Table1_Efficacy and safety of metformin for melasma treatment: a systematic review and meta-analysis.pdf

Objective: Metformin has recently been demonstrated to have an anti-melanogenic activity. Nevertheless, clinical evidence of the effectiveness of metformin in melasma is lacking. The objective of this study was to assess the efficacy and safety of metformin in the treatment of melasma.Methods: MEDLINE, Embase, PubMed, Cochrane Library (CENTRAL), Scopus, CINAHL, and grey literature databases were searched to 4 October 2022 and updated on 26 February 2023. Randomized controlled trials (RCTs), quasi-RCTs, observational studies, case series, and case reports investigating the efficacy and safety of metformin for melasma were included. The Melasma Area Severity Index (MASI) scores that changed from baseline were pooled using fixed-effects model and expressed as standardized mean differences (SMDs) and 95% confidence intervals (CIs).Results: Three RCTs including 140 patients with melasma were included. The results demonstrated that after 8 weeks, 15% topical metformin significantly reduced the Melasma Area Severity Index (MASI) score compared to placebo (1 trial; n = 60; MD, −0.56; 95% CI, −1.07 to −0.04; p = 0.034). Furthermore, when compared to triple combination cream (TCC), 30% topical metformin demonstrated similar efficacy in reducing the MASI score after 8 weeks (2 trials; n = 80; MD, 0.19, 95% CI, −0.25 to 0.63; p = 0.390). Patients using 30% topical metformin had fewer adverse events compared to TCC users, although no statistical difference was found.Conclusion: Topical metformin was as effective as triple combination cream (TCC) in decreasing changes in the MASI score in patients with melasma, with minimum adverse events. Further studies with larger sample sizes, longer follow-up times, and well-designed trials are required.Systematic Review Registration: Identifier PROSPERO (CRD42022351966).

研究目的：近期研究表明二甲双胍具有抗黑色素生成活性。然而，关于二甲双胍在治疗黄褐斑中的临床有效性的证据尚显不足。本研究的目的是评估二甲双胍在治疗黄褐斑中的疗效与安全性。研究方法：截至2022年10月4日，检索了MEDLINE、Embase、PubMed、Cochrane图书馆（CENTRAL）、Scopus、CINAHL和灰色文献数据库，并在2023年2月26日进行了更新。纳入了随机对照试验（RCTs）、准随机对照试验、观察性研究、病例系列和病例报告，这些研究调查了二甲双胍在治疗黄褐斑中的疗效与安全性。使用固定效应模型对基线时变化的黄褐斑面积严重指数（MASI）评分进行汇总，并以标准化平均差异（SMDs）和95%置信区间（CIs）表示。研究结果：纳入了3项RCTs，共包含140名黄褐斑患者。结果表明，在8周后，与安慰剂相比，15%局部二甲双胍显著降低了黄褐斑面积严重指数（MASI）评分（1项试验；n = 60；MD，−0.56；95% CI，−1.07至−0.04；p = 0.034）。此外，与三联组合霜（TCC）相比，30%局部二甲双胍在8周后显示出相似的降低MASI评分的疗效（2项试验；n = 80；MD，0.19，95% CI，−0.25至0.63；p = 0.390）。使用30%局部二甲双胍的患者相比TCC使用者发生的不良事件较少，尽管没有发现统计学差异。结论：局部二甲双胍在降低黄褐斑患者MASI评分变化方面与三联组合霜（TCC）同样有效，且不良事件发生率较低。需要进一步进行更大样本量、更长时间随访和设计良好的试验。系统评价注册：标识符PROSPERO（CRD42022351966）。