Relationship between aminotransferase levels and histopathological findings in patients with nonalcoholic steatohepatitis

Identification of neutrophil extracellular trap-related biomarkers in non-alcoholic fatty liver disease through machine learning and single-cell analysis

Non-alcoholic Fatty Liver Disease (NAFLD), noted for its widespread prevalence among adults, has become the leading chronic liver condition globally. Simultaneously, the annual disease burden, particularly liver cirrhosis caused by NAFLD, has increased significantly. Neutrophil Extracellular Traps (NETs) play a crucial role in the progression of this disease and are key to the pathogenesis of NAFLD. However, research into the specific roles of NETs-related genes in NAFLD is still a field requiring thorough investigation. Utilizing techniques like AddModuleScore, ssGSEA, and WGCNA, our team conducted gene screening to identify the genes linked to NETs in both single-cell and bulk transcriptomics. Using algorithms including Random Forest, Support Vector Machine, Least Absolute Shrinkage, and Selection Operator, we identified ZFP36L2 and PHLDA1 as key hub genes. The pivotal role of these genes in NAFLD diagnosis was confirmed using the training dataset GSE164760. This study identified 116 genes linked to NETs across single-cell and bulk transcriptomic analyses. These genes demonstrated enrichment in immune and metabolic pathways. Additionally, two NETs-related hub genes, PHLDA1 and ZFP36L2, were selected through machine learning for integration into a prognostic model. These hub genes play roles in inflammatory and metabolic processes. scRNA-seq results showed variations in cellular communication among cells with different expression patterns of these key genes. In conclusion, this study explored the molecular characteristics of NETs-associated genes in NAFLD. It identified two potential biomarkers and analyzed their roles in the hepatic microenvironment. These discoveries could aid in NAFLD diagnosis and management, with the ultimate goal of enhancing patient outcomes.

PPAR-γ signaling in nonalcoholic fatty liver disease: Pathogenesis and therapeutic targets

Non-alcoholic fatty liver disease (NAFLD), currently the leading cause of global chronic liver disease, has emerged as a major public health problem, more efficient therapeutics of which are thus urgently needed. Peroxisome proliferator-activated receptor γ (PPAR-γ), ligand-activated transcription factors of the nuclear hormone receptor superfamily, is considered a crucial metabolic regulator of hepatic lipid metabolism and inflammation. The role of PPAR-γ in the pathogenesis of NAFLD is gradually being recognized. Here, we outline the involvement of PPAR-γ in the pathogenesis of NAFLD through adipogenesis, insulin resistance, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. In addition, the evidence for PPAR-γ- targeted therapy for NAFLD are summarized. Altogether, PPAR-γ is a promising therapeutic target for NAFLD, and the development of drugs that can balance the beneficial and undesirable effects of PPAR-γ will bring new light to NAFLD patients.

Plasma Metabolite Signatures in Male Carriers of Genetic Variants Associated with Non-Alcoholic Fatty Liver Disease

Both genetic and non-genetic factors are important in the pathophysiology of non-alcoholic fatty liver disease (NAFLD). The aim of our study was to identify novel metabolites and pathways associated with NAFLD by including both genetic and non-genetic factors in statistical analyses. We genotyped six genetic variants in the PNPLA3, TM6SF2, MBOAT7, GCKR, PPP1R3B, and HSD17B13 genes reported to be associated with NAFLD. Non-targeted metabolomic profiling was performed from plasma samples. We applied a previously validated fatty liver index to identify participants with NAFLD. First, we associated the six genetic variants with 1098 metabolites in 2 339 men without NAFLD to determine the effects of the genetic variants on metabolites, and then in 2 535 men with NAFLD to determine the joint effects of genetic variants and non-genetic factors on metabolites. We identified several novel metabolites and metabolic pathways, especially for PNPLA3, GCKR, and PPP1R38 variants relevant to the pathophysiology of NAFLD. Importantly, we showed that each genetic variant for NAFLD had a specific metabolite signature. The plasma metabolite signature was unique for each genetic variant, suggesting that several metabolites and different pathways are involved in the risk of NAFLD. The FLI index reliably identifies metabolites for NAFLD in large population-based studies.

Role of peroxisome proliferator-activated receptors in non-alcoholic fatty liver disease inflammation

Overweight and obesity have been identified as the most important risk factors for many diseases, including cardiovascular disease, type 2 diabetes and lipid disorders, such as non-alcoholic fatty liver disease (NAFLD). The metabolic changes associated with obesity are grouped to define metabolic syndrome, which is one of the main causes of morbidity and mortality in industrialized countries. NAFLD is considered to be the hepatic manifestation of metabolic syndrome and is one of the most prevalent liver diseases worldwide. Inflammation plays an important role in the development of numerous liver diseases, contributing to the progression to more severe stages, such as non-alcoholic steatohepatitis and hepatocellular carcinoma. Peroxisome proliferator-activated receptors (PPARs) are binder-activated nuclear receptors that are involved in the transcriptional regulation of lipid metabolism, energy balance, inflammation and atherosclerosis. Three isotypes are known: PPAR-α, PPARδ/β and PPAR-γ. These isotypes play different roles in diverse tissues and cells, including the inflammatory process. In this review, we discuss current knowledge on the role PPARs in the hepatic inflammatory process involved in NAFLD as well as new pharmacological strategies that target PPARs.

