Comparing the Diagnostic Criteria of MAFLD and NAFLD in the Chinese Population: A Population-based Prospective Cohort Study

Differences in the prevalence of NAFLD, MAFLD, and MASLD according to changes in the nomenclature in a health check-up using MRI-derived proton density fat fraction

PURPOSE

International expert panels proposed new nomenclatures, metabolic dysfunction-associated fatty liver disease (MAFLD) in 2020 and metabolic dysfunction-associated steatotic liver disease (MASLD) in 2023, along with revised diagnostic criteria to replace non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the differences in NAFLD, MAFLD, and MASLD prevalence with changing nomenclature in a health check-up using magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) to assess hepatic steatosis. We also examined the prevalence of the sub-classifications of steatotic liver disease (SLD) and the differences in characteristics among the sub-categories.

METHODS

We included 844 participants who underwent liver MRI-PDFF at our health check-up clinic between January 2020 and November 2022. Hepatic steatosis was defined as MRI-PDFF ≥ 5%. Participants were categorized according to NAFLD, MAFLD, MASLD, and sub-classifications of SLD.

RESULTS

The prevalence rates of NAFLD, MAFLD, and MASLD were 25.9%, 29.5%, and 25.2%, respectively. 30.5% of the participants was categorized as SLD. The prevalence rates of the SLD sub-categories were 25.2% for MASLD, 3.7% for MASLD and alcohol-associated liver disease (MetALD), 0.1% for alcohol-associated liver disease, 1.3% for specific etiology SLD, and 0.1% for cryptogenic SLD. Compared with patients in the MASLD group, those in the MetALD group were younger, predominantly male, and exhibited higher levels of serum aspartate aminotransferase, gamma-glutamyl transpeptidase, and triglycerides.

CONCLUSION

The prevalences of NAFLD and MASLD assessed using MRI-PDFF were similar, with MASLD accounting for 97.3% of the patients with NAFLD. The separate MetALD sub-category may have clinical characteristics that differ from those of MASLD.

Association between Atherogenic Dyslipidemia and Subclinical Myocardial Injury in the General Population

Background: Subclinical myocardial injury (SCMI) is associated with an increased risk of poor cardiovascular disease (CVD) outcomes. Understanding the underlying risk factors for SCMI is crucial for the prevention and management of CVD. We hypothesized that atherogenic dyslipidemia, a combination of high triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C), is associated with an increased risk of SCMI. Methods: This analysis from the third National Health and Nutrition Examination Survey (NHANES-III) included 7093 participants (age 59.3 ± 13.4 years, 52.8% women, and 49.4% White) free of CVD. Atherogenic dyslipidemia was defined as TG ≥ 150 mg/dL and HDL-C < 40 mg/dL in men or <50 mg/dL in women. A validated electrocardiographic-based cardiac infarction injury score (CIIS) ≥ 10 was considered positive for SCMI. Multivariable logistic regression analysis was used to examine the association of different combinations of TG and HDL-C groups, including atherogenic dyslipidemia with SCMI. Results: About 22.5% (n = 1594) of participants had atherogenic dyslipidemia, and 26.3% (n = 1862) had SCMI. Compared to participants with normal TG and normal HDL-C, those with atherogenic dyslipidemia had a higher prevalence of SCMI (31.2% vs. 23.9%, p-value < 0.001). In a multivariable logistic regression model, atherogenic dyslipidemia was associated with the highest odds of SCMI followed by high TG/normal HDL-C, then low HDL-C/normal TG [OR (95% CI): 131 (1.14, 1.52), 1.13 (0.97, 1.33), and 1.01 (0.86, 1.20), respectively). Conclusions: Atherogenic dyslipidemia is associated with a higher risk of SCMI, which highlights the role of nontraditional risk factors in the development of subclinical CVD.

Prevalence and Characteristics of Metabolic Dysfunction-Associated Fatty Liver Disease among an Iranian Adult Population with Ethnic and Genetic Diversity: Results of the PolyIran-Liver Study

Background

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a rising global public health concern. It has been demonstrated that its prevalence and characteristics vary by region and racial/ethnicity. We aimed to investigate the prevalence of MAFLD and its characteristics among Turkmen and non-Turkmen ethnic groups in a multiethnic population region of Iran.

