Background & Aims

The applicability of the novel MAFLD definition has been studied in numerous cohorts and compared to NAFLD. No consensus has been reached on which definition is preferred. Therefore, this meta-analysis aims to compare the epidemiological and clinical features of NAFLD and MAFLD in the general and non-general population.

Methods

We searched Medline, Embase and Web of Science for studies comparing MAFLD to NAFLD. Based on MAFLD and NAFLD status, the following subgroups were investigated for liver health: overlap fatty liver disease, NAFLD-only and MAFLD-only. Data were pooled using random-effects models.

Results

We included 17 studies comprising 9,808,677 individuals. In the general population, MAFLD was present in 33.0% (95%CI 29.7-36.5%) and NAFLD in 29.1% (95%CI 27.1-31.1%). Among those with fatty liver disease, 4.0% (95%CI 2.4-6.4%) did not meet the MAFLD criteria but had NAFLD (NAFLD-only) and 15.1% (95%CI 11.5-19.5%) was exclusively captured by the novel MAFLD definition (MAFLD-only). Notably, this MAFLD-only group was at significantly increased risk for fibrosis (RR 4.2; 95%CI 1.3-12.9) and had higher ALT (mean difference: 8.0U/L, 95%CI 2.6-13.5) and AST (mean difference: 6.4 U/L, 95%CI 3.0-9.7), compared to NAFLD-only. Similar results were obtained among the non-general population.

Conclusions

MAFLD and NAFLD are highly prevalent in the general population, with considerable overlap between them. However, compared to NAFLD, significantly more individuals were additionally identified by MAFLD than were missed. Importantly, by using the MAFLD criteria, more individuals with liver damage were identified. Therefore, the novel MAFLD definition is superior to NAFLD on a population level.