Department of Internal Medicine, Ito Hospital, Tokyo 150-8308, Japan.
Department of Surgery, Ito Hospital, Tokyo 150-8308, Japan.
Endocr J. 2020 Jun 29;67(6):631-638. doi: 10.1507/endocrj.EJ19-0379. Epub 2020 Mar 18.
The efficacy of potassium iodide (KI) for Graves' disease (GD) has been reported, although few clinical reports have examined the long-term efficacy of treatment. The objective of this study was to investigate the efficacy and limitations of KI treatment for GD. This study enrolled patients newly diagnosed with mild GD, defined as free thyroxine (FT4) <5.0 ng/dL, between July 2014 and June 2016. KI was started at a dose of 50 mg/day, and if FT4 values did not decrease after initiation of treatment, doses were increased to 100 mg/day. Patients for whom thyroid hormone levels could not be controlled with KI at 100 mg/day were regarded as non-responders. Of the 122 patients (13 males, 109 females) included in this study, 71 (58.2%) responded to KI therapy. The remaining 51 patients (41.8%) were non-responders. The median duration required to judge non-responsiveness was 5.9 months. Multiple logistic regression analysis performed on parameters measured at the initial visit indicated FT4 (odds ratio (OR) 2.19, 95% confidence interval (CI) 1.28-3.75; p = 0.0007) and male sex (OR 3.58, 95%CI 1.04-12.3; p = 0.04) were significantly associated with KI responsiveness. Receiver operating characteristic (ROC) curve analysis of the relationship between FT4 and KI responsiveness indicated an FT4 cut-off of 2.76 ng/dL was optimal for differentiating between responders and non-responders. KI therapy was effective and safe for about 60% of patients with mild GD.
碘化钾（KI）治疗格雷夫斯病（GD）的疗效已有报道，但很少有临床报告研究治疗的长期疗效。本研究旨在探讨 KI 治疗 GD 的疗效和局限性。本研究纳入了 2014 年 7 月至 2016 年 6 月期间新诊断为轻度 GD 的患者，游离甲状腺素（FT4）<5.0ng/dL。起始剂量为 50mg/天，如果治疗开始后 FT4 值没有下降，则增加至 100mg/天。对于 100mg/天的 KI 不能控制甲状腺激素水平的患者，认为是无应答者。本研究共纳入 122 例患者（男性 13 例，女性 109 例），71 例（58.2%）对 KI 治疗有反应。其余 51 例（41.8%）为无应答者。判断无应答所需的中位数时间为 5.9 个月。对初诊时测量的参数进行多因素逻辑回归分析，结果表明 FT4（比值比（OR）2.19，95%置信区间（CI）1.28-3.75；p=0.0007）和男性（OR 3.58，95%CI 1.04-12.3；p=0.04）与 KI 反应性显著相关。FT4 与 KI 反应性的关系的受试者工作特征（ROC）曲线分析表明，FT4 截断值为 2.76ng/dL 是区分应答者和无应答者的最佳值。KI 治疗对约 60%的轻度 GD 患者有效且安全。
