From the Department of Medicine (M.O.D., S.Y.), and Department of Clinical Epidemiology and Biostatistics (A.M.), Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, Canada; and HRB-Clinical Research Facility Galway, NUI Galway, Galway, Ireland (M.O.D.).
Circ Res. 2015 Mar 13;116(6):1046-57. doi: 10.1161/CIRCRESAHA.116.303771.
Sodium is an essential nutrient. Increasing sodium intake is associated with increasing blood pressure, whereas low sodium intake results in increased renin and aldosterone levels. Randomized controlled trials have reported reductions in blood pressure with reductions in sodium intake, to levels of sodium intake <1.5 g/d, and form the evidentiary basis for current population-wide guidelines recommending low sodium intake. Although low sodium intake (<2.0 g/d) has been achieved in short-term feeding clinical trials, sustained low sodium intake has not been achieved by any of the longer term clinical trials (>6-month duration). It is assumed that the blood pressure-lowering effects of reducing sodium intake to low levels will result in large reductions in cardiovascular disease globally. However, current evidence from prospective cohort studies suggests a J-shaped association between sodium intake and cardiovascular events, based on studies from >300 000 people, and suggests that the lowest risk of cardiovascular events and death occurs in populations consuming an average sodium intake range (3-5 g/d). The increased risk of cardiovascular events associated with higher sodium intake (>5 g/d) is most prominent in those with hypertension. A major deficit in the field is the absence of large randomized controlled trials to provide definitive evidence on optimal sodium intake for preventing cardiovascular events. Pending such trials, current evidence would suggest a recommendation for moderate sodium intake in the general population (3-5 g/d), with targeting the lower end of the moderate range among those with hypertension.
钠是一种必需的营养物质。增加钠的摄入量与血压升高有关，而低钠摄入会导致肾素和醛固酮水平升高。随机对照试验报告称，减少钠的摄入量可以降低血压，摄入量降至<1.5 g/d，这为目前建议低钠摄入的人群指南提供了证据基础。尽管在短期喂养临床试验中已经实现了低钠摄入(<2.0 g/d)，但没有任何一项长期临床试验(>6 个月)实现了持续的低钠摄入。人们认为，将钠摄入量降低到低水平会降低血压，从而在全球范围内大幅降低心血管疾病的发病率。然而，目前来自前瞻性队列研究的证据表明，基于超过 30 万人的研究，钠摄入量与心血管事件之间呈“J”形关联，并表明在摄入平均钠量范围(3-5 g/d)的人群中，心血管事件和死亡的风险最低。与较高的钠摄入量(>5 g/d)相关的心血管事件风险的增加在高血压患者中最为明显。该领域的一个主要缺陷是缺乏大型随机对照试验来提供有关预防心血管事件的最佳钠摄入量的明确证据。在等待这些试验的结果时，目前的证据表明，建议普通人群适度摄入钠(3-5 g/d)，对于高血压患者，应将中等摄入量范围的低端作为目标。
