COVID-19, adaptative immune response and metabolic-associated liver disease

Metabolic diseases are associated with a higher risk of a severer coronavirus disease 2019 (COVID-19) course, since fatty liver is commonly associated with metabolic disorders, fatty liver itself is considered as a major contributor to low-grade inflammation in obesity and diabetes. Recently a comprehensive term, metabolic (dysfunction) associated fatty liver disease (MAFLD), has been proposed. The hepatic inflammatory status observed in MAFLD patients is amplified in presence of severe acute respiratory syndrome coronavirus 2 infection. Intestinal dysbiosis is a powerful activator of inflammatory mediator production of liver macrophages. The intestinal microbiome plays a key role in MAFLD progression, which results in non-alcoholic steatohepatitis and liver fibrosis. Therefore, patients with metabolic disorders and COVID-19 can have a worse outcome of COVID-19. This literature review attempts to disentangle the mechanistic link of MAFLD from COVID-19 complexity and to improve knowledge on its pathophysiology.

Ameliorative effects of Cirsium japonicum extract and main component cirsimaritin in mice model of high-fat diet-induced metabolic dysfunction-associated fatty liver disease

The objective of this study was to determine biological effects of Cirsium japonicum extract and its main component cirsimaritin on high-fat diet (HFD)-induced metabolic dysfunction-associated fatty liver disease (MAFLD) in a mouse model. Mice were fed with a HFD to induce MAFLD and simultaneously administered with C. japonicum extract (CJE) or cirsimaritin. Various MAFLD biomarkers were evaluated using biological methods. Results demonstrated that triglyceride, aspartate aminotransferase, alanine aminotransferase, and malondialdehyde levels in the liver of mice were significantly reduced upon administration of CJE or cirsimaritin. Treatment with CJE or cirsimaritin also reduced the severity of liver injury in the experimental mouse model of MAFLD by inhibiting hepatic steatosis, oxidative stress, inflammation, and liver fibrosis. These results demonstrate that CJE and cirsimaritin as its main compound have a preventive action against the progression of hepatic steatosis to fibrosis and cirrhosis. Our study suggests that CJE and cirsimaritin might be promising agents for preventing and/or treating MAFLD.

Clinical characteristics of metabolic associated fatty liver disease (MAFLD) in subjects with myotonic dystrophy type 1 (DM1)

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a rare inherited neuromuscular disease associated with insulin resistance, and its association with metabolically associated fatty liver disease (MAFLD) has never been explored in prospective studies. The aim of this study was to assess the clinical features of MAFLD in DM1 patients.

METHODS

We investigated the prevalence and the diagnostic features of MAFLD in a cohort of 29 outpatient fully characterized DM1 patients; afterward, we compared the selected cohort of DM1-MAFLD individuals with a propensity-matched cohort of non-DM1-MAFLD RESULTS: 13/29 (44.83%) DM1 patients received a clinical diagnosis of MAFLD. Compared to DM1 patients with normal liver, DM1-MAFLD individuals showed a higher male prevalence (p = 0.008), BMI (p = 0.014), HOMA score (p = 0.012), and GGT levels (p = 0.050). The statistical comparison showed that the DM1-MAFLD group had a more severe MAFLD according to the FIB4 score than non-DM1-MAFLD patients. This association of a more severe form of liver disease with DM1 remained significant after logistic regression analysis (OR: 6.12, 95% CI 1.44- 26.55).

Danning tablets alleviate high fat diet-induced obesity and fatty liver in mice via modulating SREBP pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese formula Danning tablets exhibit wide clinical applications in liver and gallbladder diseases, and currently it is reported to be effective on fatty liver disease in clinical trials. However, the underlying mechanisms remain elusive.

AIM OF THE STUDY

The purpose of the present study was to assess the effects and potential pharmacological mechanisms of Danning tablet against high fat diet (HFD)-induced obesity, fatty liver, and related metabolic disorders in mice.

MATERIALS AND METHODS

C57BL/6 J male mice were treated with HFD for 12 weeks to trigger obesity and fatty liver condition. Then those mice were randomly divided into 5 groups, namely HFD, Danning tablet (0.75, 1.5 or 3 g/kg bodyweight) or lovastatin (30 mg/kg bodyweight) for extra 6 weeks' treatment of HFD. Food intake and bodyweight were recorded each week. In the last week, before the mice were sacrificed, fasting blood glucose levels and insulin levels were measured. Furthermore, insulin and glucose tolerance tests were performed. Blood and hepatic lipid levels were examined, the lipid metabolism-associated gene expressions and protein levels in the liver or adipose tissues were assayed after sacrificing all mice.

RESULTS

Our results demonstrated that a high dose of Danning tablet (3 g/kg) treatment mitigated body weight gain, reduced blood and hepatic cholesterol and triglyceride levels. The morphology analysis showed that Danning tablets could reduce lipid accumulation in both liver and brown adipose tissue. Moreover, Danning tablets could improve fasting blood glucose levels and ameliorate glucose and insulin tolerance in HFD-induced obese mice. Furthermore, qRT-PCR analysis revealed that the mRNA expressions of SREBP-1 and SREBP-2 as well as their target genes were remarkedly down-regulated in the liver and adipose tissue of diet-induced obesity (DIO) mice after treating those mice with Danning tablets.

CONCLUSION

Our results indicated that Danning tablets could improve the obesity-induced metabolic associated fatty liver disease (MAFLD) and related metabolic disorders. The potential mechanism may probably involve the regulation of the SREBP pathway.

Exercise prevents fatty liver by modifying the compensatory response of mitochondrial metabolism to excess substrate availability

Objective

Liver mitochondria adapt to high-calorie intake. We investigated how exercise alters the early compensatory response of mitochondria, thus preventing fatty liver disease as a long-term consequence of overnutrition.

Methods

We compared the effects of a steatogenic high-energy diet (HED) for six weeks on mitochondrial metabolism of sedentary and treadmill-trained C57BL/6N mice. We applied multi-OMICs analyses to study the alterations in the proteome, transcriptome, and lipids in isolated mitochondria of liver and skeletal muscle as well as in whole tissue and examined the functional consequences by high-resolution respirometry.

Results

HED increased the respiratory capacity of isolated liver mitochondria, both in sedentary and in trained mice. However, proteomics analysis of the mitochondria and transcriptomics indicated that training modified the adaptation of the hepatic metabolism to HED on the level of respiratory complex I, glucose oxidation, pyruvate and acetyl-CoA metabolism, and lipogenesis. Training also counteracted the HED-induced glucose intolerance, the increase in fasting insulin, and in liver fat by lowering diacylglycerol species and c-Jun N-terminal kinase (JNK) phosphorylation in the livers of trained HED-fed mice, two mechanisms that can reverse hepatic insulin resistance. In skeletal muscle, the combination of HED and training improved the oxidative capacity to a greater extent than training alone by increasing respiration of isolated mitochondria and total mitochondrial protein content.

Conclusion

We provide a comprehensive insight into the early adaptations of mitochondria in the liver and skeletal muscle to HED and endurance training. Our results suggest that exercise disconnects the HED-induced increase in mitochondrial substrate oxidation from pyruvate and acetyl-CoA-driven lipid synthesis. This could contribute to the prevention of deleterious long-term effects of high fat and sugar intake on hepatic mitochondrial function and insulin sensitivity.

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High-energy diet promotes mitochondrial respiration in liver independent of training.

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High-energy diet combined with training disconnects substrate oxidation from lipid synthesis.

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High-energy diet combined with training reduces complex I formation in the liver.

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Trained skeletal muscle unburdens the liver from substrate overload.

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Comprehensive resource of mitochondrial adaptations to high-energy diet and training.

