Estrogenicity Of Soy Formula

染料木素和大豆苷元是在大豆中发现的雌激素异黄酮类化合物。尽管它们的效力与雌二醇相当，但喂食大豆配方奶粉的婴儿的血清浓度比雌二醇高出4个数量级。在喂食大豆的婴儿中，还没有找到雌激素暴露的解剖学、超声和其他生化证据。无论这种广泛使用的产品在婴儿中是否具有临床可检测到的雌激素活性，每公斤接触量最高的一组，在临床上是重要的；此外，这可能是对实验室雌激素活性测量预测人类实际内分泌反应能力的关键测试。我们已经开展了试点研究，以检查新生儿雌激素反应生理学的自然历史，并将利用这些结果对大豆配方奶粉对婴儿可能产生的雌激素效应进行纵向研究。<br>在费城儿童医院，我们收集了400多份尿液和唾液样本，以及88份血液样本，这些样本来自两天到一岁的儿童，他们喂食了大豆、牛奶配方奶粉或母乳。我们分析了它们的性激素、促性腺激素、性激素结合球蛋白、皮质醇、白介素6、甲状腺激素和促甲状腺激素。尽管母乳喂养的孩子皮质醇水平较高，豆奶喂养的女孩睾丸激素水平较低，但大多数情况下，激素水平并没有因喂养方式的不同而有所差异。我们目前正在研究大豆喂养儿童的性激素、促性腺激素和异黄酮浓度之间的关系。 利用这个项目的样本，我们正在与疾病控制中心合作，看看美国供水的污染物高氯酸盐是否会像对成年女性一样降低婴儿的甲状腺激素水平。我们目前正在重新联系那些告诉我们在分析他们的孩子样本中不同于最初研究计划的物质之前询问他们的家庭。我们将使用那些现在同意的人的样本，加上那些最初同意一般使用他们的样本的人，来测量我们已经测量过甲状腺激素的婴儿的高氯酸盐、碘和硫氰酸盐的浓度。

Genistein and daidzein are estrogenic isoflavones found in soybeans. Although they are about 110,000 as potent as estradiol, infants fed soy formula have serum concentrations that are up to 4 orders of magnitude higher than estradiol. Anatomic, sonographic, and other biochemical evidence of estrogen exposure has not been looked for in infants fed soy. Whether such widely used products do or do not have clinically detectable estrogenic activity in infants, the group with the highest exposure per kilo, is important clinically; in addition, it may be a crucial test of the ability of laboratory measures of estrogenicity to predict actual endocrine response in humans. We have done the field work for pilot studies to examine the natural history of estrogen responsive physiology in the newborn, and will use the results to develop a longitudinal study of the possible estrogenic effects of soy formula on infants. <br>At the Childrens Hospital of Philadelphia, we collected over 400 samples of urine and saliva and 88 blood samples from children aged 2 days to one year, fed soy, cow milk formula, or breast milk. We analyzed them for sex hormones, gonadotropins, sex hormone binding globulin, cortisol, interleukin 6, thyroid hormone, and thyroid stimulating hormone. For the most part, hormone levels do not differ by feeding method, although breast fed children have higher cortisol levels and soy fed girls lower testosterone. We are currently examining the relation between sex hormones, gonadotropins, and isoflavone concentrations in the soy fed children. Using samples from this project, we are collaborating with the Centers for Disease Control to see if perchlorate, a contaminant of the US water supply, lowers thyroid hormone levels in infants as it does in adult females. We are currently recontacting families who told us to ask them before analyzing their childs samples for substances other than those in the original study plan. We will use the samples from those who give their consent now, plus those who originally gave consent for general use of their samples, to measure concentrations of perchlorate, iodine, and thiocyanate in infants for whom we have already measured thyroid hormone.