Noninvasive biomarkers in non-alcoholic fatty liver disease: Current status and a glimpse of the future

Diffuse and focal liver fat: advanced imaging techniques and diagnostic insights

The fatty liver disease represents a complex, multifaceted challenge, requiring a multidisciplinary approach for effective management and research. This article uses conventional and advanced imaging techniques to explore the etiology, imaging patterns, and quantification methods of hepatic steatosis. Particular emphasis is placed on the challenges and advancements in the imaging diagnostics of fatty liver disease. Techniques such as ultrasound, CT, MRI, and elastography are indispensable for providing deep insights into the liver's fat content. These modalities not only distinguish between diffuse and focal steatosis but also help identify accompanying conditions, such as inflammation and fibrosis, which are critical for accurate diagnosis and management.

Non-invasive testing and risk-stratification in patients with MASLD

The development and validation of non-invasive fibrosis tests (NITs) has changed clinical practice in Hepatology over the last 15 years. Metabolic associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease in western countries, with up to a third of the unselected adult population affected. In this article, we review the use of NITs in the diagnosis and staging of MASLD. We discuss their use in the diagnosis of steatosis, steatohepatitis and fibrosis and critically evaluate recently published data. These NITs include a variety of approaches, such as serum markers like FIB-4, pro-C3 and ELF, imaging techniques like Fibroscan® and MRE, and combined scores like Agile 3+ and Agile 4, offering a range of options for healthcare providers. Furthermore, these non-invasive tests also serve as valuable prognostic tools, allowing for better risk assessment and improved patient management, particularly in predicting liver-related events and overall mortality.

Evaluation of Hepatosteatosis-Induced Increase in Fibrosity by Two-Dimensional Shear Wave Elastography in Children with Obesity and Comparison with Healthy Peers

OBJECTIVE

The increase in the prevalence of obesity, nonalcoholic fatty liver disease (NAFLD), and related comorbidities in children creates a social and financial burden. In our study, we aimed to evaluate liver findings together with anthropometric and laboratory data with twodimensional shear wave elastography (2D-SWE), one of the SWE types, which is a noninvasive method for assessing tissue stiffness in children with obesity, and to obtain quantitative data that can be used in early diagnosis and follow-up.

MATERIALS AND METHODS

In our single-center, observational cross-sectional study, liver gray scale findings, 2D-SWE findings, anthropometric measurements, and laboratory values of 48 children with obesity and 50 healthy children aged between 5 and 18 years, both between groups and in prepubertal and pubertal subgroups, are compared.

RESULTS

A significant difference was found in the liver stiffness indicator kilopascal (kPA) values and between aspartate aminotransferase values in the prepubertal period and alanine aminotransferase values in the pubertal period (P < .001). No significant difference was found between insulin, HOMA-IR, waist circumference, waist/height ratio, and kPA.

CONCLUSION

Two-dimensional shear wave elastography can be easily applied in the pediatric population as a practical, noninvasive, reproducible, and highly compatible technique. In this regard, 2D-SWE may be useful in the early diagnosis and follow-up of hepatosteatosis and fibrosis in children with obesity and NAFLD-risky cases.

Updates in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) in Children

The obesity epidemic is one of the major health concerns of the 21st century. Nonalcoholic fatty liver disease (NAFLD) is linked with the increased adiposity associated with obesity. NAFLD has become the most frequent cause of chronic liver disease in adults and children worldwide. Metabolic dysfunction-associated fatty liver disease (MAFLD) also known in children as pediatric fatty liver disease (PeFLD) type 2 has begun to supersede NAFLD as the preferred nomenclature in the pediatric population. Evidence suggests the etiology of MAFLD is multifactorial, related to the complex interplay of hormonal, nutritional, genetic, and environmental factors. Current limitations in accurate diagnostic biomarkers have rendered it a diagnosis of exclusion and it is important to exclude alternative or coexisting causes of PeFLD. Lifestyle changes and modifications remains the primary treatment modality in MAFLD in children. Weight loss of 7%-10% is described as reversing MAFLD in most patients. The Mediterranean diet also shows promise in reversing MAFLD. Pharmacological intervention is debatable in children, and though pediatric trials have not shown promise, other agents undergoing adult clinical trials show promise. This review outlines the latest evidence in pediatric MAFLD and its management.

Advances in Noninvasive Biomarkers for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) currently represents one of the most common liver diseases worldwide. Early diagnosis and disease staging is crucial, since it is mainly asymptomatic, but can progress to nonalcoholic steatohepatitis (NASH) or cirrhosis or even lead to the development of hepatocellular carcinoma. Over time, efforts have been put into developing noninvasive diagnostic and staging methods in order to replace the use of a liver biopsy. The noninvasive methods used include imaging techniques that measure liver stiffness and biological markers, with a focus on serum biomarkers. Due to the impressive complexity of the NAFLD's pathophysiology, biomarkers are able to assay different processes involved, such as apoptosis, fibrogenesis, and inflammation, or even address the genetic background and "omics" technologies. This article reviews not only the currently validated noninvasive methods to investigate NAFLD but also the promising results regarding recently discovered biomarkers, including biomarker panels and the combination of the currently validated evaluation methods and serum markers.

Role of microRNA in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH): a comprehensive review

Non-alcoholic fatty liver disease (NAFLD) is a prevalent liver condition that affects people who do not overconsume alcohol. Uncertainties exist over how microRNAs (miRNAs) in the blood and liver relate to NAFLD. The aim of this narrative review was to investigate the role of miRNAs in the onset and progression of non-alcoholic steatohepatitis (NASH) from NAFLD, and explore their potential as diagnostic tools and treatment targets for NAFLD patients. Liver miRNA-34a levels were found to accurately represent the degree of liver damage, with lower levels suggesting more damage. In patients with NAFLD and severe liver fibrosis, higher levels of miRNA-193a-5p and miRNA-378d were found. Moreover, miRNA-34a, miRNA-122, and miRNA-192 levels might aid in differentiating NASH from NAFLD. Similar to this, miRNA-21 and miRNA-27 levels in rats were able to distinguish between steatosis and steatohepatitis. High-fat diets enhanced the expression of 15 distinct miRNAs in rats, and there were substantial differences in the miRNA expression patterns between obese and lean people. The results from the present review imply that miRNA microarrays and sequencing may be helpful diagnostic tools, and miRNAs may be a possible treatment target for patients with NAFLD.

Perirenal fat thickness and liver fat fraction are independent predictors of MetS in adults with overweight and obesity suspected with NAFLD: a retrospective study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has a multidirectional relationship with metabolic syndrome (MetS) and used to be considered a hepatic manifestation of MetS. Perirenal fat, as a part of visceral adipose tissue (VAT), was reported to be correlated with MetS components, but data for intraorgan fat are lacking. This study was undertaken to assess the value of peripheral and intraorgan fat to predict MetS in adults with overweight and obesity with suspected NAFLD.

METHODS

We studied 134 sequential adults (mean age, 31.5 years; 47% female) with overweight and obesity with suspected NAFLD. All participants underwent abdominal magnetic resonance imaging (MRI) examination. Anthropometric and metabolic parameters and perirenal fat thickness (PRFT), subcutaneous adipose tissue thickness (SATT), liver fat fraction (LFF), pancreas fat fraction (PFF), and lumbar spine fat fraction (LSFF) were collected. MetS was defined according to the International Diabetes Federation (IDF) criteria. Statistical analyses included basic statistics, linear correlation and logistic regression analysis.

RESULTS

A total of 63 adults with MetS and 71 adults with advanced liver steatosis (grades 2 and 3) were included in our study. Patients with MetS had greater PRFT (p = 0.026) and LFF (p < 0.001), as well as greater homeostasis model assessment of insulin resistance (HOMA-IR), alanine transaminase (ALT), aspartate transaminase (AST), and decreased SATT. MetS patients had a higher proportion of advanced steatosis than those without MetS (P < 0.001). The MetS score was associated with PRFT and LFF. Logistic regression analysis showed that the PRFT and LFF were independent predictors of MetS after adjusting for age and sex. A cutoff of 9.15 mm for PRFT and 14.68% for LFF could be predictive of MetS.

CONCLUSIONS

This study shows that the absolute cutoff level of 9.15 mm for PRFT and 14.68% for LFF may be clinically important markers for identifying patients who are at high risk of MetS among adults with overweight and obesity with suspected NAFLD, irrespective of sex and age. Moreover, ectopic fat levels in pancreas and lumbar spine are positively associated with PRFT.

TRIAL REGISTRATION

Not applicable.

