Toxicity Of Lead In Children--Clinical Trial

在一项降低血铅浓度的口服螯合剂琥珀酸的随机临床试验中，血铅含量在每分升20到44微克的儿童在大约两岁时被给予琥珀酸或安慰剂，随后进行认知和行为测试。我们之前报道过，尽管在治疗过程中血铅水平较低，但服用琥珀酸葡胺的儿童的测试成绩与五岁或七岁时服用安慰剂的儿童没有什么不同。今年，我们使用试验数据集来确定血铅对行为的影响是直接的，还是通过对智商的影响而调节的。我们发现铅对外化行为(推搡、喊叫)有直接影响，但对内化行为(恐惧、担忧)没有直接影响。 我们已经与疾病控制与预防中心安排对该项目中采集的血液样本进行汞分析，这将允许在不招募任何新的受试者或收集任何样本的情况下，对琥珀酸汞螯合进行随机试验。我们还使用试验数据来观察螯合疗法是否降低了血压，而事实并非如此。

In a randomized clinical trial of succimer, an oral chelating agent that lowers blood lead concentration, children with blood leads of 20 to 44 micrograms per deciliter were given succimer or placebo when they were about 2 years old and followed with cognitive and behavioral testing. We reported previously that, despite lower blood lead levels during treatment, children given succimer had test scores that were no different from those of children given placebo at ages five or seven years. This year we used the trial data set to determine whether the effects of blood lead on behavior were direct or were mediated through the effect on IQ. We found that lead has direct effects on externalizing behavior (pushing, shouting) but not on internalizing behavior (fears, worries). We have arranged with CDC to analyze blood samples collected in this project for mercury, which will allow a randomized trial of succimer for mercury chelation without enrolling any new subjects or collecting any specimens. We also used trial data to see if chelation therapy lowered blood pressure, which it did not.