Development of LXR inverse agonists to treat MAFLD, NASH, and other metabolic diseases

Activation of LXR activity by synthetic agonists has been the focus of many drug discovery efforts with a focus on treatment of dyslipidemia and atherosclerosis. Many agonists have been developed, but all have been hindered due to their ability to efficaciously stimulate de novo lipogenesis. Here, we review the development of LXR inverse agonists that were originally optimized for their ability to enable recruitment of corepressors leading to silencing of genes that drive de novo lipogenesis. Such compounds have efficacy in animal models of MAFLD, dyslipidemia, and cancer. Several classes of LXR inverse agonists have been identified and one is now in clinical trials for treatment of severe dyslipidemia.

Evaluation of Liver Metabolism Biomarkers in Metabolic Associated Fatty Liver Disease According to Obesity Phenotype

OBJECTIVE

To analyze the relationship between the biochemical markers of liver metabolism in different stages of Metabolic Associated Fatty Liver Disease (MAFLD) according to the obesity phenotype.

METHODOLOGY

This is a cross-sectional study with individuals with class III obesity classified according to the obesity phenotypes proposed by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. Biochemical and anthropometric variables were analyzed according to the staging of MAFLD and obesity phenotype.

RESULTS

A total of 50 subjects with MAFLD, 62% (n = 31) with steatosis and 38% (n = 19) with steatohepatitis without fibrosis; 36% were classified as metabolically healthy obesity (MHO) and 64% as metabolically unhealthy obesity (MUHO), respectively. Mean values of alkaline phosphatase were 85.44 ± 27.27 vs. 61.92 ± 17.57 (p = 0.006); gamma-glutamyl transpeptidase, 25.77 ± 15.36 vs. 30.63 ± 19.49 (p = 0.025); and albumin, 3.99 ± 0.34 vs. 4.24 ± 0.23 (p = 0.037), were lower and statistically significant in the MHO group with steatosis. The results show when considering individuals with IR, only AP is a predictor of unhealthy phenotype (B-0.934, 0.848- 1.029, p = 0.031).

CONCLUSION

MHO individuals with steatosis present lower severe changes related to markers of liver damage and function and AP is considered the predictor of MUHO phenotype.

Impact of nonalcoholic fatty liver disease-related metabolic state on depression

Nonalcoholic fatty liver disease (NAFLD), also recently referred as metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by hepatocyte steatosis in the setting of metabolic risk conditions and in the absence of an underlying precursor, for instance alcohol consumption, hepatotropic viruses and hepatotoxic drugs. A possible association between NAFLD and depression has been proposed, owing to intersecting pathophysiological pathways. This narrative review aimed to summarize the current evidence that illustrate the potential pathophysiological and clinical linkage between NAFLD-related metabolic state and depression. Prefrontal cortex lesions are suggested to be a consequence of liver steatosis-associated systematic hyperinflammatory state, a phenomenon also occurring in depression. In addition, depressive symptoms are present in neurotransmitter imbalances. These abnormalities seem to be correlated with NAFLD/MAFLD, in terms of insulin resistance (IR), ammonia and gut dysbiosis' impact on serotonin, dopamine, noradrenaline levels and gamma aminobutyric acid receptors. Furthermore, reduced levels of nesfatin-1 and copine-6-associated BDNF (brain-derived neurotrophic factor) levels have been considered as a probable link between NAFLD and depression. Regarding NAFLD-related gut dysbiosis, it stimulates mediators including lipopolysaccharides, short-chain fatty acids and bile acids, which play significant role in depression. Finally, western diet and IR, which are mainstay components of NAFLD/MAFLD, are, also, substantiated to affect neurotransmitters in hippocampus and produce neurotoxic lipids that contribute to neurologic dysfunction, and thus trigger emotional disturbances, mainly depressive symptoms.

Metabolic dysfunction-associated fatty liver disease and liver function markers are associated with Crohn's disease but not Ulcerative Colitis: a prospective cohort study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is recently recognized as a condition featured with metabolic dysfunctions in liver. It has been supposed that MAFLD might contribute to the development of IBD, but evidence from prospective cohort studies is lacking and inconclusive.

METHODS

A total of 221,546 females and 183,867 males from the UK Biobank cohort enrolled in 2006-2010 were included to examine whether MAFLD and liver function markers were related to incident IBD. MAFLD was identified based on hepatic steatosis defined by fatty liver index plus the prevalence of overweight, type 2 diabetes mellitus, or at least two metabolic abnormalities. Biomarker related to liver function (albumin [ALB], alkaline phosphatase [ALP], alanine transaminase [ALT], aspartate transaminase [AST]; gamma-glutamyl transferase [GGT], total bilirubin [TB], total protein [TP]) was measured using colorimetric or enzymatic assays. The incidence of IBD was ascertained based on primary care and inpatient records. Cox proportional hazard model was used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for the magnitude of their associations.

RESULTS

With a mean follow-up of 12.1 years, 2228 incident IBD cases were documented. We identified 150,385 individuals with MAFLD at baseline and 86% participants' circulating liver function markers were within the normal range. Participants with MAFLD were associated with a 12% (HR 1.12, 95% CI 1.03, 1.23, p = 0.012) increased risk of IBD compared with those without MAFLD at baseline; the association was stronger (p-_{Heterogeneity} = 0.006) with Crohn's disease (HR 1.35, 95% CI 1.15, 1.59, p < 0.001) than ulcerative colitis (HR 1.03, 95% CI 0.93, 1.15, p = 0.57). As for the serum liver function markers, the HRs of IBD for per 1-SD increment in ALB, ALP, AST, and TB concentration were 0.86 (95% CI 0.83, 0.90, p < 0.001), 1.18 (95% CI 1.13, 1.24, p < 0.001), 0.95 (95% CI 0.91, 0.99, p = 0.027), 0.92 (95% CI 0.87, 0.96, p < 0.001), respectively. We did not observe significant associations of GGT and TP with IBD.

CONCLUSIONS

Individuals with MAFLD were at increased risk of developing IBD, especially CD, but not UC. Circulating levels of liver function biomarkers as the surrogate indicators of MAFLD were also associated with IBD risk.

Increased risk of MAFLD and Liver Fibrosis in Inflammatory Bowel Disease Independent of Classic Metabolic Risk Factors

BACKGROUND & AIMS

There is conflicting evidence regarding the prevalence of and risk factors for metabolic-associated fatty liver disease (MAFLD) in patients with inflammatory bowel disease (IBD). We aimed to determine MAFLD prevalence and risk factors in IBD patients.

METHODS

Cross-sectional, case-control study included all consecutive IBD patients treated at 2 different university hospitals. Controls were subjects randomly selected from the general population and matched by age, sex, type 2 diabetes status, and body mass index in a 1:2 ratio. MAFLD was confirmed by controlled attenuation parameter. Liver biopsies were collected when MAFLD with significant liver fibrosis was suspected. In addition, age- and fibrosis stage-paired non-IBD patients with biopsy-proven MAFLD served as a secondary control group.

RESULTS

Eight hundred thirty-one IBD patients and 1718 controls were included. The prevalence of MAFLD and advanced liver fibrosis (transient elastography ≥9.7 kPa) was 42.00% and 9.50%, respectively, in IBD patients and 32.77% and 2.31%, respectively, in the general population (P < .001). A diagnosis of IBD was an independent predictor of MAFLD (adjusted odds ratio, 1.99; P < .001) and an independent risk factor for advanced liver fibrosis (adjusted odds ratio, 5.55; P < .001). Liver biopsies were obtained from 40 IBD patients; MAFLD was confirmed in all cases, and fibrosis of any degree was confirmed in 25 of 40 cases (62.5%). Body mass index and type 2 diabetes prevalence were significantly lower in IBD-MAFLD patients than in severity-paired patients with biopsy-proven MAFLD.

CONCLUSIONS

MAFLD and liver fibrosis are particularly prevalent in IBD patients, regardless of the influence of classic metabolic risk factors.

