DataSheet_1_Effect of Thyroid-Stimulating Hormone Suppression on Muscle Function After Total Thyroidectomy in Patients With Thyroid Cancer.docx

ContextThyroid-stimulating hormone (TSH) suppression is recommended to reduce tumor recurrence following surgery for differentiated thyroid cancer (DTC). However, prolonged subclinical hyperthyroidism caused by levothyroxine treatment has deleterious effects on various organs.
ObjectiveTo evaluate the relationships of TSH concentration with muscle mass, muscle strength, and physical performance related to sarcopenia in patients with DTC undergoing TSH suppression following surgery.
MethodsWe studied 134 patients of >60 years who were undergoing TSH suppression therapy following surgery for DTC. We evaluated muscle mass and muscle function-related parameters and diagnosed sarcopenia using the threshold for Asian people.
ResultsThe participants were 68.3 ± 7.2 years old and 36/134 (26.9%) were diagnosed with sarcopenia. They were allocated to high-TSH and low-TSH groups using a threshold concentration of 0.40 μU/mL, and grip strength was significantly lower in the low-TSH group. The data were further analyzed according to age and sex, and in the low-TSH group, male participants and those of <70 years were found to have significantly lower grip strength.
ConclusionsLow-TSH concentrations is associated with low grip strength, and this is most pronounced in individuals of <70 years of age. Therefore, muscle function should be considered an adverse effect of TSH suppression in patients with DTC who undergo TSH suppression therapy, especially in men of <70 years.

【背景】促甲状腺激素（thyroid-stimulating hormone, TSH）抑制治疗被推荐用于降低分化型甲状腺癌（differentiated thyroid cancer, DTC）患者术后的肿瘤复发风险。然而，左甲状腺素（levothyroxine）治疗引发的长期亚临床甲状腺功能亢进症会对多个脏器产生不良影响。
【研究目的】评估接受术后TSH抑制治疗的分化型甲状腺癌患者中，TSH浓度与肌少症（sarcopenia）相关的肌肉量、肌肉力量及身体活动能力之间的关联。
【研究方法】本研究纳入134名年龄超过60岁、接受分化型甲状腺癌术后TSH抑制治疗的患者。我们检测了肌肉量及肌肉功能相关参数，并采用亚洲人群诊断阈值确诊肌少症。
【研究结果】受试者平均年龄为68.3±7.2岁，其中36例（26.9%）被确诊为肌少症。以0.40 μU/mL为界值，将受试者分为高TSH组与低TSH组，低TSH组的握力（grip strength）显著更低。进一步按年龄与性别分层分析后发现，低TSH组中的男性受试者及年龄低于70岁的患者握力显著更低。
【研究结论】低TSH浓度与握力降低相关，这一关联在年龄低于70岁的人群中最为显著。因此，对于接受TSH抑制治疗的分化型甲状腺癌患者而言，肌肉功能受损应被视为TSH抑制治疗的不良反应之一，尤其针对年龄低于70岁的男性患者。