Treatment with Lobeglitazone Attenuates Hepatic Steatosis in Diet-Induced Obese Mice

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with insulin resistance. The peroxisome proliferator-activated receptor (PPAR) activators, thiazolidinediones, (TZDs), are insulin sensitizers used as a treatment for NAFLD. However, TZDs are a controversial treatment for NAFLD because of conflicting results regarding hepatic steatosis and fibrosis. To evaluate a possible effective drug for treatment of NAFLD, we investigated the effects of a newly developed TZD, lobeglitazone, with an emphasis on hepatic lipid metabolism. Lobeglitazone treatment for 4 weeks in high fat diet- (HFD-) induced obese mice (HL group) improved insulin resistance and glucose intolerance compared to HFD-induced obese mice (HU group). The gene levels related to hepatic gluconeogenesis also decreased after treatment by lobeglitazone. The livers of mice in the HL group showed histologically reduced lipid accumulation, with lowered total plasma cholesterol and triglyceride levels. In addition, the HL group significantly decreased the hepatic expression of genes associated with lipid synthesis, cholesterol biosynthesis, and lipid droplet development and increased the hepatic expression of genes associated with fatty acid β-oxidation, thus suggesting that lobeglitazone decreased hepatic steatosis and reversed hepatic lipid dysregulation. Livers with steatohepatitis contained increased levels of PPARγ and phosphorylated PPARγ at serine 273, leading to downregulation of expression of genes associated with insulin sensitivity. Notably, the treatment of lobeglitazone increased the protein levels of PPARα and diminished levels of PPARγ phosphorylated at serine 273, which were increased by a HFD, suggesting that induction of PPARα and posttranslational modification of PPARγ in livers by lobeglitazone might be an underlying mechanism of the improvement seen in NAFLD. Taken together, our data showed that lobeglitazone might be an effective treatment for NAFLD.

The Role of Nonalcoholic Fatty Liver Disease on Cardiovascular Manifestations and Outcomes

Cardiovascular disease has been postulated as the leading cause of mortality among patients with nonalcoholic fatty liver disease (NAFLD), rather than from sequalae of liver disease specifically. While there is ample evidence validating the association between NAFLD and increased cardiovascular comorbidities, events, and mortality, current data presents a challenge in attributing this effect solely due to NAFLD given the rampant presence of insulin resistance and type 2 diabetes mellitus (T2DM). Endpoints of increased cardiovascular risk remains tightly linked to the concomitant presence of insulin resistance and T2DM. Prospective studies accentuating early detection of NAFLD are imperative to institute early intervention and prevent future cardiovascular events.

The therapeutic effect of silymarin in the treatment of nonalcoholic fatty disease: A meta-analysis (PRISMA) of randomized control trials

BACKGROUND

Silymarin (SIL) is an active extraction of the silybum marianum, milk thistle, which is an ancient medicinal plant for treatment of various liver diseases for centuries. This study is to assess the therapeutic effect of SIL in the treatment of nonalcoholic fatty liver disease through meta-analysis.

METHODS

Published randomized controlled trials (RCTs) were included from electronic databases (PubMed, Embase, Cochrane library, Web of Science, and so forth). Cochrane handbook was applied to evaluate the methodological quality. All statistical analyses were directed by Revman 5.3 software, and statistical significance was defined as P < .05.

RESULTS

Eight RCTs involved 587 patients were included in this study. The results showed that SIL reduced the AST and ALT levels more significantly than the control group (AST UI/L: MD = -6.57; 95% CI, -10.03 to -3.12; P = .0002; ALT UI/L: MD = -9.16; 95% CI, -16.24 to -2.08; P = .01). Compared with other interventions, there were significant differences decreasing AST and ALT levels when SIL was used alone (AST UI/L: MD = -5.44; 95% CI, -8.80 to -2.08; P = .002; ALT UI/L: MD = -5.08; 95% CI, -7.85 to -2.32; P = .0003).

CONCLUSION

SIL has positive efficacy to reduce transaminases levels in NAFLD patients. SIL can be an encouraging and considerable phytotherapy for NAFLD patients.

Prevalence and Factors Associated with Nonalcoholic Fatty Liver Disease in a Nonobese Korean Population

Background/Aims

Nonalcoholic fatty liver disease (NAFLD) is an emerging problem in Asia, but little is known about the disease in the nonobese population. The aims of this study were to investigate the prevalence of NAFLD and the factors associated with it in a nonobese Korean population and to compare the clinical characteristics of nonobese and obese subjects with NAFLD.

Methods

This cross-sectional study used data from 2,058 subjects who participated in a medical checkup program.

Results

The prevalence of NAFLD was 12.4% (213/1,711) in the nonobese population. A higher body mass index (BMI), higher homeostasis model assessment of insulin resistance (HOMA-IR) values, higher alanine aminotransferase (ALT) levels, triglyceride concentrations 150 mg/dL, and hyperuricemia were independently associated with the presence of NAFLD in the nonobese subjects. Compared with the obese subjects with NAFLD, the nonobese subjects with NAFLD were composed of a higher proportion of females and had lower BMIs, smaller waist circumferences, lower HOMA-IR values, and fewer metabolic irregularities.

Conclusions

Higher BMIs, HOMA-IR values, ALT levels, hypertriglyceridemia, and hyperuricemia were associated with NAFLD in the nonobese subjects. Clinicians should be particularly aware of the possibility of NAFLD in nonobese Asian people.

Biochemical Profile of Nonalcoholic Fatty Liver Disease Patients in Eastern India with Histopathological Correlation

Aminotransferase assay is often used as a screening test as well as an endpoint for resolution of disease in nonalcoholic fatty liver disease (NAFLD). Aim of the study was to evaluate the relationship of transaminase level with metabolic variables and histology in NAFLD. Single center observational study was conducted in a gastroenterology clinic at Cuttack in coastal Odisha. Subjects were consecutive patients presenting with functional bowel disease and undergoing abdominal sonography. All participants were evaluated for the presence of metabolic syndrome (MS), insulin resistance, liver function test and lipid profile. Various parameters were compared between NAFLD subjects and controls. 53.5 % of NAFLD had normal serum transaminases, whereas 20.8 % of healthy controls had transaminitis. NAFLD patients had significantly higher BMI, fasting plasma glucose, serum transaminases, serum triglycerides, serum insulin and homeostatic model assessment (HOMA) IR than controls. NAFLD patients who had transaminitis had significantly higher incidence of MS and higher mean HOMA IR than those without. There was no significant difference in histopathological features between NAFLD with and without transaminitis. To conclude, over half of NAFLD subjects do not have transaminitis while transaminitis is present in a fifth of healthy people without fatty liver. Hence serum transaminase should not be used as screening test for NAFLD. NAFLD patients with transaminitis had a higher incidence of MS and insulin resistance than those without. However, there was no significant difference in histopathological features between these two groups.

