老年人甲状腺功能检测的生物学变异及其临床意义。

Biological variation in thyroid function tests in older adults and clinical implications.

机构信息

Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.

Department of Geriatric Medicine, Aalborg University Hospital, Aalborg, Denmark.

出版信息

Clin Endocrinol (Oxf). 2023 Dec;99(6):598-605. doi: 10.1111/cen.14973. Epub 2023 Sep 18.

DOI:10.1111/cen.14973

PMID:37723656

Abstract

OBJECTIVE

Interpreting thyroid function tests can be challenging due to inherent variation, and the need for tests rises with age. While age-related changes in thyrotropin (TSH) levels are known, the biological variation in older adults remains unclear.

DESIGN

We recruited nineteen 65-99-year-old (older adults) without thyroid disease for monthly blood sampling for 1 year.

PATIENTS AND MEASUREMENTS

Serum was stored at -20C°, and TSH, total thyroxine (TT4) and total triiodothyronine (TT3) were analysed in random order in a single batch for each participant. Results were compared to test results from 15 euthyroid men aged 24-53 years (younger adults) collected previously using a similar methodology.

RESULTS

Interindividual coefficients of variation in older/younger adults were 46.7%/44.0% for TSH, 12.7%/19.5% for TT4 and 14.6%/22.4% for TT3. Intraindividual coefficients of variation (CV ) were 19.0%/25.4% for TSH, 5.5%/10.8% for TT4 and 6.9%/13.2% for TT3. The index of individuality was below 0.6 for all hormones in all age groups. The number of samples required to determine the homoeostatic set-point at 10% precision in older adults was 14-21 for TSH and 2 for TT4 and TT3. TT4 in older adults was the only parameter in any group with comparable CV between individuals (p = .22).

CONCLUSIONS

CV for TT4 and TT3 was halved in older compared to younger adults with two tests of TT4 needed to describe the individual set-point. Similar CV between older adults caused TT4 to provide a reliable estimate of thyroid function, and the added value of measuring thyroxine could improve clinical practice.

摘要

目的

由于固有变异，甲状腺功能测试的解读具有挑战性，并且随着年龄的增长，对测试的需求也会增加。虽然已知年龄相关的促甲状腺激素（TSH）水平变化，但老年人的生物学变异仍不清楚。

设计

我们招募了 19 名 65-99 岁（老年人）无甲状腺疾病的患者，进行为期 1 年的每月血液采样。

患者和测量方法

血清在-20°C 下储存，然后对每位参与者的所有样本按随机顺序进行 TSH、总甲状腺素（TT4）和总三碘甲状腺原氨酸（TT3）的分析。结果与之前使用类似方法收集的 15 名 24-53 岁（年轻人）的甲状腺功能正常男性的测试结果进行了比较。

结果

老年人/年轻人的个体间变异系数分别为 TSH 的 46.7%/44.0%、TT4 的 12.7%/19.5%和 TT3 的 14.6%/22.4%。个体内变异系数（CV）分别为 TSH 的 19.0%/25.4%、TT4 的 5.5%/10.8%和 TT3 的 6.9%/13.2%。在所有年龄组中，所有激素的个体指数均低于 0.6。在老年人中，要以 10%的精度确定体内平衡设定点，需要 14-21 个 TSH 样本和 2 个 TT4 和 TT3 样本。只有老年人的 TT4 是个体之间具有可比 CV 的唯一参数（p = .22）。