The importance and impact of recognizing metabolic dysfunction-associated fatty liver disease in patients with chronic hepatitis C

Overlapping group between non-alcoholic fatty liver disease and metabolic associated fatty liver disease better for liver research

AIMS

Metabolic associated fatty liver disease (MAFLD) was proposed to replace "non-alcoholic fatty liver disease (NAFLD) with new diagnostic criteria." The group meeting these two diagnostic criteria is called "Overlapping Fatty Liver Disease (FLD)." Its clinical characteristics remain unknown.

METHODS

This study included participants from the Taiwan Bio-Bank database, where NAFLD was defined as hepatic steatosis in liver ultrasound, with exclusion of other known chronic liver diseases. MAFLD was defined as the presence of hepatic steatosis plus metabolic dysfunction, defined as having any of following three criteria: overweight/obesity, type 2 diabetes mellitus (DM), or ≥2 metabolic risk abnormalities in lean/normal weight subjects. According to these two diagnostic criteria, three groups were identified: "overlapping FLD", "NAFLD alone", and "MAFLD alone." NAFLD fibrosis score (NFS) >0.675 was defined as advanced liver fibrosis.

RESULTS

Eight thousand thirty-eight NAFLD participants (age 55.86 ± 10.12; males 41.07%) were included in the final analysis. Of them, "overlapping FLD" was diagnosed in 7377 (91.8%) and "NAFLD alone" in 661 (8.2%) participants. "Overlapping FLD" patients were older and had a higher percentage of male, worse metabolic profiles, higher NFS, and the percentage of carotid plaques was higher than those with "NAFLD alone." Multivariate analysis showed age, hypertension, DM, and BMI were positively associated with advanced liver fibrosis in "overlapping FLD" patients.

CONCLUSIONS

"Overlapping FLD" is better for liver research due to identifying a high-risk population among NAFLD patients. NAFLD definition introduces the heterogeneity through "NAFLD alone" group and MAFLD criteria overcome this limitation.

Translational research on drug development and biomarker discovery for hepatocellular carcinoma

Translational research plays a key role in drug development and biomarker discovery for hepatocellular carcinoma (HCC). However, unique challenges exist in this field because of the limited availability of human tumor samples from surgery, the lack of homogenous oncogenic driver mutations, and the paucity of adequate experimental models. In this review, we provide insights into these challenges and review recent advancements, with a particular focus on the two main agents currently used as mainstream therapies for HCC: anti-angiogenic agents and immunotherapy. First, we examine the pre-clinical and clinical studies to highlight the challenges of determining the optimal therapeutic combinations with biologically effective dosage for HCC. Second, we discuss biomarker studies focusing on anti-PD1/anti-PD-L1-based combination therapy. Finally, we discuss the progress made in our collective understanding of tumor immunology and in multi-omics analysis technology, which enhance our understanding of the mechanisms underlying immunotherapy, characterize different patient subgroups, and facilitate the development of novel combination approaches to improve treatment efficacy. In summary, this review provides a comprehensive overview of efforts in translational research aiming at advancing our understanding of and improving the treatment of HCC.

Metabolic Dysfunction-Associated Fatty Liver Disease and Chronic Viral Hepatitis: The Interlink

Metabolic dysfunction-associated fatty liver disease (MAFLD) has now affected nearly one-third of the global population and has become the number one cause of chronic liver disease in the world because of the obesity pandemic. Chronic hepatitis resulting from hepatitis B virus (HBV) and hepatitis C virus (HCV) remain significant challenges to liver health even in the 21st century. The co-existence of MAFLD and chronic viral hepatitis can markedly alter the disease course of individual diseases and can complicate the management of each of these disorders. A thorough understanding of the pathobiological interactions between MAFLD and these two chronic viral infections is crucial for appropriately managing these patients. In this comprehensive clinical review, we discuss the various mechanisms of chronic viral hepatitis-mediated metabolic dysfunction and the impact of MAFLD on the progression of liver disease.

