Changing trends of liver transplantation and mortality from non-alcoholic fatty liver disease

Natural Products in the Modulation of Farnesoid X Receptor Against Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a global health concern with a high prevalence and increasing economic burden, but official medicine remains unavailable. Farnesoid X receptor (FXR), a nuclear receptor member, is one of the most promising drug targets for NAFLD therapy that plays a crucial role in modulating bile acid, glucose, and lipid homeostasis, as well as inhibits hepatic inflammation and fibrosis. However, the rejection of the FXR agonist, obecholic acid, by the Food and Drug Administration for treating hepatic fibrosis raises a question about the functions of FXR in NAFLD progression and the therapeutic strategy to be used. Natural products, such as FXR modulators, have become the focus of attention for NAFLD therapy with fewer adverse reactions. The anti-NAFLD mechanisms seem to act as FXR agonists and antagonists or are involved in the FXR signaling pathway activation, indicating a promising target of FXR therapeutic prospects using natural products. This review discusses the effective mechanisms of FXR in NAFLD alleviation, and summarizes currently available natural products such as silymarin, glycyrrhizin, cycloastragenol, berberine, and gypenosides, for targeting FXR, which can facilitate development of naturally targeted drug by medicinal specialists for effective treatment of NAFLD.

Metabolic puzzle: Exploring liver fibrosis differences in Asian metabolic-associated fatty liver disease subtypes

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a liver condition marked by excessive fat buildup in the absence of heavy alcohol use. It is primarily linked with metabolic issues like insulin resistance, obesity, and abnormal lipid levels, and is often observed with other conditions such as type 2 diabetes and cardiovascular disease. However, whether the subtypes of MAFLD based on the metabolic disorder differentially impact liver fibrosis is not well explicated, especially in the Asian population.

AIM

To compare the severity of liver fibrosis among different MAFLD subtypes.

METHODS

A total of 322 adult patients of either gender with fatty liver on ultrasound were enrolled between January to December 2021. MAFLD was defined as per the Asian Pacific Association for the Study of the Liver guidelines. Fibrosis-4 index (Fib-4) and nonalcoholic fatty liver disease fibrosis score (NFS) were employed to evaluate liver fibrosis.

RESULTS

The mean age was 44.84 ± 11 years. Seventy-two percent of the patients were female. Two hundred and seventy-three patients were classified as having MAFLD, of which 110 (40.3%) carried a single, 129 (47.3%) had two, and 34 (12.5%) had all three metabolic conditions. The cumulative number of metabolic conditions was related to elevated body mass index, triglyceride (TG) levels, and glycated hemoglobin, lower high-density lipoprotein (HDL) levels, higher liver inflammation (by aspartate aminotransferase and γ-glutamyl transferase), and higher likelihood of fibrosis (by NFS and Fib-4 scores) (P < 0.05 for all). The proportion of advanced fibrosis also increased with an increase in the number of metabolic conditions (4.1%, 25.5%, 35.6%, and 44.1% by NFS and 6.1%, 10.9%, 17%, and 26.5% by Fib-4 for no MAFLD and MAFLD with 1, 2, and 3 conditions, respectively). Among MAFLD patients, those with diabetes alone were the eldest and had the highest mean value of NFS score and Fib-4 score (P < 0.05), while MAFLD patients diagnosed with lean metabolic dysfunction exhibited the highest levels of TG and alanine aminotransferase but the lowest HDL levels (P < 0.05).

CONCLUSION

The study suggests that the severity of liver fibrosis in MAFLD patients is influenced by the number and type of metabolic conditions present. Early identification and management of MAFLD, particularly in patients with multiple metabolic conditions, are crucial to prevent liver-related complications.

What Is New in Metabolic Dysfunction-Associated Steatotic Liver Disease in Lean Individuals: From Bench to Bedside

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world's adult population. While it is associated with obesity and metabolic syndrome, emerging evidence has shown that a substantial number of MASLD patients have a normal body mass index ("lean individuals with MASLD"). In this article, we provide an overview of the definition, epidemiology, pathogenesis, and clinical outcomes associated with lean individuals with MASLD and updates on current management.

