Nonalcoholic fatty liver disease (NAFLD) should now be referred to as metabolic dysfunction–associated steatotic liver disease (MASLD), according to a recent commentary by leading hepatologists.
This update, which was determined by a panel of 236 panelists from 56 countries, is part of a broader effort to rebrand “fatty liver disease” as “steatotic liver disease” (SLD), reported lead author Alina M. Allen, MD, of Mayo Clinic, Rochester, Minnesota, and colleagues.
Mayo Clinic
Dr. Alina M. Allen
Writing in Gastroenterology, they described a range of reasons for the nomenclature changes, from the need for better characterization of disease subtypes, to the concern that the term “fatty” may be perceived as stigmatizing by some patients.
“The scientific community and stakeholder organizations associated with liver diseases determined there was a need for new terminology to cover liver disease related to alcohol alone, metabolic risk factors (until recently termed NAFLD/nonalcoholic steatohepatitis [NASH]) alone, the combination of alcohol and metabolic risk factors, and hepatic steatosis due to other specific etiologies,” the authors wrote.
Naming conventions in this area have been flawed since inception, Dr. Allen and colleagues wrote, noting that “nonalcoholic” is exclusionary rather than descriptive, and is particularly misplaced in the pediatric setting. These shortcomings could explain why the term “NASH” took more than a decade to enter common usage, they suggested, and why the present effort is not the first of its kind.
“There have been several movements to change the nomenclature [of NAFLD], including most recently to ‘metabolic dysfunction–associated fatty liver disease’ (MAFLD), a term that received limited traction,” the authors wrote.
Still, a change is needed, they added, as metabolic dysfunction is becoming increasingly common on a global scale, driving up rates of liver disease. Furthermore, in some patients, alcohol consumption and metabolic factors concurrently drive steatosis, suggesting an intermediate condition between alcohol-related liver disease (ALD) and NAFLD that is indescribable via current naming conventions.
SLD (determined by imaging or biopsy) now comprises five disease subtypes that can be determined via an algorithm provided in the present publication.
If at least one metabolic criterion is present, but no other causes of steatosis, then that patient has MASLD. The three other metabolic subtypes include MetALD (2-3 drinks per day for women and 3-4 drinks per day for men), ALD (more than 3 drinks per day for women and more than 4 drinks per day for men), and monogenic miscellaneous drug-induced liver injury (DILI).
Patients without metabolic criteria can also be classified with monogenic miscellaneous DILI with no caveat, whereas patients with metabolic criteria need only consume 2 or 3 drinks per day for women or 3-4 drinks per day for men, respectively, to be diagnosed with ALD.
Finally, patients with no metabolic criteria or other cause of steatosis should be characterized by cryptogenic SLD.
“While renaming and redefining the disease was needed, the implementation is not without challenges,” Dr. Allen and colleagues wrote. “A more complex classification may add confusion in the mind of nonhepatology providers when awareness and understanding of the implications of SLD are already suboptimal.”
Still, they predicted that the new naming system could lead to several positive outcomes, including improved SLD screening among individuals with metabolic risk factors, more accurate phenotyping of patients with moderate alcohol consumption, increased disease awareness in nonhepatology practices, and improved multidisciplinary collaboration.
Only time will tell whether these benefits come to fruition, Dr. Allen and colleagues noted, before closing with a quote: “In the words of Jean Piaget, the developmental psychologist of the 20th century, who coincidentally died the year the term NASH was coined, ‘Scientific knowledge is in perpetual evolution; it finds itself changed from one day to the next.’”
The authors disclosed no conflicts of interest.
