[Fatty liver disease's renaming impacts on drug clinical trials]

Fatty liver disease has undergone a major name change, with metabolic dysfunction-associated fatty liver disease (MASLD) replacing nonalcoholic fatty liver disease. The definition of MASLD no longer requires the exclusion of other co-existing liver diseases but instead associates hepatic steatosis with overweight/obesity, type 2 diabetes mellitus, or metabolic disorders and clearly defines the amount of alcohol consumption. The new definition also introduces the concepts of metabolic-related alcoholic liver disease and cryptogenic fatty liver disease. These changes will bring new challenges and opportunities for the design of clinical trials of fatty liver disease drugs and the selection of target populations.

[Effect of the nomenclature of non-alcoholic fatty liver disease on diagnosis and treatment of fatty liver disease concomitant with other liver diseases]

Fatty liver disease (FLD) is one of the major causes of chronic liver disease worldwide. With the increasing incidence of obesity and metabolic syndrome worldwide, FLD concomitant with other liver diseases is becoming more common, and multiple etiological overlap is associated with poor disease prognosis. Therefore, FLD concomitant with other liver diseases is a clinical concerning issue. Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease continuum from non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH), and relative end stage liver disease, excluding other factors that may lead to fatty liver disease such as excessive alcohol consumption et. al. Following the nomenclature of NAFLD with metabolic associated fatty liver disease (MAFLD), an international panel of experts proposed a new name in June 2023 as Metabolic dysfunction - associated steatotic liver disease (MASLD), replacing the word "fatty" with "steatotic," The effect of lipid toxicity on FLD progression was highlighted. Compared with the concept of MAFLD, the disease spectrum of MASLD is broader, and the etiology and mechanism are more clear. The nomenclature of FLD brings some influence to the diagnosis and treatment of chronic liver diseases concomitant with FLD, including chronic hepatitis B, alcoholic fatty liver disease and genetic metabolic diseases. This article reviews the influence of renaming FLD on the diagnosis and treatment of FLD concomitant with other etiologies caused liver diseases.