TOXICITY OF LEAD IN CHILDREN--CLINICAL TRIAL

工作概述：生命早期接触铅会导致长期的发育迟缓。目前尚不清楚从药理学上降低血铅是否可以预防或改善随后的延迟，如果可以，是否可以在可接受的安全程度上进行。治疗铅暴露儿童（TLC）试验是一项多中心、安慰剂对照的临床试验，比较口服螯合药物琥珀酸盐与安慰剂在预防幼儿发育迟缓、生长迟缓和行为障碍方面的作用。所有儿童都得到家庭清洁和维生素和矿物质补充。一半接受活性药物治疗，一半接受安慰剂治疗。1994年8月开始登记儿童，到1997年1月，所有780名儿童被随机分配。这些儿童的年龄在12到32个月之间，他们的血铅含量在每分升20到44微克之间。所有的孩子将被跟踪3年，并测量他们的发展和行为。该试验的设计假设是，在美国，儿童在2岁左右达到血导联峰值，导致4岁及以上儿童发育迟缓，并且在试验合格范围内，琥珀酸盐将降低血导联。随机儿童的平均血铅为每分升26微克，治疗目标为每分升15微克。血铅每分升变化10微克，IQ测量值就会有3分的差异。该试验的统计能力约为。8检测3分差。TLC还测量发育的其他方面，如血压、身高和行为。-螯合;铅中毒，儿童发育；临床试验;dimercaptosuccinic酸;琥珀胺-人类受试者

SUMMARY OF WORK: Exposure to lead in early life produces long-lasting developmental delay. It is not known whether pharmacologically lowering blood lead prevents or ameliorates subsequent delays, and, if it does, whether it can be done with an acceptable degree of safety. The Treatment of Lead-exposed Children (TLC) Trial is a multi-center, placebo-controlled, clinical trial comparing the use of the oral chelating drug succimer with placebo in the prevention of developmental delay, slowed growth, and behavior disorders in toddlers. All children receive home clean up and vitamin and mineral supplementation. Half receive active drug and halfplacebo. Enrollment of children began in August 1994 and all 780 children were randomized by January, 1997. The children were between 12 and 32 months of age, and have blood lead levels between 20 and 44 micrograms per deciliter. All children will be followed for 3 years, and their development and behavior measured. The trial is designed on the assumptions that peak blood leads, achieved in the US by children at about age 2 years, cause developmental delays in children 4 years old and older, and that succimer will lower blood leads in the range of eligibility of the trial. Mean blood lead in the randomized children is 26 micrograms per deciliter, and the treatment goal is 15 micrograms per deciliter. A 10 microgram per deciliter change in blood lead is expected to result in a 3 point difference in measured IQ. The trial has a statistical power of about .8 to detect a 3 point difference. TLC also measures other aspects of development, as well as blood pressure, height, and behavior. - chelation; lead poisoning, child development; clinical trials; dimercaptosuccinic acid; succimer - Human Subjects