J Endocrinol Invest. 2014 Mar;37(3):303-8. doi: 10.1007/s40618-014-0054-0.
Due to the lack of specific pediatric studies, no data are available about natural history of endogenous subclinical hyperthyroidism (SH) in childhood.
(a) To investigate for the first time the natural history of SH [suppressed thyrotropin (TSH) and normal free thyroxine free thyroxine (FT4) levels] when presenting as initial manifestation of Hashimoto's thyroiditis (HT) in childhood (group A); (b) to compare spontaneous evolution of HT-related SH with that observed in age-matched patients with HT-related frank hyperthyroidism (suppressed TSH and elevated FT4 levels), i.e., Hashitoxicosis Htx (group B).
In the 11 patients of group A, TSH normalization spontaneously occurred 1-24 months after diagnosis, while in the 10 patients of group B it occurred 3-9 months after diagnosis, with no differences between the 2 groups in terms of time interval from entry to TSH normalization. In group A, this time interval was related to baseline thyroid peroxidase antibodies (r=0.78, p = 0.04). During follow-up, eight patients of each group remained euthyroid, whereas two became hypothyroid (in both groups) and one developed Graves' disease (in group A).
(a) HT should be included among the causes of endogenous SH in pediatric age; (b) in children with HT-related SH, spontaneous normalization of TSH levels occurs within the first 24 months after diagnosis, as well as in age-matched patients with Htx; (c) in both these conditions, a further deterioration of thyroid function might re-present in some patients during follow-up; (d) Ht-related SH and Htx might be possibly seen as different biochemical stages along the same continuum.
由于缺乏特定的儿科研究，目前尚无儿童内源性亚临床甲状腺功能亢进症（SH）自然史的数据。
（a）首次研究儿童桥本甲状腺炎（HT）初发表现时 SH [促甲状腺激素（TSH）抑制和正常游离甲状腺素游离甲状腺素（FT4）水平]的自然史（A 组）；（b）比较 HT 相关 SH 的自发演变与年龄匹配的 HT 相关真性甲状腺功能亢进症（TSH 抑制和 FT4 升高）即桥本毒症 Htx（B 组）患者观察到的演变。
在 A 组的 11 例患者中，TSH 于诊断后 1-24 个月内自发恢复正常，而在 B 组的 10 例患者中，诊断后 3-9 个月内恢复正常，两组之间从进入到 TSH 正常化的时间间隔无差异。在 A 组中，该时间间隔与基线甲状腺过氧化物酶抗体相关（r=0.78，p=0.04）。在随访期间，每组有 8 例患者仍处于甲状腺功能正常状态，而有 2 例发展为甲状腺功能减退症（在两组中），1 例发展为格雷夫斯病（在 A 组中）。
（a）HT 应被列入儿科内源性 SH 的病因之一；（b）在 HT 相关 SH 的儿童中，TSH 水平的自发正常化发生在诊断后 24 个月内，与年龄匹配的 Htx 患者相同；（c）在这两种情况下，在随访期间，一些患者的甲状腺功能可能会进一步恶化；（d）HT 相关 SH 和 Htx 可能是沿着同一连续体的不同生化阶段。
