Metabolic dysfunction-associated steatotic liver disease: Update and impact of new nomenclature on the American Association for the Study of Liver Diseases practice guidance on nonalcoholic fatty liver disease

Recent developments in non-invasive methods for assessing metabolic dysfunction-associated fatty liver disease

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is increasing, affecting over one-third of the global population and contributing to significant morbidity and mortality. Diagnosing MAFLD, especially with advanced fibrosis, remains challenging due to the limitations of liver biopsy, the current gold standard. Non-invasive tests are crucial for early detection and management. Among these, the fibrosis-4 index (Fib-4) is widely recommended as a first-line test for screening for liver fibrosis. Advanced imaging techniques, including ultrasound-based elastography and magnetic resonance elastography, offer high accuracy but are limited by cost and availability. Combining biomarkers, such as in the enhanced liver fibrosis score and FibroScan-AST score, enhances diagnostic precision and is recommended to further stratify patients who are considered to be intermediate or high risk from the Fib-4 score. We believe that the future lies in the combined use of biomarkers to improve diagnostic accuracy.

Identifying metabolic dysfunction-associated steatotic liver disease in patients with type 2 diabetes mellitus using clinic-based prediction tools

Background

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a global cause of chronic liver disease. The prevalence of MASLD is high in patients with type 2 diabetes mellitus (T2DM). Various non-invasive tools such as the fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS), liver ultrasound, and FibroScan can aid in the detection of liver fibrosis in MASLD, while the Hamaguchi ultrasound-based liver grading system has demonstrated high sensitivity and specificity comparable to liver biopsy.

Objective

We assessed the frequency of MASLD in patients with T2DM using the liver ultrasound Hamaguchi score and the accuracy of NFS and Fib-4 in identifying MASLD.

Patients and methods

We retrospectively collected data and reviewed the charts of all patients with T2DM who underwent liver ultrasound and laboratory tests during the past 5 years.

Results

A total of 6,214 medical records were screened, and only 153 patients (68.6% women; mean age, 59 ± 12.2 years) fulfilled the selection criteria. MASLD was diagnosed using the Hamaguchi grading criteria in 45.1% of patients. A high/intermediate NFS had a higher sensitivity (79.7%) for diagnosing MASLD with a specificity of 10.7%, while a high/intermediate Fib-4 score showed only 30.4% sensitivity but a higher specificity of 54.8%.

Conclusion

Our study indicates that MASLD is frequent in patients with T2DM, and clinical prediction tools such as NFS and Fib-4 can be applied in clinic/primary care settings with variable results.

Prevalence of Non-Alcoholic Fatty Liver Disease and Its Impact on Fibrosis Risk in Inactive Chronic Hepatitis B Patients: Insights from a Cross-Sectional Study

Background: Chronic hepatitis B (CHB) and non-alcoholic fatty liver disease (NAFLD) are significant causes of chronic liver disease, potentially leading to liver cirrhosis and hepatocellular carcinoma. Moreover, the coexistence of CHB and NAFLD is increasingly common, although the relationship between NAFLD and inactive CHB infection remains poorly understood. Objectives: This study aimed to investigate the prevalence of NAFLD among patients with inactive CHB, identify risk factors for NAFLD, and determine predictors of significant fibrosis in these patients. Methods: This single-center cross-sectional study targeted patients with inactive CHB at Sultan Qaboos University Hospital from January 2010 to November 2021. Results: A total of 425 patients with inactive CHB were identified, of which 53.1% were male and 62.6% were aged 40-60 years. The prevalence of NAFLD was 47.8%. Various independent factors were associated with NAFLD, including type 2 diabetes mellitus, elevated low-density lipoprotein levels, high hemoglobin levels, low platelet counts, and normal alpha-fetoprotein levels. Significant associations were noted between NAFLD and significant fibrosis, with 10.5% of CHB patients with NAFLD exhibiting significant fibrosis compared to 1.4% of those without NAFLD. Other significant parameters included male gender, increased age, high alanine transaminase levels, elevated hemoglobin, and decreased platelet levels. Conclusions: The high prevalence of NAFLD in patients with inactive CHB and its associations with increased fibrosis and cirrhosis risk underscore the need for comprehensive management strategies for these patients.

