甲状腺素及甲状腺内注射地塞米松治疗伴亚临床甲减的桥本甲状腺炎

目的:口服左旋甲状腺素钠(LT4)联合甲状腺内注射地塞米松磷酸钠治疗伴亚临床甲减(SCH)的桥本甲状腺炎(HT).方法:294例伴SCH的HT患者随机分为2组(n=147):(1)左旋甲状腺素钠组(LT组):口服LT4维持血清游离甲状腺素(FT4)和促甲状腺激素(STSH)在正常参考值范围共20周;(2)地塞米松组(DX组):除同LT组处理外,甲状腺内注射地塞米松磷酸钠注射液(5 mg,每周1次×8次,以后每2周1次×4次,共12次).2组于治疗前及治疗后第6、12、18及24个月随访,检查症状、甲状腺肿、FT4、游离三碘甲状腺原氨酸(FT3)、STSH、抗甲状腺球蛋白抗体(TGAb)、抗甲状腺过氧化物酶抗体(TPOAb)、皮质醇、促肾上腺皮质激素(ACTH),以出现临床甲减(OVH)作为研究终点.结果:LT组147例中,3例(2%)退出,垂体甲状腺轴功能38例(26%)转为正常,9例(6.25%)转为OVH,97例仍为SCH;DX组147例中2例(1.4%)退出,68例(47%)转为正常,2例(1.38%)转为OVH,75例仍为SCH.HT患者由SCH进展为OVH,DX组相对危险度减少78%,绝对危险度减少为4.87%,防止1例OVH需治疗人数为21;HT患者由SCH逆转为正常垂体甲状腺轴功能,DX组相对获益增加率为81%,绝对获益增加率为21%,逆转1例SCH需治疗人数为5.DX组在缩小甲状腺肿、降低甲状腺自身抗体滴度及改善颈部外观及压迫症状等方面均优于LT组(P＜0.05).结论:口服LT4联合甲状腺内注射地塞米松磷酸钠预防HT患者由SCH进展为OVH及逆转为正常垂体甲状腺轴功能明显优于单用LT4.

Effect of oral levothyroxine plus intrathyroidal injection of dexamethasone on conversion of subclinical hypothyroidism caused by Hashimoto thyroiditis

Objective: To evaluate the effect of oral levothyroxine plus intrathyroidal injection of dexamethasone on conversion of subclinical hypothyroidism caused by Hashimoto thyroiditis. Methods: In a 2-year prospective study,294 subjects with Hashimoto thyroiditis were randomly divided into 2 groups. Subjects in levothyroxine group(147 cases) were treated with oral levothyroxine sodium for 20 weeks to maintain normal levels of free T 4,free T 3 and sensitive TSH in serum. Subjects in dexamethasone group (147 cases) were treated with oral levothyroxine plus intrathyroidal injection of dexamethasone (5 mg,once per week for 8 weeks and then once every 2 weeks for another 8 weeks). Serum FT 3,FT 4,STSH and other parameters were evaluated every 6 months for 2 years. Primary end point was the time of overt hypothyroidism onset. Results: Of 147 levothyroxine-treated patients, 98% completed treatment,compared with 99% in levothyroxine plus dexamethasone injected recipients. At the end of the study, the cumulative incidence of overt hypothyroidism was 6.25% with levothyroxine and 1.38% with levothyroxine plus dexamethasone, corresponding to a relative risk reduction of 78% and the number needed to treat of 21. The cumulative incidence with conversion to normal pituitary-thyroid function was 26% in levothyroxine group and 47% in levothyroxine plus dexamethasone group,corresponding to a relative benefit increase of 81% and the number needed to treat of 5. Levothyroxine plus dexamethasone therapy proved more effective in shrinking goiter and improving pressure symptom and cosmetic symptom on neck and reducing titres of thyroid autoantibodies in serum. No major side effects occurred in both groups. Conclusion: Levothyroxine plus dexamethasone therapy greatly reduces the incidence of overt hypothyroidism,which may be associated with levothyroxine replacement therapy caused thyroid follicle cell rest and dexamethasone therapy caused autoimmunity.