餐对餐后内皮功能的影响。
我们在33名接受治疗的高血压个体中进行了一项研究者盲法随机交叉试验。参与者分别食用高钾餐（约2400毫克）和低钾餐（约543毫克），中间间隔一周的洗脱期。主要终点是通过餐前及餐后60分钟和120分钟的FMD评估的内皮功能。使用希尔斯 - 阿米蒂奇方法在每个时间点比较餐食。
33名个体纳入研究（48%为男性，平均年龄68岁）。在禁食状态（基线）以及餐后60分钟时，食用任何一种餐后参与者的桡动脉FMD无显著差异（基线：高钾餐4.2±2% 对低钾餐2.6±3%，P = 0.93；60分钟：高钾餐3.8±4% 对低钾餐4.1±3%，P = 0.69）。然而，在120分钟时，高钾餐后参与者的FMD（5.2±4.1%）往往高于低钾餐后（3.9±4.1%）（P = 0.07）。餐食之间参与者的桡动脉直径和血流量无差异。
本研究不支持我们的假设，即单次高钾餐可改善接受治疗的高血压个体的血管功能。这与钾摄入量增加与较低血压相关的临床证据并不矛盾，但表明仅通过饮食增加钾摄入量及其作为降低血压的介导因素对内皮功能的影响的机制研究很复杂，并非仅仅由于单一营养素介导的血管功能改善。
