Non-alcoholic Fatty Liver Diseases or Metabolic Associated Fatty Liver Disease—Which Is More Comprehensive When Associated with Obesity?

Non-alcoholic steatohepatitisNon-alcoholic steatohepatitis was first described in 1980. In 2020, a panel of experts proposed a change in nomenclature to “Metabolic Associated Fatty Liver DiseaseFatty liver disease (MAFLD). The overall prevalence of MAFLD (39.22%) has been estimated to be higher than Non-alcoholic fatty liver diseaseNon-alcoholic fatty liver disease (NAFLD) (25.24%). A more extensive study found that the discordant weighted prevalence in patients who met MAFLD criteria but not NAFLD was accounted for by patients with significant alcohol consumption and/or viral hepatitis. Patients with MAFLD are older, have a higher body mass indexBody mass index, and higher proportions of metabolic comorbidities. MAFLD and NAFLD have been similarly associated with a higher risk of diabetesDiabetes, chronic kidney disease, and cardiovascular diseaseCardiovascular disease. An observational study found no differences between the prevalence of advanced fibrosis based on non-invasive scores when comparing NAFLD and MAFLD. A central argument for the change in nomenclature has been the problem associated with the negative form “non-alcoholic” to define the disease and its implications on disease awareness among healthcare workers, patients, and patients’ families. Some disputes that adding the term “metabolic” do not take away the ambiguity given that there is no consensus over the meaning of “metabolic health” and the existence of other metabolic diseases that can cause fatty accumulation in the liver and are not covered by the term. For the last 15 years, it has been made clear that the definition of NAFLD does not encompass the pathophysiology, associated comorbidities, and different patient outcomes. Although most community members would agree that the definition of NAFLD is unsatisfactory, some do not agree that MAFLD covers all the inadequacies. The association of fatty liver diseaseFatty liver disease with obesity and/or type 2 diabetesType 2 diabetes mellitus has been well established. However, there is not enough information to decide if these comorbidities should be embedded in the definition or if we should stratify patients’ risk of disease progression based on the associated comorbidities. If the change in nomenclature is done prematurely, it may prove counterproductive. A better understanding of pathophysiological routes, genetic and epigeneticEpigenetic factors, molecular pathways, and associated risks should be accomplished before a change done in terminology.