Liraglutide ameliorates non-alcoholic fatty liver disease by enhancing mitochondrial architecture and promoting autophagy through the SIRT1/SIRT3-FOXO3a pathway

AIM

Overwhelming oxidative stress is implicated as crucial in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Liraglutide, a well-established antidiabetes drug, was recently reported to ameliorate NAFLD with an elusive mechanism. We used a mouse model to examine whether liraglutide could ameliorate NAFLD and explored the possible mechanisms.

METHODS

Twenty C57BL/6J mice were randomly treated with a normal-fat diet or high-fat diet for 16 weeks, then further distributed into four groups and subjected to s.c. injection of liraglutide or saline for 4 weeks. The growth/metabolism, oxidative stress, mitochondrial architecture and autophagy were assessed prospectively at the 20th week.

RESULTS

High-fat diet inducement resulted in severe NAFLD while liraglutide treatment significantly reversed the trend, marked by reduced bodyweight, improved glucose tolerance and liver triglyceride composition. Reduced hepatic malondialdehyde level, increased mRNA and protein levels of CATALASE and MNSOD indicated liraglutide affected both the oxidative and antioxidative process to ameliorate oxidative stress. After liraglutide administration, the upregulated mRNA and protein levels of mitochondrial fission and fusion-related DRP1, OPA1 and respiratory chain-related COMPLEX1, UCP2 demonstrated the enhancement of mitochondrial architecture which may attenuate the generation of reactive oxygen species (ROS), while the diminished mRNA and protein level of P62 and increased levels of Beclin1 and LC3II/I ratio indicated the promoting autophagy, which probably contribute to the ROS elimination. Further, restored protein levels of Sirtuin1/Sirtuin3 and the downstream p-FOXO3a reveal the probable pathways of liraglutide acting on autophagy.

CONCLUSION

Liraglutide diminishes oxidative stress by enhancing mitochondrial architecture and promoting autophagy through the SIRT1/SIRT3-FOXO3a-LC3 pathway to ameliorate diet-induced NAFLD.

Laparoscopic Adjustable Gastric Banding In Patients with Unexpected Cirrhosis: Safety and Outcomes

BACKGROUND

The safety and efficacy of laparoscopic adjustable gastric banding (LAGB) in the context of cirrhosis have not been established. We hypothesized that LAGB in cirrhotic patients is a safe procedure that may offer positive long-term benefits, both in terms of obesity and avoiding progression of liver disease.

METHODS

Data were gathered from a prospectively maintained database of 8402 patients who had undergone LAGB from November 1993 and April 2014.

RESULTS

Fourteen patients with biopsy-proven cirrhosis were identified in the database. In all cases, cirrhosis was an unexpected macroscopic finding at the time of surgery, confirmed with intraoperative biopsy. All patients were either Child-Pugh A or B. No patients had preoperative clinical evidence of decompensated liver disease. The mean initial weight was 116.6 kg and BMI 38.9. There was no operative mortality. Two patients experienced a surgical complication (Clavien-Dindo grade II and grade IIIa). At 12 months, the mean excess weight loss was 61.3% giving a mean BMI 31.7. Repeat biopsies were available in three patients. All demonstrated improvement in inflammation and two had fibrosis regression. Baseline liver biochemistry was compared in nine patients who had repeat biochemistry studies after 12 months. There was a significant improvement in alanine transaminase (ALT) (p = 0.04) and aspartate transaminase (AST) (p = 0.02). Two patients developed hepatocellular carcinoma (HCC). One has died as a result of this disease 11 years after LAGB surgery.

CONCLUSION

LAGB may be a safe and effective bariatric intervention in patients with compensated cirrhosis. Our findings support the need for a prospective study with paired liver biopsies.

Non-alcoholic fatty liver disease: The diagnosis and management

Non-alcoholic fatty liver disease (NAFLD) is now the most frequent chronic liver disease that occurs across all age groups and is recognized to occur in 14%-30% of the general population, representing a serious and growing clinical problem due to the growing prevalence of obesity and overweight. Histologically, it resembles alcoholic liver injury but occurs in patients who deny significant alcohol consumption. NAFLD encompasses a spectrum of conditions, ranging from benign hepatocellular steatosis to inflammatory nonalcoholic steatohepatitis, fibrosis, and cirrhosis. The majority of hepatocellular lipids are stored as triglycerides, but other lipid metabolites, such as free fatty acids, cholesterol, and phospholipids, may also be present and play a role in disease progression. NAFLD is associated with obesity and insulin resistance and is considered the hepatic manifestation of the metabolic syndrome, a combination of medical conditions including type 2 diabetes mellitus, hypertension, hyperlipidemia, and visceral adiposity. Confirmation of the diagnosis of NAFLD can usually be achieved by imaging studies; however, staging the disease requires a liver biopsy. Current treatment relies on weight loss and exercise, although various insulin-sensitizing agents, antioxidants and medications appear promising. The aim of this review is to highlight the current information regarding epidemiology, diagnosis, and management of NAFLD as well as new information about pathogenesis, diagnosis and management of this disease.