Methods

In this cross-sectional study, we analyzed baseline data for 1614 participants, aged above 50 years, from the PolyIran-Liver trial who were randomly selected from Gonabad city and determined the prevalence of MAFLD and its demographic and metabolic disorders for both the Turkmen and non-Turkmen ethnic groups. Multivariate binary logistic regressions were applied to identify MAFLD-associated factors for men and women separately for the Turkmen and non-Turkmen populations.

Results

The mean (SD) age of the participants was 59.1(6.7) years. Of the participants, 51.5% (n=831) were men, and 52.9% (n=854) were Turkmen. The prevalence of MAFLD among the overall study population was 39.8% (n=614). It was more common among women (45.8% vs. 34.1% in men, P<0.001), non-Turkmens (43.9% vs. 36.1% in Turkmens, P<0.001), and at age 50-64 (41.5% vs.36.1% in age≥65 P=0.004). The fully adjusted multivariate analysis in sex strata exhibited an independent negative association between Turkmen ethnicity only among men but not among women. The increased waist circumference (WC) was the most common metabolic disorder, observed in more than 95.5% of patients with MAFLD (P<0.001). Multivariate analysis in sex/ethnic strata with adjustment for potential confounders revealed an independent association of MAFLD with increased WC, insulin resistance, impaired fasting glucose/diabetes type 2, and high alanine aminotransferase (ALT) among women in both ethnic groups while with elevated triglyceride (TG) only among Turkmen and high body mass index (BMI) only among non-Turkmen women. Increased WC had the strongest independent association with MAFLD among women and the highest odds ratio (OR) with MAFLD in Turkmen women (OR: 6.10; 95% CI 1.56-23.86 vs. 4.80 in non-Turkmen women). Among men, MAFLD was independently associated with insulin resistance, high BMI, and high ALT in both ethnic groups and elevated TG only in non-Turkmen men (all P<0.001). Insulin resistance had the strongest independent OR with MAFLD among men with similar size in both ethnic groups (4.68 [95% CI 2.56-8.55]) in non-Turkmen men and 4.37 (95% CI 2.27-8.42 in Turkmen men).

Conclusion

This study revealed the high prevalence of MAFLD with a sex and ethnic disparity in the middle-aged population of Gonabad city. Further research is needed to understand the factors contributing to the higher prevalence of MAFLD in this region, particularly in women. Furthermore, considering the diverse ethnic population of Iran, it is suggested that future investigations on the sex and ethnic aspects of MAFLD in the Iranian population be conducted to provide targeted prevention strategies better suited for the Iranian population.

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

Relationship between skeletal muscle mass loss and metabolic dysfunction-associated fatty liver disease among Chinese patients with metabolic dysregulation

OBJECTIVE

The aim of this study was to explore the correlation between skeletal muscle content and the presence and severity of metabolic dysfunction-associated fatty liver disease in patients with metabolic dysregulation in China.

METHODS

A cross-sectional study was conducted among patients from the endocrinology outpatient department at Ningbo First Hospital, in Ningbo, China, in April 2021. Adult patients with metabolic dysregulation who accepted FibroScan ultrasound were included in the study. However, those without clinical data on skeletal muscle mass were excluded. FibroScan ultrasound was used to noninvasively evaluate metabolic dysfunction-associated fatty liver disease. The controlled attenuation parameter was used as an evaluation index for the severity of liver steatosis. Bioelectrical impedance analysis was used to measure the skeletal muscle index.

RESULTS

A total of 153 eligible patients with complete data were included in the final analysis. As the grading of liver steatosis intensifies, skeletal muscle index decreases (men: Ptrend<0.001, women: Ptrend=0.001), while body mass index, blood pressure, blood lipid, uric acid, aminotransferase, and homeostatic model assessment of insulin resistance increase (Ptrend<0.01). After adjusting for confounding factors, a negative association between skeletal muscle index and the presence of metabolic dysfunction-associated fatty liver disease was observed in men (OR=0.691, p=0.027) and women (OR=0.614, p=0.022). According to the receiver operating characteristic curve, the best cutoff values of skeletal muscle index for predicting the metabolic dysfunction-associated fatty liver disease presence were 40.37% for men (sensitivity, 87.5%; specificity, 61.5%) and 33.95% for women (sensitivity, 78.6%; specificity, 63.8%).

