橋本氏甲狀腺炎是一種常見疾病，其特徵是甲狀腺慢性發炎導致甲狀腺功能減退。這是一種自體免疫疾病，意味著人體自身的免疫系統會攻擊甲狀腺，導致甲狀腺無法產生足夠的甲狀腺激素（甲狀腺功能低下）。常見臨床表現包括怕冷、情緒低落、皮膚乾燥、眼睛浮腫、便秘、體重增加、心率減慢、關節和肌肉疼痛以及疲勞。有些 (並非全部) 患有橋本事甲狀腺炎的人甲狀腺會腫大，也稱作 甲狀腺腫 。橋本氏甲狀腺炎在女性中更常見，並且往往有家族遺傳傾向。也常常同時發生其他自體免疫疾病，例如白斑症、類風濕性關節炎和第 1 型糖尿病。這種疾病並非總是需要治療，但如果需要治療，則採用合成甲狀腺激素替代療法（有時會使用乾燥的甲狀腺激素，這種激素並非合成的）。硒是一種必需的微量元素，少量硒對於免疫系統和甲狀腺的正常運作至關重要。
本研究納入了 4 項存在不明確或高度偏差風險的研究，共涉及 463 名參與者。平均研究期間為 7.5 個月（範圍 3 至 18 個月）。所有研究均未涉及我們的主要結果—「與健康相關的生活品質」。我們的兩項次要結果──「研究結束時左旋甲狀腺素（即甲狀腺荷爾蒙） 替代劑量相較基線的變化」以及「經濟成本」──也未被評估。一篇有高偏差風險的研究顯示，與安慰劑加甲狀腺素相比，亞硒酸鈉 200 μg 加甲狀腺素可顯著改善主觀幸福感（分別為 14/18 和 3/18）。三項研究表明，硒甲硫氨酸 200 μg 可降低血清中抗甲狀腺過氧化物酶抗體的水平，雖然與基線相比的變化具有統計學意義，但其臨床意義尚不清楚。兩項研究報告了不良事件，硒補充劑並未導致比安慰劑更多的不良事件。在兩項研究中，硒甲硫氨酸 200 μg 加甲狀腺素組均報告了一例不良事件。而對照組則沒有。
總之，這四項研究的結果不足以提供足夠的證據支持使用硒治療橋本氏甲狀腺炎。
閱讀完整摘要
Hashimoto's thyroiditis is a common auto-immune disorder. The most common presenting symptoms may include anxiety, negative mood, depression, dry skin, cold intolerance, puffy eyes, muscle cramps and fatigue, deep voice, constipation, slow thinking and poor memory. Clinical manifestations of the disease are defined primarily by low levels of thyroid hormones; therefore it is treated by hormone replacement therapy, which usually consists of levothyroxine (LT 4 ). Selenium might reduce antibody levels and result in a decreased dosage of LT 4 and may provide other beneficial effects (e.g. on mood and health-related quality of life).
目的
To assess the effects of selenium supplementation on Hashimoto's thyroiditis.
搜尋策略
We searched the following databases up to 2 October 2012: CENTRAL in The Cochrane Library (2012, Issue 10), MEDLINE, EMBASE, and Web of Science; we also screened reference lists of included studies and searched several online trial registries for ongoing trials (5 November 2012).
選擇標準
Randomised controlled clinical trials that assessed the effects of selenium supplementation for adults diagnosed with Hashimoto's thyroiditis.
資料收集與分析
Study selection, data extraction, assessment of risk of bias, and analyses were carried out by two independent review authors. We assessed the quality of the evidence of included studies using GRADE. We were unable to conduct a meta-analysis because clinical heterogeneity between interventions that were investigated is substantial.
主要結果
Four studies at unclear to high risk of bias comprising 463 participants were included. The mean study duration was 7.5 months (range 3 to 18 months). One of our primary outcomes－'change from baseline in health related quality of life'－and two of our secondary outcomes－'change from baseline in LT 4 replacement dosage at end of the study' and 'economic costs'－were not assessed in any of the studies. One study at high risk of bias showed statistically significant improvement in subjective well-being with sodium selenite 200 μg plus titrated LT 4 compared with placebo plus titrated LT 4 (relative risk (RR) 4.67, 95% confidence interval (CI) 1.61 to 13.50; P = 0.004; 36 participants; number needed to treat (NNT) = 2 (95% CI 2 to 3)).
Selenomethionine 200 μg reduced the serum levels of anti-thyroid peroxidase antibodies compared with placebo in two studies (mean difference (MD) -917 U/mL, 95% CI -1056 to -778; P < 0.001; 85 participants) and (MD -345 IU/mL, 95% CI -359 to -331; P < 0.001; 169 participants). Pooling of the studies was not feasible due to marked clinical heterogeneity (I 2 = 99%). In a further comparison within the first study where selenomethionine was combined with LT 4 the reduction in TPO antibodies was even more noticeable (MD -1508 U/mL, 95% CI -1671 to -1345; P < 0.001; 86 participants). In a third study, where LT 4 was added to both intervention arms, a reduction in serum levels of anti-thyroid peroxidase antibodies favoured the selenomethionine arm as well (MD -235 IU/mL, 95% CI -374 to -95; P = 0.001; 88 participants). Although the changes from baseline were statistically significant in these three studies, their clinical relevance is unclear. Serum antibodies were not statistically significantly affected in the study comparing sodium selenite 200 μg plus titrated LT 4 with placebo plus titrated LT 4 (MD -25, 95% CI -181 to 131; P = 0.75; 36 participants).
Adverse events were reported in two studies (1 of 85 and 1 of 88 participants, respectively). Selenium supplementation did not appear to have a statistically significant impact on the incidence of adverse events (RR 2.93, 95% CI 0.12 to 70.00; and RR 2.63, 95% CI 0.11 to 62.95).
作者結論
Results of these four studies show that evidence to support or refute the efficacy of selenium supplementation in people with Hashimoto's thyroiditis is incomplete. The current level of evidence for the efficacy of selenium supplementation in the management of people with Hashimoto's thyroiditis is based on four randomised controlled trials assessed at unclear to high risk of bias; this does not at present allow confident decision making about the use of selenium supplementation for Hashimoto's thyroiditis. This review highlights the need for randomised placebo-controlled trials to evaluate the effects of selenium in people with Hashimoto's thyroiditis and can ultimately provide reliable evidence to help inform clinical decision making.
翻譯者: 曾雅聘 (弘興藥局，藥師)【本翻譯計畫由臺北醫學大學考科藍臺灣研究中心(Cochrane Taiwan)及東亞考科藍聯盟(EACA)統籌執行。聯絡E-mail：cochranetaiwan@tmu.edu.tw】
本篇考科藍文獻回顧最初是以英文撰寫。翻譯的準確性由翻譯團隊負責。翻譯內容經過謹慎處理，並遵循標準流程以確保品質。若與原文不符、翻譯不準確或不恰當之處，皆以英文原文為準。