Associations of advanced liver fibrosis with heart failure with preserved ejection fraction in type 2 diabetic patients according to obesity and metabolic goal achievement status

Background

Heart failure with preserved ejection fraction (HFpEF), a major cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM), is frequently coexisted with obesity, poor glycemic, blood pressure (BP), and/or lipid control. We aimed to investigate the associations of nonalcoholic fatty liver disease (NAFLD) and its advanced fibrosis with HFpEF according to obesity, glycated hemoglobin A1c (HbA1c), BP, and low-density lipoprotein cholesterol (LDL-C) goal achievement status in T2DM patients.

Methods

A total of 2,418 T2DM patients who were hospitalized were cross-sectionally assessed. Liver fibrosis was evaluated by non-invasive biomarkers. Logistic regression analysis was used to evaluate the independent and combined associations of fibrosis status and diabetic care goal attainments with HFpEF risk.

Results

Simple steatosis was not associated with HFpEF risk compared with patients without steatosis, while advanced liver fibrosis was found to have significantly higher odds for HFpEF risk (odds ratio,1.59; 95% confidence interval, 1.22-2.08). Advanced fibrosis in NAFLD was significantly associated with an increased risk of HFpEF, regardless of obesity status, HbA1c, BP, and LDL-C goal achievement status. P values for the interactions between fibrosis status and HbA1c control status, fibrosis status and BP control status, fibrosis status and LDL-C control status, and fibrosis status and body mass index (BMI) status on HFpEF risk were 0.021, 0.13, 0.001, and 0.23, respectively.

Conclusion

In patients with T2DM, advanced hepatic fibrosis was significantly associated with HFpEF risk, irrespective of obesity status, HbA1c, BP, and LDL-C goal attainment status. Further, HbA1c and LDL-C goal attainment status modified this association.

Characterization of hepatic fatty acids using magnetic resonance spectroscopy for the assessment of treatment response to metformin in an eNOS-/- mouse model of metabolic nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. Liver biopsy remains the gold standard for diagnosis and staging of disease. There is a clinical need for noninvasive diagnostic tools for risk stratification, follow-up, and monitoring treatment response that are currently lacking, as well as preclinical models that recapitulate the etiology of the human condition. We have characterized the progression of NAFLD in eNOS^-/- mice fed a high fat diet (HFD) using noninvasive Dixon-based magnetic resonance imaging and single voxel STEAM spectroscopy-based protocols to measure liver fat fraction at 3 T. After 8 weeks of diet intervention, eNOS^-/- mice exhibited significant accumulation of intra-abdominal and liver fat compared with control mice. Liver fat fraction measured by ¹ H-MRS in vivo showed a good correlation with the NAFLD activity score measured by histology. Treatment of HFD-fed NOS3^-/- mice with metformin showed significantly reduced liver fat fraction and altered hepatic lipidomic profile compared with untreated mice. Our results show the potential of in vivo liver MRI and ¹ H-MRS to noninvasively diagnose and stage the progression of NAFLD and to monitor treatment response in an eNOS^-/- murine model that represents the classic NAFLD phenotype associated with metabolic syndrome.

Approach to the Patient With Nonalcoholic Fatty Liver Disease

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes (T2D), causing substantial burden from hepatic and extrahepatic complications. However, endocrinologists often follow people who are at the highest risk of its more severe form with nonalcoholic steatohepatitis or NASH (i.e., T2D or obesity with cardiometabolic risk factors). Endocrinologists are in a unique position to prevent cirrhosis in this population with early diagnosis and treatment.

OBJECTIVE

This work aims to offer endocrinologists a practical approach for the management of patients with NAFLD, including diagnosis, fibrosis risk stratification, and referral to hepatologists.