Metabolic dysfunction associated fatty liver disease and coronavirus disease 2019: clinical relationship and current management

The coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). At present, the COVID-19 has been prevalent worldwide for more than a year and caused more than four million deaths. Liver injury was frequently observed in patients with COVID-19. Recently, a new definition of metabolic dysfunction associated fatty liver disease (MAFLD) was proposed by a panel of international experts, and the relationship between MAFLD and COVID-19 has been actively investigated. Several previous studies indicated that the patients with MAFLD had a higher prevalence of COVID-19 and a tendency to develop severe type of respiratory infection, and others indicated that liver injury would be exacerbated in the patients with MAFLD once infected with COVID-19. The mechanism underlying the relationship between MAFLD and COVID-19 infection has not been thoroughly investigated, and recent studies indicated that multifactorial mechanisms, such as altered host angiotensin converting enzyme 2 (ACE2) receptor expression, direct viral attack, disruption of cholangiocyte function, systemic inflammatory reaction, drug-induced liver injury, hepatic ischemic and hypoxic injury, and MAFLD-related glucose and lipid metabolic disorders, might jointly contribute to both of the adverse hepatic and respiratory outcomes. In this review, we discussed the relationship between MAFLD and COVID-19 based on current available literature, and summarized the recommendations for clinical management of MAFLD patients during the pandemic of COVID-19.

Network pharmacology-based identification of significant pathway for protection of Yinhuang granule in a mice model of metabolic-associated fatty liver disease

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a spectrum of liver disorders. Nonalcoholic steatohepatitis (NASH) is defined as a more serious process of MAFLD with liver inflammation.

PURPOSE

This study aims to observe the alleviation of Yinhuang granule (YHG), a Chinese patent medicine, on methionine and choline-deficient diet (MCD)-induced MAFLD in mice.

METHODS

Network pharmacology was used to analyze the improving effect of YHG on MAFLD and possible targets. MAFLD was induced in mice by MCD diet feeding for 6 weeks. In the last 2 weeks, the mice were orally given with YHG (400, 800 mg/kg) every day. Biochemical parameters of serum and liver, as well as hepatic gene expression were detected.

RESULTS

Network pharmacology showed that YHG could improve MAFLD, inflammation, liver fibrosis, and oxidative stress. In animal experiments, YHG reduced hepatocellular damage and hepatic lipids accumulation which induced by MCD. In terms of liver inflammation, YHG attenuated MCD-induced liver inflammation in mice. YHG also inhibited the activation of hepatic stellate cells (HSCs) and alleviated liver fibrosis in MCD-fed mice. Through nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, YHG alleviated liver oxidative stress injury in mice which induced by MCD.

CONCLUSION

YHG ameliorated MCD-induced MAFLD in mice by reducing hepatic lipids accumulation, alleviating liver oxidative, inflammatory injury and attenuating hepatic fibrosis.

Differential Clinical Characteristics and Mortality Outcomes in Persons With NAFLD and/or MAFLD

BACKGROUND & AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) establishes new criteria for diagnosing fatty liver disease independent of alcohol intake and concomitant viral hepatitis infection. However, the long-term outcomes of patients with MAFLD are sparse. We aimed to describe the characteristics and long-term survival of persons meeting criteria for nonalcoholic fatty liver disease (NAFLD) only (non-MAFLD NAFLD), for both NAFLD and MAFLD (NAFLD-MAFLD), and for MAFLD only (non-NAFLD MAFLD).

METHODS

Using data from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994, 2997 participants with fatty liver identified via ultrasound were categorized into 3 distinct groups: non-MAFLD NAFLD, NAFLD-MAFLD, and non-NAFLD MAFLD.

RESULTS

Participants in the NAFLD-MAFLD and non-NAFLD MAFLD groups were older, had more metabolic traits and higher mean liver enzymes. Nearly 8% of participants in the non-NAFLD MAFLD group had advanced fibrosis (Fibrosis-4 index >2.67), while only 1.3% and 1.9% in the NAFLD-MAFLD and non-MAFLD NAFLD groups did, respectively (P < .0001). Non-NAFLD MAFLD participants had the highest cumulative incidence of all-cause mortality (26.2%) followed by those with NAFLD-MAFLD then non-MAFLD NAFLD participants (21.1% and 10.6%, respectively; P < .0001). Similar findings were observed for cardiovascular disease-related and other-cause (noncardiovascular disease, noncancer) mortality. Non-NAFLD MAFLD was independently associated with all-cause mortality compared with non-MAFLD NAFLD (adjusted hazard ratio, 2.4; 95% confidence interval, 1.2-4.6; P = .01).

CONCLUSIONS

MAFLD criteria identified a significant group of people with more comorbidities and worse prognosis compared with those with NAFLD only. These criteria should be considered in the general population to identify high-risk groups for early interventions.

Metabolic-associated fatty liver disease and autoimmune hepatitis: an overlooked interaction

INTRODUCTION

Metabolic-associated fatty liver disease (MAFLD) is the most common liver disease globally, and affects about a quarter of the general population. Autoimmune hepatitis (AIH) is a severe (sometimes fatal) liver disease that affects children and adults, with a rising prevalence. Thus, not surprisingly, both conditions can frequently coexist, with potential synergistic impact on the course of the disease and response to therapy of both entities.

AREAS COVERED

In this work, the authors aimed to provide a narrative updated review on this interaction, diagnosis, and management of MAFLD/AIH and the current challenges.

EXPERT OPINION

Clarifying the nature of the complex interaction between the two diseases was hampered by a myriad of factors, particularly the previous diagnosis of exclusion for fatty liver disease associated with metabolic dysfunction. The recent redefinition of fatty liver disease that led to the development of positive diagnostic criteria for MAFLD has the premise to help in circumventing some of these challenges.

Latin American Association for the study of the liver (ALEH) practice guidance for the diagnosis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chronic liver disease, affecting 20-30% of the general population. Furthermore, its prevalence is predicted to increase exponentially in the next decades, concomitantly with the global epidemic of obesity, type 2 diabetes mellitus (T2DM), and sedentary lifestyle. NAFLD is a clinical syndrome that encompasses a wide spectrum of associated diseases and hepatic complications such as hepatocellular carcinoma (HCC). Moreover, this disease is believed to become the main indication for liver transplantation in the near future. Since NAFLD management represents a growing challenge for primary care physicians, the Asociación Latinoamericana para el Estudio del Hígado (ALEH) has decided to organize this Practice Guidance for the Diagnosis and Treatment of Non-Alcoholic Fatty Liver Disease, written by Latin-American specialists in different clinical areas, and destined to general practitioners, internal medicine specialists, endocrinologists, diabetologists, gastroenterologists, and hepatologists. The main purpose of this document is to improve patient care and awareness of NAFLD. The information provided in this guidance may also be useful in assisting stakeholders in the decision-making process related to NAFLD. Since new evidence is constantly emerging on different aspects of the disease, updates to this guideline will be required in future.

Metabolic dysfunction-associated fatty liver disease increases risk of adverse outcomes in patients with chronic hepatitis B

Background & Aims

A recent consensus document has defined metabolic dysfunction-associated fatty liver disease (MAFLD) as hepatic steatosis together with overweight, diabetes, and/or a combination of other metabolic risk factors. The clinical relevance of this novel diagnosis is unknown among patients with chronic hepatitis B (CHB). We studied the association between MAFLD (with or without steatohepatitis) and adverse clinical outcomes in patients with CHB.

Methods

We performed a retrospective long-term follow-up cohort study at 2 tertiary hospitals in patients with CHB who underwent liver biopsy. Biopsies were reassessed for steatosis, degree of fibrosis, and presence of steatohepatitis. Associations with event-free hepatocellular carcinoma (HCC)-free and transplant-free survival were explored.

Results

In our cohort, 1076 patients were included, median follow-up was 9.8 years (25th-75th percentile: 6.6-14.0), and 107 events occurred in 78 patients, comprising death (n = 43), HCC (n = 36), liver decompensation (n = 21), and/or liver transplantation (n = 7). MAFLD was present in 296 (27.5%) patients and was associated with reduced event-free (adjusted hazard ratio [aHR] 2.00, 95% CI 1.26-3.19), HCC-free (aHR 1.93, 95% CI 1.17-3.21), and transplant-free survival (aHR 1.80, 95% CI 0.98-3.29) in multivariable analysis. Among patients with MAFLD, the presence of steatohepatitis (p = 0.95, log-rank test) was not associated with adverse outcomes.

