The Journey of NAFLD to MAFLD and MASLD

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is 30% and is increasing. This requires urgent and comprehensive strategies to raise awareness and address all aspects of NAFLD on local, regional and global levels.

According to Global Regions data collected between 1990 and 2019, the prevalence of NAFLD is highest in Latin America at 44.4%; it is 33.8% in South Asia, 33.0% in South East Asia, 29.7% in East Asia, 31.2% in North America and 25.1% in Western Europe.

A change in nomenclature from NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) has been suggested. This has generated a lot of debate.

The basis of changing the nomenclature of NAFLD to MAFLD was to make an inclusive diagnosis and prioritize the metabolic abnormalities. The key factor that has induced the debate does not lie in why but how to concretize this change in the most appropriate way.

The new nomenclature questions the validity of previous clinical as well as ongoing therapeutic trials where the inclusion and exclusion criteria are not synchronous with the new proposed criteria. Adoption by the US FDA and other regulatory agencies of MASLD criteria for clinical trials will take time. Assessment of ongoing clinical trials that use NAFLD criteria may be problematic.

It has been shown that the change from NAFLD to MAFLD criteria may result in identifi cation of a greater number of persons with metabolically complicated fatty liver and high-risk for incident cardiovascular disease.

 The prevalence of MAFLD is comparable to that of NAFLD. The clinical characteristics of both are also generally similar. The percentage of overlap between both entities is around 80%; in the remaining 20%, there is either MAFLD without NAFLD or NAFLD without MAFLD.

 There are outcome differences between NAFLD and MAFLD. Insulin resistance and high-risk fi brosis are associated with signifi cantly increased risk for cardiacspecifi c mortality among the NAFLD+ patients, but not the MAFLD+. The major risk factors for liver-specifi c mortality were fi brosis, ALD and CKD in MAFLD+ patients. The overall risk for total mortality is greater with MAFLD than NAFLD. The risks for cardiovascular, neoplasm and diabetes-related mortality were similar.

Almost all patients with NAFLD meet the criteria for MAFLD and therefore the natural history is identical. The need of the hour is to educate the masses and the caregivers to prevent NAFLD. Improve diagnostics and therapeutic armamentarium. More research is required on NAFLD including its progression.

India is the fi rst country in the world to identify the need for action for NAFLD. In February 2021, the operational guidelines for integration of NAFLD with National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases & Stroke (NPCDCS) were launched.