PATIENTS

(1) An asymptomatic patient with obesity and cardiometabolic risk factors, found to have hepatic steatosis; (2) a patient with T2D and NASH with clinically significant liver fibrosis; and (3) a liver transplant recipient with a history of NASH cirrhosis, with significant weight regain and with recurrent NAFLD on the transplanted organ.

CONCLUSION

NASH can be reversed with proper management of obesity and of T2D. While no agents are currently approved for the treatment of NASH, treatment should include lifestyle changes and a broader use of structured weight-loss programs, obesity pharmacotherapy, and bariatric surgery. Diabetes medications such as pioglitazone and some glucagon-like peptide 1 receptor agonists may also improve liver histology and cardiometabolic health. Sodium-glucose cotransporter-2 inhibitors and insulin may ameliorate steatosis, but their effect on steatohepatitis remains unclear. Awareness by endocrinologists about, establishing an early diagnosis of fibrosis (ie, FIB-4, liver elastography) in patients at high-risk of cirrhosis, long-term monitoring, and timely referral to the hepatologist are all critical to curve the looming epidemic of cirrhosis from NAFLD.

Profiling of cell-free DNA methylation and histone signatures in pediatric NAFLD: A pilot study

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in children and adolescents, increasing the risk of its progression toward nonalcoholic steatohepatitis (NASH), cirrhosis, and cancer. There is an urgent need for noninvasive early diagnostic and prognostic tools such as epigenetic marks (epimarks), which would replace liver biopsy in the future. We used plasma samples from 67 children with biopsy-proven NAFLD, and as controls we used samples from 20 children negative for steatosis by ultrasound. All patients were genotyped for patatin-like phospholipase domain containing 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2), membrane bound O-acyltransferase domain containing 7 (MBOAT7), and klotho-β (KLB) gene variants, and data on anthropometric and biochemical parameters were collected. Furthermore, plasma cell-free DNA (cfDNA) methylation was quantified using a commercially available kit, and ImageStream(X) was used for the detection of free circulating histone complexes and variants. We found a significant enrichment of the levels of histone macroH2A1.2 in the plasma of children with NAFLD compared to controls, and a strong correlation between cfDNA methylation levels and NASH. Receiver operating characteristic curve analysis demonstrated that combination of cfDNA methylation, PNPLA3 rs738409 variant, coupled with either high-density lipoprotein cholesterol or alanine aminotransferase levels can strongly predict the progression of pediatric NAFLD to NASH with area under the curve >0.87. Conclusion: Our pilot study combined epimarks and genetic and metabolic markers for a robust risk assessment of NAFLD development and progression in children, offering a promising noninvasive tool for the consistent diagnosis and prognosis of pediatric NAFLD. Further studies are necessary to identify their pathogenic origin and function.

Current status of liver transplantation for non-B non-C liver cirrhosis and hepatocellular carcinoma

Recently, non-B non-C chronic liver diseases, including alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), have markedly increased worldwide. Liver transplantation (LT) is an effective curative therapy for hepatocellular carcinoma (HCC) as well as decompensated liver cirrhosis. In Japan, where the source of liver grafts is strongly dependent on living donors, efforts have been made to unify the indications for eligibility of HCC patients for LT, leading to the development of 5-5-500 criteria. Along with the expansion of eligibility for LT, the current changing trends in underlying liver diseases of LT recipients, which are related to the rising tide of non-B non-C cirrhosis and HCC, are highlighting the importance of peri-transplant management of patients with various comorbidities. The post-LT prognosis of patients with ALD is significantly affected by de novo malignancies and metabolic syndrome-related complications as well as posttransplant alcohol relapse. NAFLD/NASH patients often suffer from obesity, type 2 diabetes mellitus, and other metabolic syndrome-related disorders, and nonneoplastic factors such as cardiovascular events and recurrence of NAFLD/NASH have a significant impact on post-LT outcomes. Patient management in the peri-transplant period as well as risk assessment for LT are key to improving post-LT outcomes in the era of a growing number of cases of LT for non-B non-C liver diseases.

