BACKGROUND Severe iodine deficiency adversely affects neurodevelopment; however, evidence regarding the association of non-severe deficiency and child cognitive functioning is inconclusive. METHODS This prospective mother-child cohort study was nested in a population-based nutritional supplementation trial in Bangladesh (Maternal and Infant Nutrition Interventions in Matlab [MINIMat]). Participants with data on cognitive abilities at 5 and 10 years of age (n = 1530) and at least one measurement of urinary iodine concentration (UIC) (gestational week 8, 5, and 10 years) were selected. Cognitive abilities were assessed using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) and Wechsler Intelligence Scale for Children (WISC-IV). UICs were measured with inductively coupled plasma mass spectrometry and thereafter adjusted for specific gravity. RESULTS Median UICs in our population: (282 μg/L [pregnancy]; 406 μg/L [5 years]; 294 μg/L [10 years]) indicated that iodine intake corresponded to above 'adequate' or even 'excessive', according to the WHO classification. Maternal 'UIC <150 μg/L' was associated with lower full-scale and verbal scores at 5 and 10 years, although the associations were weakened in the fully adjusted models. A tendency of decreased verbal scores was also observed for maternal 'UIC ≥500 μg/L' but not for the corresponding child iodine category (≥300 μg/L). Child 'UIC <100 μg/L' was associated with lower processing speed (B=-3.1, 95% CI [-6.2, -0.1]; P-value = 0.041) compared with the reference group (100 μg/L≤ UIC <300 μg/L). CONCLUSIONS Current findings add to the growing evidence of a causal association of early-life iodine intake with cognitive development, indicating that low iodine intake during childhood is associated with reduced processing speed and non-optimal gestational iodine intake is weakly associated with slightly poorer verbal development outcomes.

中文翻译：

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孟加拉国农村纵向母子队列中的妊娠和儿童尿碘浓度和儿童的认知功能。

背景 严重的碘缺乏会对神经发育产生不利影响；然而，关于非严重缺陷与儿童认知功能之间关联的证据尚无定论。方法 这项前瞻性母子队列研究嵌套在孟加拉国一项基于人群的营养补充试验中（Matlab 中的母婴营养干预 [MINIMat]）。选择了具有 5 岁和 10 岁 (n = 1530) 认知能力数据和至少一次尿碘浓度 (UIC) 测量值（妊娠第 8、5 和 10 年）的参与者。使用 Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) 和 Wechsler Intelligence Scale for Children (WISC-IV) 评估认知能力。使用电感耦合等离子体质谱法测量 UIC，然后根据比重进行调整。结果 我们人群中的 UIC 中位数：（282 μg/L [怀孕]；406 μg/L [5 岁]；294 μg/L [10 岁]）表明碘摄入量相当于上述“充足”甚至“过量”，按照WHO分类。母亲的“UIC <150 μg/L”与 5 年和 10 年时较低的全面评分和语言评分相关，尽管这种关联在完全调整的模型中被削弱了。对于母亲“UIC ≥ 500 μg/L”，但对于相应的儿童碘类别 (≥ 300 μg/L)，也观察到语言分数下降的趋势。儿童“UIC <100 μg/L”与较低的处理速度相关（B=-3.1，95% CI [-6.2，-0.1]；P 值 = 0。041)与参照组(100 μg/L≤UIC <300 μg/L)比较。结论 目前的研究结果增加了越来越多的证据表明生命早期碘摄入量与认知发育之间存在因果关系，表明儿童时期碘摄入量低与处理速度降低有关，而非最佳妊娠期碘摄入量与语言发育稍差相关性较弱结果。