Cutler J A, Follmann D, Elliott P, Suh I
Division of Epidemiology and Clinical Applications, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md 20892.
Hypertension. 1991 Jan;17(1 Suppl):I27-33. doi: 10.1161/01.hyp.17.1_suppl.i27.
To test for effects on systolic and diastolic blood pressure and to provide precise estimates of their magnitude, we conducted an overview of randomized clinical trials that aimed to reduce the intake of sodium in human subjects. We excluded from pooled analyses trials with confounded designs, those that compared intake levels beyond the usual range in the population, and those without published reports. Two reviewers abstracted information in duplicate and differences were reconciled. Twenty-three trials with outcome data from an aggregate of 1,536 subjects were included. Data were pooled both separately for hypertensive and normotensive subjects and for all trials combined. With the use of sample size weighting, blood pressure reductions (net of controls) were 4.9 +/- 1.3/2.6 +/- 0.8 mm Hg (systolic and diastolic, respectively, with 95% confidence limits) in hypertensive subjects and 1.7 +/- 1.0/1.0 +/- 0.7 mm Hg in normotensive subjects. The combined blood pressure reductions were 2.9 +/- 0.8/1.6 +/- 0.5 mm Hg. These changes were associated with mean reduction of urinary sodium excretion ranging from 16 to 171 mmol/24 hr for individual trials. A dose-response relation across trials was found, both in normotensive and in hypertensive subjects. These results indicate that sodium reduction lowers mean blood pressure in both hypertensive and normotensive individuals for periods of at least several months. The findings are highly consistent with results of observational epidemiological studies and have implications for preventive strategies of blood pressure control.
为了测试对收缩压和舒张压的影响，并精确估计其幅度，我们对旨在减少人类受试者钠摄入量的随机临床试验进行了一项综述。我们在汇总分析中排除了设计存在混淆的试验、那些比较人群中超出正常范围摄入量水平的试验以及那些没有发表报告的试验。两名评审员独立提取信息，并对差异进行了核对。纳入了23项试验，共有1536名受试者的结果数据。分别对高血压和血压正常的受试者以及所有试验合并的数据进行了汇总。采用样本量加权法，高血压受试者的血压降低值（扣除对照组）为4.9±1.3/2.6±0.8 mmHg（分别为收缩压和舒张压，95%置信区间），血压正常的受试者为1.7±1.0/1.0±0.7 mmHg。合并的血压降低值为2.9±0.8/1.6±0.5 mmHg。这些变化与各试验中尿钠排泄量平均减少16至171 mmol/24小时相关。在血压正常和高血压受试者中均发现了各试验间的剂量反应关系。这些结果表明，减少钠摄入至少在几个月的时间内可降低高血压和血压正常个体的平均血压。这些发现与观察性流行病学研究的结果高度一致，对血压控制的预防策略具有启示意义。