Anthropometric and biochemical characteristics of patients with nonalcoholic fatty liver diagnosed by non-invasive diagnostic methods

INTRODUCTION

Non-alcoholic (NAFLD) encompasses a spectrum of disease states, from steatosis (fatty liver) to non-alcoholic steatohepatitis (also called NASH steatosis with inflammatory changes) followed by progression to fibrosis and cirrhosis and hepatocellular carcinoma Excess liver fat is believed to be a manifestation of the metabolic syndrome and not surprisingly NASH is associated with obesity, insulin resistance, dyslipidemia and type 2 diabetes in humans.

AIM OF THE STUDY

Is to establish anthropometric and biochemical specificities in patients with non-alcoholic steatohepatitis diagnosed with non-invasive diagnostic methods.

MATERIAL AND METHODS

Study enrolled 170 participants, 130 with NASH steatosis. The non-alcoholic group (control), consisted of 40 normal weight patients without metabolic syndrome. Alcohol intake was estimated with established protocol. Routine biochemistry analysis were performed by standard laboratory procedures; serum levels of serum levels of fasting cholesterol and triglycerides, fasting glucose and insulin, insulin resistance estimated by HOMA index (Homeostasis model assessment), biochemistry tests and a liver ultrasound examination.

RESULTS

In study participants group, patients were more obese comparing with controls p < 0.01, waist line extent also was of greater statistical significance in the non-alcoholic group fatty liver (p < 0, 01). Comparing biochemical parameter values, significant statistical deference has been noted in glaucosis and insulin levels, total cholesterol and gama-glutamil transferase levels, between groups (p < 0.01). Fasting glucose and insulin levels, HOMA-IR were significantly greater in study cohort group patients, as was significantly positive correlation between BMI and waist line extent.

CONCLUSION

Patients with non-alcoholic fatty liver are excessively obese, have greater waist line extent, consequently insulin resistance and impaired glucose metabolism, insulin resistance, dyslipidemia, risk factors known to be associated with the development of cardiovascular disease.

Alanine aminotransferase-old biomarker and new concept: a review

Measurement of serum alanine aminotransferase (ALT) is a common, readily available, and inexpensive laboratory assay in clinical practice. ALT activity is not only measured to detect liver disease, but also to monitor overall health. ALT activity is influenced by various factors, including viral hepatitis, alcohol consumption, and medication. Recently, the impact of metabolic abnormalities on ALT variation has raised concern due to the worldwide obesity epidemic. The normal ranges for ALT have been updated and validated considering the metabolic covariates in the various ethnic districts. The interaction between metabolic and demographic factors on ALT variation has also been discussed in previous studies. In addition, an extremely low ALT value might reflect the process of aging, and frailty in older adults has been raised as another clinically significant feature of this enzyme, to be followed with additional epidemiologic investigation. Timely updated, comprehensive, and systematic introduction of ALT activity is necessary to aid clinicians make better use of this enzyme.

From fatty liver to fibrosis: A tale of “second hit”

Although much is known about how fat accumulates in the liver, much remains unknown about how this causes sustained hepatocellular injury. The consequences of injury are recognized as nonalcoholic steatohepatitis (NASH) and progressive fibrosis. The accumulation of fat within the hepatocytes sensitizes the liver to injury from a variety of causes and the regenerative capacity of a fatty liver is impaired. An additional stressor is sometimes referred to as a “second hit” in a paradigm that identifies the accumulation of fat as the “first hit”. Possible candidates for the second hit include increased oxidative stress, lipid peroxidation and release of toxic products such as malondialdehyde and 4-hydroxynonenal, decreased antioxidants, adipocytokines, transforming growth factor (TGF)-β, Fas ligand, mitochondrial dysfunction, fatty acid oxidation by CYPs (CYP 2E1, 4A10 and 4A14), and peroxisomes, excess iron, small intestinal bacterial overgrowth, and the generation of gut-derived toxins such as lipopolysaccharide and ethanol. Oxidative stress is one of the most popular proposed mechanisms of hepatocellular injury. Previous studies have specifically observed increased plasma and tissue levels of oxidative stress markers and lipid peroxidation products, with reduced hepatic and plasma levels of antioxidants. There is also some indirect evidence of the benefit of antioxidants such as vitamin E, S-adenosylmethionine, betaine, phlebotomy to remove iron, and N-acetylcysteine in NASH. However, a causal relationship or a pathogenic link between NASH and oxidative stress has not been established so far. A number of sources of increased reactive oxygen species production have been established in NASH that include proinflammatory cytokines such as tumor necrosis factor (TNF)-α, iron overload, overburdened and dysfunctional mitochondria, CYPs, and peroxisomes. Briefly, the pathogenesis of NASH is multifactorial and excess intracellular fatty acids, oxidant stress, ATP depletion, and mitochondrial dysfunction are important causes of hepatocellular injury in the steatotic liver.

Retinol binding protein-4 circulating levels were higher in nonalcoholic fatty liver disease vs. histologically normal liver from morbidly obese women

OBJECTIVE

We aimed to analyze the retinol binding protein-4 (RBP4) messenger RNA (mRNA) expression profiles in adipose tissues and liver of morbidly obese (MO) women with or without nonalcoholic fatty liver disease (NAFLD), and to study the relationships with other pro- and anti-inflammatory adipokines in vivo and in vitro.

DESIGN AND METHODS

We performed a cross-sectional analysis of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and liver samples from four lean and 45 MO women with or without NAFLD by enzyme-linked immunosorbent assay and real-time reverse transcription-PCR. We also studied RBP4 expression in HepG2 hepatocytes under various inflammatory stimuli.

RESULTS

Circulating RBP4 levels were higher in MO women, and specifically, in MO subjects with NAFLD compared with normal liver controls (lean and MO). RBP4 liver expression was higher in nonalcoholic steatohepatitis (NASH)-moderate/severe than in NASHmild. Overall RBP4 gene expression was higher in liver than in adipose tissues. Among them, the higher expression corresponded to SAT. VAT expression was lower in the MO cohort. In HepG2, RBP4 mRNA expression was reduced by tumor necrosis factor (TNF)-α and increased by adiponectin treatment.

