Abstract and Introduction
Background and Aims: Metabolic associated fatty liver disease (MAFLD) is a novel concept proposed in 2020, the utility of which has not been tested and validated in real world. We aimed to compare the characteristics of MAFLD and non-alcoholic fatty liver disease (NAFLD).
Methods: The data was retrieved from the third National Health and Nutrition Examination Surveys of the United States, which is an unbiased survey dataset and frequently used for the study of fatty liver disease.
Results: A total of 13 083 cases with completed ultrasonography and laboratory data were identified from the NHANES III database. MAFLD was diagnosed in 4087/13 083 (31.24%) participants, while NAFLD in 4347/13 083 (33.23%) amongst the overall population and 4347/12 045 (36.09%) in patients without alcohol intake and other liver diseases. Compared with NAFLD, MAFLD patients were significantly older, had higher BMI level, higher proportions of metabolic comorbidities (diabetes, hypertension) and higher HOMA-IR, lipid and liver enzymes. MAFLD patients with alcohol consumption were younger than those without, and more likely to be male. They had less metabolic disorder but higher liver enzymes. There were more cases with advance fibrosis in MAFLD patients with alcohol consumption.
Conclusion: MAFLD definition is more practical for identifying patients with fatty liver disease with high risk of disease progression.
Fatty liver disease (FLD) is prevalent worldwide with the estimated prevalence of 25%. As a result of the insidious onset and prolonged course, the patient pool is continuously increasing. Based on the history of alcohol intake, it is currently artificially classified into two common forms: alcoholic liver disease (ALD) and non-alcoholic fatter liver disease (NAFLD). The definition however is far from perfect because of widespread use of mild to moderate amount of alcohol consumption in patients labelled as "NAFLD" and increasing prevalence of metabolic dysfunction in patients consuming harmful amount of alcohol and labelled as "ALD". Co-existence of mild-moderate alcohol consumption and metabolic derangements is fairly common in day-to-day clinical practice and its often challenging to classify patients into either of the two groups.[4,5] Mis-reporting and under-reporting of alcohol consumption adds further complexity to the already complex definitions.
Metabolic associated fatty liver disease (MAFLD) is a novel concept proposed by an international consensus in 2020. MAFLD is significantly different from previous diagnostic criteria for NAFLD.[7,8] The two most important and significant differences between MAFLD and NAFLD are, MAFLD diagnosis does not require exclusion of patients with alcohol intake, or other chronic liver diseases and the presence of metabolic abnormality is necessary for diagnosis of MAFLD.
As MAFLD criteria are recently developed based on consensus, utility of these criteria has not been tested and validated in real world. The difference in the characteristics of MAFLD and NAFLD has not been thoroughly explored. To address this specific question, we used a population-based data from National Health and Nutrition Examination Surveys (NHANES) to compare the differences between MAFLD and NAFLD criteria. The aim of this study is to characterize patients based on recently proposed MAFLD definition and compare the diagnostic ability of two definitions (NAFLD and MAFLD).
Liver International. 2020;40(9):2082-2089. © 2020 Blackwell Publishing