MAFLD is associated with increased all-cause mortality in low cardiovascular-risk individuals but not in intermediate to high-risk individuals

BACKGROUND AND AIMS

Metabolic-associated fatty liver disease (MAFLD) is increasingly recognized as a systematic disease rather than just a liver disease alone, which raises concerns about its long-term impact on different populations. This study aimed to clarify the effects of MAFLD on long-term outcomes among different cardiovascular risk-stratified populations.

METHODS AND RESULTS

Eligible individuals in the Third National Health and Nutrition Examination Surveys (NHANES Ⅲ, 1988-1994) were enrolled. Participants were classified into low, intermediate, or high cardiovascular-risk populations according to the Framingham general equations. Kaplan-Meier survival analysis and Cox regression models were used to investigate the association between MAFLD and long-term outcomes in different cardiovascular-risk populations. A total of 8897 adults were enrolled in the final analysis. The median ages in the non-MAFLD and MAFLD groups were 44 and 49 years old, respectively. During a median follow-up of 22.8 years, a total of 2991 deaths were recorded, including 1694 deaths (30.3%) in non-MAFLD and 1297 deaths (39.2%) in MAFLD (P < 0.001). In the low cardiovascular-risk population, MAFLD individuals had increased all-cause mortality than non-MAFLD individuals (HR = 1.206, 95% CI:1.0338-1.400, P = 0.014). However, similar results were not observed in intermediate or high-cardiovascular-risk individuals. Further analysis of cause-specific mortality suggested that MAFLD was associated with higher cancer-related mortality in the low-risk population (HR = 1.313, 95% CI:1.000-1.725, P = 0.049).

CONCLUSIONS

MAFLD was associated with increased all-cause mortality among individuals with low cardiovascular risk, rather than those with an intermediate or high cardiovascular risk.

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.

Impaired Function of Solute Carrier Family 19 Leads to Low Folate Levels and Lipid Droplet Accumulation in Hepatocytes

Low serum folate levels are inversely related to metabolic associated fatty liver disease (MAFLD). The role of the folate transporter gene (SLC19A1) was assessed to clarify its involvement in lipid accumulation during the onset of MAFLD in humans and in liver cells by genomic, transcriptomic, and metabolomic techniques. Genotypes of 3 SNPs in a case-control cohort were initially correlated to clinical and serum MAFLD markers. Subsequently, the expression of 84 key genes in response to the loss of SLC19A1 was evaluated with the aid of an RT² profiler-array. After shRNA-silencing of SLC19A1 in THLE2 cells, folate and lipid levels were measured by ELISA and staining techniques, respectively. In addition, up to 482 amino acids and lipid metabolites were semi-quantified in SLC19A1-knockdown (KD) cells through ultra-high-performance liquid chromatography coupled with mass spectrometry. SNPs, rs1051266 and rs3788200, were significantly associated with the development of fatty liver for the single-marker allelic test. The minor alleles of these SNPs were associated with a 0.6/-1.67-fold decreased risk of developing MAFLD. When SLC19A1 was KD in THLE2 cells, intracellular folate content was four times lower than in wild-type cells. The lack of functional SLC19A1 provoked significant changes in the regulation of genes associated with lipid droplet accumulation within the cell and the onset of NAFLD. Metabolomic analyses showed a highly altered profile, where most of the species that accumulated in SLC19A1-KD-cells belong to the chemical groups of triacylglycerols, diacylglycerols, polyunsaturated fatty acids, and long chain, highly unsaturated cholesterol esters. In conclusion, the lack of SLC19A1 gene expression in hepatocytes affects the regulation of key genes for normal liver function, reduces intracellular folate levels, and impairs lipid metabolism, which entails lipid droplet accumulation in hepatocytes.

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.

Overview of Cellular and Soluble Mediators in Systemic Inflammation Associated with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is currently the most prevalent chronic liver disease in Western countries, affecting approximately 25% of the adult population. This condition encompasses a spectrum of liver diseases characterized by abnormal accumulation of fat in liver tissue (non-alcoholic fatty liver, NAFL) that can progress to non-alcoholic steatohepatitis (NASH), characterized by the presence of liver inflammation and damage. The latter form often coexists with liver fibrosis which, in turn, may progress to a state of cirrhosis and, potentially, hepatocarcinoma, both irreversible processes that often lead to the patient's death and/or the need for liver transplantation. Along with the high associated economic burden, the high mortality rate among NAFLD patients raises interest, not only in the search for novel therapeutic approaches, but also in early diagnosis and prevention to reduce the incidence of NAFLD-related complications. In this line, an exhaustive characterization of the immune status of patients with NAFLD is mandatory. Herein, we attempted to gather and compare the current and relevant scientific evidence on this matter, mainly on human reports. We addressed the current knowledge related to circulating cellular and soluble mediators, particularly platelets, different leukocyte subsets and relevant inflammatory soluble mediators.

A low-carbohydrate diet induces hepatic insulin resistance and metabolic associated fatty liver disease in mice

OBJECTIVES

Metabolic-associated fatty liver disease (MAFLD) is the most common chronic liver disease that can range from hepatic steatosis to non-alcoholic steatohepatitis (NASH), which can lead to fibrosis and cirrhosis. Recently, ketogenic diet (KD), a low carbohydrate diet, gained popularity as a weight-loss approach, although it has been reported to induce hepatic insulin resistance and steatosis in animal model systems via an undefined mechanism. Herein, we investigated the KD metabolic benefits and its contribution to the pathogenesis of NASH.

METHODS

Using metabolic, biochemical and omics approaches, we identified the effects of a KD on NASH and investigated the mechanisms by which KD induces hepatic insulin resistance and steatosis.

RESULTS

We demonstrate that KD can induce fibrosis and NASH regardless of body weight loss compared to high-fat diet (HFD) fed mice at thermoneutrality. At ambient temperature (23 °C), KD-fed mice develop a severe hepatic injury, inflammation, and steatosis. In addition, KD increases liver cholesterol, IL-6, and p-JNK and aggravates diet induced-glucose intolerance and hepatic insulin resistance compared to HFD. Pharmacological inhibition of IL-6 and JNK reverses KD-induced glucose intolerance, and hepatic steatosis and restores insulin sensitivity.

CONCLUSIONS

Our studies uncover a new mechanism for KD-induced hepatic insulin resistance and NASH potentially via IL-6-JNK signaling and provide a new NASH mouse model.

The Burden of Non-Alcoholic Fatty Liver Disease in Adolescents with Polycystic Ovary Syndrome: A Case-Control Study

The aim of this case-control study was to assess the burden of non-alcoholic fatty liver disease (NAFLD) in adolescents with polycystic ovary syndrome (PCOS) and its associations with insulin resistance, hyperandrogenism, and other metabolic characteristics of the syndrome. A total of 87 Caucasian adolescent girls (47 with PCOS and 40 controls), aged 12.3-20.4 years, underwent blood sampling for glucose metabolism, hormonal and lipid profile, gynecological and liver ultrasound, and liver elastography. Indices of insulin resistance, liver steatosis, and liver fibrosis were calculated. NAFLD diagnosed by ultrasound was more prevalent in adolescents with PCOS than controls (22.7% vs. 6.1%, p = 0.046), and was also verified by liver steatosis indices. The latter was not apparent for hepatic fibrosis, as assessed by Fibroscan^® and calculated indices. The homeostatic model assessment for insulin resistance (HOMA-IR) was found to predict NAFLD diagnosis by the liver fat score (LFS) index (β = 0.709, p = 0.002). Adolescents with PCOS and high free androgen index (FAI) presented worse NAFLD than those adolescents with PCOS and lower FAI. In addition, adolescents with PCOS and concurrent NAFLD had worse insulin sensitivity indices (HOMA-IR, QUICKI, and glucose to insulin ratio) than adolescents with PCOS alone. Adolescent insulin resistance could be considered a confounder of the association between PCOS and NAFLD.

Low thyroid function is associated with an increased risk of advanced fibrosis in patients with metabolic dysfunction-associated fatty liver disease

AIMS

Observational studies showed that low thyroid function may perturb liver function. We aimed to evaluate the association of low thyroid function with both metabolic dysfunction-associated fatty liver disease (MAFLD) and advanced hepatic fibrosis.