CONCLUSIONS

The results obtained in MO women with NAFLD, brings up the use of RBP4 and other adipokines as a panel of noninvasive molecular biomarkers when NAFLD is suspected. Further studies are needed with other obesity groups.

The efficacy of licorice root extract in decreasing transaminase activities in non-alcoholic fatty liver disease: a randomized controlled clinical trial

This study was performed to investigate the effects of licorice on non-alcoholic fatty liver disease (NAFLD). In this double blind randomized clinical trial, 66 patients were divided into case and control groups. All patients had elevated liver enzymes and had increased liver echogenicity (lipid accumulation) on sonography. The case group was treated with one capsule containing 2 g aqueous licorice root extract per day for 2 months while the control group was treated in the same manner with a placebo. Weight, body mass index (BMI) and liver transaminase levels were measured for each patient before and after the study. In the case group, the mean alanine aminotransferase (ALT) level decreased from 64.09 to 51.27 IU/mL and the aspartate aminotransferase (AST) level decreased from 58.18 to 49.45 IU/mL, which were statistically significant (p < 0.001 and p < 0.001). But in the control group, a drop in the ALT and AST levels was not statistically significant. The BMI difference before and after the study was not statistically significant in both groups. Despite the significant drop in liver enzymes following administration of licorice root extract, it is recommended that further studies that include histological examination are necessary.

Obesity, Visceral Fat, and NAFLD: Querying the Role of Adipokines in the Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of clinicopathologic conditions ranging from steatosis alone to nonalcoholic steatohepatitis (NASH), with varying risks for progression to cirrhosis and hepatocellular carcinoma. There is mounting evidence that NAFLD not only complicates obesity, but also perpetuates its metabolic consequences. Critical event that leads to progressive liver injury in NAFLD is unknown. Obesity reflects a generalized proinflammatory state with its increased inflammatory markers like C reactive protein, IL-6, IL-8, IL-10, PAI-1, TNF-α, and hepatocyte growth factor. The elevated production of these adipokines is increasingly considered to be important in the development of diseases linked to obesity and the metabolic syndrome. Disordered cytokine production is likely to play a role in the pathogenesis of NAFLD. There is no effective treatment for NAFLD, though weight loss may halt disease progression and revert histological changes, the underlying mechanism remaining elusive. All stages of the disease pathway from prevention, early identification/diagnosis, and treatment require an understanding of the pathogenesis of liver injury in NAFLD.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease

The diagnostic procedures in patients with suspected fatty liver disease-with or without known alcohol consumption-should be standardized and generally accepted. We therefore present a guideline, summarizing the current concepts of etiology, diagnostic as well as differential diagnostic of patients with fatty liver disease. Alcoholic as well as and non-alcoholic fatty liver are characterised by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected. Liver biopsy represents the "golden standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease. The differential diagnosis of ASH vs. NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present. People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis. Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

The relationship between normal serum uric acid and nonalcoholic fatty liver disease

The objective of the present study was to determine the relationship between serum uric acid (SUA) level and the presence of nonalcoholic fatty liver disease (NAFLD). We analyzed data of 9,019 Koreans who visited a health check up center. The SUA levels of all of these subjects were within the normal range. The participants were divided into 4 groups according to the quartiles of the SUA levels for both sexes. Hepatic steatosis was diagnosed on the basis of ultrasonographic findings. Multivariate logistic regression modeling was performed across the SUA quartiles. The presence of NAFLD and metabolic abnormalities were found significantly in subjects with high-normal SUA levels. After adjustment for age, metabolic components, and the liver-function test, the adjusted odds ratio (OR, 95% CIs) for the presence of NAFLD in the subjects with the highest SUA level was 1.46 (1.17-1.82) for men and 2.13 (1.42-3.18) for women, as compared to the subjects with the lowest SUA level. Our results suggest that increased SUA concentrations, even within the normal range, are independently associated with the presence of NAFLD.

[Histopathological diagnosis of non-alcoholic and alcoholic fatty liver disease. Grade 2 consensus-based guidelines]

Both alcoholic (AFL) and non-alcoholic fatty liver (NAFL) are characterized by lipid deposition in hepatocytes. The diagnosis of steatosis is made when lipid deposition exceeds 5% of hepatocytes, while involvement of more than 50% is called "fatty liver ". An additional inflammatory reaction leads to alcoholic (ASH) or non-alcoholic steatohepatitis (NASH). Steatohepatitis is present when both inflammatory infiltrates of mixed cells in the small liver lobules as well as liver cell injury in terms of ballooning can be detected.Liver biopsy represents the "gold standard" for confirming diagnosis and determining inflammatory activity and potential fibrosis of fatty liver disease.The differential diagnosis of ASH-NASH cannot be made on the basis of histological criteria alone. Steatosis, inflammatory changes and hepatocytic injury can be semiquantified as a "Brunt Score" or "NAS" (NAFLD activity score), providing the basis on which to decide whether or not steatohepatitis is present.People at increased risk of developing a fatty liver possess an increased risk of developing chemotherapy-associated steatohepatitis (CASH).Histologically, pediatric NASH differs from adult NASH and is often only clinically manifest through a mild if persistent elevation in transaminases.

Nonalcoholic steatohepatitis, animal models, and biomarkers: what is new?

Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological term that encompasses a spectrum of abnormalities ranging from simple triglyceride accumulation in the hepatocytes (hepatic steatosis) to hepatic steatosis with inflammation (steatohepatitis, also known as nonalcoholic steatohepatitis or NASH). NASH can also progress to cirrhosis and hepatocellular carcinoma (HCC). Steatohepatitis has been estimated to affect around 5% of the total population and 20% of those who are overweight. The mechanisms leading to NASH and its progression to cirrhosis and HCC remain unclear, but it is a condition typically associated with obesity, insulin resistance, diabetes, and hypertriglyceridemia. This point corroborates the need for animal models and molecular markers that allow us to understand the mechanisms underlying this disease. Nowadays, there are numerous mice models to study abnormal liver function such as steatosis, NASH, and hepatocellular carcinoma. The study of the established animal models has provided many clues in the pathogenesis of steatosis and steatohepatitis, although these remain incompletely understood and no mice model completely fulfills the clinical features observed in humans. In addition, there is a lack of accurate sensitive diagnostic tests that do not involve invasive procedures. Current laboratory tests include some biochemical analysis, but their utility for diagnosing NASH is still poor. For that reason, a great effort is being made toward the identification and validation of novel biomarkers to assess NASH using high-throughput analysis based on genomics, proteomics, and metabolomics. The most recent discoveries and their validation will be discussed.

Age-related fat deposition in multifidus muscle could be a marker for nonalcoholic fatty liver disease

BACKGROUND

Although nonalcoholic fatty liver disease (NAFLD) is associated with visceral obesity, the relationship between visceral fat accumulation and skeletal muscle steatosis in patients with NAFLD has not been established. We evaluated: (1) the relationship between multifidus muscular tissue steatosis, visceral fat accumulation, and biochemical data in a cross-sectional study, and (2) the influence of weight reduction on multifidus muscular tissue steatosis in a longitudinal study.

METHODS

Three hundred thirty-three NAFLD patients were enrolled. Hepatic steatosis, visceral fat area, and the multifidus muscle/subcutaneous fat attenuation ratio (MM/F ratio) were evaluated by computed tomography. To evaluate how weight reduction produced by diet and exercise affected the MM/F ratio, changes in the MM/F ratio were compared between weight reduction and non-weight reduction groups.

RESULTS

There was a gender difference in MM/F ratios. The MM/F ratio was significantly correlated with age (male r = 0.613, P < 0.01; female r = 0.440, P < 0.01). The MM/F ratio was positively correlated with visceral fat area (male: r = 0.262, P < 0.01; female: r = 0.214, P < 0.01). A decrease in the MM/F ratio, concomitant with reduced visceral fat accumulation, led to alleviation of hepatic steatosis in 20 patients with weight reduction, but not in 22 patients without weight reduction.

CONCLUSIONS

The MM/F ratio was closely related to aging and visceral fat accumulation. The MM/F ratio was improved by weight reduction, indicating that fat accumulation in the multifidus muscle evaluated by computed tomography might be a therapeutic indicator of NAFLD.

Implication of normal liver enzymes in liver disease

Chronic liver disease is usually asymptomatic until its late stages and also significant hepatic necroinflammation and fibrosis may be present in persistently normal ALT levels HBV, HCV carriers or similarly, in patients with nonalcoholic fatty liver disease. Given the large number of persons in the general population which may harbor a clinically significant liver disease behind the screen of normal alanine aminotransferase, more attention should be devoted to future research for alternative noninvasive markers of liver damage.

Pathogenesis and management issues for non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has, although it is a very common disorder, only relatively recently gained broader interest among physicians and scientists. Fatty liver has been documented in up to 10 to 15 percent of normal individuals and 70 to 80 percent of obese individuals. Although the pathophysiology of NAFLD is still subject to intensive research, several players and mechanisms have been suggested based on the substantial evidence. Excessive hepatocyte triglyceride accumulation resulting from insulin resistance is the first step in the proposed ‘two hit’ model of the pathogenesis of NAFLD. Oxidative stress resulting from mitochondrial fatty acids oxidation, NF-κB-dependent inflammatory cytokine expression and adipocytokines are all considered to be the potential factors causing second hits which lead to hepatocyte injury, inflammation and fibrosis. Although it was initially believed that NAFLD is a completely benign disorder, histologic follow-up studies have showed that fibrosis progression occurs in about a third of patients. A small number of patients with NAFLD eventually ends up with end-stage liver disease and even hepatocellular carcinoma. Although liver biopsy is currently the only way to confirm the NAFLD diagnosis and distinguish between fatty liver alone and NASH, no guidelines or firm recommendations can still be made as for when and in whom it is necessary. Increased physical activity, gradual weight reduction and in selected cases bariatric surgery remain the mainstay of NAFLD therapy. Studies with pharmacologic agents are showing promising results, but available data are still insufficient to make specific recommendations; their use therefore remains highly individual.

Prevalence and risk factors of nonalcoholic fatty liver disease in an adult population of taiwan: metabolic significance of nonalcoholic fatty liver disease in nonobese adults

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) is rarely reported in Taiwan.

GOALS

To determine the prevalence and risk factors of NAFLD in an adult population of Taiwan.

STUDY

The cross-sectional community study examined 3245 adults in a rural village of Taiwan. The diagnostic criteria for NAFLD included no excessive alcohol intake, no chronic viral hepatitis, no known etiologies of liver disease, and ultrasonography consistent with fatty liver.

