A multi-society Delphi consensus statement on new fatty liver disease nomenclature.

UNLABELLED: The principal limitations of the terms nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are the reliance on exclusionary confounder terms and the use of potentially stigmatising language. This study set out to determine if content experts and patient advocates were in favour of a change in nomenclature and/or definition.

METHODS: A modified Delphi process was led by three large pan-national liver associations. Consensus was defined a priori as a supermajority (67%) vote. An independent committee of experts external to the nomenclature process made the final recommendation on the acronym and its diagnostic criteria.

RESULTS: A total of 236 panellists from 56 countries participated in four online surveys and two hybrid meetings. Response rates across the 4 survey rounds were 87%, 83%, 83% and 78%, respectively. 74% of respondents felt that the current nomenclature was sufficiently flawed to consider a name change. The terms 'non-alcoholic' and 'fatty' were felt to be stigmatising by 61% and 66% of respondents, respectively. Steatotic liver disease (SLD) was chosen as an overarching term to encompass the various aetiologies of steatosis. The term steatohepatitis was felt to be an important pathophysiological concept that should be retained. The name chosen to replace NAFLD was metabolic dysfunction-associated steatotic liver disease (MASLD). There was consensus to change the definition to include the presence of at least one of five cardiometabolic risk factors. Those with no metabolic parameters and no known cause were deemed to have cryptogenic SLD. A new category, outside pure MASLD, termed MetALD was selected to describe those with MASLD who consume greater amounts of alcohol per week (140 to 350 g/week and 210 to 420 g/week for females and males respectively).

CONCLUSIONS: The new nomenclature and diagnostic criteria are widely supported, non-stigmatising and can improve awareness and patient identification.