Supplementary Material for: Soy Consumption Reduces Risk of Ischemic Stroke: A Case-Control Study in Southern China

<i>Background:</i> Experimental studies have suggested that soybean products may protect against ischemic stroke, but only limited epidemiological evidence is available. <i>Objective:</i> Our aim was to investigate the relationship between soy food consumption and the risk of ischemic stroke among the Chinese population. <i>Methods:</i> A case-control study was conducted in southern China during 2007–2008. Soy food consumption, dietary intake and lifestyle information were obtained from 374 incident ischemic stroke patients and 464 hospital-based controls. Logistic regression analyses were performed to assess the association between soy food intake and the ischemic stroke risk. <i>Results:</i> The mean weekly soy food intake was significantly lower (p = 0.001) among cases (89.9, SD = 239.3 g) than control subjects (267.7, SD = 426.1 g). Increased consumptions of dried soybean, tofu, soymilk and total soy foods were associated with reduced risks of ischemic stroke after adjusting for confounding factors. The corresponding adjusted odds ratios for the highest versus lowest level (&lt;50 g) of intake were 0.20 (95% confidence interval = 0.09–0.48), 0.56 (0.36–0.89), 0.18 (0.06–0.51) and 0.23 (0.14–0.39), with significant dose-response relationships observed. <i>Conclusion</i>: The results provided evidence of inverse association between habitual soy food consumption and the risk of ischemic stroke for Chinese adults.

**背景**：已有实验研究表明，豆制品可能对缺血性脑卒中（ischemic stroke）具有保护作用，但目前相关流行病学证据仍较为有限。
**研究目的**：本研究旨在探究中国人群豆制品摄入与缺血性脑卒中发病风险之间的关联。
**研究方法**：本研究于2007年至2008年在中国南方开展一项病例对照研究。研究纳入374例新发缺血性脑卒中患者与464例医院来源对照人群，收集其豆制品摄入、膳食摄入及生活方式相关信息。采用logistic回归（logistic regression）分析评估豆制品摄入与缺血性脑卒中发病风险的关联。
**研究结果**：病例组每周平均豆制品摄入量为89.9 g（标准差standard deviation, SD=239.3 g），显著低于对照组的267.7 g（SD=426.1 g，p=0.001）。在校正混杂因素后，干大豆、豆腐、豆浆及总豆制品的摄入量增加，均与缺血性脑卒中发病风险降低显著相关。摄入水平最高组与最低组（<50 g）对应的校正后比值比（odds ratio, OR）分别为0.20（95%置信区间（confidence interval, CI）：0.09~0.48）、0.56（0.36~0.89）、0.18（0.06~0.51）及0.23（0.14~0.39），且观察到显著的剂量-反应关系。
**研究结论**：本研究结果为中国成年人日常豆制品摄入与缺血性脑卒中发病风险间的负相关关联提供了流行病学证据支持。