代謝相關脂肪肝病（metabolic associated fatty liver disease, MAFLD）指代謝失能的脂肪肝，包含非酒精性脂肪肝病（nonalcoholic fatty liver disease, NAFLD）的大部分病人，為最常見的慢性肝病。2019年新型冠狀病毒感染症19（COVID-19）肆虐全球，衝擊健康。COVID-19病人常見肝指數異常。多個統合分析發現：MAFLD與NAFLD增加COVID-19重症風險，未明顯增加入住加護病房及死亡風險。MAFLD與COVID-19之間病情作用的可能機轉包括SARS-CoV-2病毒的直接細胞毒性、發炎反應、缺氧性傷害、藥物影響、腸道微菌叢失衡（gut dysbiosis）、脂質代謝物作用、COVID-19隔離政策等。MAFLD病人在COVID-19疫情期間，應依措施預防SARS-CoV-2感染。COVID-19病人，尤其住院者，應該評估他們有無MAFLD。偵測出高風險者，及早治療並在出院後密切追蹤。

MAFLD was defined as hepatic steatosis with overweight/obesity, type 2 diabetes mellitus, or evidence of metabolic dysregulation. MAFLD comprises most patients formerly diagnosed as NAFLD. MAFLD is the most common chronic liver disease worldwide. COVID-19 pandemic has impact on global health. Liver biochemistry abnormalities appear to be common in COVID-19 patients. Meta-analysis studies showed that MAFLD is associated with heavy COVID-19 but is not associated with ICU admission and mortality. The potential mechanisms for COVID-19 promoting MAFLD progression include direct cytotoxicity of virus, inflammatory response, hypoxic injury, drug-induced liver injury, gut dysbiosis, dysregulation of hepatic lipid metabolism and the quarantine policies of COVID-19. Patients with MAFLD should prevent infection of SARS-CoV-2. Patients with COVID-19, especially those admitted to the hospital, should be screened for the presence of MAFLD. Efforts should be made to detect patients at risk and do the proper treatment. Close follow-up is encouraged after discharge.