Non-Alcoholic Steatohepatitis (NASH): Risk Factors in Morbidly Obese Patients. Int J Mol Sci. 2015;16:25552-25559. [PMID: 26512661 PMCID: PMC4632815 DOI: 10.3390/ijms161025552]

Assessment of Metabolic and Bariatric Surgery Safety in Patients with Advanced Liver Fibrosis

PURPOSE

The well-established relationship between obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) is a key etiological factor in the development of liver cirrhosis. Bariatric surgery is an effective treatment for weight loss in patients with moderate-to-severe obesity, also playing a role in controlling MASLD. However, surgical safety in patients with advanced fibrosis remains to be established. This study aimed to evaluate the safety and repercussions of bariatric surgery according to fibrosis stage.

MATERIALS AND METHODS

Patients undergoing bariatric surgery who had an intraoperative liver biopsy were retrospectively evaluated. Preoperative and postoperative data were collected from medical records, and results were stratified according to fibrosis stage into early fibrosis (no fibrosis or stages 1 and 2) and advanced fibrosis (stages 3 and 4).

RESULTS

The study included 1185 patients: 1129 with early fibrosis and 56 with advanced fibrosis. The advanced fibrosis group had higher percentage of men (35.7% vs 21.6%, p = 0.014) and of people with diabetes (42.9% vs 16.5%, p < 0.001) and hypertension (57.1% vs 41.4%, p = 0.012). Patients with advanced fibrosis also required longer hospitalizations (4.64 vs 4.06 days, p < 0.001) and were more frequently admitted to the intensive care unit (7.1% vs 2.9%, p = 0.038). The groups did not differ significantly in other outcomes. There were no deaths in either group.

CONCLUSION

Bariatric surgery proved to be safe, with similar complication rates in patients with advanced fibrosis and in those with early fibrosis.

Nonalcoholic steatohepatitis critically rewires the ischemia/reperfusion-induced dysregulation of cardiolipins and sphingolipids in mice

Background

Lipid dysregulation plays a fundamental role in nonalcoholic steatohepatitis (NASH), which is an emerging critical risk factor that aggravates hepatic ischemia/reperfusion (I/R) injury. However, the specific lipids that mediate the aggressive I/R injury in NASH livers have not yet been identified.

Methods

The mouse model of hepatic I/R injury on NASH was established on C56B/6J mice by first feeding the mice with a Western-style diet to induce NASH, then the NASH mice were subjected to surgical procedures to induce hepatic I/R injury. Untargeted lipidomics were performed to determine hepatic lipids in NASH livers with I/R injury through ultra-high performance liquid chromatography coupled with mass spectrometry. The pathology associated with the dysregulated lipids was examined.

Results

Lipidomics analyses identified cardiolipins (CL) and sphingolipids (SL), including ceramides (CER), glycosphingolipids, sphingosines, and sphingomyelins, as the most relevant lipid classes that characterized the lipid dysregulation in NASH livers with I/R injury. CER were increased in normal livers with I/R injury, and the I/R-induced increase of CER was further augmented in NASH livers. Metabolic pathway analysis revealed that the enzymes involved in the synthesis and degradation of CER were highly upregulated in NASH livers with I/R injury, including serine palmitoyltransferase 3 (Sptlc3), ceramide synthase 2 (Cers2), neutral sphingomyelinase 2 (Smpd3), and glucosylceramidase beta 2 (Gba2) that produced CER, and alkaline ceramidase 2 (Acer2), alkaline ceramidase 3 (Acer3), sphingosine kinase 1 (Sphk1), sphingosine-1-phosphate lyase (Sgpl1), and sphingosine-1-phosphate phosphatase 1 (Sgpp1) that catalyzed the degradation of CER. CL were not affected by I/R challenge in normal livers, but CL was dramatically reduced in NASH livers with I/R injury. Consistently, metabolic pathway analyses revealed that the enzymes catalyzing the generation of CL were downregulated in NASH-I/R injury, including cardiolipin synthase (Crls1) and tafazzin (Taz). Notably, the I/R-induced oxidative stress and cell death were found to be aggravated in NASH livers, which were possibly mediated by the reduction of CL and accumulation of CER.

Conclusions

The I/R-induced dysregulation of CL and SL were critically rewired by NASH, which might potentially mediate the aggressive I/R injury in NASH livers.