METHODS

Participants who underwent abdominal ultrasonography and thyroid function test in a Chinese hospital from 2015 to 2021were enrolled. Fibrosis-4 index (FIB-4) > 2.67 and/or non-alcoholic fatty liver disease fibrosis score (NFS) > 0.676 were used to define advanced fibrosis. Descriptive analyses were performed to characterize the epidemiology of MAFLD according to levels of thyroid-stimulating hormone (TSH). The logistic regression model was applied to estimate the association of low thyroid function with MAFLD and advanced fibrosis.

RESULTS

A total of 19,946 participants (52.78% males, mean age: 47.31 years, 27.55% MAFLD) were included, among which 14,789 were strict-normal thyroid function, 4,328 were low-normal thyroid function, 829 were subclinical hypothyroidism. TSH levels were significantly higher in MAFLD patients with a FIB-4 > 2.67 and /or NFS > 0.676 than their counterparts. The logistic regression model adjusted for age and sex showed that low-normal thyroid function increased the risk of MAFLD (odds ratio [OR] = 1.09; 95% confidence interval [CI] 1.01-1.18). Multivariable regression model adjusted for age, sex, body mass index, type 2 diabetes, and hypertension showed low-normal thyroid function increased the risk of advanced fibrosis in patients with MAFLD (FIB-4 > 2.67: OR = 1.41, 95% CI 1.02-1.93; NFS > 0.676: OR = 1.72, 95% CI 1.08-2.72).

CONCLUSION

Elevated TSH concentrations are associated with advanced hepatic fibrosis, even in the euthyroid state.

Association between self-reported snoring and metabolic-associated fatty liver disease: A cross-sectional analysis of the NHANES 2017-2018

BACKGROUND

Snoring may play an important role in a variety of diseases, especially metabolic diseases. However, there are no reports on the relationship between snoring and the risk of metabolic-associated fatty liver disease (MAFLD). This study aimed to investigate the association between snoring and MAFLD.

METHODS

A cross-sectional analysis was performed based on the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Self-reported snoring frequency was grouped into four categories (never, rarely, occasionally, and frequently). MAFLD was diagnosed based on the evidence of hepatic steatosis and any of the following three conditions: overweight/obesity, diabetes mellitus or metabolic dysfunction. Logistic regression with sampling weights was used to examine the association between snoring and MAFLD.

RESULTS

A total of 5016 patients were included, and 50.14% of individuals had MAFLD. Compared with nonsnorers, those who snored frequently were associated with increased odds for MAFLD (odds ratio (OR): 1.376, 95% confidence interval (CI): 1.122-1.688, p trend <0.001). The subgroup analyses suggested that no significant interactions were found between snoring and other potential effect modifiers, including age, sex, body mass index (BMI), smoking status, chronic obstructive pulmonary disease (COPD) and hypertension.

CONCLUSION

Snoring was independently and positively associated with a higher prevalence of MAFLD, suggesting that attention to snoring may contribute to the early detection of MAFLD.

Comparison between traditional and new obesity measurement index for screening metabolic associated fatty liver disease

Objectives

Obesity measurement indexes have certain screening value for metabolic diseases. To investigate associations between metabolic associated fatty liver disease (MAFLD) and obesity measurement indexes, including traditional indexes (BMI, WC, WHtR) and new indexes (ABSI, BRI, VAI, LAP), and assess their screening ability.

Methods

12,658 subjects aged 18-75 at the Health Center of a Class III Grade A Hospital were included, who were divided into MAFLD and non-MAFLD groups. Spearman's rank correlation was used to study the correlation between MAFLD and obesity measurement indexes. Receiver operating characteristic (ROC) curves were used to calculate the area under the curve (AUC) to evaluate their screening accuracy.

Results

MAFLD had strong correlation with traditional BMI and new index LAP. ROC analysis showed that BMI had the highest AUC (0.89), followed by LAP (0.87). Stratification by BMI, LAP had the highest AUC (0.90) for MAFLD in population without obesity (BMI< 23kg/m²), and its optimal cutoff value was 20.75, with a sensitivity and specificity of 85.9% and 79.0%, respectively.

Conclusions

We proposed a two-step screening strategy for MAFLD, combining BMI and LAP, and defined a high-risk population for MAFLD as follows: 1) BMI ≥ 23 kg/m²; and 2) BMI< 23 kg/m² and LAP ≥ 20.75.

Incidence and Predictors of Liver-Related Events in Patients With Nonalcoholic Fatty Liver Disease

Background

Nonalcoholic fatty liver disease (NAFLD) is the commonest type of liver disease worldwide. We aimed to assess the incidence and predictors of liver-related events (LREs) and mortality in NAFLD patients.

Methods

NAFLD patients (n = 957) evaluated between January 2000 and November 2021 were included. Patients were categorised as noncirrhosis (NC), compensated cirrhosis (CC) and decompensated cirrhosis (DC), and the incidence of LRE and mortality were estimated and compared.

Results

The proportions of NC, CC and DC were 87.8% (n = 840), 8.8% (n = 84) and 3.4% (n = 33), respectively. The median follow-up duration was 3.9 (3.0-5.7) years, and the total cumulative duration was 4633 person-years. The incidence of LRE per 100 person-years was 0.14, 2.72 and 10.24 in patients with NC, CC and DC, respectively. The incidence of mortality was 0.12, 1.05 and 4.24 per 100 person-years, respectively, in the 3 groups. The causes of mortality in the 3 groups were liver related in 1/5 (20%), 3/4 (75%) and 6/9 (66.7%), respectively. Overall, the mortality rate was higher in those with diabetes than those without diabetes (log-rank P value = 0.005). On further analysis, diabetes was associated with poor outcomes only in NC group (log-rank P value = 0.036), and not in CC (log-rank P value = 0.353) or DC groups (log-rank P value = 0.771). On multivariate Cox proportional hazard analysis, age (hazard ratio [HR] 1.070), hypertension (HR 4.361) and DC (HR 15.036) were independent predictors of poor outcomes. Liver stiffness measurement, bilirubin, CC and DC were independent predictors of LRE.

Conclusion

In our study of NAFLD from India, the incidence of LRE was found to be similar to that seen in Western studies. In NC NAFLD, diabetes was associated with poor outcomes.

Insights into the role of nucleotide methylation in metabolic-associated fatty liver disease

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease characterized by fatty infiltration of the liver. In recent years, the MAFLD incidence rate has risen and emerged as a serious public health concern. MAFLD typically progresses from the initial hepatocyte steatosis to steatohepatitis and then gradually advances to liver fibrosis, which may ultimately lead to cirrhosis and carcinogenesis. However, the potential evolutionary mechanisms still need to be clarified. Recent studies have shown that nucleotide methylation, which was directly associated with MAFLD's inflammatory grading, lipid synthesis, and oxidative stress, plays a crucial role in the occurrence and progression of MAFLD. In this review, we highlight the regulatory function and associated mechanisms of nucleotide methylation modification in the progress of MAFLD, with a particular emphasis on its regulatory role in the inflammation of MAFLD, including the regulation of inflammation-related immune and metabolic microenvironment. Additionally, we summarize the potential value of nucleotide methylation in the diagnosis and treatment of MAFLD, intending to provide references for the future investigation of MAFLD.

Effects of lifestyle intervention on adults with metabolic associated fatty liver disease: A systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis evaluates the overall effects of lifestyle interventions upon hepatic fat content and metabolism-related indicators among adults with metabolic associated fatty liver disease.

METHODS

It was registered under PROSPERO (CRD42021251527). We searched PubMed, EMBASE, MEDLINE, Cochrane, CINAHL, Scopus, CNKI, Wan-fang, VIP, and CBM from the inception of each database to May 2021 for RCT studies of lifestyle interventions on hepatic fat content and metabolism-related indicators. We used Review Manager 5.3 for meta-analysis and used text and detailed tabular summaries when heterogeneity existed.

RESULTS

Thirty-four RCT studies with 2652 participants were included. All participants were obesity, 8% of whom also had diabetes, and none was lean or normal weight. Through subgroup analysis, we found low carbohydrate diet, aerobic training and resistance training significantly improved the level of HFC, TG, HDL, HbA1c, and HOMA-IR. Moreover, low carbohydrate diet is more effective in improving HFC than low fat diet and resistance training is better than aerobic training in reduction in HFC and TG (SMD, -0.25, 95% CI, -0.45 to -0.06; SMD, 0.24, 95% CI, 0.03 to 0.44, respectively).