Impact of Physical Activity on Overall Survival and Liver Cirrhosis Incidence in Steatotic Liver Disease: Insights from a Large Cohort Study Using Inverse Probability of Treatment Weighting

Physical activity is a cornerstone of a healthy lifestyle, with benefits in managing chronic diseases. This study investigates the relationship between physical activity and liver-related outcomes with or without steatotic liver diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD) and MASLD and increased alcohol intake (MetALD). The primary outcomes of interest were overall survival in the entire population, individuals without steatotic liver disease, patients with MASLD, and those with MetALD. The secondary outcomes included the incidence of liver cirrhosis. Participants were categorized based on physical activity frequency and Kaplan-Meier survival curves and Cox proportional hazards models were used for analysis. Higher physical activity was associated with significantly better survival in the overall cohort and MASLD cohort before and after inverse probability of treatment weighting (IPTW). In participants without steatotic liver disease and the MetALD cohort, higher physical activity showed significant survival improvement after IPTW. For the incidence of liver cirrhosis, higher physical activity showed significant associations before IPTW in the overall cohort and MASLD cohort, but these associations were not significant after IPTW. Marginal significance was observed in the MetALD cohort before and after IPTW. In conclusion. promoting physical activity may be key in improving liver-related outcomes.

Noninvasive Tests to Assess Fibrosis and Disease Severity in Metabolic Dysfunction-Associated Steatotic Liver Disease

Risk of disease progression and clinical outcomes in metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with fibrosis stage and presence of "at-risk metabolic dysfunction-associated steatohepatitis (MASH)." Although liver biopsy is considered the gold standard to diagnose MASH and stage of fibrosis, biopsy is infrequently performed in clinical practice and has associated sampling error, lack of interrater reliability, and risk for procedural complications. Noninvasive tests (NITs) are routinely used in clinical practice for risk stratification of patients with MASLD. Several NITs are being developed for detecting "at-risk MASH" and cirrhosis. Clinical care guidelines apply NITs to identify patients needing subspecialty referral. With recently approved Food and Drug Administration treatment for MASH and additional emerging pharmacotherapy, NITs will identify patients who will most benefit from treatment, monitor treatment response, and assess risk for long-term clinical outcomes. In this review, we examine the performance of NITs to detect "at-risk MASH," fibrosis stage, response to treatment, and risk of clinical outcomes in MASLD and MASH.

Metabolic dysfunction-associated steatotic liver disease and diabetes: the cross-talk between hepatologist and diabetologist

INTRODUCTION

Metabolic dysfunction-associated steatotic liver disease (MASLD) and type 2 diabetes mellitus (DM) are the most prevalent metabolic disorders globally. The numbers affected in both disorders are also rapidly increasing with alarming trends in children and young adults.

AREAS COVERED

Insulin resistance (IR) and the subsequent metabolic dysregulation are the fundamental pathogenesis pathways of the prevalent metabolic disorders. The interaction and impacts are bidirectional between MASLD and DM in terms of disease mechanisms, disease course, risks, and prognosis. There's a pressing issue for highlighting the links between MASLD and DM for both care specialists and primary care providers. The review collected the scientific evidence addressing the mutual interactions between the two disorders. The strategies for surveillance, risk stratification, and management are discussed in a practical manner. It also provides individualized viewpoints of patient care in hepatology and diabetology.

EXPERT OPINION

Both MASLD and DM shared similar disease mechanisms, and affected the disease development and progression in a bidirectional manner. The high prevalence and the cross-link between the two disorders raise clinical issues from awareness, screening, risk stratification, optimal referral, to appropriate management for primary care providers.

Metabolic dysfunction-associated steatotic liver disease related cirrhosis and incidence of portal vein thrombosis

BACKGROUND

There is heterogeneous data on whether metabolic-associated steatohepatitis is an independent risk factor for portal vein thrombosis (PVT). We aim to compare the incidence of PVT in patients with cirrhosis with and without metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

This is a single-center retrospective study of patients with cirrhosis seen between 1 January 2016 and 31 January 2021. Patients with a history of hepatocellular cancer, liver transplant, Budd-Chiari syndrome, and intra-abdominal malignancies were excluded. Patients with cirrhosis were followed from their first hepatology visit for 180 days to determine the incidence of PVT. Cox proportional hazard regression was used to determine the relationship between MASLD with PVT.

