Prevalence and characteristics of MAFLD in Chinese adults aged 40 years or older: A community-based study

Nonalcoholic fatty liver disease (NAFLD) was recently proposed to be renamed metabolic dysfunction-associated fatty liver disease (MAFLD) with the diagnostic criteria revised. We investigated the similarities and differences in the prevalence and clinical characteristics of MAFLD and NAFLD in Chinese adults.

A cross-sectional study of 9980 Chinese individuals aged 40 years or older was performed between 2011 and 2012 using randomized, stratified cluster sampling in Shanghai, China. A detailed questionnaire and the results of abdominal ultrasonography, a standardized 2-h 75-g oral glucose tolerance test and blood biochemical examinations were collected.

A total of 9927 subjects were included in this study. The prevalence of MAFLD (40.3%) was significantly higher than that of NAFLD (36.9%) (P < 0.05). MAFLD was highly prevalent in type 2 diabetes mellitus (T2DM) (53.8%), impaired fasting glucose (35.7%) and impaired glucose tolerance (40.9%). High risk of advanced fibrosis based on fibrosis-4 was highly prevalent (14.7%) in lean MAFLD with T2DM. Among 9927 subjects, 3481 (35.1%) fulfilled the diagnostic criteria for MAFLD and NAFLD (MAFLD+NAFLD+), 521 (5.2%) MAFLD+NAFLD-, and 181 (1.8%) MAFLD-NAFLD+. The MAFLD+NAFLD- group had more significant metabolic disorders than those in the MAFLD+NAFLD+ group (all P < 0.05). Among MAFLD-NAFLD+ subjects, 82.9% had metabolic disorders.

The new definition of MAFLD may better reflect the pathogenesis related to metabolism. Future research should focus on studying the natural history, pathogenesis and treatment effectivity of the overlap and non-overlap of NAFLD and MAFLD subjects.