Metabolic dysfunction-associated fatty liver disease (MAFLD) has an “astonishingly high prevalence rate in overweight and obese adults,” according to the results of a study published in Clinical Gastroenterology and Hepatology.1
MAFLD is the new terminology proposed to more accurately differentiate the condition from nonalcoholic fatty liver disease (NAFLD), which affects more than 1 billion people worldwide.1,2 However, studies on the global prevalence of MAFLD in this population are lacking. Therefore, a team of investigators sought to identify the approximate global prevalence of MAFLD specifically in overweight and obese adults from the general population.
A total of 116 relevant studies conducted from 2000 through 2020 were obtained from Medline, Embase, Web of Science, Cochrane, and Google Scholar database. The studies comprised data from 2,667,052 overweight or obese adults from the general population. Data analysis was performed by DerSimonian-Laird random-effects model with logit transformation. In pooled statistics with high heterogeneity, sensitivity analysis and meta-regression were used to explore predictors of MAFLD prevalence.
The investigators found that the estimated global prevalence of MAFLD was 50.7% (95% CI, 46.9-54.4) among overweight and obese adults, irrespective of diagnostic techniques. Most of the studies (n=95) employed ultrasound as the diagnostic technique, which yielded a prevalence rate of 51.3% (95% CI 49.1-53.4).
The prevalence of MAFLD was found to be significantly higher in men compared with women (59.0% vs 47.5%; P =.02).
The investigators found MAFLD prevalence rates to be comparable based on classical NAFLD and non-NAFLD studies in the general population. In addition, the estimated pooled prevalence of comorbidities in overweight and obese individuals with MAFLD — such as type 2 diabetes and metabolic syndrome — was 19.7% (95% CI, 12.8-29.0) and 57.5% (95% CI, 49.9-64.8), respectively.
This study had several limitations, such as its retrospective design and including limited data from Africa and Oceania, which could have affected the accuracy in estimation. Also, additional covariates such as race and genetic background were not investigated. Another limitation was that the GRADE approach indicated a suboptimal quality of evidence for the overall results. The study population only consisted of overweight and obese people. Additional epidemiologic studies are therefore warranted.
Despite these limitations, the study findings of a significantly increased prevalence of MAFLD in overweight and obese adults require attention to mitigate potential adverse outcomes in this population.
1. Liu J, Ayada I, Zhang X, et al. Estimating global prevalence of metabolic dysfunction-associated fatty liver disease in overweight or obese adults. Clinical Gastroenterology and Hepatology. Published online February 19, 2020. doi.org/10.1016/j.cgh.2021.02.030
2. Eslam M, Sanyal AJ, George J, on behalf of the International Consensus Panel. MAFLD: a consensus-driven proposed nomenclature for metabolic associated fatty liver disease. Gastroenterol. 2020;158(7):P1999-P2014. doi:10.1053/j.gastro.2019.11.312