RESULTS

The prevalence of NAFLD was 11.5% (372/3245). The risk factors for NAFLD in the general population were male sex [odds ratio (OR), 1.44; 95% confidence interval (CI), 1.09-1.90], elevated alanine aminotransferase (ALT) (OR, 5.66; 95% CI, 3.99-8.01), obesity (OR, 7.21; 95% CI, 5.29-9.84), fasting plasma glucose > or =126 mg/dL (OR, 2.08; 95% CI, 1.41-3.05), total cholesterol > or =240 mg/dL (OR, 1.50; 95% CI, 1.06-2.13), triglyceride > or =150 mg/dL (OR, 1.76; 95% CI, 1.32-2.35), and hyperuricemia (OR, 1.53; 95% CI, 1.16-2.01). Age > or =65 years was inversely related to NAFLD (OR, 0.53; 95% CI, 0.36-0.77). The only NAFLD risk factors among nonobese subjects were age between 40 and 64 years (OR, 2.35; 95% CI, 1.34-4.11, P=0.003), elevated ALT (OR, 15.45; 95% CI, 8.21-29.09, P<0.001), and triglyceride > or =150 mg/dL (OR, 2.48; 95% CI, 1.42-4.32, P=0.001). In subjects with NAFLD, the prevalence of elevated ALT in the presence of each metabolic risk factor, such as obesity, fasting plasma glucose > or =126 mg/dL, total cholesterol > or =240 mg/dL, triglyceride > or =150 mg/dL, and hyperuricemia, did not differ from that of subjects with normal ALT levels.

CONCLUSIONS

NAFLD is closely associated with elevated ALT, obesity, diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, and hyperuricemia. Among the metabolic disorders, only hypertriglyceridemia was related to NAFLD in nonobese subjects. Serum ALT level was not a good predictor of metabolic significance in subjects with NAFLD.

Nonalcoholic fatty liver disease: a clinical review

Nonalcoholic fatty liver disease may be the most common liver disease in the United States, with a high prevalence in the obese, type 2 diabetic population, and it is probably underestimated as a cause for cirrhosis. Clinicopathologically, it represents a wide spectrum of histologic abnormalities and clinical outcomes, ranging from benign hepatic steatosis to cirrhosis. Pathophysiologically, insulin resistance is thought to be pivotal in the development of steatosis, after which a second oxidative stressor produces lipid peroxidation and nonalcoholic steatohepatitis (NASH). Liver biopsy is the gold standard for diagnosis and prognosis. The need for an effective treatment is both clear and urgent, yet in the absence of proven therapies, treatment is directed toward weight loss and comorbidity management. For patients with NAFLD at risk of disease progression, there is a lack of large, randomized, placebo-controlled trials of adequate treatment duration, with baseline stratification according to histologic severity.

Review article: the evolving role of liver biopsy

Liver biopsy is traditionally the 'gold standard' for the evaluation of liver diseases. There are several situations in which its role is being challenged. In hepatitis C, liver biopsy helps assess prognosis and treatment candidacy. An important exception is genotype 2 or 3 because treatment is more likely to succeed and therapy is relatively short in duration. For hepatitis B, liver biopsy gives some prognostic information, but serologic tests and hepatic biochemical tests are the primary determinants of treatment candidacy. Non-alcoholic fatty liver disease can be accurately diagnosed without a liver biopsy and, furthermore, there are no specific therapies available. The role of liver biopsy to assess methotrexate-associated hepatotoxicity remains controversial. Finally, patients with focal liver lesions usually do not require biopsy and, in the case of hepatocellular carcinoma, biopsy carries a risk of needle-track seeding. In short, the need for liver biopsy depends on the specific situation and should be performed when there is sufficient uncertainty about diagnosis, severity of disease, prognosis, and treatment decisions.

Factors associated or related to with pathological severity of nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has been more and more often regarded as a serious disorder, because nonalcoholic steatohepatitis (NASH), a part of NAFLD, may progress to the end stage of liver disease. Though an advanced age, obesity, diabetes mellitus (DM) etc. being not infrequent conditions in Korea, are known to exacerbate the severity of this disease, there are only a few Korean reports on this subject. The purpose of this study is to identify possible factors that might add up to the pathological severity of this disorder in Korean patients.

METHODS

Of 60 patients with steatosis found at liver biopsy, 43 NAFLD patients were reviewed retrospectively after exclusion of other liver diseases.

RESULTS

The cases of steatosis were mild, moderate, and severe in 9. 10, and 24 patients, respectively. The degree of necroinflammatory activity was mild, moderate, and severe in 33, 9, and 1 patients, respectively. There were no established factors directly related to these classes. As to fibrosis, the cases were classified as none, mild, moderate, severe, and cirrhotic in 9, 11, 16, 7, and 0 patients, respectively. The stage of fibrosis correlated with the age (p < 0.001), BMI (body mass index) (p = 0.032), and the platelet count (p = 0.009), but the presence of NASH was associated only with BMI (p = 0.002) and obesity (p = 0.001).

CONCLUSION

It seems that there are no factors that are directly related to the degree of steatosis or necroinflammatory activity. BMI seems to be a unique factor directly related to both the severity of fibrosis and the presence of NASH. The age and the platelet count are factors that are directly related to the degree of fibrosis but not to the presence of NASH.

Non-alcoholic steatohepatitis: review of a growing medical problem

Non-alcoholic steatohepatitis (NASH) is a metabolic liver disorder that is seen in 2-6% of the general population. It manifests itself by elevated liver enzymes, frequently without symptoms. The histological findings include steatosis, inflammation, fibrosis, and cirrhosis. Three case reports are presented to illustrate features of NASH. A two-hit model has been proposed in the pathogenesis of NASH. The first hit is hepatic steatosis. A hypercaloric diet with high levels of carbohydrates and saturated fatty acids results in elevated plasma free fatty acids (FFA) and expands the adipose tissue. Insulin resistance develops and augments steatosis. Oxidation of FFA yields toxic free radicals, resulting in lipid peroxidation. They cause the second hits: increased oxidative stress on hepatocytes and induction of pro-inflammatory cytokines. When the antioxidant capacities of the liver are insufficient, mitochondrial dysfunction and tumor necrosis factor alpha (TNF-alpha) cause inflammation and fibrosis. Treatment consists of life style modifications, particularly weight loss and exercise. Many drugs have been tried in the treatment of NASH. The insulin-sensitizing drugs metformin, rosiglitazone, and pioglitazone, and the antioxidant vitamin E show promising results. Further investigation of therapeutic options is needed to direct the choice of therapy in the future.

