Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a maternally inherited multisystemic disorder caused by mutations in mitochondrial DNA that result in cellular energy deficiency. MELAS affects the most metabolically active organs, including the brain, skeletal muscles, cochlea, retina, heart, kidneys, and pancreas. As a result, about 85% of carriers of m.3243A > G, the most common mutation in MELAS, develop diabetes by the age of 70. Although metformin is the most widely prescribed drug for diabetes, its usefulness in mitochondrial dysfunction remains controversial. Here, we present the case of a 32-year-old Korean patient diagnosed with MELAS who presented with exacerbated stroke-like episodes and lactic acidosis triggered by metformin.

线粒体肌病、脑病、乳酸性酸中毒和中风样发作 (MELAS) 是一种母系遗传的多系统疾病，由线粒体 DNA 突变导致细胞能量缺乏引起。 MELAS 影响代谢最活跃的器官，包括大脑、骨骼肌、耳蜗、视网膜、心脏、肾脏和胰腺。因此，大约 85% 的 m.3243A > G（MELAS 中最常见的突变）携带者在 70 岁时患上糖尿病。尽管二甲双胍是治疗糖尿病最广泛使用的药物，但其在线粒体功能障碍中的作用仍存在争议。在此，我们介绍一名被诊断患有 MELAS 的 32 岁韩国患者的病例，该患者出现中风样发作加剧和二甲双胍引发的乳酸性酸中毒。