RESULTS

We analyzed data from 2785 patients with cirrhosis who met inclusion and exclusion criteria [mean age: 61.0 ± 12.3 years, 44.3% female, 63.8% Whites and mean model for end-stage liver disease-sodium (MELD-Na) score: 11.7 ± 6.1]. MASLD was present in 21.7% of patients. A total of 89 patients developed PVT during the follow-up, which was fewer in patients with MASLD [2.0% vs. 3.5%, P  = 0.04, unadjusted heart rate (HR): 0.60, 95% confidence interval (CI): 0.27-0.96, P  = 0.04]. After adjusting for the demographics, MASLD-related comorbid conditions and MELD-Na score, MASLD was associated with a lower incidence of PVT as compared to non-MASLD cirrhosis (HR: 0.44, 95% CI: 0.21-0.92, P  = 0.03). After adjusting for the indicators of Child-Pugh Turcotte score, the risk of PVT in patients with MASLD compared to non-MASLD was not statistically significant (HR: 0.50, 95% CI: 0.22-1.13, P  = 0.096).

CONCLUSION

PVT incidence was lower in patients with MASLD cirrhosis as compared to non-MASLD cirrhosis. However, the difference was not significantly different after adjusting for liver decompensation.

Excessive free fatty acid sensing in pituitary lactotrophs elicits steatotic liver disease by decreasing prolactin levels

The pituitary is the central endocrine gland with effects on metabolic dysfunction-associated steatotic liver disease (MASLD). However, it is not clear whether the pituitary responds to free fatty acid (FFA) toxicity, thus dysregulating hepatic lipid metabolism. Here, we demonstrate that decreased prolactin (PRL) levels are involved in the association between FFA and MASLD based on a liver biospecimen-based cohort. Moreover, overloaded FFAs decrease serum PRL levels, thus promoting liver steatosis in mice with both dynamic diet intervention and stereotactic pituitary FFA injection. Mechanistic studies show that excessive FFA sensing in pituitary lactotrophs inhibits the synthesis and secretion of PRL in a cell-autonomous manner. Notably, inhibiting excessive lipid uptake using pituitary stereotaxic virus injection or a specific drug delivery system effectively ameliorates hepatic lipid accumulation by improving PRL levels. Targeted inhibition of pituitary FFA sensing may be a potential therapeutic target for liver steatosis.

Liver stiffness progression in biopsy-proven metabolic dysfunction-associated steatotic disease among people with diabetes versus people without diabetes: A prospective multicenter study

BACKGROUND AND AIMS

There are limited data on the progression of liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) in people with type 2 diabetes mellitus (T2DM) versus those without T2DM in biopsy-proven metabolic dysfunction-associated steatotic liver disease. We examined LSM progression in participants with T2DM versus those without T2DM in a large, prospective, multicenter cohort study.

APPROACH AND RESULTS

This study included 1231 adult participants (62% female) with biopsy-proven metabolic dysfunction-associated steatotic liver disease who had VCTEs at least 1 year apart. LSM progression and regression were defined by a ≥20% increase and an upward or downward change, respectively, in the LSM category in the Baveno VII categories for compensated advanced chronic liver disease, compared between participants with T2DM (n = 680) versus no T2DM (n = 551) at baseline. The mean (±SD) age and body mass index were 51.8 (±12.0) years and 34.0 (±6.5) kg/m 2 , respectively. The median (IQR) time between the first and last VCTE measurements was 4.1 (2.5-6.5) years. Participants with T2DM had higher LSM progression at 4 years (12% vs. 10%), 6 years (23% vs. 16%), and 8 years (50% vs. 39%), p = 0.04. Using a multivariable Cox proportional hazards model adjusted for multiple confounders, the presence of T2DM remained an independent predictor of LSM progression (adjusted HR: 1.35, 95% CI: 1.01-1.81, p = 0.04). T2DM was not associated with LSM regression ( p = 0.71). Mean HbA1c was significantly associated with LSM progression ( p = 0.003) and regression ( p = 0.02).

CONCLUSIONS

Using serial VCTE data from a multicenter study of participants with biopsy-proven metabolic dysfunction-associated steatotic liver disease, we demonstrate that T2DM and HbA1c are associated with LSM progression.

Exploring Varied Treatment Strategies for Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a liver disorder characterized by steatosis with underlying metabolic risk factors. The prevalence of MASLD continues to rise, leading to increased patient risk of various complications. Recent research has been focused on new therapeutic strategies to reduce the incidence of MASLD and provide effective treatment plans to prevent further irreversible liver damage. The treatment approach is multifactorial, with a primary focus on weight loss and management of underlying comorbidities through lifestyle modifications, pharmacotherapy, or surgical options. Ongoing research is exploring new pharmacological therapies that could enhance the treatment of MASLD.