Lipid metabolism in non-alcoholic fatty liver disease in patients with different body weights in mid-mountain conditions

Aim. To study the peculiarities of lipid metabolism disorders in non-alcoholic fatty liver disease in lean and obese patients in medium altitude conditions. Materials and methods. The study was carried out within the framework of the project Etiopathogenetic features and rates of development of non-alcoholic fatty liver disease (NAFLD) in the conditions of Kyrgyzstan (№ of state registration MHN/TZ-2020-3). An open comparative study of patients with two forms of NAFLD: fatty liver and non-alcoholic steatohepatitis (n=236) living in low mountains (Bishkek, altitude above sea level 750800 m; n=111) and middle mountains (At-Bashy district , Naryn region, height above sea level 20462300 m; n=125) Kyrgyzstan. The average age of the patients was 55.70.95 years. Given that genetic factors may play a role in the development of NAFLD, we analyzed a population represented only by ethnic Kyrgyz. Patients in each group were divided into lean (BMI23) and obese (BMI23) groups. To determine physical activity, a physical activity questionnaire was used, which was compiled on the basis of the materials of the International Physical Activity Prevalence Study www.ipaq.ki.se. Physical examination included measurement of anthropometric parameters (height, body weight, waist circumference), calculation of body mass index (BMI), skeletal muscle mass index (SMM), percentage of body fat. According to the grades of the WHO, the degree of obesity was assessed by BMI for Asians. Blood samples were taken for research in the morning on an empty stomach after at least 12 hours of fasting. The following indicators were determined: glucose, lipid spectrum (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides), alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels. The BARD scale was used as a predictor for assessing the development of liver fibrosis in patients with NAFLD. The scoring system included three variables: BMI, AST/ALT, and the presence of DM 2. The diagnosis of NAFLD made on the basis of history, laboratory tests, ultrasound examination of the liver, and exclusion of other liver diseases. The results were analyzed using the SPSS 16.0 statistical software package for Windows. A p-value0.05 was considered statistically significant at the 95% confidence level. Results. It was found that the inhabitants of the middle mountains with NAFLD are represented by a lower BMI relative to the inhabitants of the low mountains. In women, the levels of SMM and the percentage of fat are significantly and statistically significantly correlated (r=-0.971; p0.001), while in men these two indicators are not related. Men showed a trend towards higher percentages of fat, regardless of body weight and region of residence. For women, this indicator was within acceptable limits and did not exceed 31%. There was found a statistically significant difference in total cholesterol levels between low and middle mountain people in the group of obese patients (p0.001) suffering from NAFLD. Statistically significant low ALT indices were revealed in the group of obese patients living in mid-mountain conditions. Conclusion. Taken together, our results suggest that chronic mid-mountain hypoxia may slow down the course of overweight-induced NAFLD.

Lutein-loaded nanoparticles reverse oxidative stress, apoptosis, and autism spectrum disorder-like behaviors induced by prenatal valproic acid exposure in female rats

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social interaction and repetitive behaviors. In this study, we assessed the effect of lutein-loaded nanoparticles on ASD-like behaviors induced by prenatal valproic acid (VPA) exposure in female offspring rats and the possible involvement of oxidative stress and apoptosis. Pregnant female Wistar rats received a single intraperitoneal injection of VPA (600 mg/kg), on the gestational day 12.5. The VPA-exposed female offspring rats were divided into two subgroups and received either lutein-loaded nanoparticles (5 mg/kg) or saline by oral gavage, for 14 days. The animals were submitted to the three-chamber test and open field to evaluate ASD-like behaviors. The hippocampus was removed for the determination of oxidative stress indicators (ROS; TBARS; SOD and Nrf2) and apoptosis biomarkers (Hsp-70; p38-MAPK; Bax and Bcl-2). The exposure to lutein-loaded nanoparticles reversed sociability deficit, social memory deficit, and anxiety-like and repetitive behaviors induced by VPA, and restored the oxidative stress indicators and apoptosis biomarkers in the hippocampus. This neurochemical effect must be associated with the reversal of ASD-like behaviors. These results provide evidence that lutein-loaded nanoparticles are an alternative treatment for VPA-induced behavioral damage in female rats and suggest the involvement of oxidative stress.

Lessons on Drug Development: A Literature Review of Challenges Faced in Nonalcoholic Fatty Liver Disease (NAFLD) Clinical Trials

NAFLD is the most common chronic liver disease worldwide, occurring in both obese and lean patients. It can lead to life-threatening liver diseases and nonhepatic complications, such as cirrhosis and cardiovascular diseases, that burden public health and the health care system. Current care is weight loss through diet and exercise, which is a challenging goal to achieve. However, there are no FDA-approved pharmacotherapies for NAFLD. This review thoroughly examines the clinical trial findings from 22 drugs (Phase 2 and above) and evaluates the future direction that trials should take for further drug development. These trialed drugs can broadly be categorized into five groups-hypoglycemic, lipid-lowering, bile-pathway, anti-inflammatory, and others, which include nutraceuticals. The multitude of challenges faced in these yet-to-be-approved NAFLD drug trials provided insight into a few areas of improvement worth considering. These include drug repurposing, combinations, noninvasive outcomes, standardization, adverse event alleviation, and the need for precision medicine with more extensive consideration of NAFLD heterogenicity in drug trials. Understandably, every evolution of the drug development landscape lies with its own set of challenges. However, this paper believes in the importance of always learning from lessons of the past, with each potential improvement pushing clinical trials an additional step forward toward discovering appropriate drugs for effective NAFLD management.

Risk Predictors of Advanced Fibrosis in Non-Alcoholic Fatty Liver Disease

The assessment of fibrosis in chronic liver diseases using non-invasive methods is an important topic in hepatology. The aim of this study is to identify patients with non-alcoholic fatty liver disease (NAFLD) and advanced liver fibrosis by establishing correlations between biological/ultrasound markers and non-invasively measured liver stiffness. This study enrolled 116 patients with non-alcoholic fatty liver disease, which were evaluated clinically, biologically, and by ultrasound. Liver fibrosis was quantified by measuring liver stiffness by shear wave elastography (SWE). Multiple correlation analysis of predictors of liver fibrosis identified a number of clinical, biological, and ultrasound parameters (BMI, blood glucose, albumin, platelet count, portal vein diameter, bipolar spleen diameter) that are associated with advanced liver fibrosis in patients with non-alcoholic fatty liver disease. The correlations between the degree of liver fibrosis and the risk values of some serological and ultrasound markers obtained in our study could be useful in clinical practice for the identification of advanced fibrosis in patients with NAFLD.

Association of Metabolic-Associated Fatty Liver Disease With Various Anthropometric Parameters in Pre-diabetes in Comparison With Diabetes and Control: A Single Tertiary Care Center Study

Introduction

Individuals with pre-diabetes and metabolic-associated fatty liver disease (MAFLD) have an increased risk of developing diabetes mellitus (type-2) when compared with individuals with pre-diabetes without MAFLD. Patients with any of the components of metabolic syndrome should be screened for the risk of MAFLD, as all its components are well correlated with the degree of liver fat content. In this research article, we have highlighted the association of MAFLD with various anthropometric parameters in pre-diabetes as compared to diabetes and normal individual.

Methods

In this cross-sectional study a total of 356 patients more than 18 years of age who meet the criteria for diabetes and pre-diabetes according to WHO, were enrolled. Anthropometric indices like body mass index (BMI), waist-hip ratio, waist to height ratio, and neck circumference were recorded. Patients underwent ultrasonography of liver and blood investigations like lipid profile, and liver function tests.

Results

The prevalence of MAFLD observed in this study was 44.1% in diabetics and 22% in pre-diabetics, compared to 9.2% in healthy controls. The ROC analyses showed that MAFLD predict pre-diabetes using the waist-hip ratio was higher in women compared to men (0.750 and 0.693 respectively). In men, the waist-hip ratio was followed by 0.648 for Neck Circumference, 0.646 for BMI, and 0.635 for waist-to-height ratio respectively, whereas the ROC analyses in women showed that other than waist-hip ratio, no other anthropometric index that had consistently higher AUC value.

Conclusion

Though there was an association between high BMI, waist-hip ratio, waist to height ratio, and neck circumference with MAFLD in pre-diabetes, it was not strongly associated as in the diabetic group.

Clinical and Molecular Biomarkers for Diagnosis and Staging of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic pathology in industrialized countries, affecting about 25% of the general population. NAFLD is a benign condition, however, it could evolve toward more serious diseases, including non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and finally, hepatocellular carcinoma (HCC). Liver biopsy is still the gold standard for NAFLD diagnosis. Due to the risks associated with liver biopsy and the impossibility to apply it on a large scale, it is now necessary to identify non-invasive biomarkers, which may reliably identify patients at higher risk of progression. Therefore, several lines of research have tried to address this issue by identifying novel biomarkers using omics approaches, including lipidomics, metabolomics and RNA molecules' profiling. Thus, in this review, we firstly report the conventional biomarkers used in clinical practice for NAFL and NASH diagnosis as well as fibrosis staging, and secondly, we pay attention to novel biomarkers discovered through omics approaches with a particular focus on RNA biomarkers (microRNAs, long-noncoding RNAs), showing promising diagnostic performance for NAFL/NASH diagnosis and fibrosis staging.