The impact of concomitant hepatitis C virus infection on liver and cardiovascular risks in patients with metabolic-associated fatty liver disease

BACKGROUND

Chronic hepatitis C virus (HCV)-infected patients with hepatic steatosis are excluded from the diagnosis of nonalcoholic fatty liver disease (NAFLD). The new name and diagnostic criteria of metabolic-associated fatty liver disease (MAFLD) were proposed in 2020 to replace the original term NAFLD. The clinical outcome of MAFLD patients with concomitant chronic HCV infection requires further investigation.

METHODS

The participants from Taiwan bio-bank cohort were included. MAFLD is defined as the presence of fatty liver, plus any of the following three conditions: overweight/obesity, type 2 diabetes, or metabolic dysfunction. The patients with positive anti-HCV were considered chronic HCV infections. The severity of liver fibrosis was determined using the fibrosis-4 index and NAFLD fibrosis score (NFS). The risk of cardiovascular disease (CVD) was assessed using intima-media thickness (IMT) or plaques of carotid duplex ultrasound.

RESULTS

A total of 18 907 participants (age 55.79 ± 10.42; males 31.9%) were included for final analysis. The prevalence of MAFLD and chronic HCV infections were 39.2% and 2.6%, respectively. According to the status of MAFLD and chronic HCV infection, they were distributed to four groups: 'dual etiology group', 'MAFLD alone', 'HCV alone', and healthy controls. Compared with the 'MAFLD alone' group, the 'dual etiology' group had a lower frequency of the male sex, reduced levels of serum triglyceride, total cholesterol, and LDL; but overall older age, a higher percentage of hypertension history. In addition, they had higher levels of serum aspartate aminotransferase, fibrosis-4 index, and NFS; but no difference in levels of alanine aminotransferase, gamma-glutamyl transferase, fatty liver index, IMT, and the percentage of carotid plaques. Using binary logistic regression, chronic HCV infection was associated with more severe liver fibrosis, but not with carotid plaques in MAFLD patients.

CONCLUSION

MAFLD patients with concomitant HCV infection, a specific phenotype of MAFLD may include a higher risk of advanced liver fibrosis, but a similar risk of atherosclerotic cardiovascular disease compared to those without.

Diabetic MAFLD is associated with increased risk of hepatocellular carcinoma and mortality in chronic viral hepatitis patients

Metabolic dysfunction-associated fatty liver disease (MAFLD) can coexist with chronic viral hepatitis. MAFLD is a heterogeneous disease because the diagnostic criteria include various metabolic traits. We aimed to identify patients at high risk of poor long-term outcomes based on MAFLD subgroups in chronic viral hepatitis patients. We evaluated 63 273 chronic hepatitis B and C patients. Patient with a fatty liver index ≥30 was defined to have hepatic steatosis. MAFLD was defined as the presence of hepatic steatosis with any one of the following three conditions, overweight/obesity, type 2 diabetes or ≥2 metabolic risk factors. The prevalence of MAFLD was 38.4% (n = 24 290). During a median 8.8-year follow-up, 1839 HCCs and 2258 deaths were documented in MAFLD patients. Among MAFLD patients, diabetes could identify patients at high risk of HCC and mortality, whereas overweight/obesity and metabolic risk factors did not. Compared with non-MAFLD patients, risk of HCC and mortality was significantly higher in diabetic MAFLD patients (adjusted hazard ratio [aHR] = 1.34, 95% confidence interval [CI] = 1.26-1.43 for HCC; aHR = 1.15, 95% CI = 1.08-1.22 for mortality). Risk of HCC and mortality was significantly higher in diabetic MAFLD patients (aHR = 1.40, 95% CI = 1.26-1.55 for HCC; aHR = 1.77, 95% CI = 1.63-1.93 for mortality) compared with non-diabetic MAFLD patients. Diabetic MAFLD is associated with increased risk of HCC and mortality among chronic viral hepatitis patients. Our findings highlight the need for close surveillance and effective treatment for these high-risk patients to reduce HCC and mortality in patients with chronic viral hepatitis.