CONCLUSION

Skeletal muscle mass loss among patients with metabolic dysregulation was positively associated with metabolic dysfunction-associated fatty liver disease severity in both sexes. The skeletal muscle index cutoff value could be used to predict metabolic dysfunction-associated fatty liver disease.

Association between the traditional Chinese medicine constitution and metabolic dysfunction-associated fatty liver disease in older people: A cross-sectional study

Background

Few studies have focused on the relationship between the traditional Chinese medicine constitution (TCMC) and metabolic dysfunction-associated fatty liver disease (MAFLD) in older populations. We sought to investigate the distribution of MAFLD and the TCMC in older people, and provide a theoretical basis for TCMC-based management of MAFLD in this population.

Methods

A cross-sectional study was conducted among older (≥65 years) individuals in Zhongshan, China. Information on common sociodemographic characteristics, medical history, anthropometric measurements, and the TCMC was collected. The chi-square test, multivariable logistic regression analysis, subgroup analysis, and inverse probability weighting of the propensity score were used to explore the relationship between MAFLD and the TCMC.

Results

Of 7085 participants, 1408 (19.9 %) had MAFLD. The three most common TCMC types in MAFLD patients were "phlegm-dampness", "gentleness", and "yin-deficiency". After adjustment for gender, age, tobacco smoking, alcohol consumption, body mass index, abnormal waist-to-hip ratio, hypertension, diabetes mellitus, and dyslipidemia, MAFLD was positively associated with the phlegm-dampness constitution (PDC) (ORadjusted (95 % CI) = 1.776 (1.496-2.108), P < 0.001), and negatively correlated with the qi-depression constitution (0.643 (0.481-0.860), 0.003). A stronger correlation between the PDC and MAFLD was observed in men compared with women (ORadjusted = 2.04 (95%CI = 1.47-2.84) vs. 1.70 (95%CI = 1.39-2.08), Pinteraction = 0.003) as well as between people who smoked tobacco and non-tobacco-smoking individuals (2.11 (1.39-3.21) vs. 1.75 (1.45-2.12), 0.006).

Conclusions

A positive relationship was observed between MAFLD and the PDC in older people living in Zhongshan. Early detection and treatment of the PDC (especially in men and smokers) could prevent the occurrence and development of MAFLD.

Prevalence and clinical outcomes in subtypes of metabolic associated fatty liver disease

BACKGROUND/PURPOSE

In 2020, metabolic Associated Fatty Liver Disease (MAFLD) was proposed to replace non-alcoholic fatty liver disease (NAFLD) with new diagnostic criteria. The prevalence and clinical outcomes of MAFLD subtypes remained unclear.

METHODS

The participants from Taiwan bio-bank cohort were included. MAFLD was defined as the presence of fatty liver, plus any of the following three conditions: overweight/obesity, diabetes mellitus (DM), or metabolic dysfunction. The patients with positive HBsAg or anti-HCV were considered as chronic HBV or HCV infection. NAFLD fibrosis score (NFS) > 0.676 plus fibrosis 4 (FIB-4) score > 2.67 was defined as advanced liver fibrosis. Atherosclerosis was diagnosed as having carotid plaques on duplex ultrasounds. The clinical outcomes were assessed among four subtypes of MAFLD including DM, obesity, chronic HBV infection, and chronic HCV infection.

RESULTS

A total of 21,885 participants (mean age 55.34 ± 10.31; 35.69% males) were included in the final analysis. Among them, 38.83% were diagnosed with MAFLD. The prevalence of MAFLD was 66.95% in DM patients, 65.07% in obese participants, 33.74% in chronic HBV patients, and 30.23% in chronic HCV patients. Logistic regression analysis showed that the subtypes of DM and chronic HCV infection were associated with an increased risk of advanced liver fibrosis in MAFLD patients. Additionally, the subtypes of DM and lean were associated with an increased risk of atherosclerosis, but a decreased risk of atherosclerosis in the subtype of chronic HBV infection.

CONCLUSION

This population-based study proves the concept that subtypes of MAFLD can help risk stratification of clinical outcomes.