DISCUSSION

Overall, this is the first review that systematically synthesizes studies focused on the effects of various lifestyle on adults with MAFLD. The data generated in this systematic review were more applicable to obesity MAFLD rather than lean or normal weight MAFLD.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier (CRD42021251527).

Impaired ketogenesis is associated with metabolic-associated fatty liver disease in subjects with type 2 diabetes

AIMS

The ketogenic pathway is an effective mechanism by which the liver disposes of fatty acids (FAs) to the peripheral tissues. Impaired ketogenesis is presumed to be related to the pathogenesis of metabolic-associated fatty liver disease (MAFLD), but the results of previous studies have been controversial. Therefore, we investigated the association between ketogenic capacity and MAFLD in subjects with type 2 diabetes (T2D).

METHODS

A total of 435 subjects with newly diagnosed T2D was recruited for the study. They were classified into two groups based on median serum β-hydroxybutyrate (β-HB) level: intact vs. impaired ketogenesis groups. The associations of baseline serum β-HB and MAFLD indices of hepatic steatosis index, NAFLD liver fat score (NLFS), Framingham Steatosis index (FSI), Zhejian University index, and Chinese NAFLD score were investigated.

RESULTS

Compared to the impaired ketogenesis group, the intact ketogenesis group showed better insulin sensitivity, lower serum triglyceride level, and higher low-density lipoprotein-cholesterol and glycated hemoglobin levels. Serum levels of liver enzymes were not different between the two groups. Of the hepatic steatosis indices, NLFS (0.8 vs. 0.9, p=0.045) and FSI (39.4 vs. 47.0: p=0.041) were significantly lower in the intact ketogenesis group. Moreover, intact ketogenesis was significantly associated with lower risk of MAFLD as calculated by FSI after adjusting for potential confounders (adjusted odds ratio 0.48, 95% confidence interval 0.25-0.91, p=0.025).

CONCLUSIONS

Our study suggests that intact ketogenesis might be associated with decreased risk of MAFLD in T2D.

Fatty liver disease in children (MAFLD/PeFLD Type 2): unique classification considerations and challenges

In children, fatty liver disease is a group of disorders that often overlaps with inherited metabolic disorders (IMDs), which requires prompt diagnosis and specific management. Metabolic dysfunction-associated fatty liver disease (MAFLD) or, formerly, non-alcoholic fatty liver disease (NAFLD) is the hepatic component of a multisystemic disease that requires a positive criteria in metabolic dysfunction for diagnosis. However, in children, the diagnosis of MAFLD is one of the exclusions of an IMD [paediatric fatty liver disease (PeFLD) type 1] including the possibility that an IMD can be identified in the future following investigations that may be negative at the time. Therefore, while children with fatty liver with metabolic dysfunction could be classified as MAFLD (PeFLD type 2) and managed that way, those who do not fulfil the criteria for metabolic dysfunction should be considered separately bearing in mind the possibility of identifying a yet undiagnosed IMD (PeFLD type 3). This concept is ever more important in a world where MAFLD is the most common cause of liver disease in children and adolescents in whom about 7% are affected. The disease is only partially understood, and awareness is still lacking outside hepatology and gastroenterology. Despite its increasing pervasiveness, the management is far from a one-size-fits-all. Increasing complexities around the genetic, epigenetic, non-invasive modalities of assessment, psychosocial impacts, therapeutics, and natural history of the disease have meant that an individualised approach is required. This is where the challenge lies so that children with fatty liver are considered on their own merits. The purpose of this review is to give a clinical perspective of fatty liver disease in children with relevance to metabolic dysfunction.

Experimental diets dictate the metabolic benefits of probiotics in obesity

Growing evidence supports the use of probiotics to prevent or mitigate obesity-related dysmetabolism and non-alcoholic fatty liver disease (NAFLD). However, frequent reports of responders versus non-responders to probiotic treatment warrant a better understanding of key modifiers of host-microbe interactions. The influence of host diet on probiotic efficacy, in particular against metabolic diseases, remains elusive. We fed C57BL6/J mice a low fat reference diet or one of two energy-matched high fat and high sucrose diets for 12 weeks; a classical high fat diet (HFD) and a customized fast food-mimicking diet (FFMD). During the studies, mice fed either obesogenic diet were gavaged daily with one of two probiotic lactic acid bacteria (LAB) strains previously classified as Lactobaccillus, namely Limosilactobacillus reuteri (L. reuteri)or Lacticaseibacillus paracaseisubsp. paracasei (L. paracasei), or vehicle. The tested probiotics exhibited a reproducible efficacy but dichotomous response according to the obesogenic diets used. Indeed, L. paracaseiprevented weight gain, improved insulin sensitivity, and protected against NAFLD development in mice fed HFD, but not FFMD. Conversely, L. reuteri improved glucoregulatory capacity, reduced NAFLD development, and increased distal gut bile acid levels associated with changes in predicted functions of the gut microbiota exclusively in the context of FFMD-feeding. We found that the probiotic efficacy of two LAB strains is highly dependent on experimental obesogenic diets. These findings highlight the need to carefully consider the confounding impact of diet in order to improve both the reproducibility of preclinical probiotic studies and their clinical research translatability.

Diet was less significant than physical activity in the prognosis of people with sarcopenia and metabolic dysfunction-associated fatty liver diseases: Analysis of the National Health and Nutrition Examination Survey III

BACKGROUND

Sarcopenia is prevalent in metabolic dysfunction-associated fatty liver diseases (MAFLD), and the primary treatment for both diseases is lifestyle modification. We studied how dietary components and physical activity affect individuals with sarcopenia and MAFLD.

MATERIALS AND METHODS

We conducted a study utilizing National Health and Nutrition Examination Survey (NHANES) III (1988-1994) data with Linked Mortality file (through 2019). The diagnosis of fatty liver disease (FLD) was based on ultrasound images revealing moderate and severe steatosis. Using bioelectrical measures, sarcopenia was assessed. Using self-report data, dietary intake and physical activity levels were evaluated.

RESULTS

Among 12,259 participants, 2,473 presented with MAFLD, and 290 of whom had sarcopenia. Higher levels of physical activity (odds ratio [OR] = 0.51 [0.36-0.95]) and calorie (OR = 0.58 [0.41-0.83]) intake reduced the likelihood of sarcopenia in MAFLD patients. During a median follow-up period of 15.3 years, 1,164 MAFLD and 181 MAFLD patients with sarcopenia perished. Increased activity levels improved the prognosis of patients with sarcopenia (Insufficiently active, HR = 0.75 [0.58-0.97]; Active, HR = 0.64 [0.48-0.86]), which was particularly pronounced in older patients.

CONCLUSION

In the general population, hyperglycemia was highly related to MAFLD prognosis. Physical inactivity and a protein-restricted diet corresponded to sarcopenia, with physical inactivity being connected to poor outcomes. Adding protein supplements would be beneficial for older people with sarcopenia who are unable to exercise due to frailty, while the survival benefits were negligible.

The relationship between metabolic dysfunction-associated fatty liver disease and the incidence rate of extrahepatic cancer

BACKGROUND

The associations between metabolic dysfunction-associated fatty liver disease (MAFLD) and cancer development, especially extrahepatic cancers, are unknown. The aims of the current study were to investigate the cancer incidence rates of MAFLD and analyze the associations between MAFLD and the development of cancers.

METHODS

This historical cohort study included participants who underwent ultrasonographic detection of hepatic steatosis at a tertiary hospital in China from January 2013 to October 2021. MAFLD was diagnosed in accordance with The International Expert Consensus Statement. Cox proportional hazards regression modeling was used to assess the associations between MAFLD and the development of cancers.

