Beevers D G
Department of Medicine, City Hospital, Birmingham B18 7QH, UK.
Clin Auton Res. 2002 Oct;12(5):353-7. doi: 10.1007/s10286-002-0061-7.
The relationship between salt intake and blood pressure was once highly controversial. Early comparisons of populations did support the salt hypothesis but were difficult to interpret because of unmeasured confounding variables. However, the INTERSALT project, published in 1988 overcame many of these problems and reported within - and between - population gradients of sodium excretion and blood pressure or the rise in blood pressure with advancing age. Of the five long-term follow-up studies of salt intake and cardiovascular disease, two suggested that a low salt intake might be harmful. These studies are however open to much criticism. The three other studies reported positive relationships between salt intake and stroke or heart attack. Whilst there is little doubt that salt restriction lowers blood pressure in hypertensive patients, there remains some uncertainty whether any effect is seen in normotensives. The effects, if present, are small (reducing systolic pressure by about 2 mmHg) and not clinically useful, although if applied on a population-wide basis they might reduce the prevalence of hypertension by about 17 %. In many countries food producers and food standards agencies are beginning to respond by cutting the salt content of processed foods.
盐摄入量与血压之间的关系曾极具争议。早期对不同人群的比较确实支持了盐假说，但由于存在未测量的混杂变量，难以进行解读。然而，1988年发表的国际盐摄入与血压关系研究（INTERSALT）项目克服了许多此类问题，并报告了人群内部和人群之间钠排泄与血压的梯度关系，以及血压随年龄增长的升高情况。在五项关于盐摄入量与心血管疾病的长期随访研究中，有两项表明低盐摄入可能有害。然而，这些研究备受诸多批评。其他三项研究报告了盐摄入量与中风或心脏病发作之间的正相关关系。虽然毫无疑问，限盐可降低高血压患者的血压，但对于血压正常者是否有任何影响仍存在一些不确定性。即便存在影响，其作用也很小（收缩压降低约2毫米汞柱），且在临床上并无实际用途，不过如果在全人群范围内应用，可能会使高血压患病率降低约17%。在许多国家，食品生产商和食品标准机构已开始通过降低加工食品的含盐量来做出回应。