Associations of Combined Lifestyle Factors with MAFLD and the Specific Subtypes in Middle-Aged and Elderly Adults: The Dongfeng-Tongji Cohort Study

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the crucial pathogenesis for intra-hepatic and extra-hepatic diseases, especially in elderly adults. Lifestyle management may be a modifiable cost-effective measure for MAFLD prevention, but the evidence is limited. A total of 23,408 middle-aged and elderly individuals were included in a longitudinal study from 2008 to 2018. Combined lifestyle scores (range 0-6) were evaluated by BMI, smoking, drinking, diet, physical activity, and sleep. Logistic regression models were used to calculate ORs for the risks of MAFLD and specific subtypes. The mean age of participants was 61.7 years, and 44.5% were men. Compared with poor lifestyle (scores 0-2), ORs (95% CIs) of the ideal lifestyle (scores 5-6) were 0.62 (0.57-0.68) for MAFLD, 0.31 (0.28-0.34) for MAFLD with excess weight and obesity, 0.97 (0.75-1.26) for MAFLD with diabetes, and 0.56 (0.51-0.62) for MAFLD with metabolic dysregulation. Additionally, lifestyle improvement was associated with lower risks of MAFLD (OR, 0.76; 95% CI, 0.68-0.86), MAFLD with excess weight and obesity (OR, 0.72; 95% CI, 0.63-0.81), MAFLD with diabetes (OR, 0.74; 95% CI, 0.54-1.02) and MAFLD with metabolic dysregulation (OR, 0.49; 95% CI, 0.43-0.55), respectively. Our findings suggest that adherence to a combined healthy lifestyle was associated with lower risks of MAFLD, particularly in excess weight/obese individuals or those with metabolic dysregulation.

Shift in prevalence and systemic inflammation levels from NAFLD to MAFLD: a population-based cross-sectional study

BACKGROUND

Variations in the prevalence and systemic inflammatory (SI) status between non-alcoholic fatty liver disease (NAFLD) and newly defined metabolic dysfunction-associated fatty liver disease (MAFLD) have only been reported by few studies. Hence, this study aimed to compile data on the prevalence and the systemic inflammation levels of MAFLD and NAFLD in a general population from Southeast China was summarized to explore the potential effect of the transformation of disease definition.

METHODS

A total of 6718 general population participants aged 35-75 were enrolled. Logistic regression and restricted cubic spline (RCS) models were used to examine the relationship between 15 SI indicators and NAFLD and MAFLD. The predicted values of MAFLD and NAFLD were analyzed using the receiver operating characteristic (ROC) curve.

RESULTS

The prevalence of MAFLD and NAFLD was 34.7% and 32.4%, respectively. Their overlapping rate was 89.7%, while only 8.3% and 1.9% of participants were MAFLD-only and NAFLD-only. Among three FLD groups, the MAFLD-only group had the highest levels of 8 SI indicators, including CRP, WBC, LYMPH, NEUT, MONO, ALB, NLR, and SIRI. The non-FLD group had the lower levels of all 15 SI indicators compared with all FLD subgroups. The odds ratios (ORs) of 10 SI indicators were significant in both multivariable-adjusted logistic regression and RCS analyses of MAFLD or NAFLD, including CRP, WBC, LYMPH, NEUT, MONO, ALB, PLR, LMR, ALI and CA. ROC analysis showed that the AUC values of all SI were lower than 0.7 in both MAFLD and NAFLD.

CONCLUSIONS

MAFLD could cover more FLD than NAFLD, and the MAFLD-only group had a more severe inflammation status, whereas the NAFLD-only exhibited lower levels. Moreover, there was not a high AUC and a high sensitivity of SI indicators, suggesting that SI indicators are not good indicators to diagnose NAFLD/MAFLD.

Current understanding and future perspectives on the impact of changing NAFLD to MAFLD on global epidemiology and clinical outcomes

INTRODUCTION

For the first time in nearly half a century, fatty liver disease has undergone a change in name and definition, from the exclusive term, non-alcoholic fatty liver disease (NAFLD), to the inclusion-based, metabolic-associated fatty liver disease (MAFLD). This has led investigators across the globe to evaluate the impact the nomenclature change has had on the epidemiology and natural history of the disease.