The Effect of Roux-en-Y Gastric Bypass on Non-Alcoholic Fatty Liver Disease Fibrosis Assessed by FIB-4 and NFS Scores-An 11.6-Year Follow-Up Study

Severe obesity is a strong risk factor for non-alcoholic fatty liver disease (NAFLD). Roux-en-Y gastric bypass (RYGB) surgery effectively induces weight loss, but few studies have described the long-term effects of RYGB on NAFLD-related fibrosis. Data from 220 patients with severe obesity operated by RYGB in Central Norway were analysed. Variables incorporated in NAFLD Fibrosis Score (NFS), Fibrosis-4 (FIB-4) index and anthropometric data were collected before surgery and a mean of 11.6 years postoperatively. FIB-4 > 1.3 or NFS > 0.675 were used as cut-off values for advanced fibrosis. Proportions with advanced fibrosis decreased from 24% to 14% assessed by FIB-4 and from 8.6% to 2.3% using NFS, with resolution rates of advanced fibrosis of 42% and 73%, respectively. The shift towards lower fibrosis categories was significant (NFS p < 0.0001; FIB-4 p = 0.002). NFS decreased from −1.32 (IQR −2.33−−0.39) to −1.71 (IQR −2.49−−0.95, p < 0.001) 11.6 years after surgery, whereas FIB-4 did not change: 0.81 (IQR 0.59−1.25) to 0.89 (IQR 0.69−1.16, p = 0.556). There were weak correlations between change in fibrosis scores and weight loss. In conclusion, the majority of patients with advanced fibrosis at baseline had improvement after 11.6 years. Factors associated with reduction in fibrosis were not identified.

PERFORMACE OF TRIGLYCERIDE-GLUCOSE INDEX ON DIAGNOSIS AND STAGING OF NAFLD IN OBESE PATIENTS

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the world, and its prevalence is increasing alongside obesity. In United States, NAFLD is already the second leading cause of liver transplantation. The spectrum of the disease ranges from simple steatosis, which has a benign course, to steatohepatitis, which may progress to cirrhosis and its complications. The rising of noninvasive methods for diagnosing and staging non-alcoholic steatohepatitis (NASH) and fibrosis decreases the need of liver biopsy, as well as the costs and the occurrence of complications related to it.

OBJECTIVE

To analyze the performance of the triglyceride-glucose index to evaluate steatosis, NASH and liver fibrosis in obese patients with NAFLD.

METHODS

This is a retrospective cross-sectional study. Every medical record of patients who were candidates for bariatric surgery at a leading hospital in Southern Brazil were analyzed. The triglyceride-glucose index (TyG Index), a method composed only of two simple laboratory tests (serum triglycerides and fasting glucose levels), was performed prior to surgery. The TyG Index performance regarding the anatomopathological findings was evaluated, and the AUROC curve was calculated to evaluate the best cut-off point for diagnosing steatosis, non-alcoholic steatohepatitis and liver fibrosis grade. Also, the NAFLD fibrosis Score (NFS) was evaluated.

RESULTS

A total of 423 patients were evaluated. The TyG Index with a cut-off point of 8.76 excluded significant simple steatosis (grade 2-3) in obese patients, with 67.6% sensitivity, 65.1% specificity, 46.3% positive predictive value (PPV), 81.8% negative predictive value (NPV), 65.8% accuracy and 0.66 AUROC (P=0.005). In the evaluation of NASH, the TyG Index with a cut-off point of 8.82 excluded significant NASH (grade 2-3) with 57.3% sensitivity, 58.6% specificity, 33.7% PPV, 78.8% NPV, 58.2% accuracy and 0.58 AUROC (P=0.022). When evaluating liver fibrosis, the TyG Index with a cut-off point of 8.91 showed a sensitivity of 61.8%, a specificity of 62.5%, a PPV of 13.8 and a NPV of 94.4% for exclusion of advanced fibrosis (F3-4), with a 62.4% accuracy and 0.69 AUROC (P<0.001). When analyzing the performance of NFS in the diagnosis of advanced fibrosis, the cut-off point <-1.455 excluded advanced fibrosis with sensitivity of 59.4%, specificity of 51%, PPV of 11%, NPV of 92.4% and accuracy of 51.7%. However, the cut-off point of 0.676 to diagnose advanced fibrosis presented sensitivity of 21.9%, specificity of 83%, PPV of 11.7%, NPV of 91.2% and 77.3% accuracy. The AUROC was 0.54 (P=0.480).

CONCLUSION

TyG Index did not perform well in the diagnosis of significant steatosis and NASH. However, it was able to exclude advanced fibrosis in obese patients who are candidates for bariatric surgery.

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.