Metabolic analysis of early nonalcoholic fatty liver disease in humans using liquid chromatography-mass spectrometry

Background

Nonalcoholic fatty liver disease (NAFLD) is a common metabolic disease that affects 20–30% of individuals worldwide. Liver puncture remains the gold standard for the diagnosis of liver diseases despite limitations regarding invasive nature and sample variability. It is of great clinical significance to find noninvasive biomarkers to detect and predict NAFLD.

Objective

The aims of this study were to identify potential serum markers in individuals with early-stage NAFLD and to advance the mechanistic understanding of this disease using a high-throughput mass spectrometry-based untargeted metabolomics approach.

Methods

One hundred and twelve patients with early-stage NAFLD aged 18–55 were recruited according to the guidelines. The control group included 112 healthy participants. The demographic, anthropometric, clinical and laboratory data of all participants were systematically collected. Serum samples were obtained after an overnight fast. The comprehensive serum metabolomic analysis was performed by ultra-performance liquid chromatography-Orbitrap mass spectrometry. The resultant data was processed by Compound Discover and SIMCA-P software to validate the potential biomarkers. Significantly altered metabolites were evaluated by variable importance in projection value (VIP > 1) and ANOVA (p < 0.01). Pathway analysis was performed using MetaboAnalyst 4.0.

Results

The liver function test of early NAFLD patients showed no statistical differences to control group (p > 0.05). However, obvious differences in blood lipids were observed between subjects with NAFLD and controls (p < 0.001). In total, 55 metabolites showed significant changes in experimental group were identified. The area under curve (AUC) values deduced by receiver operating curve (ROC) analysis indicated that these newly identified biomarkers have high predictability and reliability. Of these, 15 metabolites with AUC greater than 0.9 were of great diagnostic value in early NAFLD patients.

Conclusion

In this study, a total of 15 serum metabolites were found to strongly associate with early NAFLD. These biomarkers may have great clinical significance in the early diagnosis of NAFLD, as well as to follow response to therapeutic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02820-7.

Quantification of Liver Fat by MRI-PDFF Imaging in Patients with Suspected Non-alcoholic Fatty Liver Disease and Its Correlation with Metabolic Syndrome, Liver Function Test and Ultrasonography

BACKGROUND

Magnetic resonance imaging (MRI)-estimated proton density fat fraction (PDFF) has emerged to be a promising tool in quantification of liver fat. Aim of this study was to quantify liver fat using MRI-PDFF in patients with suspected non-alcoholic fatty liver disease (NAFLD) and to correlate it with the presence of metabolic syndrome (MetS), ultrasonography (USG) and liver function test (LFT).

METHODS

We included 111 consecutive patients who were suspected to have NAFLD on the basis of clinical, laboratory or USG findings. A 3 Tesla Phillips MRI machine was used with a software named "mDixon Quant" for quantification of the liver fat.

RESULTS

MRI-PDFF revealed hepatic steatosis grading as Grade 0 in 31 patients (28%), Grade I in 40 (36%), Grade II in 19 (17.1%) and Grade III in 21 patients (18.9%). MetS patients had higher proportion of advanced steatosis (Grades II and III) as compared to those without MetS (P < 0.001). ALT (alanine transaminase) was found to be significantly elevated (>1.5 times) in the patients with advanced steatosis as compared to patients with Grades I and 0 fatty liver on MRI-PDFF (P < 0.001). The Kappa measure of agreement between USG and MRI-PDFF was found to be 0.2, which suggests a low level of agreement between the two tests.

CONCLUSION

MetS patients have higher proportion of advanced steatosis (Grades II and III) at MRI-PDFF as compared to those without MetS. Patients with advanced steatosis at MRI-PDFF had higher proportion of abnormal LFTs as compared to those with Grades 0 and I hepatic steatosis. There was a dis-correlation between MRI-PDFF and USG in the evaluation of NAFLD.

Uncovering epigenetic landscape: a new path for biomarkers identification and drug development

Scientific advances in recent decades have revealed an incredible degree of plasticity in gene expression in response to various environmental, nutritional, physiological, pathological, and behavioral conditions. Epigenetics emerges in this sense, as the link between the internal (genetic) and external (environmental) factors underlying the expression of the phenotype. Methylation of DNA and histone post-translationa modifications are canonical epigenetic events. Additionally, noncoding RNAs molecules (microRNAs and lncRNAs) have also been proposed as another layer of epigenetic regulation. Together, these events are responsible for regulating gene expression throughout life, controlling cellular fate in both normal and pathological development. Despite being a relatively recent science, epigenetics has been arousing the interest of researchers from different segments of the life sciences and the general public. This review highlights the recent advances in the characterization of the epigenetic events and points promising use of these brands for the diagnosis, prognosis, and therapy of diseases. We also present several classes of epigenetic modifying compounds with therapeutic applications (so-call epidrugs) and their current status in clinical trials and approved by the FDA. In summary, hopefully, we provide the reader with theoretical bases for a better understanding of the epigenetic mechanisms and of the promising application of these marks and events in the medical clinic.

Efficacy of Glucagon-Like Peptide-1 Analogs in Nonalcoholic Fatty Liver Disease: A Systematic Review

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. It is believed to be the hepatic manifestation of the metabolic syndrome. Many treatment approaches have been suggested so far, and several types of studies have been done to find treatment for NAFLD, the most promising of which are those with lifestyle interventions.

Objective

The aim of this systematic review was to evaluate the efficacy and safety of glucagon-like peptide-1 (GLP-1) analogs on the management of NAFLD.

Methods

The PubMed, MEDLINE, and Cochrane Central Library were searched to identify randomized controlled trials, single arm trials, and cohorts that compared GLP-1 analogs with a control treatment or baseline values with respect to efficacy and safety in patients living with NAFLD. The key outcomes were a change in serum transaminase, resolution of disease status measured by imaging or histological techniques, improvement in insulin resistance, and reduction in body weight.

Results

Initial searching retrieved 201 peer-reviewed articles and abstracts. Ten studies met all inclusion criteria. The review included a total of 590 participants with NAFLD. Following administration of GLP-1 analogs, a decrease in serum transaminases, improvement in liver histology and insulin resistance, and a reduction in body weight were observed. Compared with baseline, body weight, alanine aminotransferase, aspartate aminotransferase, and gamma glutamyltransferase were decreased by 5.5%, 59.5%, 52.8%, and 44.8%, respectively, due to GLP-1. Likewise, a reduction of proinflammatory cytokines and fibrosis markers and an enhancement of protective adipokines were observed in some of the studies.

Conclusion

The decrease in a key biochemical marker of liver injury following treatment with GLP-1 analogs, as well as improvements in imaging and histology, suggests that these agents may be effective alternatives for managing NAFLD.

Registration

CRD42018087262.

Applying Non-Invasive Fibrosis Measurements in NAFLD/NASH: Progress to Date

Nonalcoholic fatty liver disease (NAFLD) has now become a worldwide health issue due to the obesity epidemic, affecting approximately 90% of the obese population and 15-40% of the general population. It is the most common form of chronic liver disease in the United States. NAFLD constitutes a spectrum of diseases ranging in severity from mild, such as fatty liver, progressing into nonalcoholic steatohepatitis (NASH), then fibrosis, and ending with cirrhosis. NASH and increasing fibrosis stage are associated with increased morbidity and mortality; the fibrosis stage is therefore a critical element of risk stratification needed to determine therapeutic approach and also the response to treatment. Liver biopsy is considered the 'gold standard' in the diagnosis of NAFLD. However, it is not practical for widespread clinical use because it is invasive, costly, and associated with complications including occasional death. These limitations have driven the development of noninvasive tests that can accurately predict the fibrosis stage in those with NAFLD. In this review, we provide a concise overview of different non-invasive measurements used for NAFLD/NASH.

Assessment of function, histopathological changes, and oxidative stress in liver tissue due to ionizing and non-ionizing radiations

BACKGROUND

Compared to past decades, humans are exposed to rapidly increasing levels of radiofrequency electromagnetic radiations (RF-EMF). Despite numerous studies, the biological effects of human exposure to different levels of RF-EMF are not fully understood yet. This study aimed to evaluate the bioeffects of exposure to "900/1800 MHz" and "2.4 GHz" RF-EMFs, and x-rays alone as well as their potential interactions, i.e. inducing simple additive, adaptive, or synergistic effects.