METHODS

This systematic review provides a comprehensive overview on how the shift in name and diagnostic criteria has influenced point prevalence in different geographic regions, as well as morbidity and mortality risk, whilst highlighting gaps in the literature that need to be addressed.

CONCLUSIONS

MAFLD prevalence is higher than NAFLD prevalence, carries a higher risk of overall mortality, with greater granularity in risk-stratification amongst MAFLD subtypes.

Non-alcoholic fatty liver disease in women - Current knowledge and emerging concepts

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease worldwide, affecting up to 30% of adults. Progression to non-alcoholic steatohepatitis (NASH) is a key risk factor for cirrhosis, hepatocellular carcinoma and cardiovascular events. Alterations in reproductive hormones are linked to the development and/or progression of NAFLD/NASH in women. Women with polycystic ovary syndrome and those with oestrogen deficiency are at increased risk of NAFLD/NASH, with higher mortality rates in older women compared to men of similar ages. NAFLD/NASH is currently the leading indication for liver transplantation in women without hepatocellular carcinoma. Therefore, a better understanding of NAFLD in women is needed to improve outcomes. In this review, we discuss the hormonal and non-hormonal factors that contribute to NAFLD development and progression in women. Furthermore, we highlight areas of focus for clinical practice and for future research.

Lean Metabolic-Associated Fatty Liver Disease

Since the nomenclature change from nonalcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD), much work has been undertaken to establish the clinical characteristics as well as the hepatic and extrahepatic complications of the different MAFLD subtypes. Currently, there has been significant work performed to evaluate previously acknowledged evidence in the lean NAFLD population to determine its applicability to the new entity. This article examines recently published data on lean MAFLD cohorts to highlight the prevalence, pathophysiological characteristics, associated liver fibrosis, genetics, hepatic and extrahepatic complications, prognosis, treatment, and research into this unique subtype of MAFLD.

Increased risk of incident diabetes in patients with MAFLD not meeting the criteria for NAFLD

We aimed to compare the risk of incident diabetes according to fatty liver disease (FLD) definition, focusing on the comparison between those who met criteria for either metabolic dysfunction-associated fatty liver disease (MAFLD) or nonalcoholic fatty liver disease (NAFLD) but not the other. This was a 5.0-year (interquartile range, 2.4-8.2) retrospective longitudinal cohort study of 21,178 adults who underwent at least two serial health checkup examinations. The presence of hepatic steatosis was determined by abdominal ultrasonography at the first health examination. Cox proportional hazard analyses were used to compare the risk of incident diabetes among five groups. Incident diabetes cases occurred in 1296 participants (6.1%). When non-FLD without metabolic dysfunction (MD) group was set as a reference, the risk of incident diabetes increased in the order of NAFLD-only, non-FLD with MD, both FLD, and MAFLD-only groups. The presence of excessive alcohol consumption and/or hepatitis B virus (HBV)/hepatitis C virus (HCV) infection, FLD, and MD synergistically increased the risk of incident diabetes. MAFLD-only group showed a greater increase in incidence of diabetes than non-FLD with MD and NAFLD-only groups. The interaction among excessive alcohol consumption, HBV/HCV infection, MD, and hepatic steatosis on the development of diabetes should not be overlooked.

The Transition of Cardiovascular Disease Risks from NAFLD to MAFLD

The increased burden of nonalcoholic fatty liver disease (NAFLD) parallels the increased incidence of overweight and metabolic syndrome worldwide. Because of the close relationship between metabolic disorders and fatty liver disease, a new term, metabolic-related fatty liver disease (MAFLD), was proposed by a group of experts to more precisely describe fatty liver disease resulting from metabolic disorders. According to the definitions, MAFLD and NAFLD populations have considerable discrepancies, but overlap does exist. This new definition has a nonnegligible impact on clinical practices, including diagnoses, interventions, and the risk of comorbidities. Emerging evidence has suggested that patients with MAFLD have more metabolic comorbidities and an increased risk of all-cause mortality, particularly cardiovascular mortality than patients with NAFLD. In this review, we systemically summarized and compared the risk and underlying mechanisms of cardiovascular disease (CVD) in patients with NAFLD or MAFLD.

Epidemiological characteristics and management of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis in China: A narrative review

AIM

With industrialization and spread of the westernized lifestyle, the number of people affected by non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is growing rapidly in China; this has become a major public health concern. To better understand the burden and characteristics of NAFLD/NASH in China, we aim to perform a narrative review of the literature published in this field.