Conclusions

The presence of MAFLD in patients with CHB was associated with an increased risk for liver-related clinical events and death. Among patients with MAFLD, steatohepatitis did not increase the risk of adverse outcomes. Our findings highlight the importance of metabolic dysfunction in patients with CHB.

Lay summary

Recently, metabolic dysfunction-associated fatty liver disease (MAFLD) has been defined as fatty liver disease with signs of metabolic dysfunction. Among patients with chronic hepatitis B, MAFLD was associated with liver-related events and death. Metabolic health assessment should be encouraged among patients with chronic hepatitis B, especially in those with fatty liver disease.

Changes in Total Homocysteine and Glutathione Levels After Laparoscopic Sleeve Gastrectomy in Children with Metabolic-Associated Fatty Liver Disease

PURPOSE

Paediatric obesity is a well-known risk factor for metabolic-associated fatty liver disease (MAFLD). The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy (LSG) on the levels of total homocysteine (tHcy) and total glutathione (tGSH) plasma levels in children with MAFLD.

MATERIAL AND METHODS

Twenty-four children with severe obesity who underwent LSG were included in the study. The metabolic parameters, systemic inflammatory markers, one-carbon metabolism products, ultrasound and histological improvement were evaluated at baseline (T0M) and after 12 months from LSG (T12M).

RESULTS

The patients exhibited a significant amelioration of several metabolic parameters at T12M. A significant reduction of steatosis was observed at ultrasound (from 72.7% of moderate-severe grade to 0% severe steatosis), accompanied by a statistically significant improvement of ballooning, portal and lobular inflammation and fibrosis. A statistically significant decrease of tumour necrosis factor circulating levels was also observed (T0M median = 290.3, IQR = 281.0-317.0 pg/mL; T12M median = 260.4, IQR = 240.0-279.0 pg/mL; p < 0.0001). After 12 months from LSG, a significant increase of mean plasma levels of tHcy(T0M mean = 15.7 ± 4.1 μmol/L; T12M mean = 21.1 ± 9.3 μmol/L; p = 0.0146) was also observed. The increase of tHcy showed no causal link with the improvement of MAFLD-related inflammatory, metabolic and histological pattern.

CONCLUSION

LSG in children with obesity induces an improvement of MAFLD-related metabolic derangement and liver damage, but also a mild hyperhomocysteinemia that should be avoided to prevent cardiovascular risk.

Prevalence and risk factors of metabolic associated fatty liver disease in the contemporary South China population

Background

As a newly proposed diagnosis, data on the prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is rare. We aimed to assess the prevalence and risk factors of MAFLD using new definition in the contemporary South China population.

Methods

In this population based, cross sectional study, a total of 5377 participants aged 30–79 years old were recruited from the South China between 2018 and 2019. MAFLD was diagnosed in subjects who have both hepatic steatosis and metabolic disorders according to the newly international expert consensus. The total prevalence of MAFLD and prevalence by sex and age was estimated. Demographic characteristics, history of disease, and lifestyle were recorded by participants on a questionnaire. Abdominal ultrasonography was performed and evaluated by experienced sonographers. Multivariable logistic regression was used to calculate the odds ratios (ORs) of MAFLD.

Results

Overall prevalence of MAFLD was 29.2% (95% confidence interval [CI] 28.0% to 30.5%). Prevalence was higher in women (31.7%) than in men (25.5%; p < 0.001 for sex difference) and in subjects aged 50 years or older (30.7%) than in those aged 30–49 years (19.8%; p < 0.001 for age difference). In participants diagnosed with MAFLD, the prevalence of overweight/obesity was up to 90.5%, type 2 diabetes (T2DM) and metabolic dysregulation were 25.0% and 62.2%, respectively. Risk factors for MAFLD included overweight/obesity (OR = 4.67; 95% CI, 3.76–5.83), T2DM (OR = 2.41, 95% CI, 1.68–3.47), hypertriglyceridemia (OR = 2.42, 95% CI, 2.03–2.87), high school education (OR = 1.50, 95% CI, 1.23–1.82), high income (OR = 1.22, 95% CI, 1.05–1.42). A lower risk of MAFLD was associated with high physical activity equivalent (OR = 0.71, 95% CI, 0.60–0.85). A U-shaped association of frequency of soups and ORs of MAFLD was found, the adjusted ORs (95% CI) of lower and higher frequency of soups were 1.58 (1.32–1.89) and 1.36 (1.13–1.63), respectively.

Conclusions

Our results showed a high prevalence of MAFLD in the general adult population in South China. Obesity has the greatest impact on MAFLD, physical activity and moderate consumption of soups might be the potential protective factors of MAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00611-x.

A synthetic peptide AWRK6 ameliorates metabolic associated fatty liver disease: involvement of lipid and glucose homeostasis

Metabolic associated fatty liver disease (MAFLD) is the leading common chronic liver disease affecting more than one-quarter of the population worldwide, but no pharmacological therapy was approved specifically. A synthetic peptide AWRK6 developed in our group based on the antimicrobial peptide Dybowskin-2CDYa was found to attenuated diabetes as a novel GLP-1 receptor agonist candidate. The effects of AWRK6 on MAFLD and its underlying mechanisms were investigated in this paper. In high energy diet (HED)-induced MAFLD mice, obesity and hepatic steatosis were alleviated by AWRK6 via intraperitoneal injection. The biochemistry measurements data indicated that the abnormal lipid metabolism was relieved and the glucose metabolism was improved significantly. Further, the phosphorylation of liver PI3K/AKT/AMPK/ACC was elevated significantly by AWRK6 treatment. Moreover, the effects of AWRK6 on lipid accumulation and insulin sensitivity in human cells were verified using oleic acid-induced HepG2 fatty liver cell model and insulin-induced HepG2 cells, respectively. These in vitro and in vivo results demonstrated that the peptide AWRK6 ameliorates MAFLD by improving lipid and glucose metabolism homeostasis, and it is mediated by the PI3K/AKT/AMPK/ACC signaling pathway. Thus, AWRK6 has a potential in preventing MAFLD.

Transient elastography through controlled attenuated parameter assisting the stratification of cardiovascular disease risk in NAFLD patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Transient elastography (Fibroscan ®), by assessing the controlled attenuation parameter (CAP), is a non-invasive method able to accurately assess the presence and the grade of steatosis. Its hypothetical role in stratifying cardiovascular (CV) risk is unknown. We aim to assess the role of transient elastography, namely the CAP value, in the stratification of CV risk.

METHODS

Cohort, retrospective study, including consecutive NAFLD patients that underwent Fibroscan®. Patients were followed at least one year. The correlation towards the outcome variable (cardiovascular event) was assessed with univariate and multivariate analysis.

RESULTS

We included 96 NAFLD patients, 64 (66.7%) women, with a mean age of 48.9 years-old. Fifteen (15.6%) patients presented a cardiovascular event during follow-up. The statistically significant variables associated with cardiovascular event were introduced in a multivariable binary logistic regression model according to clinical importance. The following variables kept a statistically significant independent association with cardiovascular event: CAP > 295 dB/m (OR 8.661 CI 95% [1.119-67.028]; p value 0.039); type 2 diabetes mellitus (OR 20.236 CI 95% [2.815-145.461]; p value 0.003); dyslipidaemia (OR 14.647 CI 95% [1.261-170.189]; p value 0.032) and smoking (OR 8.946 CI 95% [1.347-59.431]; p value 0.023).

CONCLUSION

A CAP value above 295 dB/m independently increased the incidence of CV events up to 8-times. Transient elastography, through CAP, is a safe and cost-effective method to evaluate NAFLD, and should be considered in the stratification of CV risk.

Antenatal FibroScan® assessment for metabolic associated fatty liver in pregnant women at risk of gestational diabetes from a multiethnic population - a pilot study

AIMS

To assess the relationship between metabolic associated fatty liver disease (MAFLD) in pregnancy and development of gestational diabetes (GDM).

