Cook Nancy R, Cutler Jeffrey A, Obarzanek Eva, Buring Julie E, Rexrode Kathryn M, Kumanyika Shiriki K, Appel Lawrence J, Whelton Paul K
Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
BMJ. 2007 Apr 28;334(7599):885-8. doi: 10.1136/bmj.39147.604896.55. Epub 2007 Apr 20.
To examine the effects of reduction in dietary sodium intake on cardiovascular events using data from two completed randomised trials, TOHP I and TOHP II.
Long term follow-up assessed 10-15 years after the original trial.
10 clinic sites in 1987-90 (TOHP I) and nine sites in 1990-5 (TOHP II). Central follow-up conducted by post and phone.
Adults aged 30-54 years with prehypertension.
Dietary sodium reduction, including comprehensive education and counselling on reducing intake, for 18 months (TOHP I) or 36-48 months (TOHP II).
Cardiovascular disease (myocardial infarction, stroke, coronary revascularisation, or cardiovascular death).
744 participants in TOHP I and 2382 in TOHP II were randomised to a sodium reduction intervention or control. Net sodium reductions in the intervention groups were 44 mmol/24 h and 33 mmol/24 h, respectively. Vital status was obtained for all participants and follow-up information on morbidity was obtained from 2415 (77%), with 200 reporting a cardiovascular event. Risk of a cardiovascular event was 25% lower among those in the intervention group (relative risk 0.75, 95% confidence interval 0.57 to 0.99, P=0.04), adjusted for trial, clinic, age, race, and sex, and 30% lower after further adjustment for baseline sodium excretion and weight (0.70, 0.53 to 0.94), with similar results in each trial. In secondary analyses, 67 participants died (0.80, 0.51 to 1.26, P=0.34).
Sodium reduction, previously shown to lower blood pressure, may also reduce long term risk of cardiovascular events.
利用两项已完成的随机试验（TOHP I和TOHP II）的数据，研究减少膳食钠摄入量对心血管事件的影响。
在原试验结束后进行10 - 15年的长期随访。
1987 - 1990年的10个诊所地点（TOHP I）和1990 - 1995年的9个地点（TOHP II）。通过邮寄和电话进行集中随访。
年龄在30 - 54岁的患有高血压前期的成年人。
减少膳食钠摄入，包括关于减少摄入量的全面教育和咨询，为期18个月（TOHP I）或36 - 48个月（TOHP II）。
心血管疾病（心肌梗死、中风、冠状动脉血运重建或心血管死亡）。
TOHP I中有744名参与者，TOHP II中有2382名参与者被随机分配到钠减少干预组或对照组。干预组的净钠减少量分别为44 mmol/24小时和33 mmol/24小时。获取了所有参与者的生命状态，并从2415名（77%）参与者中获得了发病的随访信息，其中200人报告发生了心血管事件。在对试验、诊所、年龄、种族和性别进行调整后，干预组发生心血管事件的风险降低了25%（相对风险0.75，95%置信区间0.57至0.99，P = 0.04），在进一步对基线钠排泄和体重进行调整后降低了30%（0.70，0.53至0.94），两项试验结果相似。在二次分析中，67名参与者死亡（0.80，0.51至1.26，P = 0.34）。
先前已证明减少钠摄入可降低血压，它可能还会降低心血管事件的长期风险。
