From nonalcoholic fatty liver disease to metabolic-associated fatty liver disease: Big wave or ripple?

There is some dissatisfaction with the term nonalcoholic fatty liver disease (NAFLD), which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended "metabolic (dysfunction)-associated fatty liver disease (MAFLD)" as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD, without metabolic abnormality who have been included in NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD who were excluded from MAFLD criteria are missed from the diagnosis and their potential risk can be the cause of future disease. Although huge controversies remain, this review focuses on summarizing recent studies comparing the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.