Division of Endocrinology, Diabetes and Clinical Nutrition, Oregon Health & Science University, Portland, Oregon.
Penn State Health St. Joseph, Family and Community Medicine Residency Program, Reading, Pennsylvania.
J Clin Endocrinol Metab. 2018 May 1;103(5):1997-2008. doi: 10.1210/jc.2017-02668.
The brain is a critical target organ for thyroid hormone, but it is unclear whether variations in thyroid function within and near the reference range affect quality of life, mood, or cognition.
A total of 138 subjects with levothyroxine (L-T4)-treated hypothyroidism and normal thyrotropin (TSH) levels underwent measures of quality of life (36-Item Short Form Health Survey, Underactive Thyroid-Dependent Quality of Life Questionnaire), mood (Profile of Mood States, Affective Lability Scale), and cognition (executive function, memory). They were then randomly assigned to receive an unchanged, higher, or lower L-T4 dose in double-blind fashion, targeting one of three TSH ranges (0.34 to 2.50, 2.51 to 5.60, or 5.61 to 12.0 mU/L). Doses were adjusted every 6 weeks based on TSH levels. Baseline measures were reassessed at 6 months.
At the end of the study, by intention to treat, mean L-T4 doses were 1.50 ± 0.07, 1.32 ± 0.07, and 0.78 ± 0.08 μg/kg (P < 0.001), and mean TSH levels were 1.85 ± 0.25, 3.93 ± 0.38, and 9.49 ± 0.80 mU/L (P < 0.001), respectively, in the three arms. There were minor differences in a few outcomes between the three arms, which were no longer significant after correction for multiple comparisons. Subjects could not ascertain how their L-T4 doses had been adjusted (P = 0.55) but preferred L-T4 doses they perceived to be higher (P < 0.001).
Altering L-T4 doses in hypothyroid subjects to vary TSH levels in and near the reference range does not affect quality of life, mood, or cognition. L-T4-treated subjects prefer perceived higher L-T4 doses despite a lack of objective benefit. Adjusting L-T4 doses in hypothyroid patients based on symptoms in these areas may not result in significant clinical improvement.
大脑是甲状腺激素的关键靶器官，但甲状腺功能在参考范围内及其附近的变化是否会影响生活质量、情绪或认知尚不清楚。
共有 138 名接受左甲状腺素（L-T4）治疗的甲状腺功能减退症患者和正常促甲状腺激素（TSH）水平的患者接受了生活质量（36 项简明健康调查，甲状腺功能减退症相关生活质量问卷）、情绪（心境状态问卷，情绪不稳定性量表）和认知（执行功能，记忆）的测量。然后，他们以双盲的方式随机分配接受不变、更高或更低剂量的 L-T4，目标是三个 TSH 范围之一（0.34 至 2.50、2.51 至 5.60 或 5.61 至 12.0 mU/L）。根据 TSH 水平，每 6 周调整一次剂量。在 6 个月时重新评估基线测量值。
在研究结束时，按意向治疗分析，平均 L-T4 剂量分别为 1.50±0.07、1.32±0.07 和 0.78±0.08μg/kg（P<0.001），平均 TSH 水平分别为 1.85±0.25、3.93±0.38 和 9.49±0.80mU/L（P<0.001），分别在三个臂中。三个臂之间的一些结果存在较小差异，但经多次比较校正后，差异不再显著。患者无法确定他们的 L-T4 剂量是如何调整的（P=0.55），但更喜欢他们认为更高的 L-T4 剂量（P<0.001）。
改变甲状腺功能减退症患者的 L-T4 剂量以改变参考范围内及附近的 TSH 水平不会影响生活质量、情绪或认知。尽管缺乏客观获益，接受 L-T4 治疗的患者更喜欢他们认为更高的 L-T4 剂量。基于这些领域的症状调整甲状腺功能减退症患者的 L-T4 剂量可能不会导致显著的临床改善。