MATERIALS AND METHODS

We carried out a comprehensive electronic search of five English-language and three Chinese-language databases, to identify studies regarding NAFLD or NASH published from inception to November 30, 2022. Epidemiological studies of NAFLD/NASH in China were particularly noticed and summarized. We also searched the www.

CLINICALTRIALS

gov and www.chictr.org.cn websites for the registered trials on the treatment of the disease led by Chinese investigators or located in China.

RESULTS

The increasing rate of NAFLD prevalence in China is strikingly high, reaching more than twice that in western countries. The prevalence of NAFLD is nearly 30% of the general Chinese population, making it the leading cause of chronic liver diseases. The prevalence of NAFLD/NASH varies between provinces/regions, age groups, sexes, and individuals with different metabolic profiles. NAFLD co-exists in many Chinese patients with chronic hepatitis B. Since 2020, more Chinese studies have used the term metabolic-associated fatty liver disease (MAFLD), emphasizing the underlying metabolic disorders that occur concurrently with this disease. Several clinical trials involving lifestyle interventions, antidiabetic drugs, or traditional Chinese medicines, registered by Chinese investigators, have been completed or are ongoing. Moreover, several innovative targeted therapies developed in China are revolutionizing the treatment of NAFLD/NASH.

CONCLUSIONS

NAFLD has cast a heavy burden on the Chinese healthcare system. Chinese scholars are making efforts to achieve the optimal management of this disease.

MAFLD: How is it different from NAFLD?

"Metabolic dysfunction-associated fatty liver disease (MAFLD)" is the term suggested in 2020 to refer to fatty liver disease related to systemic metabolic dysregulation. The name change from nonalcoholic fatty liver disease (NAFLD) to MAFLD comes with a simple set of criteria to enable easy diagnosis at the bedside for the general medical community, including primary care physicians. Since the introduction of the term, there have been key areas in which the superiority of MAFLD over the traditional NAFLD terminology has been demonstrated, including for the risk of liver and extrahepatic mortality, disease associations, and for identifying high-risk individuals. Additionally, MAFLD has been adopted by a number of leading pan-national and national societies due to its concise diagnostic criterion, removal of the requirement to exclude concomitant liver diseases, and reduction in the stigma associated with this condition. The current article explores the differences between MAFLD and NAFLD diagnosis, areas of benefit, some potential limitations, and how the MAFLD terminology has opened up new fields of research.

Prognosis after hepatic resection of patients with hepatocellular carcinoma related to non-alcoholic fatty liver disease: meta-analysis

BACKGROUND

Whether the safety and efficacy of hepatic resection differ between patients whose hepatocellular carcinoma (HCC) is related to non-alcoholic fatty liver disease (NAFLD) or has other aetiologies is unknown. A systematic review was performed to explore potential differences between such conditions.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library were systematically searched for relevant studies that reported hazard ratios (HRs) for overall and recurrence-free survival between patients with NAFLD-related HCC or HCC of other aetiologies.

RESULTS

The meta-analysis involved 17 retrospective studies involving 2470 patients (21.5 per cent) with NAFLD-related HCC and 9007 (78.5 per cent) with HCC of other aetiologies. Patients with NAFLD-related HCC were older and had higher body mass index (BMI), but were less likely to have cirrhosis (50.4 per cent versus 64.0 per cent, P < 0.001). The two groups suffered similar rates of perioperative complications and mortality. Patients with NAFLD-related HCC had slightly higher overall survival (HR 0.87, 95 per cent c.i. 0.75 to 1.02) and recurrence-free survival (HR 0.93, 95 per cent c.i. 0.84 to 1.02) than those with HCC of other aetiologies. In the various subgroup analyses, the only significant finding was that Asian patients with NAFLD-related HCC had significantly better overall survival (HR 0.82, 95 per cent c.i. 0.71 to 0.95) and recurrence-free survival (HR 0.88, 95 per cent c.i. 0.79 to 0.98) than Asian patients with HCC of other aetiologies.

CONCLUSION

The available evidence suggests that patients with NAFLD-related HCC have similar perioperative complications and mortality, but potentially longer overall and recurrence-free survival, compared with those with HCC of other aetiologies. Tailored surveillance strategies should be developed for patients with NAFLD without cirrhosis.

