Outcomes of NAFLD and MAFLD: Results from a community-based, prospective cohort study

Background The term “metabolic (dysfunction)-associated fatty liver disease” (MAFLD) is suggested alternative for “non-alcoholic fatty liver disease” (NAFLD), as it better reflects metabolic dysfunction. No study has compared outcomes of the two diagnostic criteria. 

Methods In an ongoing, community-based, cohort-study in suburban Sri Lanka, participants were randomly selected in 2007. They were reassessed in 2014 to evaluate new-onset metabolic traits (MTs) and cardiovascular-events (CVEs). Baseline characteristics, MTs and CVEs after 7-years were compared in NAFLD and MAFLD and vs. controls. Similarly, we compared these parameters in those excluded by the NAFLD definition but captured by the MAFLD definition and vice versa, and vs. controls. 

Findings Of 2985 recruited in 2007, 940 (31.5%) had NAFLD, 990 (33.1%) had MAFLD and 362 (12.1%) were controls. When compared to NAFLD, MAFLD captured an additional 2.9% and lost 1.3% individuals. At baseline, anthropometric and metabolic traits were similar in NAFLD and MAFLD. At follow-up in 7-years, the risk of having new-onset MTs and fatal/ non-fatal CVEs were similar in the groups, but were significantly higher compared to controls. Those excluded by the NAFLD definition but captured by the MAFLD definition showed higher baseline MTs compared to those excluded by the MAFLD definition but captured by the NAFLD definition, and had substantially higher risk for having new-onset MTs and CVEs compared to controls. 

Interpretation Although NAFLD and MAFLD had similar MTs at baseline, and similar outcomes after 7-years, those who were excluded by the NAFLD definition but captured by the MAFLD definition seem at higher risk of adverse outcomes than those excluded by the MAFLD definition but captured by the NAFLD definition. Although the increase in the index population was small, redefining NAFLD as MAFLD seemed to improve clinical utility.