METHODS

120 Wistar rats were randomly divided into ten groups of 12 each. The rats were exposed to RF-EMF, 10 cGy, and 8 Gy x-rays, a combination of these exposures, or only sham-exposed. The levels of liver enzymes were determined in serum samples by an auto-analyzer. Moreover, the histopathological changes, and the levels of malondialdehyde (MDA), nitric oxide, ferric reducing antioxidant power, total thiols, and protein carbonyl (PCO) were measured.

RESULTS

Among the markers of liver function, gamma-glutamyltransferase was not associated with irradiation but, aspartate transaminase, alanine transaminase, and alkaline phosphatase showed some levels of association. MDA and PCO levels after 8 Gy irradiation increased, but pre-exposure to RF-EMF could modulate their changes. At the cellular level, the frequency of lobular inflammation was associated with the type of intervention.

CONCLUSION

The exposure to both ionizing and non-ionizing radiations could alter some liver function tests. A short term pre-exposure to RF-EMF before exposure to an 8 Gy challenging dose of x-rays caused the alterations in oxidative stress markers and liver function tests, which indicate that oxidative stress is possibly involved in the adaptive response.

Negative Energy Balance Induced by Exercise or Diet: Effects on Visceral Adipose Tissue and Liver Fat

The indisputable association between visceral adipose tissue (VAT) and cardiometabolic risk makes it a primary target for lifestyle-based strategies designed to prevent or manage health risk. Substantive evidence also confirms that liver fat (LF) is positively associated with increased health risk and that reduction is associated with an improved metabolic profile. The independent associations between reductions in VAT, LF, and cardiometabolic risk is less clear. In this narrative review, we summarize the evidence indicating whether a negative energy balance induced by either an increase in energy expenditure (aerobic exercise) or a decrease in energy intake (hypocaloric diet) are effective strategies for reducing both VAT and LF. Consideration will be given to whether a dose-response relationship exists between the negative energy balance induced by exercise or diet and reduction in either VAT or LF. We conclude with recommendations that will help fill gaps in knowledge with respect to lifestyle-based strategies designed to reduce VAT and LF.

Nonalcoholic fatty liver disease and hepatic fibrosis among perinatally HIV-monoinfected Asian adolescents receiving antiretroviral therapy

To assess and compare the prevalence of persistent hepatic abnormalities, including nonalcoholic fatty liver disease (NAFLD) and/or hepatic fibrosis, among perinatally HIV-monoinfected Asian adolescents with history of abnormal hepatic enzymes to those without, using noninvasive diagnostic tools. A multicenter cohort study was conducted in Thailand and Indonesia. Adolescents aged 10–25 years who were on antiretroviral treatment (ART), had virologic suppression (HIV RNA<400 copies/mL within the past 6 months), and had no history of chronic hepatitis B/C infection were enrolled. Participants were pre-classified into 2 subgroups (1:1 ratio) as participants with history of elevated versus normal aminotransferase enzymes. NAFLD was defined as hepatic steatosis (any severity) evaluated by liver ultrasonography. Significant hepatic fibrosis was defined as liver stiffness ≥7.4 kPa evaluated by transient elastography. Participants who met the criteria for protocol-defined NAFLD and/or hepatic fibrosis were re-assessed to evaluate disease progression (persistent versus transient hepatic abnormalities) at one year later. Of 120 participants, 62 (51.7%) were male, 7 (5.8%) had central obesity, and 19 (15.8%) had insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR] >3.16). At enrollment, the median age and duration of ART (IQR) were 17.0 (14.6–19.2) years and 10.5 (7.1–12.0) years, respectively. Persistent hepatic abnormalities were identified in 5/60 participants listed in the group having history of elevated aminotransferases, corresponding to the prevalence of 8.3% (95% CI: 2.8–18.4%), whereas none (0/60) were among the group having history of normal hepatic enzymes. All 5 participants had persistent aminotransferase elevation (≥2 episodes within the past 12 months). Baseline alanine aminotransferase (ALT) >30 U/L (adjusted odds ratio [aOR]: 29.1; 95% CI: 1.7–511.8), and HOMA-IR >3.16 (aOR: 17.9; 95% CI: 1.1–289.7) were independently associated with persistent hepatic abnormalities. Among perinatally HIV-monoinfected Asian adolescents with history of elevated aminotransferase enzymes, persistent hepatic abnormalities are not uncommon. Screening for liver complications by noninvasive diagnostic tools might be considered in at risk individuals, including those with persistent ALT elevation and insulin resistance.

A Microphysiological System for Studying Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the most severe form of nonalcoholic fatty liver disease (NAFLD), which to date has no approved drug treatments. There is an urgent need for better understanding of the genetic and molecular pathways that underlie NAFLD/NASH, and currently available preclinical models, be they in vivo or in vitro, do not fully represent key aspects of the human disease state. We have developed a human in vitro co‐culture NASH model using primary human hepatocytes, Kupffer cells and hepatic stellate cells, which are cultured together as microtissues in a perfused three‐dimensional microphysiological system (MPS). The microtissues were cultured in medium containing free fatty acids for at least 2 weeks, to induce a NASH‐like phenotype. The co‐culture microtissues within the MPS display a NASH‐like phenotype, showing key features of the disease including hepatic fat accumulation, the production of an inflammatory milieu, and the expression of profibrotic markers. Addition of lipopolysaccharide resulted in a more pro‐inflammatory milieu. In the model, obeticholic acid ameliorated the NASH phenotype. Microtissues were formed from both wild‐type and patatin‐like phospholipase domain containing 3 (PNPLA3) I148M mutant hepatic stellate cells. Stellate cells carrying the mutation enhanced the overall disease state of the model and in particular produced a more pro‐inflammatory milieu. Conclusion: The MPS model displays a phenotype akin to advanced NAFLD or NASH and has utility as a tool for exploring mechanisms underlying the disease. Furthermore, we demonstrate that in co‐culture the PNPLA3 I148M mutation alone can cause hepatic stellate cells to enhance the overall NASH disease phenotype.

Practical Use of Transient Elastography in Screening for Nonalcoholic Steatohepatitis in a Japanese Population

Background and Aims: Fatty infiltration of liver may induce insulin resistance (IR), and a proportion of patients with nonalcoholic fatty liver disease (NAFLD) is diagnosed with nonalcoholic steatohepatitis. Transient elastography is gaining popularity as a means of non-invasively determining both liver stiffness (fibrosis level) and degree of fatty infiltration, expressed as controlled attenuation parameter (CAP) value. Methods: The aims of this study were to investigate the association between IR and level of fatty liver, and to identify the group at a greater risk of nonalcoholic steatohepatitis using transient elastography and other noninvasive fibrosis markers. A total of 169 patients without chronic hepatitis B and C were analyzed. Results: The CAP value was significantly associated with IR (HOMA-IR ≥2.5; AUROC = 0.81), and the optimal cut-off to discriminate IR was 264 dB/m. The liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index values were significantly higher for CAP ≥264 than in CAP <264. The 9 patients among the overall 169 patients (5.3%) and among the 102 NAFLD patients (8.8%) who showed ≥264 dB and ≥7.0 kPa in transient elastography could represent good candidates for liver biopsy. Conclusions: Evaluation of NAFLD based on CAP values was useful in diagnosing IR. About 9% of NAFLD patients in a Japanese outpatient clinic with a few metabolic complications might be considered good candidates for liver biopsy to confirm nonalcoholic steatohepatitis.

Elevated levels of circulating ITIH4 are associated with hepatocellular carcinoma with nonalcoholic fatty liver disease: from pig model to human study

BACKGROUND

Noninvasive biomarkers are urgently needed for optimal management of nonalcoholic fatty liver disease (NAFLD) for the prevention of disease progression into nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). In order to identify the biomarkers, we generated the swine hepatocellular carcinoma (HCC) model associated with NAFLD and performed serum proteomics on the model.

METHODS

Microminipigs were fed a high-fat diet to induce NAFLD and a normal diet as the control. To induce HCC, diethylnitrosamine was intraperitoneally administered. Biopsied liver samples were histopathologically analyzed every 12 weeks. Serum proteins were separated by blue native two-dimensional gel electrophoresis and proteins of interest were subsequently identified by MALDI-TOF MS/MS. Human serum samples were analyzed to validate the candidate protein using antibody-mediated characterization.

RESULTS

In the NAFLD pigs, hepatic histology of nonalcoholic steatohepatitis (NASH) was observed at 36 weeks, and HCC developed at 60 weeks. Among serum proteins identified with MALDI-TOF MS/MS, serum inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), an acute response protein which is secreted primarily by liver, was identified as the most characteristic protein corresponding with NAFLD progression and HCC development in the NAFLD pigs. With immunoassay, serum ITIH4 levels in the NAFLD pigs were chronologically increased in comparison with those in control animal. Furthermore, immunohistochemistry showed ITIH4 expression in hepatocytes also increased in both the cancer lesions and parenchyma as NAFLD progressed. Human study is also consistent with this observation because serum ITIH4 levels were significantly higher in HCC-NAFLD patients than in the simple steatosis, NASH, and virus-related HCC patients. Of note, HCC-NAFLD patients who had higher serum ITIH4 levels exhibited poorer prognosis after hepatectomy.