METHODS

50 pregnant women were enrolled before 24 weeks gestation from a multiethnic obstetrics service in Sydney, Australia. Two FibroScan® assessments were performed, one prior to 24 weeks and one after 30 weeks gestation, to assess hepatic steatosis and stiffness. A control attenuated parameter (CAP) score ≥ 233.5 dB/m signified MAFLD. GDM was determined by an antenatal 75-gram oral glucose tolerance testing.

RESULTS

6 (12%) women had evidence of FibroScan®-detected MAFLD in early pregnancy; whilst none had abnormal hepatic stiffness. 16 (32%) women developed GDM. No significant difference was observed in GDM rates (50% vs. 29.5%, p=0.37) between those with MAFLD in early pregnancy and those without. At the second scan (completed by 34 women), those who developed GDM had a lower observed mean increase in CAP scores (11.1±23.3 dB/m vs. -14.9±26.0 dB/m, p=0.004) and lower maternal weight gain (0.6±0.2 kg/week vs. 0.4±0.2 kg/week, p=0.04).

CONCLUSIONS

There was no statistically significant association between FibroScan®-detected MAFLD in early pregnancy and subsequent development of GDM in this pilot study. Maternal weight gain may be associated with changes in the CAP scores, which reflect steatosis, during pregnancy. This article is protected by copyright. All rights reserved.

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD)-Rather a Bystander Than a Driver of Mortality

CONTEXT

Recently, the novel metabolic dysfunction-associated fatty liver disease (MAFLD) definition has been introduced.

OBJECTIVE

To assess the relevance of MAFLD for mortality.

METHODS

Single-center cohort-study using colorectal cancer screening program involving 4718 subjects aged 45 to 80 who were grouped according to their body mass index (BMI) and the presence or absence of MAFLD. Mortality was compared among these groups by performing a systematic read-out of the national health insurance system, fatty liver (FL) was diagnosed using ultrasound.

RESULTS

Overall prevalence of FL was 47.9%: 1200 (25.4%) patients were lean (BMI < 25 kg/m2) and did not have MAFLD, 73 (1.5%) patients were lean and had nonalcoholic fatty liver disease but did not fulfill criteria for MAFLD, and 221 (4.7%) patients were lean and fulfilled criteria for MAFLD. Additionally, 1043 (22.1%) and 925 (19.6%) subjects had MAFLD with overweight (BMI 25-30 kg/m2) and obesity (BMI ≥ 30 kg/m2), respectively, while 1041 (22.1%) and 215 (4.6%) had overweight and obesity, respectively, without FL. During a median follow-up of 7.5 (interquartile range: 4.0-9.6) years, 278 deaths (5.9%) occurred. Of these, 98 (2.1%) were cancer-related, 65 (1.4%) were cardiovascular, and 17 (0.4%) were liver-related. Overall survival was similar between patient strata (after 5 years: 93.9%-98.2%) with lean MAFLD having the numerically worst survival. Although lean and overweight patients with MAFLD had a numerically worse outcome compared to their non-MAFLD counterparts, this association was driven by age and metabolic comorbidities (predominantly diabetes) rather than the presence of MAFLD.

CONCLUSION

Presence of MAFLD does not increase mortality in a cohort of individuals aged 45 to 80 years.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

SYK-3BP2 Pathway Activity in Parenchymal and Myeloid Cells Is a Key Pathogenic Factor in Metabolic Steatohepatitis

BACKGROUND & AIMS

Spleen tyrosine kinase (SYK) signaling pathway regulates critical processes in innate immunity, but its role in parenchymal cells remains elusive in chronic liver diseases. We investigate the relative contribution of SYK and its substrate c-Abl Src homology 3 domain-binding protein-2 (3BP2) in both myeloid cells and hepatocytes in the onset of metabolic steatohepatitis.

METHODS

Hepatic SYK-3BP2 pathway was evaluated in mouse models of metabolic-associated fatty liver diseases (MAFLD) and in obese patients with biopsy-proven MAFLD (n = 33). Its role in liver complications was evaluated in Sh3bp2 KO and myeloid-specific Syk KO mice challenged with methionine and choline deficient diet and in homozygous Sh3bp2^KI/KI mice with and without SYK expression in myeloid cells.

RESULTS

Here we report that hepatic expression of 3BP2 and SYK correlated with metabolic steatohepatitis severity in mice. 3BP2 deficiency and SYK deletion in myeloid cells mediated the same protective effects on liver inflammation, injury, and fibrosis priming upon diet-induced steatohepatitis. In primary hepatocytes, the targeting of 3BP2 or SYK strongly decreased the lipopolysaccharide-mediated inflammatory mediator expression and 3BP2-regulated SYK expression. In homozygous Sh3bp2^KI/KI mice, the chronic inflammation mediated by the proteasome-resistant 3BP2 mutant promoted severe hepatitis and liver fibrosis with augmented liver SYK expression. In these mice, the deletion of SYK in myeloid cells was sufficient to prevent these liver lesions. The hepatic expression of SYK is also up-regulated with metabolic steatohepatitis and correlates with liver macrophages in biopsy-proven MAFLD patients.

CONCLUSIONS

Collectively, these data suggest an important role for the SYK-3BP2 pathway in the pathogenesis of chronic liver inflammatory diseases and highlight its targeting in hepatocytes and myeloid cells as a potential strategy to treat metabolic steatohepatitis.

Copy number variation and expression of exportin-4 associates with severity of fibrosis in metabolic associated fatty liver disease

Background

Liver fibrosis risk is a heritable trait, the outcome of which is the net deposition of extracellular matrix by hepatic stellate cell-derived myofibroblasts. Whereas nucleotide sequence variations have been extensively studied in liver fibrosis, the role of copy number variations (CNV) in which genes exist in abnormal numbers of copies (mostly due to duplication or deletion) has had limited exploration.

Methods

The impact of the XPO4 CNV on histological liver damage was examined in a cohort comprised 646 Caucasian patients with biopsy-proven MAFLD and 170 healthy controls. XPO4 expression was modulated and function was examined in human and animal models.

Findings

Here we demonstrate in a cohort of 816 subjects, 646 with biopsy-proven metabolic associated liver disease (MAFLD) and 170 controls, that duplication in the exportin 4 (XPO4) CNV is associated with the severity of liver fibrosis. Functionally, this occurs via reduced expression of hepatic XPO4 that maintains sustained activation of SMAD3/SMAD4 and promotes TGF-β1-mediated HSC activation and fibrosis. This effect was mediated through termination of nuclear SMAD3 signalling. XPO4 demonstrated preferential binding to SMAD3 compared to other SMADs and led to reduced SMAD3-mediated responses as shown by attenuation of TGFβ1 induced SMAD transcriptional activity, reductions in the recruitment of SMAD3 to target gene promoters following TGF-β1, as well as attenuation of SMAD3 phosphorylation and disturbed SMAD3/SMAD4 complex formation.

Interpretation

We conclude that a CNV in XPO4 is a critical mediator of fibrosis severity and can be exploited as a therapeutic target for liver fibrosis.

Funding

ME and JG are supported by the Robert W. Storr Bequest to the Sydney Medical Foundation, University of Sydney; a National Health and Medical Research Council of Australia (NHMRC) Program Grant (APP1053206) and Project and ideas grants (APP2001692, APP1107178 and APP1108422). AB is supported by an Australian Government Research Training Program (RTP) scholarship. EB is supported by Horizon 2020 under grant 634413 for the project EPoS.

Statin use is associated with lower prevalence of advanced liver fibrosis in patients with type 2 diabetes

BACKGROUND

Patients with type 2 diabetes (T2D) are at increased risk of both cardiovascular disease (CVD) and advanced liver fibrosis related to non-alcoholic fatty liver disease (NAFLD). Statin use is known to reduce the incidence of CVD while evidence on an effect on NAFLD severity is limited.