RESULTS

Of the 47,801 participants, 16,093 (33.7%) had MAFLD. During the total follow-up of 175,137 person-years (median 3.3 years), the cancer incidence rate in the MAFLD group was higher than that in the non-MAFLD group [473.5 vs. 255.1 per 100,000 person-years; incidence rate ratio 1.86; 95% confidence interval (CI) 1.57-2.19]. After adjustment for age, gender, smoking status, and alcohol status, MAFLD was moderately associated with cancers of the female reproductive system/organs (labium, uterus, cervix, and ovary) [hazard ratio (HR) 2.24; 95% CI 1.09-4.60], thyroid (HR 3.64; 95% CI 1.82-7.30), and bladder (HR 4.19; 95% CI 1.15-15.27) in the total study cohort.

CONCLUSION

MAFLD was associated with the development of cancers of the female reproductive system/organs (labium, uterus, cervix, and ovary), thyroid, and bladder in the total study cohort.

Time-trends in disease characteristics and comorbidities in patients with chronic hepatitis B in the period 1980-2020

BACKGROUND & AIMS

The incidence of chronic hepatitis B (CHB) is declining due to successful implementation of vaccination programs and widespread use of antiviral therapy. We aimed to study time-trends in disease characteristics and comorbidities in newly referred CHB patients.

METHODS

We collected information on hepatitis B virus (HBV) related disease characteristics (including hepatitis B e-antigen (HBeAg) status, viremia, stage of liver fibrosis and indication for treatment and/or hepatocellular carcinoma (HCC) surveillance) and presence of comorbidities in all CHB patients referred to our center from 1980 through 2020. Patient characteristics were compared according to referral date (before 2000, between 2000 and 2010 and after 2010).

RESULTS

We identified 1515 eligible patients. Patients referred after 2010 were older (36 versus 34 years, p < 0.001), more often non-Caucasian (82.3% versus 55.0%, p < 0.001) and more frequently HBeAg negative (81.5% versus 49.8%, p < 0.001) when compared to patients referred before 2000. Adjusted for ethnicity, sex and age, patients referred after 2010 were less likely to have significant fibrosis (adjusted odds ratio [aOR]:0.178, p < 0.001) or indication for antiviral therapy (aOR:0.342, p < 0.001) but were more likely to be affected by the metabolic syndrome (aOR:1.985, p = 0.013), hepatic steatosis (aOR:1.727, p < 0.001) and metabolic dysfunction associated fatty liver disease (MAFLD) (aOR:1.438, p = 0.013).

CONCLUSIONS

The characteristics of the CHB populations are changing. Newly referred patients are older, have less active HBV related liver disease but are more likely to be co-affected by MAFLD. These findings provide guidance for adequate allocation of resources to cope with the changing characteristics of the CHB population.

FUNDING

Foundation for Liver and Gastrointestinal Research Rotterdam, the Netherlands and Gilead Sciences.

Identifying advanced MAFLD in a cohort of T2DM and clinical features

BACKGROUND

MAFLD is the most common cause of chronic liver disease, affecting 25% of the global population. Patients with T2DM have an increased risk of developing MAFLD. In addition, patients with T2DM have a higher risk of advanced forms of steatohepatitis and fibrosis. Identifying those patients is critical in order to refer them to specialist and appropriate management of their disease.

AIMS AND OBJECTIVES

To estimate advanced fibrosis prevalence in a cohort of patients with T2DM and to identify possible predictors.

METHODS

subjects with T2DM during regular health check-up were enrolled. Demographic and general characteristics were measured, including metabolic parameters and homeostasis model assessment of insulin resistance (HOMA2-IR). Four non-invasive fibrosis scores (NAFLD fibrosis scores, FIB-4, APRI, Hepamet fibrosis score) were measure and compared with transient elastography (TE).

RESULTS

96 patients (21%) presented risk of significant fibrosis (≥F2) measured by TE and 45 patients (10%) presented with risk of advanced fibrosis F3-F4. Liver fibrosis was related to BMI, AC, HOMA2-IR. The results of the non-invasive fibrosis scores have been validated with the results obtained in the TE. It is observed that the index with the greatest area under the curve (AUC) is APRI (AUC=0.729), with a sensitivity of 62.2% and a specificity of 76.1%. However, the test with better positive likelihood ratio (LR+) in our study is NAFLD fibrosis score.

CONCLUSIONS

Our results show that in a general T2DM follow up, 10% of patients were at risk of advanced fibrosis. We found a positive correlation between liver fibrosis and BMI, AC and HOMA2-IR. Non-invasive fibrosis markers can be useful for screening, showing NAFLD Fibrosis score a better LHR+ compared to TE. Further studies are needed to validate these results and elucidate the best screening approach to identify those patients at risk of advanced MAFLD.

Screening for MAFLD: who, when and how?

Metabolic-associated fatty liver disease (MAFLD) is a highly prevalent disease with increasing prevalence worldwide. Currently, no universal screening methods have been standardized, even when this disease poses a major health burden. MAFLD as a spectrum of diseases can range from simple steatosis, and steatohepatitis to fibrosis and hepatocellular carcinoma. Its extra-hepatic manifestations are vast and include cardiovascular diseases, extra-hepatic malignancies, cognitive and respiratory alterations. Given its extensive damage targets as well as its high prevalence, timely identification of the high-risk population presenting metabolic dysfunction should undergo universal non-invasive screening methods, which can be carried out through blood tests, easy and effective imaging techniques, such as ultrasound, score calculation and general clinical information brought together from primary patient-physician contact.

Emerging trends and hotspots in metabolic dysfunction-associated fatty liver disease (MAFLD) research from 2012 to 2021: A bibliometric analysis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the most common chronic liver disease. MAFLD is a major risk factor for end-stage liver disease including cirrhosis and primary liver cancer. The pathogenesis of MAFLD is complex and has not yet been clarified. To the best of our knowledge, few studies have conducted quantitative bibliometric analysis to evaluate published MAFLD research. In this study, we conducted a comprehensive analysis of MAFLD publications over the past decade to summarize the current research hotspots and predict future research directions in this field.

METHODS

Articles into MAFLD published from 2012 to 2021 were identified from the Science Citation Index-Expanded of Web of Science Core Collection. CiteSpace software, VOSviewer, the "bibliometrix" R package, and the Online Analysis Platform of Literature Metrology were used to analyze the current publication trends and hotspots.

RESULTS

We retrieved 13959 English articles about MAFLD published from 2012 to 2021. Primary sites of publication were dominated by the United States until 2014, when China became the source of most published MAFLD-related research papers. The United States was found to be the most engaged country in international cooperative efforts. Shanghai Jiao Tong University was the most productive institution. Loomba R was the most productive author with 123 articles. The co-cited keyword cluster tag showed ten main clusters: #0 liver fibrosis, #1 hemoglobin, #2 metabolic associated fatty liver disease, #3 egcg, #4 myocardial infarction, #5 heart disease, #6 pnpla3, #7 hepatocellular carcinoma, #8 noninvasive marker, and #9 children. Keyword burst analysis showed that gut microbiota was the highest-intensity research hotspot.

CONCLUSION

In the past decade, the number of publications on MAFLD increased dramatically, especially in the last three years. Gut microbiota became an important research direction for etiological and therapeutic investigations into MAFLD. Insulin resistance was also a key factor in studying the development of MAFLD in recent years. Liver fibrosis was an important focus of disease development. This study provides systematic information, helps guide future research, and helps to identify mechanisms and new treatment methods for MAFLD.

Prevalence and Risk Factors of Metabolic-Associated Fatty Liver Disease Among Hospital Staff

Background

The prevalence of metabolism-related fatty liver disease (MAFLD) has been rarely reported in hospital staffs. The aim of this study was to assess the prevalence and risk factors for MAFLD in hospital staffs aged ≥18 years.

Methods

Based on type B ultrasonic, hospital staffs who underwent medical examinations at the second Affiliated Hospital of Hainan Medical University from January 2022 to March 2022 were classified into health control group (661 subjects) and MAFLD group (223 subjects), demographic, biochemical and blood examination information were compared between 2 groups. Independent risk factors for MAFLD were determined by logistic regression. Predictive values of risk factors of MAFLD were evaluated by receiver operating characteristic (ROC) curves.