The Hidden Epidemic: The Prevalence and Impact of Concurrent Liver Diseases in Patients Undergoing Liver Transplantation in Australia and New Zealand

Prevalence of concurrent liver diseases among liver transplant recipients and impact on posttransplant outcomes are unknown.

Methods

This retrospective study included adult liver transplants between January 1' 1985' and December 31' 2019' from the Australian and New Zealand Liver and Intestinal Transplant Registry. Up to 4 liver disease causes were recorded for each transplant; concurrent liver diseases were defined as >1 liver disease indication for transplantation, excluding hepatocellular carcinoma. Impact on posttransplant survival was determined using Cox regression.

Results

A total of 840 (15%) of 5101 adult liver transplant recipients had concurrent liver diseases. Recipients with concurrent liver diseases were more likely male (78% versus 64%) and older (mean age 52 versus 50 y). A higher proportion of liver transplants for hepatitis B (12% versus 6%), hepatitis C (33% versus 20%), alcohol liver disease (23% versus 13%), and metabolic-associated fatty liver disease (11% versus 8%, all P < 0.001) were identified when all indications were included than with primary diagnosis only. The number and proportion of liver transplants performed for concurrent liver diseases have increased from 8 (6%) during Era 1 (1985-1989) to 302 (20%) during Era 7 (2015-2019; P < 0.001). Concurrent liver diseases were not associated with increased posttransplant mortality (adjusted hazard ratio, 0.98, 95% confidence interval, 0.84-1.14).

Conclusions

Concurrent liver diseases are increasing among adult liver transplant recipients in Australia and New Zealand; however, they do not appear to impact posttransplant survival. Reporting all liver disease causes in the transplant registry reports provides more accurate estimates of liver disease burden.

Reactive Oxygen Species Induce Fatty Liver and Ischemia-Reperfusion Injury by Promoting Inflammation and Cell Death

Liver transplantation is the ultimate method for treating end-stage liver disease. With the increasing prevalence of obesity, the number of patients with non-alcoholic fatty liver, a common cause of chronic liver disease, is on the rise and may become the main cause of liver transplantation in the future. With the increasing gap between the number of donor livers and patients waiting for liver transplantation and the increasing prevalence of non-alcoholic fatty liver, the proportion of steatosis livers among non-standard donor organs is also increasing. Ischemia-reperfusion injury has historically been the focus of attention in the liver transplantation process, and severe ischemia-reperfusion injury leads to adverse outcomes of liver transplantation. Studies have shown that the production of reactive oxygen species and subsequent oxidative stress play a key role in the pathogenesis of hepatic ischemia and reperfusion injury and non-alcoholic fatty liver. Furthermore, the sensitivity of fatty liver transplantation to ischemia-reperfusion injury has been suggested to be related to the production of reactive oxygen species (ROS) and oxidative stress. In ischemia-reperfusion injury, Kupffer cell and macrophage activation along with mitochondrial damage and the xanthine/xanthine oxidase system promote marked reactive oxygen species production and the inflammatory response and apoptosis, resulting in liver tissue injury. The increased levels of ROS and lipid peroxidation products, vicious circle of ROS and oxidative stress along with mitochondrial dysfunction promoted the progress of non-alcoholic fatty liver. In contrast to the non-fatty liver, a non-alcoholic fatty liver produces more reactive oxygen species and suffers more serious oxidative stress when subjected to ischemia-reperfusion injury. We herein review the effects of reactive oxygen species on ischemia-reperfusion injury and non-alcoholic fatty liver injury as well as highlight several treatment approaches.

Non-alcoholic Fatty Liver Disease Is Associated With Aortic Calcification: A Cohort Study With Propensity Score Matching

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) greatly affects cardiovascular disease, but evidence on the associations between NAFLD and markers of aortic calcification is limited. We aim to evaluate the association between NAFLD and aortic calcification in a cohort of Chinese adults using propensity score-matching (PSM) analysis.

