Dietary supplements & suppression of bone resorption & lead mobilization

该项目将在墨西哥城进行，利用我们目前的超级基金（SF）支持的项目。最近的证据表明，在怀孕和哺乳期间，铅从母体骨骼进入血液循环的活动明显增加。此外，我们的SF数据和其他人的数据表明，这种现象具有显著的胎儿毒性风险，表现为生长（出生体重下降，头围，出生长度）和随后的认知发育。这些发现构成了一个重大的公共卫生问题，即使是在铅暴露水平下降的社会中，由于长期存在高铅暴露的地区（包括一些居住在危险废物附近的社区）以及铅在骨骼中的长期驻留团队（数年至数十年）。正如我们的SF数据和其他研究所建议的那样，在怀孕期间抑制金属骨铅储存动员的一种可能策略是营养干预。我们建议在墨西哥城招募一个新的骨铅水平相对较高的妇女样本，并进行一项随机、双盲、安慰剂对照试验，研究含有钙的补充剂作为抑制骨吸收的手段，以及由此产生的含有钙的骨补充剂中铅的动员，作为抑制骨吸收的手段，以及由此产生的铅在怀孕期间从骨中动员到血浆中，并在产后期间进入母乳。我们将采取母亲测量（1）孕前和产后骨铅使用我们的K-X射线荧光技术;（2）骨吸收（通过测定（1）使用我们的K-X射线荧光技术的孕前和产后骨铅;（2）骨吸收（通过测定尿中I型胶原的N-端肽[尿NTX]），（3）全血铅，及（4）于怀孕前、怀孕初期、中期、晚期及产后一个月及四个月，采用特殊的收集技术及IDTIMSJ测量血浆铅含量;及（5）于产后一个月及四个月，母乳铅含量。我们将测量母体血浆和母乳中的铅水平，因为这些是胎儿和婴儿铅暴露的最直接来源，最近的研究表明，母体静脉血水平不能充分反映这些参数。我们将检验补充剂会显著降低尿NTX、血浆铅和母乳铅水平的假设。我们还将探讨血浆铅水平的关系，我们还将探讨血浆铅水平与出生人体测量措施的关系。这项研究如果成功，可能会提供一种预防育龄妇女铅负荷累积引起的二次毒性的方法。

This project will take place in Mexico City, taking advantage of our current Superfund (SF)-supported project. Recent evidence indicates that there is a marked increase in the mobilization of lead from maternal bone stories into circulation during pregnancy and lactation. Furthermore, our SF data and the data of others indicate that this phenomenon carries a significant risk of fetal toxicity in the form of growth (decreased birth weight, head circumference, birth length) and subsequent cognitive development. These findings pose a major public health problem, even among societies with declining lead exposure, given the persistence of pockets of high lead exposure (including some communities living in proximity to hazardous waste) as well as the long residence team of lead in bone (years to decades). As suggested by our SF data and other studies, one possible strategy for suppressing the mobilization of metal bone lead stores during pregnancy is nutritional intervention. We propose to recruit a new sample of women of women in Mexico City who have relatively high bone lead levels and conduct a randomized, double-blinded, placebo-controlled trial of supplements containing calcium as a means of suppressing bone resorption and the resulting mobilization of lead from bone supplements containing calcium as a means of suppressing bone resorption and the resulting mobilization of lead from bone into plasma during pregnancy, and into breast milk during the postpartum period. We will take maternal measurements of (1) pre-pregnancy and postpartum-bone lead using our K-x-ray fluorescence technology; (2) bone resorption (by assaying (1) pre-pregnancy and postpartum bone lead using our K-x-ray fluorescence technology; (2) bone resorption (by assaying N-telopeptide of type I collagen in urine [urinary NTX]), (3) whole blood lead, and (4) plasma lead (using special collection techniques and measured by IDTIMSJ during pre-pregnancy, the first, second, third trimesters and at one and four months postpartum; and (5) breast milk lead levels are at one and four months postpartum. We will measure maternal plasma and breast milk lead levels as these are the most direct sources of fetal and infant lead exposures, and recent research suggests that maternal venous blood levels do not adequately reflect either of these parameters. We will test the hypothesis that supplements will significantly decrease urinary NTX, plasma lead, and breast milk lead levels. We will also explore the relationship plasma lead levels We will also explore the relationship of plasma lead levels to birth anthropometry measures. This research, if successful, may provide a means of preventing secondary toxicity from accumulated lead burdens among women of reproductive age.