Results

The prevalence of MAFLD was 33.7%. Older age (OR=1.08, p<0.001), H. pylori infection (OR=0.234, p=0.02), triglyceride-glucose (TyG) (OR=7.001, p<0.001), low-density lipoprotein cholesterol (LDL-C) (OR=2.076, p=0.028), red blood cell (RBC) (OR=2.386, p=0.001), eating out (OR=0.048, p=0.001), regular exercise (OR=23.017, p<0.001), and overweight (OR=3.891, p=0.003) were independently associated factors for MAFLD. The AUC of model predicting MAFLD is 0.910 [95% CI (0.886, 0.934)], with 0.794 sensitivity, 0.908 specificity. The diagnostic value of model was higher in the female MAFLD group after stratified analysis according to gender. The model showed that TyG was the factor contributing more to MAFLD. The diagnostic value of TyG was higher in the female MAFLD group than male MAFLD group.

Conclusion

The prevalence of MAFLD among hospital staffs was 33.7%. TyG can be used to predict MAFLD especially for female hospital staffs for early intervention.

Serum metabolomics-based heterogeneities and screening strategy for metabolic dysfunction-associated fatty liver disease (MAFLD)

BACKGROUND AND AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) brings heavy clinical and economic burdens to society, while understandings on heterogeneities are limited.

MATERIALS AND METHODS

We conducted a serum metabolomics study to reveal the metabolic heterogeneities and develop a diagnostic strategy for MAFLD using a discovery set consisting of 122 biopsy-proven MAFLD patients [lean (n = 12), overweight (n = 20), obese (n = 74), type 2 diabetes mellitus (T2DM, n = 16)] and 35 controls, and a validation set containing 60 biopsy-proven MAFLD patients (20 lean, 20 obese and 20 T2DM) and 20 controls.

RESULTS

Mitochondrial dysfunction, destructed phospholipids homeostasis, and folate deficiency were most severe in MAFLD concurrent T2DM patients. Formiminoglutamate, sphinganine and sphingosine correlated positively with HbA1c, while glycoursodeoxycholicacidsulfate correlated positively with AST. Additionally, the linear discriminant analysis (LDA) model using metabolites 5-hydroxyhexanoate, ribitol and formiminoglutamate demonstrated pretty good performance in screening for MAFLD patients, with AUC for validation samples being 0.94 (CI: 0.88-1.0). For easier clinical applications, an M-index based on the three metabolites was further designed.

CONCLUSION

Our study supports that MAFLD concurrent T2DM patients deserve particular attentions in clinical follow-up, and paves the way for developing more effective diagnostic options in future studies.

Sex-stratified associations between fatty liver disease and Parkinson's disease: The Rotterdam study

Fatty liver disease was not associated with Parkinsonism or Parkinson's disease in an elderly European population, the Rotterdam Study, (n = 8.848), neither in men nor women. Results were consistent either using non-alcoholic fatty liver disease (NAFLD) or metabolic-dysfunction associated fatty liver disease (MAFLD) as exposure defined by either fatty liver index (FLI) or ultrasound.

MAFLD: a multisystem disease

Nonalcoholic fatty liver disease (NAFLD), affecting about 25% of general population and more than 50% of dysmetabolic patients, is an emerging cause of chronic liver disease and its complications. Recently, an international consensus of experts proposed to rename this disease as 'Metabolic dysfunction-Associated Fatty Liver Disease' (MAFLD) to focus on the bidirectional interplay between fatty liver and metabolic alterations and to stress the need of assessing fatty liver independently from alcohol consumption and other coexisting causes of liver disease. The peculiarity of NAFLD/MAFLD lies in the presence of a higher risk of not only - as expected - liver-related events but also of extrahepatic events, mostly cardiovascular and cancers. Available evidence suggests that these associations are not only the expression of sharing the same risk factors but shed light about the ability of NAFLD/MAFLD and particularly of its progressive form - nonalcoholic/metabolic dysfunction-associated steatohepatitis - to act as an independent risk factor via promotion of atherogenic dyslipidemia and a proinflammatory, profibrogenic, and procoagulant systemic environment. The present review summarizes available epidemiological and clinical evidence supporting the concept of NAFLD/MAFLD as a multisystemic disease, and highlights potential explanatory mechanisms underlying the association between NAFLD/MAFLD and extrahepatic disorders.

Recent advances in NAFLD: current areas of contention

This brief review focuses on two contentious issues within the field of non-alcoholic fatty liver disease (NAFLD); the first is the recent effort to redefine NAFLD as metabolic (dysfunction)-associated fatty liver disease (MAFLD). The modification of "NAFLD" to "MAFLD" is expected to highlight the role of metabolic factors in the disease aetiology, which is hoped to improve patient understanding of the disease, facilitate patient-physician communication and highlight the importance of public health interventions in prevention and management. The diagnostic criteria for MAFLD allow it to coexist with other forms of liver disease, which recognises that metabolic dysfunction contributes towards disease progression in other liver pathologies, such as alcoholic liver disease. However, there remain concerns that renaming NAFLD may be premature without fully considering the broader implications, from diagnostic criteria to trial endpoints; therefore, the new definition has not yet been accepted by major societies. Another contentious issue within the field is the gap in our understanding of how patients undergoing therapeutic interventions should be monitored to assess amelioration/attenuation or the worsening of their liver disease. Biomarker scoring systems (such as the ELF test and FIB-4 test) and imaging techniques (such as transient elastography [TE] and magnetic resonance imaging [MRI] techniques) are proven to be reasonably accurate, and comparable with histology, in the diagnosis of NAFLD and evaluation of disease severity; however, their use in monitoring the response of disease to therapeutic interventions is not well established. Whilst biomarker scoring systems and TE are limited by poor diagnostic accuracy in detecting moderate fibrosis (e.g. F2 liver fibrosis defined by histology), more accurate MRI techniques are not practical for routine patient follow-up due to their expense and limited availability. More work is required to determine the most appropriate method by which therapeutic interventions for NAFLD should be monitored in clinical practice.

Gut microbiota modulation in patients with non-alcoholic fatty liver disease: Effects of current treatments and future strategies

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with metabolic disorders, being highly prevalent in obese and diabetic patients. Many concomitant factors that promote systemic and liver inflammation are involved in NAFLD pathogenesis, with a growing body of evidence highlighting the key role of the gut microbiota. Indeed, the gut-liver axis has a strong impact in the promotion of NAFLD and in the progression of the wide spectrum of its manifestations, claiming efforts to find effective strategies for gut microbiota modulation. Diet is among the most powerful tools; Western diet negatively affects intestinal permeability and the gut microbiota composition and function, selecting pathobionts, whereas Mediterranean diet fosters health-promoting bacteria, with a favorable impact on lipid and glucose metabolism and liver inflammation. Antibiotics and probiotics have been used to improve NAFLD features, with mixed results. More interestingly, medications used to treat NAFLD-associated comorbidities may also modulate the gut microbiota. Drugs for the treatment of type 2 diabetes mellitus (T2DM), such as metformin, glucagon-like peptide-1 (GLP-1) agonists, and sodium-glucose cotransporter (SGLT) inhibitors, are not only effective in the regulation of glucose homeostasis, but also in the reduction of liver fat content and inflammation, and they are associated with a shift in the gut microbiota composition towards a healthy phenotype. Even bariatric surgery significantly changes the gut microbiota, mostly due to the modification of the gastrointestinal anatomy, with a parallel improvement in histological features of NAFLD. Other options with promising effects in reprogramming the gut-liver axis, such as fecal microbial transplantation (FMT) and next-generation probiotics deserve further investigation for future inclusion in the therapeutic armamentarium of NAFLD.