CONCLUSIONS

We established an HCC pig model associated with NAFLD. Serum proteomics on the swine HCC with NAFLD model implicated ITIH4 as a non-invasive biomarker reflecting NAFLD progression as well as subsequent HCC development. Most importantly, the results in the swine study have been validated in human cohort studies. Dissecting speciation of serum ITIH4 promises to have clinical utility in monitoring the disease.

Effects of different exercise modalities on novel hepatic steatosis indices in overweight women with type 2 diabetes

BACKGROUND/AIMS

Fatty liver is a clinical and pathologic condition in individuals with type 2 diabetes (T2D). The purpose of this study is to examine the effects of different exercise modalities on non-alcoholic fatty liver indices (fatty liver index [FLI], lipid accumulation product [LAP], hepatic steatosis index [HSI], and Framingham Steatosis Index [FSI]) in women with T2D.

METHODS

Fifty-two women with T2D and a mean age of 55.07±5.92 yrs, body mass index (BMI) 28.94±4.09 kg/m2 , and hemoglobin A1c (HbA1c) 9.41±0.82% were randomized to a sprint interval training (SIT) (n=17), combined aerobic and resistance (A+R) training (n=17), or control group (n=18) for 10 weeks. Two-way repeated analysis of variance (ANOVA) was used to find differences between groups and the effects of time and Time×Group interactions after 10 weeks on non-alcoholic fatty liver indices. After this, ANOVA models were constructed to determine the effects of group allocation and change in non-alcoholic fatty liver indices.

RESULTS

There were significant time interactions for FLI (P<0.001), HSI (P<0.001), and LAP (P<0.001). Also, there were significant Time×Group interactions for fasting blood glucose (P=0.034), and HbA1c (P=0.006).

CONCLUSION

Results highlight that exercise training, independent of mode of training, is an effective strategy to improve some indices related to hepatic steatosis and blood glucose profiles in women with T2D.

The FATZO mouse, a next generation model of type 2 diabetes, develops NAFLD and NASH when fed a Western diet supplemented with fructose

BACKGROUND

Metabolic disorders such as insulin resistance, obesity, and hyperglycemia are prominent risk factors for the development of non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH). Dietary rodent models employ high fat, high cholesterol, high fructose, methionine/choline deficient diets or combinations of these to induce NAFLD/NASH. The FATZO mice spontaneously develop the above metabolic disorders and type 2 diabetes (T2D) when fed with a normal chow diet. The aim of the present study was to determine if FATZO mice fed a high fat and fructose diet would exacerbate the progression of NAFLD/NASH.

METHODS

Male FATZO mice at the age of 8 weeks were fed with high fat Western diet (D12079B) supplemented with 5% fructose in the drinking water (WDF) for the duration of 20 weeks. The body weight, whole body fat content, serum lipid profiles and liver function markers were examined monthly along with the assessment of liver histology for the development of NASH. In addition, the effects of obeticholic acid (OCA, 30 mg/kg, QD) on improvement of NASH progression in the model were evaluated.

RESULTS

Compared to normal control diet (CD), FATZO mice fed with WDF were heavier with higher body fat measured by qNMR, hypercholesterolemia and had progressive elevations in AST (~ 6 fold), ALT (~ 6 fold), liver over body weight (~ 2 fold) and liver triglyceride (TG) content (1.4-2.9 fold). Histological examination displayed evidence of NAFLD/NASH, including hepatic steatosis, lobular inflammation, ballooning and fibrosis in FATZO mice fed WDF. Treatment with OCA for 15 weeks in FATZO mice on WDF significantly alleviated hypercholesterolemia and elevation of AST/ALT, reduced liver weight and liver TG contents, attenuated hepatic ballooning, but did not affect body weight and blood TG levels.

CONCLUSION

WDF fed FATZO mice represent a new model for the study of progressive NAFLD/NASH with concurrent metabolic dysregulation.

Understanding susceptibility and targeting treatment in non-alcoholic fatty liver disease in children; moving the fulcrum

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of paediatric liver disease, affecting 10% of school-aged children and 44–70% of obese children and young people (CYP) in the western world. Encompassing a spectrum from simple steatosis to steatohepatitis and progressive fibrosis, the disease is rapidly becoming the most common indication for liver transplantation. The molecular pathogenesis of NAFLD remains only partially understood. Development and progression of NAFLD is influenced by genetic and nutritional factors, insulin resistance, oxidative stress, gut microbiome, bile acid metabolism and lipid/glucose handling and is closely associated with overweight and obesity. Lifestyle change is the only proven effective treatment for paediatric NAFLD, however this is difficult to achieve in many. Given that moderate or severe fibrosis is already present in 30–50% of children with NAFLD at the time of presentation, progression in CYP may be more rapid, though adequate outcome data do not yet exist in this cohort. CYP with NAFLD are an excellent population in which to study underlying mechanisms and interventions to correct disease progression as they are largely unaffected by other environmental influences such as alcohol and may represent the more severe end of the spectrum in terms of early onset. Undoubtedly genetic and epigenetic mechanisms determine a large proportion of susceptibility to the disease and potentially, identification of individuals at risk may allow for targeted therapy. This review with give a clinical perspective of paediatric NAFLD focused on identifying those at risk of progressive disease and what to consider in attempting to modify risk.

Childhood and Adolescent Nonalcoholic Fatty Liver Disease: Is It Different from Adults?

Paediatric nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in childhood and adolescence. Although the condition is similar in many ways to NAFLD in adults, there are important differences in predisposition, presentation, differential diagnosis and potentially also in optimal management. Antenatal and early childhood exposures and the particular vulnerabilities to environmental influences in a growing child, present unique opportunities for intervention and modification of risk. The prevalence of significant fibrosis on biopsy in preadolescent children in the context of NAFLD should not be ignored, but the relevance of this fibrosis to long-term outcome is as yet unknown. The approach to children and adolescents with suspected NAFLD needs to include an assessment of risk factors in addition to exclusion of alternative or coexisting liver diseases. Liver biopsy is indicated for younger children and for those without clear predisposing factors leading to metabolic syndrome, also for those in whom significant fibrosis is suspected. The histology in children and adolescents differs from adults in whom type 2 NAFLD may be more prevalent, which is associated in turn with more significant fibrosis. Management in children and adolescents needs to focus on lifestyle intervention, which when weight loss is achieved, demonstrates excellent results in terms of resolution of disease. Appropriate intervention in childhood and adolescence may prove instrumental in avoiding the need for later transplantation while also decreasing all-cause mortality in these at-risk individuals.

Comparison of CT and magnetic resonance mDIXON-Quant sequence in the diagnosis of mild hepatic steatosis

OBJECTIVE:

To determine the diagnostic performance of CT in the assessment of mild hepatic steatosis by comparison with MR mDIXON-Quant as a reference standard, and to explore their clinical applications.

METHODS:

In this prospective study 169 volunteers were included. Each subject underwent CT and MR mDIXON-Quant examinations. Hepatic steatosis evaluations were performed via liver attenuation alone (CT L), liver to spleen attenuation ratio (CT L/S), difference between liver and spleen attenuation (CT L-S), and MR mDIXON-Quant imaging. The effectiveness of CT L, CT L/S, and CT L-S in diagnosing hepatic steatosis severity of ≥5%, ≥10%, and ≥15% was compared, using mDIXON-Quant results as standard.

RESULTS:

65 subjects exhibited mild hepatic steatosis. Hepatic steatosis measurement with mDIXON-Quant was strongly correlated with the three CT methods. Using cutoff value, the sensitivity and specificity of diagnosing hepatic steatosis ≥5, ≥10, and ≥15% were 64.6, 91.3, 100%, and 90.4, 89.7, 93.0% for CT L; 50.8, 87.0, 100%, and 96.2, 98.6, 97.5% for CT L/S; and 67.7, 87.0, 100%, and 81.7, 98.6, 97.5% for CT L-S, respectively. ROC analysis indicated that 58.9, 56.5, and 52.8 HU for CT L; 1.06, 0.98, and 0.90 HU for CT L/S; and 6.21,-1.04, and -4.93 HU for CT L-S were cutoff values for diagnosing hepatic steatosis ≥5%,≥10%, and ≥15%, respectively.

