Santos Alejandro, Martins Maria João, Guimarães João Tiago, Severo Milton, Azevedo Isabel
Serviço de Bioquímica (U38/FCT), Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
Rev Port Cardiol. 2010 Feb;29(2):159-72.
There is a strong positive correlation between sodium chloride intake and hypertension. In industrialized countries the ingestion of carbonated and non-carbonated mineral water is an important source of calorie-free fluids. The mineral content of these waters varies greatly, with many brands containing high levels of sodium. However, some mineral waters contain greater amounts of bicarbonate instead of chloride as the anion associated with the sodium cation. This is relevant because it is well established that the effect of sodium on blood pressure depends on the corresponding anion. Additionally the pressor effect of sodium bicarbonate is much lower than that of equivalent amounts of sodium chloride. The aim of our work was to evaluate the effect of ingesting a sodium-rich carbonated mineral water (Agua das Pedras) on blood pressure values in normotensive individuals.
This crossover, non-blinded study evaluated 17 individuals (9 female and 8 male), aged 24-53 years, median body mass index (BMI) < 23, randomly allocated in two groups, ingesting 500 ml/day of Agua das Pedras or Agua Vitalis. Each arm of the study lasted 7 weeks, with 6 weeks of washout between them. Twenty-four hour urinary samples were collected at the beginning and end of each arm to determine pH and sodium and potassium excretion. Blood pressure and body weight were measured weekly throughout the study. A mixed-effects model was used to compare groups (p < 0.05). The Wilcoxon test was used to analyze electrolyte excretion.
No differences were observed in blood pressure values between treatments or from baseline values. We found a positive correlation between BMI and blood pressure.
The daily ingestion of 500 ml of Agua das Pedras had no effect on blood pressure. A study by Schorr and co-workers found that the ingestion of bicarbonate-rich water (1.5 l/day) had hypotensive effects in an elderly population. However, these results should be verified in hypertensive subjects, who are more likely to be salt sensitive, since in some of these individuals blood pressure rises even when sodium is ingested as sodium bicarbonate.
氯化钠摄入量与高血压之间存在很强的正相关关系。在工业化国家，饮用碳酸和非碳酸矿泉水是无热量液体的重要来源。这些水的矿物质含量差异很大，许多品牌含有高水平的钠。然而，一些矿泉水中与钠离子相关的阴离子是碳酸氢根而非氯离子，其含量更高。这一点很重要，因为钠对血压的影响取决于相应的阴离子。此外，碳酸氢钠的升压作用远低于等量的氯化钠。我们研究的目的是评估饮用富含钠的碳酸矿泉水（阿瓜达斯佩德拉斯矿泉水）对血压正常个体血压值的影响。
本交叉、非盲法研究评估了17名个体（9名女性和8名男性），年龄在24至53岁之间，中位体重指数（BMI）<23，随机分为两组，每天饮用500毫升阿瓜达斯佩德拉斯矿泉水或活力矿泉水。研究的每个阶段持续7周，两个阶段之间有6周的洗脱期。在每个阶段开始和结束时收集24小时尿液样本，以测定pH值以及钠和钾的排泄量。在整个研究过程中每周测量血压和体重。使用混合效应模型比较组间差异（p<0.05）。采用威尔科克森检验分析电解质排泄情况。
各治疗组之间的血压值与基线值相比均未观察到差异。我们发现BMI与血压之间存在正相关关系。
每天饮用500毫升阿瓜达斯佩德拉斯矿泉水对血压没有影响。绍尔及其同事的一项研究发现，饮用富含碳酸氢根的水（每天1.5升）对老年人群有降压作用。然而，这些结果应在更可能对盐敏感的高血压受试者中得到验证，因为在这些个体中，即使摄入碳酸氢钠形式的钠，一些人的血压也会升高。