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.

Two years on, a perspective on MAFLD

To provide clarity for research studies and clinical care, a set of positive criteria for adults and children with metabolic (dysfunction) associated fatty liver disease (MAFLD) was recently published and has subsequently been widely endorsed. The development and subsequent validation of the criteria for MAFLD has created a positive momentum for change. During the course of the ongoing discussion on the redefinition, some concerns have surfaced that we thought needs clarification. In this review, we provide a perspective on MAFLD and bringing clarity to some of the key aspects that have been recently raised.

Understanding NAFLD: From Case Identification to Interventions, Outcomes, and Future Perspectives

While non-alcoholic fatty liver disease (NAFLD) is a prevalent and frequent cause of liver-related morbidity and mortality, it is also strongly associated with cardiovascular disease-related morbidity and mortality, likely driven by its associations with insulin resistance and other manifestations of metabolic dysregulation. However, few satisfactory pharmacological treatments are available for NAFLD due in part to its complex pathophysiology, and challenges remain in stratifying individual patient's risk for liver and cardiovascular disease related outcomes. In this review, we describe the development and progression of NAFLD, including its pathophysiology and outcomes. We also describe different tools for identifying patients with NAFLD who are most at risk of liver-related and cardiovascular-related complications, as well as current and emerging treatment options, and future directions for research.

Nonalcoholic fatty liver disease versus metabolic-associated fatty liver disease: Prevalence, outcomes and implications of a change in name

Nonalcoholic fatty liver disease (NAFLD) affects about a third of the world's adult population and is a major public health concern. NAFLD is defined by the presence of hepatic steatosis and the absence of other causes of liver disease. As NAFLD is closely associated with the presence of the metabolic syndrome, several experts have called for a change in nomenclature from NAFLD to metabolic-associated fatty liver disease (MAFLD) to better reflect the underlying pathophysiology of NAFLD as a metabolically driven disease and shift to a "positive" diagnostic criteria rather than one of exclusion. Recent studies have suggested that the global prevalence of MAFLD is higher than that of NAFLD, and patients with MAFLD have more metabolic comorbidities compared to those with NAFLD. Emerging data also suggest that all-cause and cardiovascular mortality may be higher in MAFLD compared with NAFLD. In this synopsis, we discuss differences in clinical features, prevalence and clinical outcomes between NAFLD and MAFLD. In addition, we highlight the advantages and disadvantages of a name change from NAFLD to MAFLD from the perspective of the scientific community, care providers and patients.

Metabolic dysfunction-associated fatty liver disease: a year in review

PURPOSE OF REVIEW

In 2020, a novel comprehensive redefinition of fatty liver disease was proposed by an international panel of experts. This review aims to explore current evidence regarding the impact of this new definition on the current understanding of the epidemiology, pathogenesis, diagnosis, and clinical trials for fatty liver disease.

RECENT FINDINGS

The effectiveness of metabolic dysfunction-associated fatty liver disease (MAFLD) was compared to the existing criteria for nonalcoholic fatty liver disease (NAFLD). Recent data robustly suggest the superior utility of MAFLD in identifying patients at high risk for metabolic dysfunction, the hepatic and extra-hepatic complications, as well as those who would benefit from genetic testing, including patients with concomitant liver diseases. This change in name and criteria also appears to have improved disease awareness among patients and physicians.

SUMMARY

The transformation in name and definition from NAFLD to MAFLD represents an important milestone, which indicates significant tangible progress towards a more inclusive, equitable, and patient-centred approach to addressing the profound challenges of this disease. Growing evidence has illustrated the broader and specific contexts that have tremendous potential for positively influencing the diagnosis and treatment. In addition, the momentum accompanying this name change has included widespread public attention to the unique burden of this previously underappreciated disease.