Inflammatory Markers in a 2-Year Soy Intervention among Premenopausal Women

描述(由申请人提供)： 拟议的项目利用了在为期两年的随机大豆试验期间收集的现有血清样本。流行病学证据支持大豆食品和异黄酮在预防乳腺癌中的作用，但可能的作用机制尚不清楚。根据动物研究和人类干预的结果，我们假设大豆可以减少慢性炎症，这可能是乳腺癌的一个危险因素。最初的研究和其他报告表明，大豆对乳腺癌的预防作用，如果存在的话，并不是通过循环性激素来调节的。人们对癌症炎症病因学的兴趣与日俱增，以及将营养因素与免疫反应联系起来的发现，支持了我们的假设。这项研究的目的是检查每天食用两种大豆对血清炎症标志物水平的影响。此外，我们还将探讨不同种族、体重指数和终生大豆摄入量对血清炎症标志物水平的影响。在为期两年的营养干预期间，220名绝经前妇女被随机分配，并根据排卵试剂盒的测定，在黄体期捐献多个血样。干预组每天食用两份豆类食物，主要是豆腐、豆奶和大豆坚果，而对照组妇女保持正常饮食。根据几项衡量标准，对研究方案的依从性非常好。辍学人数在不同组之间没有差异：17名(15.6%)干预组妇女和14名(12.6%)对照组过早离开研究。受试者书面同意将他们的标本用于未来的分析。保存在-80℃下的冰冻血清样本将用建立的ELISA方法分析六种炎症标志物：脂联素、瘦素、白介素6、C反应蛋白、肿瘤坏死因子α和白介素1b。对于205名有血清样本的受试者(100名干预受试者和105名对照)，我们将分析四个样本，每个样本在基线时、6个月后、12个月和24个月后收集。统计分析将应用一般线性模型来比较大豆摄入量的炎症标志物水平，同时考虑重复测量设计。

DESCRIPTION (provided by applicant): The proposed project makes uses of existing serum samples collected during a 2-year randomized soy trial. Epidemiologic evidence supports a role for soy foods and isoflavones in breast cancer prevention, but the possible mechanisms of action are not well understood. Based on results from animal studies and human interventions, we hypothesize that soy reduces chronic inflammation, a possible risk factor for breast cancer. The original study and other reports indicate that the preventive effects of soy on breast cancer, if they exist, are not mediated by circulating sex hormones. The growing interest in an inflammatory etiology for cancer, as well as findings that link nutritional factors to immune responses, support our hypothesis. The aim of this study is to examine the effects of two daily servings of soy on serum levels of inflammatory markers. In addition, we will explore differences in serum levels of inflammatory markers by ethnicity, body mass index, and lifetime soy intake. During the 2-year nutritional intervention, 220 premenopausal women were randomized and donated multiple blood samples during the luteal phase as determined by an ovulation kit. The intervention group consumed two daily servings of soy foods, predominantly tofu, soy milk, and soy nuts, while the control women maintained their regular diet. According to several measures, compliance with the study regimen was excellent. The number of dropouts did not differ by group: 17 (15.6%) intervention women and 14 (12.6%) controls left the study prematurely. The subjects gave written permission to use their specimens for future analyses. Frozen serum samples stored at -80¿C will be analyzed for six inflammatory markers, adiponectin, leptin, interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor (TNF)-a, and IL-1b, using established ELISA assays. For each of the 205 subjects (100 intervention subjects and 105 controls) with serum samples, we will analyze four samples, one each collected at baseline, after 6, 12, and 24 months. The statistical analysis will apply general linear models to compare the levels of inflammatory markers by soy intake, while taking into account the repeated measurement design.