Effects of low-calorie diet on steatohepatitis in rats with obesity and hyperlipidemia

AIM: To evaluate the effects of low calorie diet (LCD) on nonalcoholic steatohepatitis (NASH) in rats with obesity and hyperlipidemia.

METHODS: 29 Sprague-Dawley (SD) rats were randomly divided into three groups. The animals in control (n = 9) and NASH group (n = 10) were fed on standard rat diet and high fat diet respectively for 12 weeks, ten rats in LCD group were fed on high fat diet for 10 weeks and then low calorie diet for 2 weeks. At the end of the experiment, body weight, abdominal adipose content, liver function, and hepatopathological changes were examined to evaluate the effect of different feeding protocols on the experimental animals.

RESULTS: There was no death of animal in the experimental period. All rats in the NASH group developed steatohepatitis according to liver histological findings. Compared with the control group, body weight (423.5 ± 65.2 vs 351.1 ± 43.0 g, P < 0.05), abdominal adipose content (14.25 ± 1.86 vs 9.54 ± 1.43, P < 0.05), liver index (3.784 ± 0.533 vs 2.957 ± 0.301%, P < 0.01), total serum cholesterol (1.60 ± 0.41 vs 1.27 ± 0.17 mmol/L, P < 0.05) and free fatty acids (728.2 ± 178.5 vs 429.2 ± 96.7 mmol/L, P < 0.01), serum alanine aminotransferase (1257.51 ± 671.34 vs 671.34 ± 118.57 nkat/L, P < 0.05) and aspartic aminotransferse (2760.51 ± 998.66 vs 1648.29 ± 414.16 nkat/L, P < 0.01) were significantly increased in the NASH group. Whereas, when rats were fed on LCD protocol, their body weight (329.5 ± 38.4 g, P < 0.01), abdominal adipose content (310.21 ± 1.52 g, P < 0.05), liver index (3.199 ± 0.552%, P < 0.05), and serum alanine aminotransferase (683.03 ± 245.49 nkat/L, P < 0.05) were significantly decreased, and the degree of hepatic steatosis (P < 0.05) was markedly improved compared with those in the NASH group. However, no significant difference was found in serum lipid variables and hepatic inflammatory changes between the two groups.

CONCLUSION: LCD might play a role in the prevention and treatment of obesity and hepatic steatosis in SD rats, but it exerts no significant effects on both serum lipid disorders and hepatic inflammatory changes.

Prevalence of nonalcoholic fatty liver among administrative officers in Shanghai: an epidemiological survey

AIM: To determine the prevalence of nonalcoholic fatty liver in a specific population in Shanghai by an epidemiological survey, and to analyze risk factors of fatty liver.

METHODS: Total 4009 administrative officers who denied regular alcohol drinking participated in the survey, and underwent physical examination and laboratory tests. The important parameters were body mass index (BMI), waist hip circumferences ratio (WHR) and levels of serum lipids. Diagnosis of fatty liver was based on established real-time ultrasonographic criteria, the presence of an ultrasonographic pattern consistent with "bright liver", with evident ultrasonographic contrast between hepatic and renal parenchyma, vessel blurring, and narrowing of the lumen of the hepatic veins. Analysis of data was performed through SPSS for Windows statistical package.

RESULTS: The overall prevalence of fatty liver was 12.9%, 15.8% in males and 7.5% in females, and the prevalence of fatty liver in males younger than 50 years old, was significantly higher (13.3%) than that of in females (2.7%). But the difference between the sexes became less significant in people older than 50 years (19.1% vs 18.1%). The prevalence of fatty liver was increased with age; this was markedly presented in females younger than 50 years. Multiple variant regression analysis demonstrated that the prevalence of fatty liver was positively correlated to several risk factors, including male, aging (> 50yr), hyperlipidemia, impaired glucose tolerance/diabetes mellitus, hypertension and overweight/obesity.

CONCLUSION: There is a high prevalence of nonalcoholic fatty liver among certain population in Shanghai, to which overweight and hyperlipidemia are closely relevant.

Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome

Nonalcoholic fatty liver disease (NAFLD) has been associated with the insulin-resistance syndrome, at present defined as the metabolic syndrome, whose limits were recently set. We assessed the prevalence of the metabolic syndrome in 304 consecutive NAFLD patients without overt diabetes, on the basis of 3 or more criteria out of 5 defined by the U.S. National Institutes of Health (waist circumference, glucose, high-density lipoprotein [HDL]-cholesterol, triglycerides, and arterial pressure). The prevalence of the metabolic syndrome increased with increasing body mass index, from 18% in normal-weight subjects to 67% in obesity. Insulin resistance (Homeostasis Model Assessment method) was significantly associated with the metabolic syndrome (odds ratio [OR], 2.5; 95% CI, 1.5-4.2; P <.001). Liver biopsy was available in 163 cases (54%). A total of 120 patients (73.6%) were classified as having nonalcoholic steatohepatitis (NASH); 88% of them had a metabolic syndrome (vs. 53% of patients with pure fatty liver; P <.0001). Logistic regression analysis confirmed that the presence of metabolic syndrome carried a high risk of NASH among NAFLD subjects (OR, 3.2; 95% CI, 1.2-8.9; P =.026) after correction for sex, age, and body mass. In particular, the syndrome was associated with a high risk of severe fibrosis (OR, 3.5; 95% CI, 1.1-11.2; P =.032). In conclusion, the presence of multiple metabolic disorders is associated with a potentially progressive, severe liver disease. The increasing prevalence of obesity, coupled with diabetes, dyslipidemia, hypertension, and ultimately the metabolic syndrome puts a very large population at risk of forthcoming liver failure in the next decades.