Dual-etiology MAFLD: the interactions between viral hepatitis B, viral hepatitis C, alcohol, and MAFLD

Metabolic dysfunction-associated fatty liver disease (MAFLD) and viral hepatitis due to chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection are common liver diseases worldwide. Excessive alcohol consumption and alcoholic liver disease (ALD) are also emerging health problems. Therefore, in clinical practice, we may encounter subjects with dual etiology of liver diseases such as coexisting MAFLD/HBV, MAFLD/HCV, and MAFLD/ALD. In this review, we summarize the epidemiology, clinical features, and mutual interactions of MAFLD with coexisting HBV, HCV, or ALD. The impact of MAFLD on the progression of liver diseases and treatment outcomes in patients with chronic viral hepatitis and the clinical questions to be addressed regarding dual MAFLD and ALD are also discussed.