METHODS

This is a cross-sectional study performed with data from the 2017-2018 cycle of the National Health and Nutrition Examination Survey (NHANES). The target population consisted in adult patients with T2D and reliable vibration-controlled transient elastography (VCTE) results. Presence of liver fibrosis and steatosis were assessed by the median values of liver stiffness measurement (LSM) and controlled attenuation parameter (CAP), respectively. Patients with evidence of viral hepatitis and significant alcohol consumption were excluded. Logistic regression analysis was performed to evaluate the association between statin treatment and both steatosis and advanced (≥F3) liver fibrosis after adjustment for potential confounders.

RESULTS

The study population consisted in 744 patients (age: 61 ± 1 years, BMI: 33.3 ± 0.5 kg/m²). NAFLD (CAP≥274 dB/m) was present in 74.9% of patients (95% CI 69.2-79.8) and 14.5% (95% CI 10.8-19.2) had advanced fibrosis (LSM ≥ 9.7 kPa). After adjustment for age, sex, race-ethnicity, BMI, albumin, total cholesterol, HbA1c, triglycerides and liver enzymes, statin use was associated with lower odds of advanced fibrosis (OR 0.35, 95% CI 0.13-0.90, p = 0.03). No significant interaction was found between statin use and steatosis.

CONCLUSION

Given the absence of approved therapies for NAFLD-fibrosis, it would be reasonable to initiate specific randomized controlled trials with statins.

The Chinese Society of Hepatology position statement on the redefinition of fatty liver disease

Fatty liver disease associated with metabolic dysfunction is of increasing concern in mainland China, the world's most populous country. The incidence of fatty liver disease is highest in China, surpassing the incidence in European countries and the USA. An international consensus panel recently published an influential report recommending a novel definition of fatty liver disease associated with metabolic dysfunction. This recommendation includes a switch in name from non-alcoholic fatty liver disease (NAFLD) to metabolic (dysfunction)-associated fatty liver disease (MAFLD) and adoption of a set of positive criteria for disease diagnosis that are independent of alcohol intake or other liver diseases. Given the unique importance of this proposal, the Chinese Society of Hepatology (CSH) invited leading hepatologists and gastroenterologists representing their respective provinces and cities to reach consensus on alternative definitions for fatty liver disease from a national perspective. The CSH endorses the proposed change from NAFLD to MAFLD (supported by 95.45% of participants). We expect that the new definition will result in substantial improvements in health care for patients and advance disease awareness, public health policy, and political, scientific and funding outcomes for MAFLD in China.

Bariatric Surgery and Liver Disease: General Considerations and Role of the Gut-Liver Axis

Weight loss is a therapeutic solution for many metabolic disorders, such as obesity and its complications. Bariatric surgery aims to achieve lasting weight loss in all patients who have failed after multiple dietary attempts. Among its many benefits, it has been associated with the regression of non-alcoholic fatty liver disease (NAFLD), which is often associated with obesity, with evidence of substantial improvement in tissue inflammation and fibrosis. These benefits are mediated not only by weight loss, but also by favorable changes in systemic inflammation and in the composition of the gut microbiota. Changes in microbial metabolites such as short-chain fatty acids (SCFAs), capable of acting as endocrine mediators, and bile acids (BAs) as well as modifications of the gut-brain axis, are among the involved mechanisms. However, not all bariatric surgeries show beneficial effects on the liver; those leading to malabsorption can cause liver failure or a marked worsening of fibrosis and the development of cirrhosis. Nevertheless, there are still many unclear aspects, including the extent of the benefits and the magnitude of the risks of bariatric surgery in cirrhotic patients. In addition, the usefulness and the safety of these procedures in patients who are candidates to or who have undergone liver transplant need solid supporting evidence. This paper aims to review literature data on the use of bariatric surgery in the setting of chronic liver disease.

Curcumin and Biochemical Parameters in Metabolic-Associated Fatty Liver Disease (MAFLD)-A Review

Metabolic-associated fatty liver disease (MAFLD), formerly non-alcoholic fatty liver disease (NAFLD), is characterized by excessive fat accumulation in hepatocytes. It is the most common chronic liver disease worldwide and is a significant public health problem. In the absence of pharmacological therapy, other treatments such as diet, physical activity, or supplementation are sought. Non-pharmacological therapies may include curcumin supplementation, which has been shown to have many health-promoting properties, including antioxidant, anti-inflammatory, and anti-cancer effects. For this reason, we reviewed available databases to analyze publications describing the effect of curcumin supplementation on biochemical parameters in MAFLD. Nine studies (eight RCTs and one CT) based solely on supplementation of patients with curcumin were included in this review. The results from the individual trials were varied and did not allow clear conclusions. Although they suggest that curcumin shows some potential in the treatment of MAFLD, further research is needed.

NAFLD and Liver Fibrosis Are Not Associated With Reduced Femoral Bone Mineral Density in the General US Population

CONTEXT

It is still debated whether nonalcoholic fatty liver disease (NAFLD) may be a risk factor for reduced bone mineral density (BMD), and it is not known whether liver fibrosis, the major predictor of future development of liver-related events in NAFLD, has an influence on BMD.

OBJECTIVE

To assess whether liver steatosis and fibrosis are associated with reduced BMD in the general US population.

METHODS

We performed a cross-sectional analysis of the population-based 2017-2018 cycle of the National Health and Nutrition Examination Survey (NHANES), in which vibration-controlled transient elastography (VCTE) and dual-energy x-ray absorptiometry (DXA) of the femoral neck were simultaneously available. Controlled attenuation parameter (CAP) ≥ 274 dB/m was considered indicative of liver steatosis, while a median liver stiffness measurement (LSM) ≥ 8 kPa indicated the presence of significant liver fibrosis. We included all participants older than 50 years with reliable VCTE and femoral neck DXA results (925 men and 859 women). The main outcome measures were femoral neck BMD values indicative of osteopenia or osteoporosis.

RESULTS

Steatosis and significant fibrosis were highly prevalent in the studied population, being present in 53.1% and 9.6% of men and 44.2% and 8.0% of women, respectively. In univariate analysis, liver steatosis was associated with a lower prevalence of osteoporosis in both men and women, while no difference was noted according to the degree of liver fibrosis. After adjustment for potential confounders, including age, BMI, race/ethnicity, cigarette smoking, and diabetes, neither CAP nor LSM were significantly associated with reduced BMD in both sexes.

CONCLUSION

Liver steatosis and fibrosis are not associated with femoral DXA-based diagnosis of osteopenia or osteoporosis in the US population older than 50 years.

The Alterations in and the Role of the Th17/Treg Balance in Metabolic Diseases

Chronic inflammation plays an important role in the development of metabolic diseases. These include obesity, type 2 diabetes mellitus, and metabolic dysfunction-associated fatty liver disease. The proinflammatory environment maintained by the innate immunity, including macrophages and related cytokines, can be influenced by adaptive immunity. The function of T helper 17 (Th17) and regulatory T (Treg) cells in this process has attracted attention. The Th17/Treg balance is regulated by inflammatory cytokines and various metabolic factors, including those associated with cellular energy metabolism. The possible underlying mechanisms include metabolism-related signaling pathways and epigenetic regulation. Several studies conducted on human and animal models have shown marked differences in and the important roles of Th17/Treg in chronic inflammation associated with obesity and metabolic diseases. Moreover, Th17/Treg seems to be a bridge linking the gut microbiota to host metabolic disorders. In this review, we have provided an overview of the alterations in and the functions of the Th17/Treg balance in metabolic diseases and its role in regulating immune response-related glucose and lipid metabolism.

Muscle mass depletion in chronic liver diseases: An accelerated model of aging or a distinct entity?