METHODS

This prospective cohort study involved adults who underwent health-screening examinations from 2009 to 2016. NAFLD was diagnosed by abdominal ultrasonography at baseline, and aortic calcification was identified using a VCT LightSpeed 64 scanner. Analyses included Cox proportional-hazards regression analysis and PSM with predefined covariates (age, gender, marital and smoking status, and use of lipid-lowering drugs) to achieve a 1:1 balanced cohort.

RESULTS

Of the 6,047 eligible participants, 2,729 (45.13%) were diagnosed with NAFLD at baseline, with a median age of 49.0 years [interquartile range, 44.0-55.0]. We selected 2,339 pairs of participants with and without NAFLD at baseline for the PSM subpopulation. Compared with those without NAFLD, patients with NAFLD were at a higher risk of developing aortic calcification during follow-up; significant results were observed before and after matching, with the full-adjusted hazard ratios and corresponding 95% confidence intervals being 1.19 (1.02-1.38) and 1.18 (1.01-1.38), respectively (both p < 0.05). In subgroup analyses, no interaction was detected according to age, gender, smoking status, body mass index, total cholesterol, low-density lipoprotein cholesterol, use of lipid-lowering drugs, hypertension, or type 2 diabetes.

CONCLUSIONS

NAFLD may be independently associated with aortic calcification. Further studies are warranted to elucidate the possible underlying mechanisms.

Non-alcoholic fatty liver disease: Current therapeutic options

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and has an estimated global prevalence of 25%. NAFLD is found in up to 80% of people with obesity and over 60% of patients with diabetes. Cardiovascular disease is the main cause of mortality, followed by extra-hepatic cancers and then liver-specific complications of cirrhosis and hepatocellular carcinoma. Lifestyle modification remains the primary intervention in NAFLD. Weight loss achieved through dietary modification and exercise can lead to histologic improvement and reversal of metabolic complications. Current drug therapy is limited to pioglitazone and vitamin E; however, several agents are currently under phase III development. This review summarises the current treatment options in NAFLD.

The prevalence of disorders of the gut-brain axis in type 2 diabetes mellitus patients with metabolic dysfunction-associated fatty liver disease: an observational study

BACKGROUND AND STUDY AIM

Disorders of the gut-brain axis (DGBI) and metabolic dysfunction-associated liver disease (MAFLD) are frequently diagnosed and exhibit pathophysiological similarities. This study aimed to estimate the prevalence of DGBI in type 2 diabetes mellitus (T2DM) patients with MAFLD.

PATIENTS AND METHODS

In this single center, observational study, in adults with T2DM demographics, diabetes-related parameters and liver tests were recorded. MAFLD was defined by the presence of hepatic steatosis on imaging. Functional dyspepsia (FD) and irritable bowel syndrome (IBS) were diagnosed based on Rome IV criteria. Quality of life (QOL), anxiety levels and depression levels were documented by validated questionnaires.

RESULTS

We included 77 patients, 44 with and 33 without steatosis. There were no significant differences in age, body mass index (BMI), waist circumference, HbA1c levels or metformin use between groups. IBS was significantly more prevalent in the liver steatosis group (9/44 vs. 2/33, p = .037), while a similar trend was observed for FD (9/35 vs. 2/31, p = .103). No differences were found in anxiety, depression and overall QOL. However, QOL subscales for health worry, food avoidance and social reaction were significantly higher in the liver steatosis group.

CONCLUSIONS

In otherwise comparable T2DM patients, DGBI, and especially IBS, are more prevalent in the presence of MAFLD. This difference could not be attributed to increased levels of anxiety or depression. Future research should target the underlying pathophysiological mechanisms.

