Sydney School of Public Health, University of Sydney, Sydney, Australia; The George Institute for Global Health, UNSW, Sydney, Australia.
The George Institute for Global Health, UNSW, Sydney, Australia; The George Institute for Global Health at Peking University Health Science Centre, Beijing, China.
Am Heart J. 2020 Mar;221:136-145. doi: 10.1016/j.ahj.2019.12.020. Epub 2020 Jan 7.
The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched salt substitute compared to usual salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of salt substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of salt substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
盐替代物与中风研究是一项正在进行的为期 5 年的大规模集群随机试验，旨在研究富含钾的盐替代物与普通盐相比对中风风险的影响。该研究涉及中国农村的 600 个村庄和 20996 个人。在 3 年期间，每隔 12 个月在一个随机的村庄子样本中测量中间风险标志物，以跟踪研究设计基本假设的进展情况。记录了 24 小时尿钠、24 小时尿钾、血压和参与者盐替代物的使用情况，通过广义线性混合模型估计干预组和对照组之间的差异。通过将前 2 年的总随访时间内确认的致命性和非致命性中风除以总人数，确定两组的年度事件发生率。24 小时尿钠的平均差异（95%CI）为-0.32g（-0.68 至 0.05），24 小时尿钾的平均差异为+0.77g（+0.60 至 +0.93），收缩压的平均差异为-2.65mmHg（-4.32 至 -0.97），舒张压的平均差异为+0.30mmHg（-0.72 至 +1.32）。干预组盐替代物的使用率为 97.5%，而对照组为 4.2%（P<0.0001）。致命性和非致命性中风的总估计年发生率为 3.2%。收缩压差异和年度中风率均符合研究设计的统计假设。该试验有望在随访结束时解决主要假设。