Sarcopenia was initially defined as loss of muscle mass, strength and function related to aging. This phenomenon is a multifactorial process. The evaluation of the geriatric population in which sarcopenia has extensively been studied opens the field for other chronic diseases. Cirrhosis is one of them and the term "sarcopenia" is now also used in this pathological situation. It must be emphasized that the pathophysiology of sarcopenia in cirrhosis is likely different from the pathogenesis in geriatric patients. Furthermore, cirrhosis has heterogeneous causes. Therefore, we need a better understanding of the changes in muscle physiology specifically in chronic liver diseases as well as easy, accurate, reproducible and validated tools, taking into consideration etiology specific aspects to identify sarcopenia in every cirrhotic patient.

NAFLD or MAFLD: Which Has Closer Association With All-Cause and Cause-Specific Mortality?-Results From NHANES III

Background: The recent change of terminology from non-alcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD) has raised heated discussion. We aim to investigate the association of MAFLD or NAFLD with all-cause and cause-specific mortality to compare the outcomes of the two diagnostic criteria in population-based study.

Methods: We recruited 12,480 participants from the Third National Health and Nutrition Examination Survey (NHANES III) with matched mortality data in 2015. Participants were divided into four groups for survival analysis: without NAFLD or MAFLD, with only NAFLD, only MAFLD. Cox proportional hazard regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality. Subgroup analysis were applied in MAFLD patients.

Results: The weighted prevalence of MAFLD and NAFLD was relatively 27.4 and 27.9%. Participants with NAFLD or MAFLD were largely overlapped (weighted Cohen's kappa coefficient 0.76). MAFLD increased the overall risk for total mortality in a greater magnitude than NAFLD [HR 2.07 (95% CI 1.86, 2.29) vs. 1.47 (1.20, 1.79)], However, the difference was non-significant after metabolic parameters were adjusted. Risks for cardiovascular, neoplasm, and diabetes-related mortality were similar between MAFLD and NAFLD. Referring to individuals without both NAFLD and MAFLD, individuals with only NAFLD showed reduced total mortality [HR 0.48 (0.34, 0.68)] and neoplasm mortality [HR 0.46 (0.24, 0.89)] in crude. Nevertheless, individuals with only MAFLD independently increased the risk for total mortality [adjusted HR 1.47 (1.22, 1.77)] and neoplasm mortality [aHR 1.58 (1.09, 2.28)]. The risk for overall mortality in MAFLD was consistent between subgroups except for race-ethnicity and whether secondary to viral hepatitis.

Conclusions: Participants with MAFLD or NAFLD were highly concordant. MAFLD showed greater risk for all-cause mortality and equal risk for cause-specific mortality referring to NAFLD. The new terminology excluded participants with lower mortality risk and included participants with higher risk. Drug development for MAFLD should consider ethnic differences.

Liver fibrosis assessed by transient elastography is independently associated with albuminuria in the general United States population

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are frequent and progressive conditions that share traditional risk factors: obesity, type 2 diabetes and hypertension.

AIMS

To evaluate whether an independent relationship exists between liver steatosis and fibrosis and different CKD phenotypes.

METHODS

Cross sectional study based on data from the 2017-18 cycle of the National Health and Nutrition Examination Survey. Vibration controlled transient elastography (VCTE) was performed in a US representative sample allowing the simultaneous assessment of liver steatosis (CAP: controlled attenuation parameter) and fibrosis (LSM: liver stiffness measurement) and their relationships with CKD phenotypes (albuminuria and reduced estimated glomerular filtration rate, eGFR).

RESULTS

4746 adult participants had a complete VCTE exam. Prevalence of liver steatosis and significant fibrosis was 33.7% (95%CI: 30.9-36.6%) and 8.9% (95%CI: 7.5-10.5%), respectively. Logistic regression analysis showed that liver fibrosis, but not steatosis, was associated with albuminuria (OR 2.19, 95%CI: 1.49-3.20) and albuminuria or reduced eGFR (OR 2.18, 95%CI: 1.59-3.00) also when adjusted for age, sex, ethnicity, BMI, diabetes, blood pressure categories, glycated haemoglobin, use of renin-angiotensin-aldosterone system blockers and CAP.

CONCLUSIONS

In the general US population liver fibrosis assessed using VCTE is associated with CKD, and in particular with the albuminuric phenotype, regardless of traditional risk factors.

Current type 2 diabetes, rather than previous gestational diabetes, is associated with liver disease in U.S. Women

AIM

To investigate the relative contribution of previous gestational diabetes mellitus (GDM) and current type 2 diabetes (T2D) on the development of liver fibrosis, the strongest predictor of end-stage liver disease.

METHODS

This is a population-based cross-sectional study based on data from the 2017-2018 cycle of the National Health and Nutrition Examination Survey. We included women age ≥ 20 years that had delivered at least one live birth and had available data on vibration-controlled transient elastography (VCTE). Liver steatosis and fibrosis were assessed by the median value of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), respectively.

RESULTS

Among the 1699 women included in the study, 144 (10.1%, 95% CI 7.7-13.2) reported a previous diagnosis of GDM. Women with previous GDM were younger, had a higher BMI, a higher prevalence of T2D and were significantly older at the time they had the last live birth. Univariate analysis did not show a significant difference between women with and without a prior history of GDM in terms of both steatosis (44.8% vs 39.4%, p = 0.464) and fibrosis (7.5% vs 7.6%, p = 0.854). Multivariable logistic regression analysis showed that BMI, γ-glutamyltranspeptidase levels, T2D (OR 2.96, 95% CI 1.48-5.93, p < 0.01), HBV and HCV infection were associated with higher odds of significant fibrosis, while previous GDM showed a neutral effect.

CONCLUSIONS

Women with previous GDM that do not develop overt T2D might not experience a poor hepatic prognosis.

Nonalcoholic fatty liver disease or metabolic dysfunction-associated fatty liver disease diagnoses and cardiovascular diseases: From epidemiology to drug approaches

BACKGROUND

A consensus of experts has proposed to replace the term nonalcoholic fatty liver disease (NAFLD), whose global prevalence is 25%, with metabolic dysfunction-associated fatty liver disease (MAFLD), to describe more appropriately the liver disease related to metabolic derangements. MAFLD is closely intertwined with type 2 diabetes, obesity, dyslipidaemia, all linked to a rise in the risk of cardiovascular disease (CVDs). Since controversy still stands on whether or not NAFLD/MAFLD raises the odds of CVD, the present review aims to evaluate the impact of NAFLD/MAFLD aetiologies on CV health and the potential correction by dietary and drug approaches.

RESULTS

Epidemiological studies indicate that NAFLD raises risk of fatal or non-fatal CVD events. NAFLD patients have a higher prevalence of arterial plaques and stiffness, coronary calcification, and endothelial dysfunction. Although genetic and environmental factors strongly contribute to NAFLD pathogenesis, a Mendelian randomization analysis indicated that the PNPLA3 genetic variant leading to NAFLD may not be causally associated with CVD risk. Among other genetic variants related to NAFLD, TM6SF2 appears to be protective, whereas MBOAT7 may favour venous thromboembolism.

CONCLUSIONS

NAFLD is correlated to a higher CVD risk which may be ameliorated by dietary interventions. This is not surprising, since new criteria defining MAFLD include other metabolic risk abnormalities fuelling development of serious adverse extrahepatic outcomes, for example CVD. The present lack of a targeted pharmacological approach makes the identification of patients with liver disease at higher CVD risk (eg diabetes, hypertension, obesity or high levels of C-reactive protein) of major clinical interest.

Association of Hepatic Steatosis With Major Adverse Cardiovascular Events, Independent of Coronary Artery Disease

BACKGROUND & AIMS

Hepatic steatosis has been associated with increased risk of major adverse cardiovascular events (MACE) but it is not clear whether steatosis is independently associated with risk of MACE. We investigated whether steatosis is associated with risk of MACE independently of the presence and extent of baseline coronary artery disease, assessed by comprehensive contrast-enhanced computed tomography angiography (CTA).

