Open issues in the transition from nafld to mafld. the experience of the plinio study

Metabolic associated fatty liver diseases (MAFLD) definition was proposed to identify fatty liver condition associated to metabolic disorders and to replace non-alcoholic fatty liver disease (NAFLD). We aimed to explore the effect of the application of the new MAFLD criteria on a preexisting cohort of NAFLD patients. The consequences of the reclassification were investigated by applying the MAFLD criteria to a prospective cohort (The Plinio Study) of dysmetabolic patients examined for the presence of NAFLD. In the Plinio cohort, 795 patients had NAFLD and 767 of them (96.5%) were reclassified as MAFLD patients. Out of these, 94.9% had overweight/obesity or diabetes, while the remaining were lean and had metabolic dysregulation defined by the presence of at least two metabolic risk abnormalities. By contrast, 3.5% of the NAFLD patients were reclassified as no-MAFLD due to the absence of overweight/obesity, diabetes, or metabolic risk abnormalities. The only significant difference between the NAFLD and MAFLD groups was the higher prevalence of subjects with BMI ≥ 25 kg/m2 in the latter (88.6% vs. 92%; p = 0.018). In the cohort, 68 subjects were defined as “lean NAFLD”. Of these, 40 were reclassified as MAFLD and 28 as no-MAFLD. In conclusion, when applying MAFLD criteria to the Plinio cohort, there is a substantial overlap between NAFLD and MAFLD diagnosis. However, some specific subgroups of patients, such as those currently defined as lean NAFLD, were excluded by the new MAFLD definition.