Metabolic associated fatty liver disease better identifying patients at risk of liver and cardiovascular complications

BACKGROUND/PURPOSE

A nomenclature of "metabolic associated fatty liver disease" (MAFLD) with a new definition was proposed in 2020 instead of the previous "non-alcoholic fatty liver disease" (NAFLD). Whether it better coheres with the clinical demand remains controversial.

METHODS

The participants with fatty liver on ultrasonography in Taiwan bio-bank cohorts were included. MAFLD is defined as the presence of fatty liver, plus any of the following three conditions: overweight/obesity, type 2 diabetes mellitus (DM), or metabolic dysfunction. The severity of liver fibrosis was determined using fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS). The risk of atherosclerotic cardiovascular disease was assessed using intima-media thickness (IMT) or plaques of carotid duplex ultrasound.

RESULTS

A total of 9,719 subjects (ages 55.9 ± 10.8; males 42.6%) were distributed among 4 groups: "overlapping group", "MAFLD only", "NAFLD only", and "neither fatty liver disease (FLD)" with the percentages of 79.7, 12, 7.1, and 1.2%, respectively. Compared with NAFLD patients, MAFLD patients had a greater percentage of males, higher levels of BMI, waist circumference, HbA1c, and triglyceride. In addition, they had higher levels of serum ALT, AST, GGT, fatty liver index (FLI), NFS, and IMT, but no difference in FIB-4 index and the percentage of carotid plaques. To note, "MAFLD only group" had greater levels of AST, ALT, GGT, FLI, FIB-4, NFS, IMT and a higher percentage of carotid plaques than the "NAFLD only group".

CONCLUSION

The grand, population-based study showed MAFLD with new diagnostic criteria to aid in identifying a greater number of high-risk patients of metabolic, liver, and cardiovascular complications, suggesting MAFLD may be a better nomenclature than NAFLD in clinical practice.

A comparison of NAFLD and MAFLD diagnostic criteria in contemporary urban healthy adults in China: a cross-sectional study

Background

A recently proposed diagnostic criteria of metabolic dysfunction-associated fatty liver disease (MAFLD) is more available for various clinical situations than nonalcoholic fatty liver disease (NAFLD), but understanding about differences between NAFLD and MAFLD in clinical practice remains limited in the general adult urban population in China.

Methods

A total of 795 subjects were recruited from Wu Song Branch of Zhongshan Hospital who participated in the general health assessment. Examination results was obtained through analysis of blood samples and abdominal ultrasonography. Participants were divided into four subgroups according to whether they had NAFLD or MAFLD (NAFLD- MAFLD-, NAFLD + MAFLD-, NAFLD- MAFLD + and NAFLD + MAFLD+).

Results

Among the urban healthy adults investigated, 345 people (43.4%) were diagnosed with NAFLD and 356 people (44.8%) with MAFLD. No significant differences in the prevalence, age, fasting blood glucose, glycosylated hemoglobin, liver enzyme examination, percentage of overweight, hypertension or dyslipidaemia were found between NAFLD and MAFLD patients. Patients with MAFLD had worse metabolic disorders than NAFLD + MAFLD- patients. The NAFLD fibrosis score (NFS) of the NAFLD- MAFLD + group was higher than that of the NAFLD + MAFLD- group. Higher proportion of patients in the NAFLD- MAFLD + group have NFS ≥-1.455.

Conclusion

MAFLD criteria have similar prevalence and patient characteristics compared with previous NAFLD but help to identify a group of patients with high risks of metabolic disorders and liver fibrosis who have been missed with NAFLD, and has superior utility.

Liver Steatosis: A Marker of Metabolic Risk in Children

Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as 'Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)', supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD's therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis.

