胰島素阻抗是代謝症候群、第2型糖尿病（T2DM）、與非酒精性肝炎（NAFLD）／代謝相關脂肪肝病（MAFLD）共同的致病機轉。胰島素阻抗增加，會造成幾個代謝異常的現象群集在一起，被稱為代謝症候群。根據NCEP-ATPIII的標準，以下5個異常只要符合3個或3個以上，即可診斷為代謝症候群：（1）腹部肥胖；（2）血壓偏高或使用降血壓藥物；（3）空腹血糖偏高或使用降血糖藥物；（4）空腹三酸甘油脂偏高或使用降三酸甘油脂藥物；（5）高密度脂蛋白膽固醇偏低。另一方面，胰島素阻抗造成的肝臟脂肪堆積，也成為MAFLD患者代謝功能障礙的關鍵因素。MAFLD逐漸被視為代謝症候群的病理風險因子，因其與肝臟和全身的胰島素阻抗密切相關。本文將針對代謝症候群、T2DM、與MAFLD的共同致病機轉，與相互的關聯性做深入的探討。並希望透過這些機制的了解，能制定更有效的預防和治療策略。

Insulin resistance is a common pathogenic mechanism shared among metabolic syndrome, type 2 diabetes (T2DM), and metabolic-associated fatty liver disease (MAFLD). Increased insulin resistance leads to a clustering of several metabolic abnormalities, known as metabolic syndrome. According to the NCEP-ATPIII criteria, diagnosis of metabolic syndrome requires the presence of three or more of the following five abnormalities: (1) abdominal obesity; (2) elevated blood pressure or use of anti-hypertensive medications; (3) elevated fasting blood glucose or use of glucose-lowering medications; (4) elevated fasting triglycerides or use of anti-hypertriglyceridemic medications; (5) low high-density lipoprotein cholesterol. On the other hand, insulin resistance-induced hepatic fat accumulation also becomes a key factor in the metabolic dysfunction of patients with MAFLD. MAFLD is increasingly recognized as a pathological risk factor for metabolic syndrome due to its close association with hepatic and systemic insulin resistance. This article will delve into the shared pathogenic mechanisms of metabolic syndrome, T2DM, and MAFLD, and their interrelationships. It is hoped that through understanding these mechanisms, more effective prevention and treatment strategies can be developed.