Nonalcoholic fatty liver disease will now be called metabolic dysfunction–associated steatotic liver disease, or MASLD, according to new nomenclature adopted by a global consensus panel composed mostly of hepatology researchers and clinicians.
The new nomenclature, published in the journal, includes the umbrella term steatotic liver disease, or SLD, which will cover MASLD and MetALD, a term describing people with MASLD who consume more than 140 grams of alcohol per week for women and 210 grams per week for men.
Metabolic dysfunction–associated steatohepatitis, or MASH, will replace the term nonalcoholic steatohepatitis, or NASH.
, of University of Chicago Medicine led the consensus group. The changes were needed, Dr. Rinella and her colleagues argued, because the terms “fatty liver disease” “and nonalcoholic” could be considered to confer stigma, and to better reflect the metabolic dysfunction occurring in the disease. Under the new nomenclature, people with MASLD must have a cardiometabolic risk factor, such as type 2 diabetes. People without metabolic parameters and no known cause will be classed as having cryptogenic SLD.
While the new nomenclature largely conserves existing disease definitions, it allows for alcohol consumption beyond current parameters for nonalcoholic forms of the disease. “There are individuals with risk factors for NAFLD, such as type 2 diabetes, who consume more alcohol than the relatively strict thresholds used to define the nonalcoholic nature of the disease [and] are excluded from trials and consideration for treatments,” the authors wrote.
Moreover, they wrote, “within MetALD there is a continuum where conceptually the condition can be seen to be MASLD or ALD predominant. This may vary over time within a given individual.”
Respondents overwhelmingly agreed, however, that even moderate alcohol use alters the natural history of the disease and that patients with more than minimal alcohol consumption should be analyzed separately in clinical trials.
The new nomenclature reflects a 3-year effort involving some 236 panelists from 56 countries who participated in several rounds of online surveys using a Delphi process. Pediatricians, gastroenterologists, and endocrinologists also participated as well as some patient advocates. Changes were based on a super-majority of opinion (67% or higher), though the consensus on whether the term “fatty” was stigmatizing never reached that threshold. In early rounds of surveys only 44% of respondents considered the word “fatty” to be stigmatizing, while more considered “nonalcoholic” to be problematic.
“Substantial proportions of the respondents deemed terms such as ‘fatty’ stigmatizing, hence its exclusion as part of any new name,” Dr. Rinella and her colleagues wrote. “Although health care professionals may contend that patients have not reported this previously, this likely reflects in part a failure to ask the question in the first place and the power imbalance in the doctor-patient relationship.” The authors noted that the new terminology may help raise awareness at a time when new therapeutics are in sight and it becomes more important to identify at-risk individuals.
Of concern was whether the new definitions would alter the utility of earlier data from registries and trials. However, the authors determined that some 98% of people registered in a European NAFLD cohort would meet the new criteria for MASLD. “Maintenance of the term, and clinical definition, of steatohepatitis ensures retention and validity of prior data from clinical trials and biomarker discovery studies of patients with NASH to be generalizable to individuals classified as MASLD or MASH under the new nomenclature, without impeding the efficiency of research,” they stated.
The effort was spearheaded by three international liver societies: La Asociación Latinoamericana para el Estudio del Hígado, the American Association for the Study of Liver Diseases, and the European Association for the Study of the Liver, as well as the cochairs of the NAFLD Nomenclature Initiative.
Each of the authors disclosed a number of potential conflicts of interest.