Exosomes from Short-Term High-Fat or High-Sucrose Fed Mice Induce Hepatic Steatosis through Different Pathways

Obesity and other closely associated diseases, such as metabolic-associated fatty liver disease (MAFLD) and type 2 diabetes, give rise to a common biometric and metabolic phenotype resulting from a different etiopathogenesis. To characterize the first stages of metabolic dysfunction induced by either obesity or hepatic steatosis, we compared two animal models of short-term feeding with either high-fat (HFD) or high-sucrose (SAC) diets. Using transcriptomic, metabolic, and calorimetric analyses, we determined that a short-term HFD leads to obesity and then hepatic steatosis through lipid storage, whereas SAC increases gluconeogenesis and de novo lipogenesis, resulting in hepatic steatosis followed later by obesity. Plasma exosomal miRNA profiles differed between HFD and SAC mice, and the injection of exosomes from HFD or SAC mice reproduced some transcriptomic and metabolic features of the donor mice. Finally, we exploited our data to identify circulating miR-22-3p as a candidate biomarker for MAFLD patient stratification. In conclusion, dietary challenges affecting adipose or hepatic metabolism regulate the abundance of exosomal miRNAs in plasma, which in turn modulate gene expression, helping the organism to adapt.

Development and Validation of a Nomogram for Prediction of the Risk of MAFLD in an Overweight and Obese Population

BACKGROUND AND AIMS

Metabolic associated fatty liver disease (MAFLD) is a serious condition, and a simple method is needed for practitioners to identify patients with the disease and have a high risk of disease progression.

METHODS

We developed and validated a nomogram for fatty liver disease and reclassified the risk factors for MAFLD. The development cohort had 335 patients who received bioelectrical impedance analysis and liver ultrasound attenuation measurements at Shenzhen People's Hospital between September 2020 and June 2021. The validation cohort had 200 patients from other hospitals who received the same evaluation. A random forest procedure and binary logistic analysis were used to screen for risk factors, establish a fatty liver disease predictive model, and forecast the risk of MAFLD. The performance of the nomogram was evaluated by measurement of discrimination, calibration, and clinical usefulness.

RESULTS

The nomogram provided good predictions in a model that included body mass index (BMI) and waist circumference. The areas under the curve of the nomogram were 0.793 in the development cohort and 0.774 in the validation cohort. The nomogram performed well for calibration, category-free net reclassification improvement, and integrated discrimination improvement. Decision curve analysis indicated the nomogram performed better than BMI for predicting net outcome.

CONCLUSIONS

The nomogram was an effective screening tool for fatty liver disease, and for those overweight individuals, may help physicians make appropriate decisions regarding treatment of MAFLD.

Encouraging Tactics with Genetically Modified Probiotics to Improve Immunity for the Prevention of Immune-Related Diseases including Cardio-Metabolic Disorders

The PI3K/AKT/mTOR signaling pathway may play crucial roles in the pathogenesis of obesity and diabetes mellitus, as well as metabolic syndromes, which could also be risk factors for cardio-metabolic disorders. Consistently, it has been shown that beneficial effects may be convoyed by the modulation of the PI3K/AKT/mTOR pathway against the development of these diseases. Importantly, the PI3K/AKT/mTOR signaling pathway can be modulated by probiotics. Probiotics have a variety of beneficial properties, with the potential of treating specific diseases such as immune-related diseases, which are valuable to human health. In addition, an increasing body of work in the literature emphasized the contribution of genetically modified probiotics. There now seems to be a turning point in the research of probiotics. A better understanding of the interactions between microbiota, lifestyle, and host factors such as genetics and/or epigenetics might lead to a novel therapeutic approach with probiotics for these diseases. This study might provide a theoretical reference for the development of genetically modified probiotics in health products and/or in functional foods for the treatment of cardio-metabolic disorders.

Novel insights into the N6-methyladenosine RNA modification and phytochemical intervention in lipid metabolism

Epitranscriptome (RNA modification) plays a vital role in a variety of biological events. N6-methyladenosine (m6A) modification is the most prevalent mRNA modification in eukaryotic cells. Dynamic and reversible m6A modification affects the plasticity of epitranscriptome, which plays an essential role in lipid metabolism. In this review, we comprehensively delineated the role and mechanism of m6A modification in the regulation of lipid metabolism in adipose tissue and liver, and summarized phytochemicals that improve lipid metabolism disturbance by targeting m6A regulator, providing potential lead candidates for drug therapeutics. Moreover, we discussed the main challenges and possible future directions in this field.

Gypenosides counteract hepatic steatosis and intestinal barrier injury in rats with metabolic associated fatty liver disease by modulating the adenosine monophosphate activated protein kinase and Toll-like receptor 4/nuclear factor kappa B pathways

CONTEXT

Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease, can develop into metabolic associated fatty liver disease (MAFLD). Gypenosides (GP), the main phytochemical component of Gynostemma pentaphylla (Thunb.) Makino (Cucurbitaceae), have been applied for treatment of metabolic diseases.

OBJECTIVE

We investigate how GP modulate MAFLD-related hepatic steatosis and intestinal barrier injury.

MATERIALS AND METHODS

In cell experiments, Caco-2 cells were treated with GP (150 or 200 μmol/L, 24 h), following lipopolysaccharide (LPS) exposure (10 μg/mL, 24 h) to mimic MAFLD in vitro. In in vivo experiments, control, model and model + GP groups were set. High fructose diet/high fat (HFD/HF)-fed (12 weeks) MAFLD rats received GP treatment (300 mg/kg, 6 weeks), followed by intra-peritoneal glucose tolerance test and histopathological examination of rat liver and intestinal mucosa using haematoxylin-eosin staining.

RESULTS

GP at 200 μM significantly reversed LPS-induced decreases in transepithelial electrical resistance (TER) value (25%), protein expression of occludin (two fold) and ZO-1 (four fold), and the ratio of p-AMPK to AMPK (five fold), while partially repressing LPS-induced leakage of FD4 (50%) and LPS-induced increases in the Toll-like receptor 4 (TLR4) level (50%) and the ratio of p-p65 to p65 (55%). Compared with the model rats, rats with GP treatment presented a reduction in gain of weight and glucose tolerance. In addition, GP alleviated HFD/HF-induced histopathological abnormalities in rat liver and intestinal mucosa.

CONCLUSIONS

GP attenuates hepatic steatosis and intestinal barrier injury in MAFLD rats via the AMPK and TLR4/nuclear factor kappa B (NF-κB) pathways, providing a potential treatment for MAFLD patients.

Effect of metabolic dysfunction-associated fatty liver disease on liver cancer risk in a population with chronic hepatitis B virus infection: A nationwide study

BACKGROUND

The association between metabolic dysfunction-associated fatty liver disease (MAFLD) and hepatocellular carcinoma (HCC) lacks clinical validation in at-risk populations. We assessed this relationship among chronic hepatitis B (CHB) patients.

METHODS

Data was collected from the National Health Insurance System database in South Korea. Chronic hepatitis B patients aged over 40 years receiving health examinations between 2011 and 2012 were recruited. The primary outcome was HCC. Metabolic dysfunction-associated fatty liver disease was defined as hepatic steatosis in combination with at least one of the following: (i) overweight, (ii) diabetes, or (iii) lean/normal weight with two or more metabolic components. Multivariable Cox regression analysis was used to estimate adjusted hazard ratios (aHRs).

RESULTS

Of 197 346 participants, 66 149 had MAFLD; 19 149, 44 475, and 2525 fulfilled diabetes (regardless of overweight), overweight alone, and lean/normal weight with two or more metabolic components, respectively. During follow-up (median 7 years), 13 771 developed HCC. Metabolic dysfunction-associated fatty liver disease was independently associated with increased risk of HCC, with aHR of 1.36 (p < 0.001). Propensity score matching confirmed the same phenomena, with aHR of 1.37 (p < 0.001). Furthermore, when stratified by liver cirrhosis and/or antiviral therapy, independent significances of MAFLD for HCC risk were maintained (all p < 0.001). Compared with the persistent non-MAFLD subgroup during the entire follow-up, diagnosis of MAFLD from at least one health examination significantly increased HCC risk with aHRs of 1.41, 1.37, and 1.14 among subgroups with persistent MAFLD, MAFLD to non-MAFLD, and non-MAFLD to MAFLD, respectively (all p < 0.05).

CONCLUSIONS

Metabolic dysfunction-associated fatty liver disease consistently increases HCC risk among CHB patients. Further studies are needed to develop an effective preventive strategy through control of metabolic health.

