Heyerdahl S, Kase B F, Lie S O
Department of Pediatric Research, National Hospital, Oslo, Norway.
J Pediatr. 1991 Jun;118(6):850-7. doi: 10.1016/s0022-3476(05)82194-8.
The relationship between the treatment serum thyroxine level and intellectual development at 2 and 6 years was investigated in 46 Norwegian children with congenital hypothyroidism identified by neonatal screening. The level of serum thyroxine during the first 2 years was positively correlated with the Mental Development Index at 2 years of age (Bayley Scales of Infant Development) and the Verbal IQ at 6 years of age (Wechsler Preschool and Primary Scale of Intelligence). Children with a mean serum thyroxine level greater than 180 nmol/L (14 micrograms/dl) during the first year had a significantly higher Mental Development Index at 2 years and Verbal IQ at 6 years than children with serum thyroxine values less than 129 nmol/L (10 micrograms/dl). Boys had a lower Mental Development Index at 2 years of age than girls (86.9 vs 105.1; p less than 0.001) and a higher frequency of elevated serum levels of thyroid-stimulating hormone during the first year (p = 0.001). No signs of toxic effects of a high hormone level at the time of IQ assessment were detected. However, high serum levels of thyroxine at ages 2 to 4 years in girls were related to lower Performance IQ at age 6 years. The results demonstrate that the serum level of thyroxine is of importance in relation to intellectual development. Thyroxine levels above the upper reference range during the first 2 years were related to best intellectual development at 2 and 6 years.
对46名通过新生儿筛查确诊为先天性甲状腺功能减退症的挪威儿童，研究了治疗期间血清甲状腺素水平与2岁和6岁时智力发育的关系。头两年血清甲状腺素水平与2岁时的心理发育指数（贝利婴儿发育量表）及6岁时的语言智商（韦氏学前及初小儿童智力量表）呈正相关。第一年平均血清甲状腺素水平大于180 nmol/L（14微克/分升）的儿童，其2岁时的心理发育指数和6岁时的语言智商显著高于血清甲状腺素值小于129 nmol/L（10微克/分升）的儿童。男孩2岁时的心理发育指数低于女孩（86.9对105.1；p<0.001），且第一年血清促甲状腺激素水平升高的频率更高（p = 0.001）。在智商评估时未检测到高激素水平的毒性作用迹象。然而，女孩2至4岁时血清甲状腺素水平高与6岁时操作智商较低有关。结果表明，血清甲状腺素水平对智力发育很重要。头两年高于参考范围上限的甲状腺素水平与2岁和6岁时最佳智力发育相关。
