Department of Public Health, Faculty of Medicine, Mutah University, Karak, Jordan.
Department of Public Health, Faculty of Medicine, Alfaisal University, Riyadh, KSA.
Endocr Regul. 2021 Dec 7;55(4):204-214. doi: 10.2478/enr-2021-0022.
Given the high prevalence of subclinical hypothyroidism (SCH), defined as high thyroid stimulating hormone (TSH) and normal free thyroxine (FT4), and uncertainty on treatment, one of the major challenges in clinical practice is whether to initiate the treatment for SCH or to keep the patients under surveillance. There is no published study that has identified predictors of short-term changes in thyroid status amongst patients with mild elevation of TSH (4.5-10 mIU/L). A cohort study was conducted on patients with SCH detected through a general population screening program, who were followed for six months. This project identified factors predicting progression to hypothyroid status, persistent SCH and transient cases. A total of 656 participants joined the study (431 controls and 225 were patients with SCH). A part of participants (12.2%) developed biochemical hypothyroidism during the follow-up, while 73.8% of the subjects became euthyroid and the remained ones (13.4%) stayed in the SCH status. The incidence of overt hypothyroidism for participants with TSH above 6.9 mIU/L was 36.7%, with incidence of 42.3% for females. Anti-thyroid peroxidase antibodies (TPO) positivity is an important predictor of development of hypothyroidism; however, it could be also positive due to transient thyroiditis. It can be concluded that females with TSH above 6.9 mIU/L, particularly those with free triiodothyronine (FT3) and FT4 in the lower half of the reference range, are more likely to develop biochemical hypothyroidism. Therefore, it is recommended to give them a trial of levothyroxine replacement. It is also recommended to repeat TSH after six months for male subjects and participants with baseline TSH equal or less than 6.9 mIU/L.
鉴于亚临床甲状腺功能减退症（SCH）的高患病率，定义为高促甲状腺激素（TSH）和正常游离甲状腺素（FT4），以及治疗的不确定性，临床实践中的主要挑战之一是是否开始治疗 SCH 或继续对患者进行监测。目前还没有发表的研究确定了 TSH 轻度升高（4.5-10 mIU/L）患者中甲状腺状态短期变化的预测因素。 一项队列研究对通过一般人群筛查计划发现的 SCH 患者进行了研究，这些患者随访了六个月。该项目确定了预测向甲状腺功能减退状态、持续 SCH 和短暂病例进展的因素。共有 656 名参与者参加了这项研究（431 名对照组和 225 名 SCH 患者）。在随访过程中，有一部分参与者（12.2%）发生了生化性甲状腺功能减退，而 73.8%的受试者成为甲状腺功能正常，其余（13.4%）仍处于 SCH 状态。TSH 高于 6.9 mIU/L 的参与者中，显性甲状腺功能减退的发生率为 36.7%，女性的发生率为 42.3%。抗甲状腺过氧化物酶抗体（TPO）阳性是甲状腺功能减退发展的重要预测因素；然而，由于短暂性甲状腺炎，它也可能呈阳性。 可以得出结论，TSH 高于 6.9 mIU/L 的女性，特别是游离三碘甲状腺原氨酸（FT3）和 FT4 在参考范围下半部分的女性，更有可能发生生化性甲状腺功能减退。因此，建议给予他们左甲状腺素替代治疗的尝试。也建议男性和基线 TSH 等于或低于 6.9 mIU/L 的参与者在六个月后重复检测 TSH。