Detangling the interrelations between MAFLD, insulin resistance, and key hormones

Metabolic dysfunction-associated fatty liver disease (MAFLD) has increasingly become a significant and highly prevalent cause of chronic liver disease, displaying a wide array of risk factors and pathophysiologic mechanisms of which only a few have so far been clearly elucidated. A bidirectional interaction between hormonal discrepancies and metabolic-related disorders, including obesity, type 2 diabetes mellitus (T2DM), and polycystic ovarian syndrome (PCOS) has been described. Since the change in nomenclature from non-alcoholic fatty liver disease (NAFLD) to MAFLD is based on the clear impact of metabolic elements on the disease, the reciprocal interactions of hormones such as insulin, adipokines (leptin and adiponectin), and estrogens have strongly pointed to the intrinsic links that lead to the heterogeneous epidemiology, clinical presentations, and risk factors involved in MAFLD in different populations. The objective of this work is twofold. Firstly, there is a brief discussion regarding the change in nomenclature as well as epidemiology, risk factors, and pathophysiologic mechanisms other than hormonal effects, which include nutrition and the gut microbiome, as well as genetic and epigenetic influences. Secondly, we review the basis of the most important hormonal factors involved in the development and progression of MAFLD that act both independently and in an interrelated manner.

MAFLD: A quick fact check

Metabolic (dysfunction)-associated fatty liver disease has taken importance during the last two years, given the new criteria for diagnosis compared to the previous criteria used to define non-alcoholic fatty liver disease. Multiple studies have also shown that this definition better adjusts to the pathogenesis and patient characteristics with fatty liver.

Evaluation of [18F]F-TZ3108 for PET Imaging of Metabolic-Associated Fatty Liver Disease

PURPOSE

Sigma-1 receptor (Sig-1R), a chaperone that resides at the mitochondrion-associated endoplasmic reticulum (ER) membrane, is an ER stress biomarker. It is thought that ER stress plays a critical role in the progression of metabolic-associated fatty liver disease (MAFLD). The aim of this study was to evaluate a positron emission tomography (PET) tracer [¹⁸F]F-TZ3108 targeting Sig-1R for MAFLD.

PROCEDURES

The mouse model of MAFLD was established by feeding high-fat diet (HFD) for 12 weeks. Dynamic (0-60 min) PET/CT scans were performed after intravenous injection of 2-deoxy-2[¹⁸F]fluoro-D-glucose ([¹⁸F]-FDG) and [¹⁸F]F-TZ3108. Tracer kinetic modeling was performed for quantification of the PET/CT imaging of the liver. Post-PET biodistribution, the liver tissue western blotting (WB), and immunofluorescence (IF) were performed to compare the expression of Sig-1R levels in the organs harvested from both MAFLD and age-matched control mice.

RESULTS

The micro PET/CT imaging revealed a significantly decreased uptake of [¹⁸F]F-TZ3108 in the livers of the MAFLD group compared to the healthy controls, while the uptake of [¹⁸F]-FDG in the livers was not significantly different between the two groups. Based on the tracer kinetic modeling, the binding disassociate rate (k₄) for [¹⁸F]F-TZ3108 was significantly increased in MAFLD group compared to healthy controls. The volume distribution (V_T), and the non-displacement binding potential (BP_ND) revealed significantly decrease in MAFLD compared to healthy controls respectively. The post-PET biodistribution (%ID/g) of [¹⁸F]F-TZ3108 in the livers of MAFLD mice was significantly reduced nearly twofold than that in the livers of control mice. WB and IF experiments further confirmed the reduction of Sig-1R expression in the MAFLD group.

CONCLUSIONS

The expression of Sig-1R in the liver, measured by the PET tracer, [¹⁸F]F-TZ3108, was significantly decreased in mouse model of MAFLD. The [¹⁸F]F-TZ3108 PET/CT imaging may provide a novel means of visualization for ER stress in MAFLD or other diseases in vivo.

Updated upper limits of normal serum alanine aminotrasferase levels for screening metabolic dysfunction-associated fatty liver disease in obese children

BACKGROUND/PURPOSE

Alanine aminotransferase (ALT) is a cost-effective screening test for asymptomatic liver diseases. The aims of this study are to redefine the ULNs of ALT using the 2010-2012 Nutrition and Health Survey in Taiwan (NAHSIT) database and to determine whether the updated ULNs can better screen for metabolic dysfunction-associated fatty liver disease (MAFLD) in obese children.

METHODS

Reference data were obtained from 2895 NAHSIT participants (1442 boys, 1453 girls) aged 6-18 years. Participants with any of MAFLD-related metabolic risk factors, including overweight/obesity, elevated triglyceride, low high-density lipoprotein cholesterol and high fasting glucose, were excluded. This study compared the sensitivities of different ULNs of ALT for detecting MAFLD in our previously established cohort of obese children.

RESULTS

The ULNs of ALT defined as the 95th percentile in metabolically healthy NAHSIT participants were 23 IU/L for boys and 18 IU/L for girls. When using the updated ULNs, the percentages of elevated ALT levels were 13.0% in boys and 7.8% in girls of all NAHSIT participants. When using the updated ULNs of ALT to detect MAFLD in obese children, the sensitivity was 84.0% in boys and 74.3% in girls. In contrast, when using the conventional ALT cutoff (>40 IU/L), the sensitivity decreased to 61.4% in boys and 36.4% in girls.

CONCLUSION

After taking into account MAFLD-related metabolic risk factors, the ULNs of ALT are 23 IU/L for boys and 18 IU/L for girls in Taiwan. The updated ULNs may be better cutoffs for screening MAFLD in obese children.

Comprehensive Review of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.

Polyphenol-Rich Liupao Tea Extract Prevents High-Fat Diet-Induced MAFLD by Modulating the Gut Microbiota

The modulation of gut microbiota dysbiosis might regulate the progression of metabolic-associated fatty liver disease (MAFLD). Here, we found that polyphenol-rich Liupao tea extract (PLE) prevents high-fat diet (HFD)-induced MAFLD in ApoE^-/- male mice accompanied by protection of the intestinal barrier and downregulation of lipopolysaccharide (LPS)-related Toll-like receptor 4 (TLR4)-myeloid differentiation primary response 88 (MyD88) signaling in the liver. Fecal microbiome transplantation (FMT) from PLE-and-HFD-treated mice delayed MAFLD development significantly compared with FMT from HFD-treated mice. In this case, 16S rRNA gene sequencing revealed that Rikenellaceae and Odoribacter were significantly enriched and that Helicobacter was significantly decreased in not only the HFD+PLE group but also the HFD+PLE-FMT group. Furthermore, the level of 3-sulfodeoxycholic acid was significantly decreased in the HFD+PLE-FMT group compared with the HFD-FMT group. In conclusion, our data demonstrate that PLE could modulate the MAFLD phenotype in mice and that this effect is partly mediated through modulation of the gut microbiota.

Multi-Omics Nutritional Approaches Targeting Metabolic-Associated Fatty Liver Disease

Currently, metabolic-associated fatty liver disease (MAFLD) is a leading global cause of chronic liver disease, and is expected to become one of the most common indications of liver transplantation. MAFLD is associated with obesity, involving multiple mechanisms such as alterations in lipid metabolism, insulin resistance, hyperinflammation, mitochondrial dysfunction, cell apoptosis, oxidative stress, and extracellular matrix formation. However, the onset and progression of MAFLD is variable among individuals, being influenced by intrinsic (personal) and external environmental factors. In this context, sequence structural variants across the human genome, epigenetic phenomena (i.e., DNA methylation, histone modifications, and long non-coding RNAs) affecting gene expression, gut microbiota dysbiosis, and metabolomics/lipidomic fingerprints may account for differences in MAFLD outcomes through interactions with nutritional features. This knowledge may contribute to gaining a deeper understanding of the molecular and physiological processes underlying MAFLD pathogenesis and phenotype heterogeneity, as well as facilitating the identification of biomarkers of disease progression and therapeutic targets for the implementation of tailored nutritional strategies. This comprehensive literature review highlights the potential of nutrigenetic, nutriepigenetic, nutrimetagenomic, nutritranscriptomics, and nutrimetabolomic approaches for the prevention and management of MAFLD in humans through the lens of precision nutrition.