Comparison of Clinical Characteristics and Outcomes of MAFLD and NAFLD in Chinese Health Examination Populations

Background and Aims: The recently proposed concept of metabolic dysfunction-associated fatty liver disease (MAFLD) has remained controversial. We aimed to describe the features and associated outcomes to examine the diagnostic ability of MAFLD for identifying high-risk individuals. Methods: In this retrospective cohort study, we enrolled 72,392 Chinese participants between 2014 and 2015. Participants were classified as MAFLD, nonalcoholic fatty liver disease (NAFLD), non-MAFLD-NAFLD, and a normal control group. The primary outcomes were liver-related and cardiovascular disease (CVD) events. Person-years of follow-up were calculated from enrolment to the diagnosis of the event, or the last date of data (June, 2020). Results: Of the 72,392 participants, 31.54% (22,835) and 28.33% (20,507) qualified the criteria for NAFLD or MAFLD, respectively. Compared with NAFLD, MAFLD patients were more likely to be male, overweight, and have higher biochemical indices including liver enzyme levels. Lean MAFLD diagnosed with ≥2 or ≥3 metabolic abnormalities presented similar clinical manifestations. During the median follow-up of 5.22 years, 919 incident cases of severe liver disease and 2,073 CVD cases were recorded. Compared with the normal control group, the NAFLD and MAFLD groups had a higher cumulative risk of liver failure and cardiac-cerebral vascular diseases. There were no significant differences in risk between the non-MAFLD-NAFLD and normal group. Diabetes-MAFLD group had the highest incidence of liver-related and cardiac-cerebral vascular diseases, lean MAFLD came second, and obese-MAFLD had the lowest incidence. Conclusions: This real-world study provided evidence for rationally assessing the benefit and practicability of the change in terminology from NAFLD to MAFLD. MAFLD may be better than NAFLD in identifying fatty liver with worse clinical features and risk profile.