NAFLD/MASLD and the Gut-Liver Axis: From Pathogenesis to Treatment Options

Nonalcoholic fatty liver disease (NAFLD) poses an emerging threat topublic health. Nonalcoholic steatohepatitis (NASH) is reported to be the most rapidly rising cause of hepatocellular carcinoma in the western world. Recently, a new term has been proposed: metabolic dysfunction-associated steatotic liver disease (MASLD). The introduction of this new terminology has sparked a debate about the interchangeability of these terms. The pathogenesis of NAFLD/MASLD is thought to be multifactorial, involving both genetic and environmental factors. Among these factors, alterations in gut microbiota and gut dysbiosis have recently garnered significant attention. In this context, this review will further discuss the gut-liver axis, which refers to the bidirectional interaction between the human gut microbiota and the liver. Additionally, the therapeutic potential of probiotics, particularly next-generation probiotics and genetically engineered bacteria, will be explored. Moreover, the role of prebiotics, synbiotics, postbiotics, and phages as well as fecal microbiota transplantation will be analyzed. Particularly for lean patients with NAFLD/MASLD, who have limited treatment options, approaches that modify the diversity and composition of the gut microbiota may hold promise. However, due to ongoing safety concerns with approaches that modulate gut microbiota, further large-scale studies are necessary to better assess their efficacy and safety in treating NAFLD/MASLD.

Celiac Disease, Gluten-Free Diet and Metabolic Dysfunction-Associated Steatotic Liver Disease

Celiac disease (CD) is a chronic autoimmune disorder triggered by the ingestion of gluten-containing food by genetically predisposed individuals. Hence, treatment of CD consists of permanent avoidance of wheat, rye, barley, and other gluten-containing foods. Lifelong adherence to a gluten-free diet (GFD) improves the symptoms of CD, but recent evidence suggests it is also associated with a higher risk for hepatic steatosis and the coexistence or emergence of other cardiometabolic risk factors. Moreover, a higher risk for liver steatosis is also reported by some authors as a potential extraintestinal complication of the CD itself. Recent nomenclature changes designate the association between hepatic steatosis and at least one of five cardiometabolic risk factors as metabolic dysfunction-associated steatotic liver disease (MASLD). An extended network of potentially causative factors underlying the association between MAFLD and CD, before and after dietary therapy is implemented, was recently described. The individualized treatment of these patients is less supported by evidence, with most of the current recommendations relying on empiric clinical judgment. This review focuses on the causative associations between CD and hepatic injury, either as an extraintestinal manifestation of CD or a side effect of GFD, also referring to potential therapeutic strategies for these individuals.

iATT liver fat quantification for steatosis grading by referring to MRI proton density fat fraction: a multicenter study

BACKGROUND

Several preliminary reports have suggested the utility of ultrasound attenuation coefficient measurements based on B-mode ultrasound, such as iATT, for diagnosing steatotic liver disease. Nonetheless, evidence supporting such utility is lacking. This prospective study aimed to investigate whether iATT is highly concordant with magnetic resonance imaging (MRI)-based proton density fat fraction (MRI-PDFF) and could well distinguish between steatosis grades.

METHODS

A cohort of 846 individuals underwent both iATT and MRI-PDFF assessments. Steatosis grade was defined as grade 0 with MRI-PDFF < 5.2%, grade 1 with 5.2% MRI-PDFF < 11.3%, grade 2 with 11.3% MRI-PDFF < 17.1%, and grade 3 with MRI-PDFF of 17.1%. The reproducibility of iATT and MRI-PDFF was evaluated using the Bland-Altman analysis and intraclass correlation coefficients, whereas the diagnostic performance of each steatosis grade was examined using receiver operating characteristic analysis.

RESULTS

The Bland-Altman analysis indicated excellent reproducibility with minimal fixed bias between iATT and MRI-PDFF. The area under the curve for distinguishing steatosis grades 1, 2, and 3 were 0.887, 0.882, and 0.867, respectively. A skin-to-capsula distance of ≥ 25 mm was identified as the only significant factor causing the discrepancy. No interaction between MRI-logPDFF and MRE-LSM on iATT values was observed.

CONCLUSIONS

Compared to MRI-PDFF, iATT showed excellent diagnostic accuracy in grading steatosis. iATT could be used as a diagnostic tool instead of MRI in clinical practice and trials. Trial registration This study was registered in the UMIN Clinical Trials Registry (UMIN000047411).

From NAFLD to MASLD: implications of the new nomenclature for preclinical and clinical research

Non-alcoholic liver disease (NAFLD) is now metabolic dysfunction-associated steatotic liver disease (MASLD), emphasizing the key metabolic factors of obesity, insulin resistance, vascular dysfunction, and dyslipidemia. Here, we discuss impacts on the existing body of clinical and preclinical liver disease research and research moving forward.