Abstract
This brief review focuses on two contentious issues within the field of non-alcoholic fatty liver disease (NAFLD); the first is the recent effort to redefine NAFLD as metabolic (dysfunction)-associated fatty liver disease (MAFLD). The modification of "NAFLD" to "MAFLD" is expected to highlight the role of metabolic factors in the disease aetiology, which is hoped to improve patient understanding of the disease, facilitate patient-physician communication and highlight the importance of public health interventions in prevention and management. The diagnostic criteria for MAFLD allow it to coexist with other forms of liver disease, which recognises that metabolic dysfunction contributes towards disease progression in other liver pathologies, such as alcoholic liver disease. However, there remain concerns that renaming NAFLD may be premature without fully considering the broader implications, from diagnostic criteria to trial endpoints; therefore, the new definition has not yet been accepted by major societies. Another contentious issue within the field is the gap in our understanding of how patients undergoing therapeutic interventions should be monitored to assess amelioration/attenuation or the worsening of their liver disease. Biomarker scoring systems (such as the ELF test and FIB-4 test) and imaging techniques (such as transient elastography [TE] and magnetic resonance imaging [MRI] techniques) are proven to be reasonably accurate, and comparable with histology, in the diagnosis of NAFLD and evaluation of disease severity; however, their use in monitoring the response of disease to therapeutic interventions is not well established. Whilst biomarker scoring systems and TE are limited by poor diagnostic accuracy in detecting moderate fibrosis (e.g. F2 liver fibrosis defined by histology), more accurate MRI techniques are not practical for routine patient follow-up due to their expense and limited availability. More work is required to determine the most appropriate method by which therapeutic interventions for NAFLD should be monitored in clinical practice.