METHODS

We conducted a nested cohort study of 3756 subjects (mean age, 60.6 years; 48.4% men) who underwent coronary CTA at 193 sites in North America, from July 2010 through September 2013, as part of the PROMISE study, which included noninvasive cardiovascular analyses of symptomatic outpatients without coronary artery disease. Independent core laboratory readers measured hepatic and splenic attenuation, using non-contrast computed tomography images to identify steatosis, and evaluated coronary plaques and stenosis in coronary CTA images. We collected data on participants' cardiovascular risk factors, presence of metabolic syndrome, and body mass index. The primary endpoint was an adjudicated composite of MACE (death, myocardial infarction, or unstable angina) during a median follow-up time of 25 months.

RESULTS

Among the 959 subjects who had steatosis (25.5% of the cohort), 42 had MACE (4.4%), whereas among the 2797 subjects without steatosis, 73 had MACE (2.6%) (hazard ratio [HR] for MACE in subjects with steatosis, 1.69; 95% CI, 1.16-2.48; P = .006 for MACE in subjects with vs without steatosis). This association remained after adjustment for atherosclerotic cardiovascular disease risk scores, significant stenosis, and metabolic syndrome (adjusted HR, 1.72; 95% CI, 1.16-2.54; P = .007) or obesity (adjusted HR, 1.75; 95% CI, 1.19-2.59; P = .005). Steatosis remained independently associated with MACE after adjustment for all CTA measures of plaques and stenosis.

CONCLUSIONS

Hepatic steatosis is associated with MACE independently of other cardiovascular risk factors or extent of coronary artery disease. Strategies to reduce steatosis might reduce risk of MACE. ClinicalTrials.gov no: NCT01174550.

Nonalcoholic Fatty Liver Disease (NAFLD) as Model of Gut-Liver Axis Interaction: From Pathophysiology to Potential Target of Treatment for Personalized Therapy

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease worldwide, affecting both adults and children and will result, in the near future, as the leading cause of end-stage liver disease. Indeed, its prevalence is rapidly increasing, and NAFLD is becoming a major public health concern. For this reason, great efforts are needed to identify its pathogenetic factors and new therapeutic approaches. In the past decade, enormous advances understanding the gut-liver axis-the complex network of cross-talking between the gut, microbiome and liver through the portal circulation-have elucidated its role as one of the main actors in the pathogenesis of NAFLD. Indeed, evidence shows that gut microbiota is involved in the development and progression of liver steatosis, inflammation and fibrosis seen in the context of NAFLD, as well as in the process of hepatocarcinogenesis. As a result, gut microbiota is currently emerging as a non-invasive biomarker for the diagnosis of disease and for the assessment of its severity. Additionally, to its enormous diagnostic potential, gut microbiota is currently studied as a therapeutic target in NAFLD: several different approaches targeting the gut homeostasis such as antibiotics, prebiotics, probiotics, symbiotics, adsorbents, bariatric surgery and fecal microbiota transplantation are emerging as promising therapeutic options.

Historical narrative from fatty liver in the nineteenth century to contemporary NAFLD - Reconciling the present with the past

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder worldwide. This historical narrative traces the evolution from basic descriptions of fatty liver in the nineteenth century to our contemporary understanding of NAFLD in the twentieth and twenty-first centuries. A detailed historiographic review of fatty liver from 1800s onwards was performed alongside a brief review of contemporary associations. Archived published literature dating back to the 1800s describe clinicopathological features of fatty liver. In the nineteenth century, doyens of medicine associated fatty liver with alcohol, malnutrition or wasting conditions, and subsequently adiposity, unhealthy diets and sedentary lifestyle. Microscopically, fatty liver was described when 5% or more hepatocytes were distended with fat. Recommendations to reverse fatty liver included reducing consumption of fat, sugar, starchy carbohydrates and alcohol, plus increasing physical exercise. Fatty liver was associated with liver fibrosis and cirrhosis in the late 1800s, and with diabetes in the early 1900s. The diagnostic labels NAFLD and non-alcoholic steatohepatitis (NASH) were introduced in the late 1900s. Metabolic dysfunction-associated fatty liver disease (MAFLD) was recently proposed to update the nosology of fatty liver, recognising the similar metabolic pathogenesis evident in individuals with typical NAFLD and those with heterogenous "secondary" co-factors including alcohol and other aetiologies. Fatty liver has emerged from being considered a disorder of nutritional extremes or alcohol excess to contemporary recognition as a complex metabolic disorder that risks progression to cirrhosis and hepatocellular carcinoma. The increasing prevalence of NAFLD and our growing understanding of its lifestyle and metabolic determinants justify the current exercise of re-examining the evolution of this common metabolic disorder.

Prevalence of NAFLD, MAFLD and associated advanced fibrosis in the contemporary United States population

Data are limited on the epidemiological implications of the recent change in terminology from nonalcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD). We therefore performed a cross-sectional study of adults recruited in the 2017-2018 National Health and Nutrition Examination Survey, a representative sample of the general US population. The prevalence of NAFLD and MAFLD based on controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) obtained through vibration-controlled transient elastography (VCTE) were 37.1% (95% CI 34.0-40.4) and 39.1% (95% CI 36.3-42.1), respectively, with higher rates among Hispanic individuals. Agreement between the two definitions was high (Cohen's κ 0.92). Patients with NAFLD and MAFLD also showed similar risk of advanced liver fibrosis (7.5% and 7.4% respectively). Our results suggest that the recent change in diagnostic criteria did not affect the prevalence of the condition in the general United States population.

Core liver homeostatic co-expression networks are preserved but respond to perturbations in an organism- and disease-specific manner

Findings about chronic complex diseases are difficult to extrapolate from animal models to humans. We reason that organs may have core network modules that are preserved between species and are predictably altered when homeostasis is disrupted. To test this idea, we perturbed hepatic homeostasis in mice by dietary challenge and compared the liver transcriptome with that in human fatty liver disease and liver cancer. Co-expression module preservation analysis pointed to alterations in immune responses and metabolism (core modules) in both human and mouse datasets. The extent of derailment in core modules was predictive of survival in the cancer genome atlas (TCGA) liver cancer dataset. We identified module eigengene quantitative trait loci (module-eQTL) for these predictive co-expression modules, targeting of which may resolve homeostatic perturbations and improve patient outcomes. The framework presented can be used to understand homeostasis at systems levels in pre-clinical models and in humans. A record of this paper's transparent peer review process is included in the supplemental information.

Lack of awareness of liver organ damage in patients with type 2 diabetes

AIMS

Liver steatosis, a typical finding in patients with type 2 diabetes (T2D), can lead to cirrhosis and hepatocellular carcinoma. The aim of the present study is to estimate the awareness of liver disease among patients with T2D and whether it differs according to the degree of liver fibrosis estimated by transient elastography (TE).

METHODS

This is a population-based cross-sectional study. We included all patients with T2D that participated in the 2017-2018 cycle of the National Health and Nutrition Examination Survey and underwent a TE examination. Presence of liver steatosis and fibrosis was assessed by the median values of controlled attenuation parameter and liver stiffness measurement, respectively.

RESULTS

Among the 825 patients included in the analysis, 8.1% (95% CI 5.1%-12.7%) of patients with steatosis were aware of having a liver condition. Even if awareness increased proportionally with increasing severity of organ damage, it remained limited even among patients with advanced fibrosis (17.9%, 95% CI 8.8%-33.3%).

CONCLUSIONS

Despite increasing evidence of a frequent hepatic involvement associated with poor prognosis, awareness of suffering of advanced liver disease in patients with T2D is remarkably low, likely reflecting little recognition also among the team of health care professionals.

Examining the gut-liver axis in liver cancer using organoid models

The World Health Organization predicts that by 2030 liver cancer will cause 1 million deaths annually, thus becoming the third most lethal cancer worldwide. Hepatocellular carcinoma and cholangiocarcinoma are the two major primary cancer subtypes involving the liver. Both are often diagnosed late, and hence response to treatment and survival are poor. It is therefore of utmost importance to understand the mechanisms by which liver cancers initiate and progress. The causes of primary liver cancer are diverse, resulting primarily from obesity, chronic alcohol abuse or viral hepatitis. Importantly, both alcohol and high fat diet can promote intestinal permeability, enabling microbial translocation from the gut into the liver. As a result, these microbial antigens and metabolites exacerbate hepatic inflammation and fibrosis, increasing the risk of primary liver cancer. Organoids are primary, three-dimensional, stem cell derived liver models that can recapitulate many of the disease phenotypes observed in vivo. This review aims to summarize the advantages of organoid culture to examine the gut-liver axis with respect to cancer initiation and progression. In particular, the use of gut and liver organoid mono- and co-cultures together and with immune cell populations to best recapitulate disease mechanisms and develop therapeutic interventions.