CONCLUSIONS:

The three CT methods exhibit better agreements with mDIXON-Quant imaging for diagnosing hepatic steatosis ≥10%. Hence, CT and mDIXON-Quant could serve as suitable tools for the accurate quantification of mild hepatic steatosis.

SIGNIFICANT FINDS OF THE STUDY:

The close agreement between the three different CT methods (based on our cutoff values) and mDIXON-Quant imaging suggests that CT could accurately diagnose hepatic steatosis ≥10%. Thus, CT and mDIXON-Quant imaging can accurately measure mild hepatic steatosis.

WHAT THIS STUDY ADDS:

Only few studies have compared hepatic steatosis quantification between CT and mDIXON-Quant. We are the first to determine the diagnostic performance of unenhanced CT for quantitatively assessing mild hepatic steatosis, in reference to magnetic resonance mDIXON-Quant imaging.

Derivation and Performance of Standardized Enhanced Liver Fibrosis (ELF) Test Thresholds for the Detection and Prognosis of Liver Fibrosis

INTRODUCTION

Noninvasive tests are increasingly used to assess liver fibrosis and determine prognosis but suggested test thresholds vary. We describe the selection of standardized thresholds for the Enhanced Liver Fibrosis (ELF) test for the detection of liver fibrosis and for prognostication in chronic liver disease.

METHODS

A Delphi method was used to identify thresholds for the ELF test to predict histological liver fibrosis stages, including cirrhosis, using data derived from 921 patients in the EUROGOLF cohort. These thresholds were then used to determine the prognostic performance of ELF in a subset of 457 patients followed for a mean of 5 years.

RESULTS

The Delphi panel selected sensitivity of 85% for the detection of fibrosis and >95% specificity for cirrhosis. The corresponding thresholds were 7.7, 9.8, and 11.3. Eighty-five percent of patients with mild or worse fibrosis had an ELF score ≥7.7. The sensitivity for cirrhosis of ELF ≥9.8 was 76%. ELF ≥11.3 was 97% specific for cirrhosis. ELF scores show a near-linear relationship with Ishak fibrosis stages. Relative to the <7.7 group, the hazard ratios for a liver-related outcome at 5 years were 21.00 (95% CI, 2.68-164.65) and 71.04 (95% CI, 9.4-536.7) in the 9.8 to <11.3 and ≥11.3 subgroups, respectively.

CONCLUSION

The selection of standard thresholds for detection and prognosis of liver fibrosis is described and their performance reported. These thresholds should prove useful in both interpreting and explaining test results and when considering the relationship of ELF score to Ishak stage in the context of monitoring.

Serum Interleukin-8, Osteopontin, and Monocyte Chemoattractant Protein 1 Are Associated With Hepatic Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

The severity of hepatic fibrosis is the primary predictor of liver‐related morbidity and mortality in patients with nonalcoholic fatty liver disease (NAFLD). Unfortunately, noninvasive serum biomarkers for NAFLD‐associated fibrosis are limited. We analyzed baseline serum samples for 24 cytokines of 97 patients with biopsy‐proven NAFLD. These patients were prospectively enrolled in a clinical study (ClinicalTrials.gov NCT00794716) to identify cytokines associated with liver fibrosis in patients with nonalcoholic steatohepatitis. Patients were stratified according to severity of hepatic fibrosis (mild, stage 0‐1, n = 37; moderate, stage 2, n = 40; and advanced, stage 3‐4, n = 20) while controlling for age, race, sex, body mass index, and diabetes mellitus. Interleukin‐8 (IL‐8), osteopontin (OPN), and monocyte chemoattractant protein 1 (MCP1) were associated with liver fibrosis (P < 0.001, P = 0.005, P = 0.016, respectively). After controlling for steatosis, lobular inflammation, hepatocyte ballooning, age, sex, body mass index, diabetes mellitus, hypertension, and metabolic syndrome status, IL‐8 remained strongly associated with fibrosis (P = 0.001). Furthermore, IL‐8 was also a strong predictor of increased fibrotic liver injury compared to established markers of hepatic fibrosis. Hepatic gene expression from 72 patients with NAFLD (n = 40 mild fibrosis; n = 32 advanced fibrosis) from the Duke University Health System NAFLD Clinical Database and Biorepository revealed IL‐8, MCP1, and OPN gene expression to be increased and differentially expressed in patients with advanced hepatic fibrosis. Thus, serum IL‐8, MCP1, and OPN may reflect up‐regulated gene expression during liver fibrosis in NAFLD. Conclusion: Serum IL‐8, MCP1, and OPN may serve as a test for advanced hepatic fibrosis in NAFLD and thus reveal novel targets for antifibrotic therapies. The increased serum IL‐8, MCP1, and OPN that correspond with associated hepatic gene expression lend strength to such analytes as ideal surrogate serum biomarkers for severity of hepatic fibrosis.

Current status of imaging in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldwide prevalence of 20% to 46%. NAFLD can be subdivided into simple steatosis and nonalcoholic steatohepatitis. Most cases of simple steatosis are non-progressive, whereas nonalcoholic steatohepatitis may result in chronic liver injury and progressive fibrosis in a significant minority. Effective risk stratification and management of NAFLD requires evaluation of hepatic parenchymal fat, fibrosis, and inflammation. Liver biopsy remains the current gold standard; however, non-invasive imaging methods are rapidly evolving and may replace biopsy in some circumstances. These methods include well-established techniques, such as conventional ultrasonography, computed tomography, and magnetic resonance imaging and newer imaging technologies, such as ultrasound elastography, quantitative ultrasound techniques, magnetic resonance elastography, and magnetic resonance-based fat quantitation techniques. The aim of this article is to review the current status of imaging methods for NAFLD risk stratification and management, including their diagnostic accuracy, limitations, and practical applicability.

Anthropometric and blood parameters for the prediction of NAFLD among overweight and obese adults

Backround

Non-alcoholic fatty liver disease (NAFLD) comprises non-progressive steatosis and non-alcoholic steatohepatitis (NASH), the latter of which may cause cirrhosis and hepatocellular carcinoma (HCC). As NAFLD detection is imperative for the prevention of its complications, we evaluated whether a combination of blood-based biomarkers and anthropometric parameters can be used to predict NAFLD among overweight and obese adults.

Methods

143 overweight or obese non-smokers free of diabetes (50% women, age: 35–65 years) were recruited. Anthropometric indices and routine biomarkers of metabolism and liver function were measured to predict magnetic resonance (MR) - derived NAFLD by multivariable logistic regression models. In addition, we evaluated to which degree the use of more novel biomarkers (adiponectin, leptin, resistin, C-reactive protein, TNF-α, IL-6, IL-8 and interferon-γ) could improve prediction models.

Results

NAFLD was best predicted by a combination of age, sex, waist circumference, ALT, HbA1c, and HOMA-IR at an area under the receiver operating characteristic curve (AUROC) of 0.87 (95% CI: 0.81, 0.93) before and 0.85 (95% CI: 0.78, 0.91) after internal bootstrap validation. The use of additional biomarkers of inflammation and metabolism did not improve NAFLD prediction. Previously published indices predicted NAFLD at AUROCs between 0.71 and 0.82.

Conclusions

The AUROC of > 0.8 obtained by our regression model suggests the feasibility of a non-invasive detection of NAFLD by anthropometry and circulating biomarkers, even though further increments in the capacity of prediction models may be needed before NAFLD indices can be applied in routine clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0840-9) contains supplementary material, which is available to authorized users.

Associations between Liver Enzyme Levels and Parameters of the Metabolic Syndrome in Obese Children

BACKGROUND

Obesity is strongly associated with insulin resistance, hypertension, dyslipidemia, and therefore risk for metabolic syndrome (MetS), which is an increasing problem in youth. The potential role of elevated liver enzyme levels in this context needs to be further investigated.

METHODS

This paper provides a post hoc analysis of a cross-sectional study of 77 obese nondiabetic children (51% female; median age 11.7 years; BMI >97th percentile) enrolled at the University of Bonn, Bonn, Germany. Anthropometric parameters, lipid profiles, glycemic control, and liver enzyme levels were evaluated. Glucose and insulin levels were determined during an oral glucose tolerance test (OGTT). Gender- and age-specific cutoff values were used to assess MetS.

RESULTS

A high prevalence of hypertension (51%), dyslipidemia (52%), elevated liver enzyme levels (51%), and hyperglycemia (24%) was found. There was considerable overlap between the presence of different MetS risk factors in individuals, and 40% of the participants had ≥3 of a maximum of 5 MetS risk factors. Elevated liver enzyme levels were significantly associated with reduced insulin sensitivity, as the OGTT-insulin response was significantly higher in participants with elevated transaminases (p = 0.01). This association was independent of hyperglycemia and dyslipidemia (p = 0.03).

