Response to: Comparison of MAFLD and NAFLD diagnostic criteria in real world

MAFLD: Renovation of clinical practice and disease awareness of fatty liver

Recently, international expert panels have proposed a new definition of fatty liver: metabolic dysfunction-associated fatty liver disease (MAFLD). MAFLD is not just a simple renaming of non-alcoholic fatty liver disease (NAFLD). The unique feature of MAFLD is the inclusion of metabolic dysfunctions, which are high-risk factors for events. In addition, MAFLD is independent of alcohol intake and the co-existing causes of liver disease. This new concept of MAFLD may have a widespread impact on patients, medical doctors, medical staff, and various stakeholders regarding fatty liver. Thus, MAFLD may renovate clinical practice and disease awareness of fatty liver. In this review, we introduce the definition of and rationale for MAFLD. We further describe representative cases showing how the diagnostic processes differ between MAFLD and NAFLD. We also summarize recent studies comparing MAFLD with NAFLD and discuss the impact of MAFLD on clinical trials, Japanese populations, and disease awareness.

MAFLD better predicts the progression of atherosclerotic cardiovascular risk than NAFLD: Generalized estimating equation approach

AIM

Metabolic associated fatty liver disease (MAFLD) partly overlaps with non-alcoholic fatty liver disease (NAFLD). Thus, using a generalized estimating equation (GEE) approach, we aimed to investigate the difference in worsening of atherosclerotic cardiovascular disease (ASCVD) risk between patients with MAFLD and NAFLD. We also investigated factors related to the difference between the two groups.

METHODS

We enrolled 2306 subjects with fatty liver (MAFLD 80.7%, NAFLD 63.4%). Subjects with MAFLD/NAFLD were sub-classified into three groups: NAFLD with no metabolic dysfunction (non-Met NAFLD), overlapping, and MAFLD with moderate alcohol consumption (mod-Alc MAFLD). ASCVD risk was estimated by non-invasive tests, including the Suita score. An event was defined as worsening of these scores from the low-risk to the high-risk group. Independent factors for the event were analyzed by Cox regression analysis with the GEE.

RESULTS

In Cox regression analysis, MAFLD (HR 1.08, 95% CI 1.02-1.15, p = 0.014) and alcohol consumption (20-39 g/day; HR 1.73, 95% CI 1.26-2.36, p = 0.001) were independently associated with worsening of the Suita score. In a subanalysis, the incidence of the event was significantly lower in non-Met NAFLD than in the overlapping group (HR 0.70, 95% CI 0.50-0.98, p = 0.042). However, no significant difference was observed in the incidence between the overlapping and mod-Alc MAFLD group (HR 1.19, 95% CI 0.89-1.58, p = 0.235).

CONCLUSIONS

The GEE approach demonstrates that MAFLD better identifies patients with worsening of ASCVD risk than NAFLD. Moreover, the superiority of MAFLD over NAFLD was due to the presence of metabolic dysfunction rather than moderate alcohol consumption.

NAFLD or MAFLD: Which Has Closer Association With All-Cause and Cause-Specific Mortality?-Results From NHANES III

Background: The recent change of terminology from non-alcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD) has raised heated discussion. We aim to investigate the association of MAFLD or NAFLD with all-cause and cause-specific mortality to compare the outcomes of the two diagnostic criteria in population-based study.

Methods: We recruited 12,480 participants from the Third National Health and Nutrition Examination Survey (NHANES III) with matched mortality data in 2015. Participants were divided into four groups for survival analysis: without NAFLD or MAFLD, with only NAFLD, only MAFLD. Cox proportional hazard regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality. Subgroup analysis were applied in MAFLD patients.

Results: The weighted prevalence of MAFLD and NAFLD was relatively 27.4 and 27.9%. Participants with NAFLD or MAFLD were largely overlapped (weighted Cohen's kappa coefficient 0.76). MAFLD increased the overall risk for total mortality in a greater magnitude than NAFLD [HR 2.07 (95% CI 1.86, 2.29) vs. 1.47 (1.20, 1.79)], However, the difference was non-significant after metabolic parameters were adjusted. Risks for cardiovascular, neoplasm, and diabetes-related mortality were similar between MAFLD and NAFLD. Referring to individuals without both NAFLD and MAFLD, individuals with only NAFLD showed reduced total mortality [HR 0.48 (0.34, 0.68)] and neoplasm mortality [HR 0.46 (0.24, 0.89)] in crude. Nevertheless, individuals with only MAFLD independently increased the risk for total mortality [adjusted HR 1.47 (1.22, 1.77)] and neoplasm mortality [aHR 1.58 (1.09, 2.28)]. The risk for overall mortality in MAFLD was consistent between subgroups except for race-ethnicity and whether secondary to viral hepatitis.

Conclusions: Participants with MAFLD or NAFLD were highly concordant. MAFLD showed greater risk for all-cause mortality and equal risk for cause-specific mortality referring to NAFLD. The new terminology excluded participants with lower mortality risk and included participants with higher risk. Drug development for MAFLD should consider ethnic differences.