Role of Insulin Resistance in MAFLD

Many studies have reported that metabolic dysfunction is closely involved in the complex mechanism underlying the development of non-alcoholic fatty liver disease (NAFLD), which has prompted a movement to consider renaming NAFLD as metabolic dysfunction-associated fatty liver disease (MAFLD). Metabolic dysfunction in this context encompasses obesity, type 2 diabetes mellitus, hypertension, dyslipidemia, and metabolic syndrome, with insulin resistance as the common underlying pathophysiology. Imbalance between energy intake and expenditure results in insulin resistance in various tissues and alteration of the gut microbiota, resulting in fat accumulation in the liver. The role of genetics has also been revealed in hepatic fat accumulation and fibrosis. In the process of fat accumulation in the liver, intracellular damage as well as hepatic insulin resistance further potentiates inflammation, fibrosis, and carcinogenesis. Increased lipogenic substrate supply from other tissues, hepatic zonation of Irs1, and other factors, including ER stress, play crucial roles in increased hepatic de novo lipogenesis in MAFLD with hepatic insulin resistance. Herein, we provide an overview of the factors contributing to and the role of systemic and local insulin resistance in the development and progression of MAFLD.

Mining Gut Microbiota From Bariatric Surgery for MAFLD

The progression of metabolic dysfunction associated fatty liver disease (MAFLD) leads to steatohepatitis, liver fibrosis and hepatocellular carcinoma. Thus far, there have been no FDA-approved medications for MAFLD. Bariatric surgery (BS) has been found to improve insulin resistance, steatohepatitis and liver fibrosis but is not recommended for treating MAFLD due to its invasiveness. Recent studies suggest the improved glucose metabolism after BS is a result of, at least partly, alterations to the gut microbiota and its associated metabolites, including short chain fatty acids and bile acids. It makes sense the improved steatohepatitis and fibrosis after BS are also induced by the gut microbiota that involves in host metabolic modulation, for example, through altering bile acids composition. Given that the gut-liver axis is a path that may harbor unexplored mechanisms behind MAFLD, we review current literatures about disentangling the metabolic benefits of MAFLD after BS, with a focus on gut microbiota. Some useful research tools including the rodent BS model, the multiomics approach, and the human microbiota associated (HMA) mice are presented and discussed. We believe, by taking advantage of these modern translational tools, researchers will uncover microbiota related pathways to serve as potential therapeutic targets for treating MAFLD.

Exome-Wide Association Study on Alanine Aminotransferase Identifies Sequence Variants in the GPAM and APOE Associated With Fatty Liver Disease

BACKGROUND & AIMS

Fatty liver disease (FLD) is a growing epidemic that is expected to be the leading cause of end-stage liver disease within the next decade. Both environmental and genetic factors contribute to the susceptibility of FLD. Several genetic variants contributing to FLD have been identified in exome-wide association studies. However, there is still a missing hereditability indicating that other genetic variants are yet to be discovered.

METHODS

To find genes involved in FLD, we first examined the association of missense and nonsense variants with alanine aminotransferase at an exome-wide level in 425,671 participants from the UK Biobank. We then validated genetic variants with liver fat content in 8930 participants in whom liver fat measurement was available, and replicated 2 genetic variants in 3 independent cohorts comprising 2621 individuals with available liver biopsy.

RESULTS

We identified 190 genetic variants independently associated with alanine aminotransferase after correcting for multiple testing with Bonferroni method. The majority of these variants were not previously associated with this trait. Among those associated, there was a striking enrichment of genetic variants influencing lipid metabolism. We identified the variants rs2792751 in GPAM/GPAT1, the gene encoding glycerol-3-phosphate acyltransferase, mitochondrial, and rs429358 in APOE, the gene encoding apolipoprotein E, as robustly associated with liver fat content and liver disease after adjusting for multiple testing. Both genes affect lipid metabolism in the liver.

CONCLUSIONS

We identified 2 novel genetic variants in GPAM and APOE that are robustly associated with steatosis and liver damage. These findings may help to better elucidate the genetic susceptibility to FLD onset and progression.

From NAFLD to MAFLD: Nurse and allied health perspective

Fatty liver disease associated with metabolic dysfunction is the most prevalent liver disease worldwide, though both patient and health professional still lack awareness of it. An international consensus panel has produced what is sure to be an influential report renaming the disease from non-alcoholic fatty liver disease (NAFLD) to metabolic (dysfunction) associated fatty liver disease (MAFLD) and suggesting how the disease should be diagnosed. This viewpoint explores the call from the perspective of nurse and allied health practitioners. This group have raised serious concerns on the existing nomenclature, which labels the disease as NAFLD, and its diagnostic criteria, including provoking nurse role confusion and representing a major barrier to various key aspects; patient-nurse communications, patient awareness, partnership working, motivation of patients to undertake lifestyle changes and multiple health behaviour change promotion and nurse-led clinics. Therefore, they are enthusiastically supportive of this call to reframe the disease that we believe will ultimately have a positive impact on nurse-patient communication, and through this, improve patient care and quality of life and reduce burden on health system.

Metabolic-associated fatty liver disease (MAFLD) in coeliac disease

BACKGROUND AND AIMS

Coeliac disease (CD) is considered a high-risk condition for developing non-alcoholic fatty liver disease (NAFLD) and other related metabolic disorders, particularly after commencing gluten-free diet (GFD). Recently, a new concept of metabolic-associated fatty liver disease (MAFLD) has been proposed to overcome the limitations of NAFLD definition. This study aimed at exploring the prevalence of NAFLD and MAFLD in CD patients at the time of CD diagnosis and after 2 years of GFD. Furthermore, we evaluated the role of PNPLA3 rs738409 in the development of NAFLD and MAFLD in the same population.

METHODS

We retrospectively enrolled all newly diagnosed CD patients who underwent clinical, laboratory and ultrasonography investigations both at diagnosis and after 2 years of follow-up. Moreover, a PNPLA3 rs738409 genotyping assay was performed.

RESULTS

Of 221 newly diagnosed CD patients, 65 (29.4%) presented NAFLD at CD diagnosis, while 32 (14.5%) met the criteria for MAFLD (k = 0.57). There were no significant differences between NAFLD and MAFLD, except for the higher rate of insulin resistance (IR) of MAFLD patients (75% vs 33.8%, P < .001). At 2 years of follow-up, 46.6% of patients developed NAFLD while 32.6% had MAFLD (k = 0.71). MAFLD subjects had higher transaminases (P = .03), LDL-cholesterol (P = .04), BMI and waist circumference and higher IR than NAFLD patients. MAFLD patients showed higher non-invasive liver fibrosis scores than NAFLD subjects (APRI = 1.43 ± 0.56 vs 0.91 ± 0.62, P < .001; NFS=-1.72 ± 1.31 vs -2.18 ± 1.41, P = .03; FIB-4 = 1.27 ± 0.77 vs 1.04 ± 0.74, P = .04). About PNPLA3 polymorphisms, at 2 years follow-up, NAFLD subjects presented a higher rate of heterozygosis (40.8%) and homozygosis (18.4%) polymorphisms than non-NAFLD (26.3% and 7.6%, respectively, P = .03 and 0.02), while no correlation between PNPLA3 polymorphisms and MAFLD was seen.

CONCLUSIONS

The new MAFLD definition better reflects the metabolic alterations following GFD in CD population. This new classification could be able to identify patients at higher risk of worse metabolic outcome, who need a close multidisciplinary approach for their multisystemic disease.