Definition of MAFLD

Abstract

In 2020, a group of international experts proposed a new name and definition for the fatty liver disease associated with metabolic dysregulation. Rather than the old term non-alcoholic fatty liver disease (NAFLD) an acronym that originated from a histopathological assessment of a liver disease whose pathophysiology was not understood except for the absence of significant alcohol consumption, the consensus proposed the term metabolic (dysfunction) associated fatty liver disease or MAFLD. Subsequently, a clinical operational definition for diagnosis was proposed to underpin the name. The adoption of MAFLD reflects the outcome of four decades of increasing knowledge on the pathophysiology of the disease, its relationship to excess adiposity and insulin resistance, and also its clinical accompaniments. This knowledge has in-turn fostered the development and adoption of MAFLD across the globe. Since publication of the original seminal papers, the last 2 years have spawned a plethora of clinical, basic and translation research on MAFLD with over 1000 original papers in the English literature. The sum of these reports and as well other reviews highlight that MAFLD better identifies a cohort of patients that are more likely to have significant hepatic and extra-hepatic disease and who would benefit from specialist referral. Unlike a NAFLD diagnosis which can only be entertained when other liver diseases are excluded, the positive criteria required to establish a diagnosis of MAFLD means that the disease can be entertained and treated concomitantly with any independent liver disease that may exist in a patient. This includes common diseases such as chronic viral hepatitis and alcohol related liver disease that is so prevalent in our region. The vast majority of patients with MAFLD will have early liver disease with less than F2 fibrosis. These individuals however have an ongoing high risk for cardiometabolic death and less so of liver related events. Hence a holistic approach is required that focusses on lifestyle intervention and strategies to reduce adiposity. The absolute prevalence of significant fibrosis in MAFLD is uncertain at a population level given that most hospital series have significant referral and ascertainment bias. However, these individuals are at highest risk of liver-related complications. Going forward, the formation of the MAIDEN consortium across the APASL region signifies not only the adoption of MAFLD into the medical lexicon, but also provides an opportunity to turbocharge research and clinical care on this disease and its manifestations in our region.