Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) was formerly known as Nonalcoholic fatty liver disease (NAFLD). MASLD is the most common cause of chronic liver disease in the United States as well as worldwide, with an estimated prevalence ranging from 25% to 40%. Metabolic associated steatohepatitis (MASH) (formerly NASH) is the aggressive form of MASLD that can progress to cirrhosis, liver failure, and hepatocellular carcinoma. MASH is also associated with substantial economic burden, inflicting $103 billion of direct medical costs each year in the United States.
The development of MASLD and MASH is closely linked to obesity, which has reached epidemic proportions in the United States. MASLD is estimated to be present in up to 30% of the adult population (or 75 million adults) and MASH in around 5% (or 15 million adults) in the United States alone. MASH is now the leading cause in liver transplantation in females in the United States and is expected to become the leading cause in males as well in the near future. In Europe, the prevalence of MASLD is between 26–33% in the general population and that of MASH is around 5%.
Current treatment of MASH is limited to lifestyle interventions (e.g., diet, exercise, and/or behavioral change), control of diabetes and/or other metabolic disturbances, and vitamin E or pioglitazone. Significant weight loss has been shown to reduce the symptoms of and/or resolve MASH, but is difficult to maintain for many individuals. Several pharmacological treatments that could potentially reduce the rising burden of MASH are in development.
This work is supported by the American Association for the Study of Liver Diseases Innovation Fund