Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Am J Clin Nutr. 2009 Nov;90(5):1264-71. doi: 10.3945/ajcn.2009.28145. Epub 2009 Sep 2.
The effects of severe iodine deficiency during critical periods of brain development are well documented. There is little known about the consequences of milder forms of iodine deficiency on neurodevelopment.
The objective was to determine whether supplementing mildly iodine-deficient children with iodine improves cognition.
A randomized, placebo-controlled, double-blind trial was conducted in 184 children aged 10-13 y in Dunedin, New Zealand. Children were randomly assigned to receive a daily tablet containing either 150 microg I or placebo for 28 wk. Biochemical, anthropometric, and dietary data were collected from each child at baseline and after 28 wk. Cognitive performance was assessed through 4 subtests from the Wechsler Intelligence Scale for Children.
At baseline, children were mildly iodine deficient [median urinary iodine concentration (UIC): 63 microg/L; thyroglobulin concentration: 16.4 microg/L]. After 28 wk, iodine status improved in the supplemented group (UIC: 145 microg/L; thyroglobulin: 8.5 microg/L), whereas the placebo group remained iodine deficient (UIC: 81 microg/L; thyroglobulin: 11.6 microg/L). Iodine supplementation significantly improved scores for 2 of the 4 cognitive subtests [picture concepts (P = 0.023) and matrix reasoning (P = 0.040)] but not for letter-number sequencing (P = 0.480) or symbol search (P = 0.608). The overall cognitive score of the iodine-supplemented group was 0.19 SDs higher than that of the placebo group (P = 0.011).
Iodine supplementation improved perceptual reasoning in mildly iodine-deficient children and suggests that mild iodine deficiency could prevent children from attaining their full intellectual potential. The trial was registered with the Australia New Zealand Clinical Trials Register as ACTRN12608000222347.
在大脑发育的关键时期，严重碘缺乏的影响已得到充分证实。但是，对于轻度碘缺乏对神经发育的影响知之甚少。
本研究旨在确定轻度碘缺乏儿童补充碘是否能改善认知能力。
在新西兰达尼丁的 184 名 10-13 岁儿童中进行了一项随机、安慰剂对照、双盲试验。儿童随机分为接受每日服用 150μg 碘或安慰剂，为期 28 周。在基线和 28 周后，从每个儿童收集生化、人体测量和饮食数据。通过儿童韦氏智力量表的 4 个分量表评估认知表现。
基线时，儿童碘缺乏（中位数尿碘浓度（UIC）：63μg/L；甲状腺球蛋白浓度：16.4μg/L）。28 周后，补充组碘状况得到改善（UIC：145μg/L；甲状腺球蛋白：8.5μg/L），而安慰剂组仍处于碘缺乏状态（UIC：81μg/L；甲状腺球蛋白：11.6μg/L）。碘补充显著提高了 4 项认知分量表中的 2 项的分数[图片概念（P=0.023）和矩阵推理（P=0.040）]，但不包括字母数字排序（P=0.480）或符号搜索（P=0.608）。补充碘组的整体认知评分比安慰剂组高 0.19 个标准差（P=0.011）。
碘补充改善了轻度碘缺乏儿童的知觉推理能力，表明轻度碘缺乏可能会阻止儿童充分发挥其智力潜能。该试验在澳大利亚新西兰临床试验注册处注册，注册号为 ACTRN12608000222347。
