Programa de Pós-Graduação em Endocrinologia, Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Rua Ramiro Barcelos, 2400, 2° andar, Porto Alegre, RS, 90035-003, Brazil.
Programa de Pós-Graduação em Cardiologia, Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Rua Ramiro Barcelos, 2400, 2° andar, Porto Alegre, RS, 90035-003, Brazil.
Endocrine. 2018 Jan;59(1):66-71. doi: 10.1007/s12020-017-1462-7. Epub 2017 Oct 27.
Non-randomized trials suggest that metformin may reduce TSH levels through unknown mechanisms.
To evaluate whether metformin can reduce TSH levels in subjects with subclinical hypothyroidism.
This is a randomized, double-blind, placebo controlled clinical trial with 3 months duration that enrolled 48 individuals, between 18 and 65 years, with subclinical hypothyroidism. The patients were randomized to the use of metformin 850 mg or placebo twice a day for 3 months. The primary outcome was the absolute decrease in TSH levels. Secondary outcomes were changes in the clinical and laboratory assessment, as well as in blood pressure assessed by ambulatory blood pressure monitoring.
After 3 months, 93.75% of participants completed the follow-up. The post treatment value of TSH in the metformin and placebo groups were 6.48 ± 3.11 and 7.02 ± 3.28 mIU/L, respectively (p = 0.57). Patients who achieved status of euthyroidism in the metformin and placebo groups were 21.7 and 18.2%, respectively (p = 0.76). There was no significant reduction of TSH within the groups [delta for TSH of 0.63 ± 0.56 (p = 0.28) and 0.54 ± 0.60 mIU/L (p = 0.38), in metformin and placebo groups, respectively]. There was a small increase in HDL cholesterol (1.62 ± 0.45 vs. 1.34 ± 0.39 mmol/L, p = 0.03) favoring the metformin group.
Since the sample size was small, the study was inconclusive and the results should be considered preliminary data of a study that needs to enroll 1626 patients to show a 0.5 mIU/L difference in TSH between the groups, with 90% power.
非随机试验表明，二甲双胍可能通过未知机制降低 TSH 水平。
评估二甲双胍是否可以降低亚临床甲状腺功能减退患者的 TSH 水平。
这是一项为期 3 个月的随机、双盲、安慰剂对照临床试验，共纳入 48 名年龄在 18 至 65 岁之间的亚临床甲状腺功能减退患者。患者被随机分为每天两次服用二甲双胍 850mg 或安慰剂，持续 3 个月。主要结局是 TSH 水平的绝对下降。次要结局是临床和实验室评估的变化，以及通过动态血压监测评估的血压变化。
3 个月后，93.75%的参与者完成了随访。在二甲双胍和安慰剂组中，治疗后的 TSH 值分别为 6.48±3.11 和 7.02±3.28mIU/L（p=0.57）。在二甲双胍和安慰剂组中，达到甲状腺功能正常状态的患者分别为 21.7%和 18.2%（p=0.76）。两组 TSH 均无显著降低[TSH 差值分别为 0.63±0.56（p=0.28）和 0.54±0.60mIU/L（p=0.38）]。HDL 胆固醇略有升高（1.62±0.45 与 1.34±0.39mmol/L，p=0.03），二甲双胍组更明显。
由于样本量较小，该研究尚无定论，结果应被视为一项需要纳入 1626 名患者的研究的初步数据，该研究需要 90%的效力才能显示两组之间 TSH 差异为 0.5mIU/L。