Mechanisms of Non-Alcoholic Fatty Liver Disease in the Metabolic Syndrome. A Narrative Review

Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) are two different entities sharing common clinical and physio-pathological features, with insulin resistance (IR) as the most relevant. Large evidence leads to consider it as a risk factor for cardiovascular disease, regardless of age, sex, smoking habit, cholesterolemia, and other elements of MS. Therapeutic strategies remain still unclear, but lifestyle modifications (diet, physical exercise, and weight loss) determine an improvement in IR, MS, and both clinical and histologic liver picture. NAFLD and IR are bidirectionally correlated and, consequently, the development of pre-diabetes and diabetes is the most direct consequence at the extrahepatic level. In turn, type 2 diabetes is a well-known risk factor for multiorgan damage, including an involvement of cardiovascular system, kidney and peripheral nervous system. The increased MS incidence worldwide, above all due to changes in diet and lifestyle, is associated with an equally significant increase in NAFLD, with a subsequent rise in both morbidity and mortality due to both metabolic, hepatic and cardiovascular diseases. Therefore, the slowdown in the increase of the "bad company" constituted by MS and NAFLD, with all the consequent direct and indirect costs, represents one of the main challenges for the National Health Systems.

MAFLD Criteria May Overlook a Subtype of Patient with Steatohepatitis and Significant Fibrosis

INTRODUCTION

Metabolic associated fatty liver disease (MAFLD) is a novel concept for fatty liver disease. Different from non-alcoholic fatty liver disease (NAFLD), the diagnosis of MAFLD requires the presence of metabolic risks. This study aimed to characterize patients with liver steatosis but without metabolic risks (non-MR-steatosis) which may not be diagnosed by MAFLD criteria.

METHODS

Consecutive patients who underwent biopsy were included in this study. The clinic-pathological characteristics of non-MR-steatosis, NAFLD and MAFLD were compared.

RESULTS

A total of 1217 cases were included. There were 426 (35.00%) cases with MAFLD, 585 (48.07%) with NAFLD and 168 (13.80%) with non-MR-steatosis. The majority of the cases were infected with HBV (93.26%). The age and metabolic profiles were highest in MAFLD and lowest in non-MR-steatosis. The body mass index (BMI) level was also lowest in non-MR-steatosis (20.78 ± 1.54 kg/m²). The ALT and AST levels of the non-MR-steatosis group were not statistically different from those of MAFLD or NAFLD groups (p > 0.05). Histologically, there was no significant difference in the degrees of inflammation and fibrosis among the three groups. The severity of steatosis in non-MR-steatosis group was lower than MAFLD or NAFLD groups (p < 0.05). These results were consistent in both HBV and non-HBV subgroups.

CONCLUSION

MAFLD criteria may overlook some steatotic patients without metabolic risks, who may also have steatohepatitis and significant fibrosis.

Metabolic associated fatty liver disease: Addressing a new era in liver transplantation

Metabolic associated fatty liver disease (MAFLD), previously termed non-alcoholic fatty liver disease, is the leading global cause of liver disease and is fast becoming the most common indication for liver transplantation. The recent change in nomenclature to MAFLD refocuses the conceptualisation of this disease entity to its metabolic underpinnings and may help to spur a paradigm shift in the approach to its management, including in the setting of liver transplantation. Patients with MAFLD present significant challenges in the pre-, peri- and post-transplant settings, largely due to the presence of medical comorbidities that include obesity, metabolic syndrome and cardiovascular risk factors. As the community prevalence of MAFLD increases concurrently with the obesity epidemic, donor liver steatosis is also a current and future concern. This review outlines current epidemiology, nomenclature, management issues and outcomes of liver transplantation in patients with MAFLD.

Making progress in nonalcoholic fatty liver disease (NAFLD) as we are transitioning from the era of NAFLD to dys-metabolism associated fatty liver disease (DAFLD)

• This is a special issue of “Metabolism” dedicated to nonalcoholic fatty liver disease. • Experts in the field provide an overview of recent progress and developments in NAFLD and offer their expert opinion on future directions. • NAFLD remains a highly prevalent disease without an approved treatment.