Atkinson Charlotte, Skor Heather E, Fitzgibbons E Dawn, Scholes Delia, Chen Chu, Wähälä Kristiina, Schwartz Stephen M, Lampe Johanna W
Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
Cancer Epidemiol Biomarkers Prev. 2002 Mar;11(3):253-60.
Dietary isoflavones are biologically active in humans, but few observational data exist on the relationship between isoflavone intake and excretion in Western populations. We examined associations between self-reported soy intakes and overnight urinary isoflavone excretion in a population-based sample of western Washington State women, and we investigated the usefulness of one versus two overnight urine samples, collected 48 h apart, as a biomarker of intake. Isoflavones (genistein, daidzein, O-desmethylangolensin, and equol) were measured in two overnight urine collections from 363 women recruited from a health maintenance organization. Soy food intakes were assessed using two 1-day diet records completed on each day prior to the urine collections and a food frequency questionnaire (FFQ) that had been completed by 312 of the women with regard to their dietary habits 3.5 years (range, 2-5 years) before the urine collections. Twenty-one percent of the women consumed soy on either day of the diet recall, and 13% and 34% of the women consumed soy at least once a week or at least once a month, respectively, according to the FFQ. Women who consumed soy at either of the two diet recalls or at the FFQ (at least once a week or at least once a month) had a significantly higher urinary excretion of isoflavones than women who did not consume soy (P < 0.01). Among women who consumed soy at either of the two diet recalls or at the FFQ (soy consumed at least once a month), isoflavone intake and excretion correlated significantly (P < 0.01). Excretion of the individual isoflavones correlated significantly between the two urine samples collected 48 h apart (genistein, r = 0.41 and P < 0.001; daidzein, r = 0.30 and P < 0.001; O-desmethylangolensin, r = 0.46 and P < 0.001; equol, r = 0.60 and P < 0.001). Differences between soy consumers and nonconsumers and associations between intakes and excretion remained significant whether one or both urine collections were considered. Measuring isoflavone excretion in one overnight urine collection serves as a biomarker of recent or past isoflavone intake, even in populations whose intake of soy foods is relatively low.
膳食异黄酮对人体具有生物活性，但关于西方人群异黄酮摄入量与排泄量之间关系的观察数据较少。我们在华盛顿州西部以人群为基础的女性样本中，研究了自我报告的大豆摄入量与过夜尿样中异黄酮排泄量之间的关联，并探讨了间隔48小时采集的一份与两份过夜尿样作为摄入量生物标志物的有效性。对从一家健康维护组织招募的363名女性的两份过夜尿样进行了异黄酮（染料木黄酮、大豆苷元、O-去甲基安哥拉紫檀素和雌马酚）检测。大豆类食物摄入量通过在每次尿样采集前一天完成的两份1天饮食记录以及312名女性在尿样采集前3.5年（范围为2 - 5年）就其饮食习惯填写的食物频率问卷（FFQ）进行评估。根据饮食回忆，21%的女性在任意一天食用了大豆；根据FFQ，13%和34%的女性分别至少每周或每月食用一次大豆。在两份饮食回忆或FFQ（至少每周或每月一次）中食用大豆的女性，其异黄酮尿排泄量显著高于未食用大豆的女性（P < 0.01）。在两份饮食回忆或FFQ（每月至少食用一次大豆）中食用大豆的女性中，异黄酮摄入量与排泄量显著相关（P < 0.01）。在间隔48小时采集的两份尿样中，各单一异黄酮的排泄量显著相关（染料木黄酮，r = 0.41，P < 0.001；大豆苷元，r = 0.30，P < 0.001；O-去甲基安哥拉紫檀素，r = 0.46，P < 0.001；雌马酚），r = 0.60，P < 0.001）。无论考虑一份还是两份尿样采集，大豆食用者与非食用者之间的差异以及摄入量与排泄量之间的关联均保持显著。即使在大豆类食物摄入量相对较低的人群中，检测一份过夜尿样中的异黄酮排泄量也可作为近期或过去异黄酮摄入量的生物标志物。
