Biologic variation is important for interpretation of thyroid function tests
Biologic variation is important for interpretation of thyroid function tests
复制标题
DOI：
10.1089/105072503770867237
复制
发表时间：
2003-11-01
期刊：
影响因子：
6.6
通讯作者：
Laurberg, P
中科院分区：
文献类型：
--
作者：
Andersen, S;Bruun, NH;Laurberg, P
血清中促甲状腺素 (TSH) 和甲状腺激素存在很大差异。变异的组成部分包括分析前变异、分析变异和生物学变异。这分为个体间变异和个体内变异。后者包括昼夜节律和季节差异，尽管有迹象表明起点是由基因决定的。个体内变异与个体间变异的比率描述了基于人群的参考范围的可靠性。血清 TSH、甲状腺素 (T-4) 和三碘甲状腺原氨酸 (T-3) 的比率较低，表明实验室参考范围对个体正常值的偏差相对不敏感。考虑了解决方案，但将血清 T-3、T-4 和 TSH 的分析变异降低到计算的分析目标 7%、5% 和 12% 以下并不能提高诊断性能。单独设定点和参考范围的确定也没有。在实践中，这意味着基于人群的参考范围是必要的，但重要的是要认识到它们在个体中使用的局限性。血清 TSH 对 T-4 和 T-3 的微小变化有放大反应。 TSH 持续异常可能表明个体的 T-4 和 T-3 不正常，即使在实验室参考范围内也是如此。这强调了 TSH 在诊断和监测甲状腺功能障碍中的重要性。此外，它还意味着亚临床甲状腺疾病可以纯粹用生化术语来定义。在妊娠等危急情况下，正常的甲状腺功能对胎儿大脑发育至关重要，因此应治疗亚临床甲状腺疾病。即使 TSH 在参考范围内，也可能与个体甲状腺功能轻度异常有关。儿童和孕妇甲状腺功能的这种微小异常对大脑发育的临床重要性仍有待阐明。
Large variations exist in thyrotropin (TSH) and thyroid hormones in serum. The components of variation include preanalytical, analytical, and biologic variation. This is divided into between- and within-individual variation. The latter consists of circadian and seasonal differences although there are indicators of a genetically determined starting point. The ratio of within- to between-individual variation describes the reliability of population-based reference ranges. This ratio is low for serum TSH, thyroxine (T-4) and triiodothyronine (T-3) indicating that laboratory reference ranges are relatively insensitive to aberrations from normality in the individual. Solutions are considered but reducing the analytical variation below the calculated analytical goals of 7%, 5% and 12% for serum T-3, T-4, and TSH does not improve diagnostic performance. Neither does determination of the individual set-point and reference range. In practice this means that population-based reference ranges are necessary but that it is important to recognize their limitations for use in individuals. Serum TSH responds with amplification to minor alterations in T-4 and T-3. A consistently abnormal TSH probably indicates that T-4 and T-3 are not normal for the individual even when inside the laboratory reference range. This underlines the importance of TSH in diagnosis and monitoring of thyroid dysfunctions. Also, it implies that subclinical thyroid disease may be defined in purely biochemical terms. Under critical circumstances such as pregnancy where normal thyroid function is of importance for fetal brain development, subclinical thyroid disease should be treated. Even TSH within the reference range may be associated with slightly abnormal thyroid function of the individual. The clinical importance of such small abnormalities in thyroid function in small children and pregnant women for brain development remains to be elucidated.