CONCLUSIONS

We conclude that liver enzyme levels are related to insulin sensitivity in obese children and could therefore be an indirect indicator for MetS. Testing for disturbed glucose metabolism should be considered for obese children with elevated liver enzymes.

Hepatoprotective Effects of Insect Extracts in an Animal Model of Nonalcoholic Fatty Liver Disease

Insects represent the largest and most diverse group of organisms on earth and are potential food and drug resources. Recently, we have demonstrated that a Forsythia viridissima extract prevented free fatty acid-induced lipid accumulation in an in vitro cellular nonalcoholic fatty liver disease (NAFLD) model. In this study, we aimed to evaluate the hepatoprotective effects of extracts of the insects Protaetia brevitarsis seulensis Kolbe, 1886 (PB), Oxya chinensis sinuosa Mishchenko, 1951 (OC), and Gryllus bimaculatus De Geer, 1773 (GB) in a high-fat diet (HFD)-induced NAFLD animal model, as well as to elucidate the underlying mechanisms. The effects of the supplementation with PB, OC, and GB extracts were evaluated histopathologically and histochemically. PB, OC, and GB extract supplementation inhibited the HFD-induced increase in body weight and body fat mass and ameliorated other adverse changes, resulting in decreased liver function parameters, lower serum triglyceride and cholesterol levels, and increased serum adiponectin levels. The expression of hepatic genes involved in lipid droplet accumulation and in fatty acid uptake also decreased upon treatment of HFD-fed mice with the extracts. These results provide evidence of the protective effects of the PB, OC, and GB extracts against HFD-induced fatty liver disease in an animal model.

Noninvasive fibrosis markers and chronic kidney disease among adults with nonalcoholic fatty liver in USA

BACKGROUND/AIMS

Studies have shown that nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of chronic kidney disease (CKD). However, it is unknown whether severe liver fibrosis is associated with a higher prevalence of CKD among NAFLD. We examined the diagnostic performance of noninvasive fibrosis markers in identifying prevalent CKD among NAFLD.

METHODS

This study represents an analysis of the National Health and Nutrition Examination Survey conducted in the USA between 1988 and 1994. NAFLD was defined by ultrasonographic evidence of hepatic steatosis without other liver diseases. CKD was defined by estimated glomerular filtration rate less than 60 ml/min/1.73 m. The presence and severity of hepatic fibrosis were determined by the NAFLD fibrosis score (NFS), FIB-4 score, APRI score, and BARD score. Multiple logistic regression was performed to generate odds ratios (ORs) and receiver operating characteristic curves were used to assess the predictive values of each marker.

RESULTS

A total of 4142 individuals with NAFLD were included; 200 (4.8%) had CKD. The area under the receiver operating characteristic curves was 0.77, 0.75, 0.62, and 0.51 for the multivariable equation with FIB-4, NFS, BARD, and APRI score, respectively. Compared with patients with a low probability of developing advanced liver fibrosis, individuals with a high probability of developing fibrosis showed significantly increased odds of CKD as estimated by NFS (adjusted OR: 4.92, 95% confidence interval: 2.96-8.15) and FIB-4 (adjusted OR: 2.27, 95% confidence interval: 1.05-4.52).

CONCLUSION

Advanced liver fibrosis, defined by NFS and FIB-4 scores, is associated independently with CKD among individuals with NAFLD. FIB-4 is the best predictor of an increased risk of prevalent CKD.

The search for noninvasive methods to identify liver fibrosis in children with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the obesity epidemic. Recent studies have clearly shown that the stage of fibrosis in adults with NAFLD is the most important histological feature in long-term outcomes and the development of liver-related complications. Despite the paucity of data regarding the natural history of pediatric NAFLD, its progression to cirrhosis and end-stage liver disease requiring liver transplantation is well documented. Given the high prevalence of NAFLD in children and adults, there is an urgent need to find safe and cost-effective alternatives to biopsy to determine the stage of liver fibrosis. In this review, we provide a concise overview of different noninvasive methods for diagnosing and staging liver fibrosis in children with NAFLD.

Quantitative Assessment of Liver Steatosis and Affected Pathways with Molecular Imaging and Proteomic Profiling

Current assessment of non-alcoholic fatty liver disease (NAFLD) with histology is time-consuming, insensitive to early-stage detection, qualitative, and lacks information on etiology. This study explored alternative methods for fast and quantitative assessment of NAFLD with hyperspectral stimulated Raman scattering (SRS) microscopy and nanofluidic proteomics. Hyperspectral SRS microscopy quantitatively measured liver composition of protein, DNA, and lipid without labeling and sensitively detected early-stage steatosis in a few minutes. On the other hand, nanofluidic proteomics quantitatively measured perturbations to the post-translational modification (PTM) profiles of selective liver proteins to identify affected cellular signaling and metabolic pathways in a few hours. Perturbations to the PTM profiles of Akt, 4EBP1, BID, HMGCS2, FABP1, and FABP5 indicated abnormalities in multiple cellular processes including cell cycle regulation, PI3K/Akt/mTOR signaling cascade, autophagy, ketogenesis, and fatty acid transport. The integrative deployment of hyperspectral SRS microscopy and nanofluidic proteomics provided fast, sensitive, and quantitative assessment of liver steatosis and affected pathways that overcame the limitations of histology.

Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. However, its molecular pathogenesis is incompletely characterized and clinical biomarkers remain scarce. The aims of these experiments were to identify and characterize liver protein alterations in an animal model of early, diet-related, liver injury and to assess novel candidate biomarkers in NAFLD patients.

Methods

Liver membrane and cytosolic protein fractions from high fat fed apolipoprotein E knockout (ApoE^−/−) animals were analyzed by quantitative proteomics, utilizing isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential protein expression was confirmed independently by immunoblotting and immunohistochemistry in both murine tissue and biopsies from paediatric NAFLD patients. Candidate biomarkers were analyzed by enzyme-linked immunosorbent assay in serum from adult NAFLD patients.

Results

Through proteomic profiling, we identified decreased expression of hepatic glyoxalase 1 (GLO1) in a murine model. GLO1 protein expression was also found altered in tissue biopsies from paediatric NAFLD patients. In vitro experiments demonstrated that, in response to lipid loading in hepatocytes, GLO1 is first hyperacetylated then ubiquitinated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 59 biopsy-confirmed adult NAFLD patients, increased serum levels of the primary methylglyoxal-derived advanced glycation endproduct, hydroimidazolone (MG-H1) were significantly correlated with body mass index (r = 0.520, p < 0.0001).

Conclusion

Collectively these results demonstrate the dysregulation of GLO1 in NAFLD and implicate the acetylation-ubquitination degradation pathway as the functional mechanism. Further investigation of the role of GLO1 in the molecular pathogenesis of NAFLD is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12953-018-0131-y) contains supplementary material, which is available to authorized users.

Diagnosis and Evaluation of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis, Including Noninvasive Biomarkers and Transient Elastography

The incidence and prevalence of nonalcoholic fatty liver disease (NAFLD) are increasing and identification of people at risk of disease progression is extremely important. The current gold standard for diagnosing NAFLD/nonalcoholic steatohepatitis (NASH) is by liver biopsy, but it has several limitations. Noninvasive tests via biomarkers and transient elastography to assess NAFLD/NASH are being used in clinical practice. The most validated diagnostic panels include the NAFLD fibrosis score, FIB-4 (Fibrosis-4), and FibroMeter. Transient elastography is very useful in evaluating advanced fibrosis and cirrhosis.

A simple scoring system using type IV collagen 7S and aspartate aminotransferase for diagnosing nonalcoholic steatohepatitis and related fibrosis

BACKGROUND

Recently we reported novel noninvasive scoring systems for diagnosing nonalcoholic steatohepatitis (NASH) and related fibrosis, namely FM-NASH index and FM-fibro index. They are highly accurate, however, they contain some items not widely used in clinical practice and require six or more items to diagnose both NASH and related fibrosis. By focusing on widely used items, we tried to identify convenient markers in common with the both diagnoses.

METHODS

To explore the markers for NASH and related fibrosis in nonalcoholic fatty liver disease (NAFLD) patients, we used data of 24 clinical items in our previous report. By logistic regression analysis, we identified items suitable for the both diagnoses. We then evaluated their accuracies by area under the receiver operator characteristic curves (AUROCs) on independent validation data.

RESULTS

We identified the combination of type IV collagen 7S and aspartate aminotransferase (AST) as the predictor both for NASH and related fibrosis. We developed a scoring system based on the combination and evaluated the prediction accuracy: the AUROCs for training/validation data sets are 0.857/0.769 for NASH and 0.918/0.842 for NASH-related fibrosis. The former was higher than that of NAFIC score, and the latter was higher than those of existing fibrosis markers: BARD score, FIB-4 index and NAFLD fibrosis score but lower than FM-fibro index.

