Praw Stephanie Smooke, Brent Gregory A
Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
Department of Medicine, VA Greater Los Angeles Healthcare System, Los Angeles, California 90073, USA.
J Clin Endocrinol Metab. 2023 Jan 17;108(2):472-482. doi: 10.1210/clinem/dgac635.
Subclinical hyperthyroidism (SCH) is a laboratory diagnosis defined by a serum thyrotropin (TSH) concentration below the reference range (< 0.4 mU/L in most assays), and a free thyroxine (FT4) and 3,5,3'-triiodothyronine levels (FT3) in the reference range. Many patients diagnosed with SCH will be clinically euthyroid while others may present with manifestations characteristic of thyroid hormone excess, such as tachycardia, tremor, intolerance to heat, bone density loss, or weight loss. In addition to the laboratory abnormalities, patient factors such as age, symptoms, and underlying heart and bone disease are used to stratify patients for the risk of adverse outcomes and determine the appropriate treatment. Evaluation should include repeat thyroid function tests to document persistent TSH suppression, investigation of the underlying cause, as well as evaluation of the patient's risk of adverse outcomes in the setting of a subnormal TSH. Persistent SCH has been associated with an increased risk of a range of adverse events, including cardiovascular events such as atrial fibrillation and heart failure, bone loss and fracture, and in some studies, cognitive decline. Despite the consistent association of these adverse events with SCH, prospective studies showing improved outcomes with treatment remain limited. Management options include observation without active therapy, radioactive iodine ablation of the thyroid, antithyroid medication, thyroid surgery, or radiofrequency ablation, as appropriate for the patient and clinical setting. The choice of therapy should be guided by the underlying etiology of disease, patient factors, and the risks and benefits of each treatment option.
亚临床甲状腺功能亢进症（SCH）是一种实验室诊断，定义为血清促甲状腺激素（TSH）浓度低于参考范围（大多数检测中<0.4 mU/L），而游离甲状腺素（FT4）和3,5,3'-三碘甲状腺原氨酸水平（FT3）在参考范围内。许多被诊断为SCH的患者临床上甲状腺功能正常，而其他患者可能会出现甲状腺激素过量的特征性表现，如心动过速、震颤、不耐热、骨密度降低或体重减轻。除了实验室异常外，还会根据年龄、症状以及潜在的心脏和骨骼疾病等患者因素，对患者进行分层，以评估不良结局的风险并确定合适的治疗方法。评估应包括重复甲状腺功能检查以记录持续的TSH抑制情况、调查潜在病因，以及评估患者在TSH低于正常水平时发生不良结局的风险。持续性SCH与一系列不良事件的风险增加有关，包括心血管事件，如心房颤动和心力衰竭、骨质流失和骨折，并且在一些研究中还与认知功能下降有关。尽管这些不良事件与SCH之间存在一致的关联，但显示治疗可改善结局的前瞻性研究仍然有限。管理选项包括根据患者和临床情况酌情选择不进行积极治疗的观察、甲状腺放射性碘消融、抗甲状腺药物、甲状腺手术或射频消融。治疗方法的选择应根据疾病的潜在病因、患者因素以及每种治疗选项的风险和益处来指导。