Relationship between the dynamics of non-alcoholic fatty liver disease and incident diabetes mellitus

The aim of the current study was to evaluate the association between changes in non-alcoholic fatty liver disease (NAFLD) over time and risk of incident diabetes mellitus (DM). In total, 3047 subjects without underlying DM were followed up for 14 years from the Anseong-Ansan cohort. NAFLD status was determined biennially using the hepatic steatosis index (HSI), and subjects were clustered into seven groups according to changes in HSI, body mass index (BMI), and homeostatic model assessment of insulin resistance (HOMA-IR): none, persistent, transient, transient resolved, resolved, incident, and recurrent NAFLD (Groups 1-7, respectively). Predictive abilities were compared between the dynamics of HSI and single time points. Regarding the changes in HSI, the risk of incident DM was highest in Group 2 (hazard ratio [HR] 2.710; P < 0.001), followed by Groups 7 (HR 2.062; P < 0.001) and 3 (HR 1.559; P = 0.027). The predictive ability for DM was powerful in order of HOMA-IR, HSI and BMI. The dynamics of NAFLD were less predictive of incident DM than single time-point NAFLD. In conclusion, NAFLD is more useful than BMI in predicting incident DM. However, NAFLD status at single time points can better predict incident DM than dynamic changes in HSI.

Systematically comparing epidemiological and clinical features of MAFLD and NAFLD by meta-analysis: Focusing on the non-overlap groups

BACKGROUND & AIMS

The applicability of the novel metabolic dysfunction associated fatty liver disease (MAFLD) definition has been studied in numerous cohorts and compared to non-alcoholic fatty liver disease (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 (FLD), 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 FLD, 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 alanine aminotransferase (mean difference: 8.0 U/L, 95% CI 2.6-13.5) and aspartate aminotransferase (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

Metabolic dysfunction associated fatty liver disease 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.

Epidemiology, natural history, and diagnosis of metabolic dysfunction-associated fatty liver disease: a comparative review with nonalcoholic fatty liver disease

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is the most common chronic liver disease worldwide - with an estimated global prevalence of 37%. Different from nonalcoholic fatty liver disease (NAFLD), which is an exclusion diagnosis, MAFLD is defined by a set of positive criteria. This recent change in terminology is challenging because MAFLD and NAFLD denote two similar, albeit not identical, clinical populations. When the diagnostic criteria for MAFLD are applied, liver histology appears more severe and clinical outcomes are less favorable. However, the clinical management of MAFLD and NAFLD remains similar. While liver biopsy is still the reference standard for achieving a final diagnosis, noninvasive imaging- or biomarker-based diagnostic modalities are currently gaining momentum. However, liver biopsy should be recommended when diagnostic challenges exist. In this review, we compared the epidemiology, natural history, and diagnosis of MAFLD with respect to the traditional NAFLD definition.

Cardiovascular and renal burdens among patients with MAFLD and NAFLD in China

BACKGROUND/PURPOSE

Metabolic associated fatty liver disease (MAFLD) was proposed as a new definition to put emphasis on the metabolic aspects of nonalcoholic fatty liver disease (NAFLD). We aim to compare the cardiovascular and renal burden between MAFLD and NAFLD patients.

METHODS

12183 participants were enrolled in East China. The cardiovascular burden (Framingham risk score and previous cardiovascular diseases (CVD)) and renal burden (eGFR and chronic kidney disease (CKD)) were measured.

RESULTS

The risk of hypertension, dyslipidemia, diabetes, overweight/obesity, and central obesity of MAFLD patients were higher than those of NAFLD. Patients with MAFLD have a similar or higher beta coefficients in Framingham risk score [beta (95%CI): male 0.062 (0.055,0.069) vs 0.041 (0.033,0.048); female 0.014 (0.012,0.016) vs 0.012 (0.01,0.014)], and higher odds ratio in previous CVD [odds ratio (95%CI): male 1.50 (1.22,1.85) vs 1.35 (1.1,1.66); female 1.58 (1.33,1.87) vs 1.45 (1.22,1.72)], compared with those with NAFLD. However, compared with males with MAFLD, the odds ratio of CKD was higher in those with NAFLD [eGFR: -2.731 (-3.422, -2.041) vs-3.578 (-4.268, -2.887). CKD: 1.44 (1.05,1.96) vs 1.56 (1.14,2.12)]. In female, CKD was only marginally associated with NAFLD [0.8 (0.62,1.02), P=0.075], but not MAFLD [0.87 (0.68,1.11), P=0.268].

CONCLUSIONS

Patients with MAFLD have a similar or higher risk of future and previous CVD compared with those with NAFLD, but the risk of CKD was higher in male with NAFLD.