CONCLUSIONS

The scoring system using type IV collagen 7S and AST named CA index can predict both NASH and related fibrosis in NAFLD patients with sufficient accuracy and could be a convenient diagnostic and screening tool for NASH and related fibrosis. The scoring system needs to be validated in independent larger populations from multiple clinical centers.

Periodontitis is associated with significant hepatic fibrosis in patients with non-alcoholic fatty liver disease

Background and aims

Non-alcoholic fatty liver disease (NAFLD) has a bidirectional association with metabolic syndrome. It affects up to 30% of the general population, 70% of individuals with diabetes and 90% with obesity. The main histological hallmark of progressive NAFLD is fibrosis. There is a bidirectional epidemiological link between periodontitis and metabolic syndrome. NAFLD, periodontitis and diabetes share common risk factors, are characterised by inflammation and associated with changes in commensal bacteria. Therefore we tested the hypothesis that periodontitis is associated with NAFLD and with significant fibrosis in two study groups.

Methods

We analyzed data from a population-based survey and a patient-based study. NHANES III participants with abdominal ultrasound and sociodemographic, clinical, and oral examination data were extracted and appropriate weighting applied. In a separate patient-based study, consenting patients with biopsy-proved NAFLD (or with liver indices too mild to justify biopsy) underwent dental examination. Basic Periodontal Examination score was recorded.

Results

In NHANES, periodontitis was significantly associated with steatosis in 8172 adults even after adjusting for sociodemographic factors. However, associations were fully explained after accounting for features of metabolic syndrome. In the patient-based study, periodontitis was significantly more common in patients with biopsy-proven NASH and any fibrosis (F0-F4) than without NASH (p = 0.009). Periodontitis was more common in patients with NASH and significant fibrosis (F2-4) than mild or no fibrosis (F0-1, p = 0.04).

Conclusions

Complementary evidence from an epidemiological survey and a clinical study show that NAFLD is associated with periodontitis and that the association is stronger with significant liver fibrosis.

Evaluation of alternative serum biomarkers to monitor the progression of chronic HBV and HCV infection

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are among the most serious health conditions affecting about 600 million people worldwide leading to a number of severe liver diseases. Due to the lack of warning signs or mild symptoms during the early stage of the infection, a molecular signature associated with disease progression would be useful. Based on our recent paper where candidate biomarkers were determined through topological and modularity analysis of protein interaction networks (PINs), this study was focused on the evaluation of MIF, TNFRSF1A, FAS and TMSB4X as diagnostic biomarkers in chronic HBV and HCV infections. The aim was to establish a molecular profile, by combining those markers, that would discriminate the different stages during the progression of chronic hepatitis. One hundred and fifteen patients infected with HBV or HCV categorized into three groups: non-cirrhotic, cirrhotic and with HCC, and 20 healthy subjects were enrolled in this study. Serum levels of the aforementioned factors were measured by ELISA. TNFRSF1A serum levels appeared statistically significantly increased in all patient groups compared to control group with a p-value of <0.05. Furthermore, the combination of TNFRSF1A and TMSB4X serum levels successfully classified 63, 47% of patients indicating an association with HBV and HCV infections. Thus, variations of serum levels of TNFRSF1A and TMSB4X could be associated with the different stages of the disease and may be utilized for further research. On the other hand, we found no contribution of MIF and FAS serum levels for successful classification of patients.

Vitamin D supplementation and non-alcoholic fatty liver disease: A critical and systematic review of clinical trials

Previous observational studies have found a relationship between vitamin D deficiency and non-alcoholic fatty liver disease (NAFLD). However, this type of study could not show the causal relationship between these two conditions. Therefore, we systematically and critically reviewed the available clinical trials to elucidate such relationship. We searched databases such as Medline, Scopus and Cochrane to identify the clinical trials that assessed the effects of vitamin D supplementation in adults with NAFLD. The outcome variables of interest were indicators of hepatic steatosis, liver enzymes, insulin resistance, inflammation and oxidative stress. A total of 6 studies were included in the qualitative analysis. Only in two studies the grade of hepatic steatosis decreased significantly after vitamin D supplementation. The changes in insulin resistance parameters were reported significant only in one. Of the 3 included studies that measured biomarkers of inflammation and oxidative stress, one revealed a significant decrease in these biomarkers after vitamin D supplementation. Findings from current review study provided new insight into the factors that could affect the therapeutic role of vitamin D in NAFLD. Factors such as gender differences, baseline serum status of vitamin D, co-supplementation with calcium and gene polymorphism should be considered when designing future clinical trials.

Sensitivity enhancement for detection of hyperpolarized 13 C MRI probes with 1 H spin coupling introduced by enzymatic transformation in vivo

PURPOSE

Although ¹ H spin coupling is generally avoided in probes for hyperpolarized (HP) ¹³ C MRI, enzymatic transformations of biological interest can introduce large ¹³ C-¹ H couplings in vivo. The purpose of this study was to develop and investigate the application of ¹ H decoupling for enhancing the sensitivity for detection of affected HP ¹³ C metabolic products.

METHODS

A standalone ¹ H decoupler system and custom concentric ¹³ C/¹ H paddle coil setup were integrated with a clinical 3T MRI scanner for in vivo ¹³ C MR studies using HP [2-¹³ C]dihydroxyacetone, a novel sensor of hepatic energy status. Major ¹³ C-¹ H coupling J_CH  = ∼150 Hz) is introduced after adenosine triphosphate-dependent enzymatic transformation of HP [2-¹³ C]dihydroxyacetone to [2-¹³ C]glycerol-3-phosphate in vivo. Application of WALTZ-16 ¹ H decoupling for elimination of large ¹³ C-¹ H couplings was first tested in thermally polarized glycerol phantoms and then for in vivo HP MR studies in three rats, scanned both with and without decoupling.

RESULTS

As configured, ¹ H-decoupled ¹³ C MR of thermally polarized glycerol and the HP metabolic product [2-¹³ C]glycerol-3-phosphate was achieved at forward power of approximately 15 W. High-quality 3-s dynamic in vivo HP ¹³ C MR scans were acquired with decoupling duty cycle of 5%. Application of ¹ H decoupling resulted in sensitivity enhancement of 1.7-fold for detection of metabolic conversion of [2-¹³ C]dihydroxyacetone to HP [2-¹³ C]glycerol-3-phosphate in vivo.

CONCLUSIONS

Application of ¹ H decoupling provides significant sensitivity enhancement for detection of HP ¹³ C metabolic products with large ¹ H spin couplings, and is therefore expected to be useful for preclinical and potentially clinical HP ¹³ C MR studies. Magn Reson Med 80:36-41, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Mediterranean Diet and Multi-Ingredient-Based Interventions for the Management of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) comprises a wide spectrum of hepatic disorders, from simple steatosis to hepatic necro-inflammation leading to non-alcoholic steatohepatitis (NASH). Although the prevalence of these multifactorial pathologies is continuously increasing in the population, there is still not an established methodology for their treatment other than weight loss and a change in lifestyle habits, such as a hypocaloric diet and physical exercise. In this framework, there is increasing evidence that several food bioactives and dietary patterns are effective for reversing and preventing the onset of these pathologies. Some studies have claimed that better responses are obtained when treatments are performed under a multifaceted approach, using different bioactive compounds that act against complementary targets. Thus, in this work, current strategies for treating NAFLD and NASH based on multi-ingredient-based supplements or the Mediterranean diet, a dietary pattern rich in bioactive compounds, are reviewed. Furthermore, the usefulness of omics techniques to design effective multi-ingredient nutritional interventions and to predict and monitor their response against these disorders is also discussed.

Screening for non-alcoholic fatty liver disease in children: do guidelines provide enough guidance?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the industrialized world in children. Its high prevalence and important health risks make NAFLD highly suitable for screening. In practice, screening is widely, albeit not consistently, performed.

AIM

To review the recommendations on screening for NAFLD in children.

METHOD

Recommendations on screening were reviewed from major paediatric obesity guidelines and NAFLD guidelines. A literature overview is provided on open questions and controversies.

RESULTS

Screening for NAFLD is advocated in all obesity and most NAFLD guidelines. Guidelines are not uniform in whom to screen, and most guidelines do not specify how screening should be performed in practice. Screening for NAFLD remains controversial, due to lack of a highly accurate screening tool, limited knowledge to predict the natural course of NAFLD and limited data on its cost effectiveness.

CONCLUSIONS

Guidelines provide little guidance on how screening should be performed. Screening for NAFLD remains controversial because not all conditions for screening are fully met. Consensus is needed on the optimal use of currently available screening tools. Research should focus on new accurate screening tool, the natural history of NAFLD and the cost effectiveness of different screening strategies in children.