Phase angle and non-alcoholic fatty liver disease before and after bariatric surgery

BACKGROUND

Obesity is a global health problem that is continuing to increase in the young population. In Brazil, the frequency of obesity in 2018 was 19.8%. Several comorbidities are directly associated with obesity, such as non-alcoholic fatty liver disease (NAFLD), which is considered the most common liver disorder in Western countries and affects up to 46% of adults. Bariatric surgery is effective in treating obesity and can improve NAFLD; however, the effect of bariatric surgery on body composition, phase angle (PA), and improving NAFLD needs to be further studied.

AIM

To analyze the PA in the postoperative period of bariatric surgery and to correlate it with changes in body composition and liver disease.

METHODS

This study is a retrospective cohort study of the analysis of the medical records of patients undergoing bariatric surgery in a reference center of a teaching hospital in Porto Alegre over a 2-year period. Patients older than 18 years whose record contained all information relevant to the study were included. The data analyzed were body composition and PA through electrical bioimpedance and NAFLD through liver biopsy in the pre- and postoperative period. The level of significance adopted for the statistical analyses was 5%.

RESULTS

We evaluated 379 patients with preoperative data. Regarding PA, 169 patients were analyzed, and 33 patients had liver biopsy pre- and postoperatively with NAFLD information. In total, 79.4% were female, with a mean age of 39.1 ± 10.6 years. The average body mass index (BMI) was 45.9 ± 7.5 kg/m². The PA showed a mean of 5.8 ± 0.62° in the preoperative period and a significant reduction in the postoperative period. A postoperative reduction in body composition data (skeletal muscle mass, fat percentage, fat mass, body cell mass, BMI and visceral fat area) was shown as well. Regarding liver disease, all patients presented a reduction in the degrees and stages of liver disease in the postoperative period, and some had no degree of liver disease at all.

CONCLUSION

PA decreased after bariatric surgery, with a direct correlation with weight loss and changes in body composition. The decrease in PA was not correlated with the improvement in NAFLD.

A New, Non-Invasive Scale for Steatosis Developed Using Real-World Data From Russian Outpatients to Aid in the Diagnosis of Non-Alcoholic Fatty Liver Disease

Introduction

The current non-invasive tools for the diagnosis of non-alcoholic fatty liver disease (NAFLD) have methodological limitations. We aimed to develop a non-invasive scale to assist in the diagnosis of NAFLD. To achieve our aim, we conducted a secondary analysis of data from a large observational study conducted in Russia.

Methods

This retrospective analysis assessed the frequency of NAFLD in the population of patients in the DIREG_L_06725 study, an epidemiological, observational, cross-sectional, multicenter study performed in 50,145 outpatients from 16 Russian cities. Among the cohort of patients diagnosed with NAFLD, we identified factors associated with the risk of NAFLD. To develop a non-invasive tool for diagnosing NAFLD, we also determined the frequency of steatohepatitis.

Results

Our analysis included 48,297 patients; NAFLD was present in 20,281 patients (42.0%). The majority (64.1%) were women (80.3% post-menopause), and 87% had a body mass index (BMI) > 27.0 kg/m². We developed a fully non-invasive scale (St-index) that showed a specificity of 91.4% for ruling in steatosis, and a sensitivity of 93.8% for ruling out steatosis. Multivariate regression analyses conducted in the subgroups of patients aged ≥ 12 and < 18 years and those with BMI < 25.0 kg/m² produced area under the receiver operating characteristic (AUROC) curve values of 0.8243 and 0.7054, respectively. The factors most strongly associated with the development of NAFLD were age > 35 years, presence of type 2 diabetes mellitus, and a waist circumference/height ratio > 0.54.

Conclusion

Our non-invasive steatosis scale, St-index, can help physicians diagnose NAFLD in high-risk patients in the absence of ultrasound data.

Transient hepatic elastography has the best performance to evaluate liver fibrosis in non-alcoholic fatty liver disease (NAFLD)

INTRODUCTION AND AIM

The gold-standard for fibrosis diagnosis in non-alcoholic fatty liver disease (NAFLD) is liver biopsy, despite its invasive approach, sampling limitations and variability among observers. The objective was to validate the performance of non-invasive methods (Fibroscan™; APRI, FIB4 and NAFLD score) comparing with liver biopsy in the evaluation of liver fibrosis in patients with NAFLD.

MATERIAL AND METHODS

NAFLD patients ≥18 years of age who were submitted to liver biopsy were included and evaluated at two reference tertiary hospitals in Brazil with transient hepatic elastography (THE) assessment through Fibroscan™, APRI, FIB4 and NAFLD scores were determined. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for the diagnosis of advanced fibrosis were calculated to evaluate the performance of these non-invasive methods in NAFLD patients, adopting liver biopsy as the gold standard.

RESULTS

A total of 104 patients were studied. At three different cutoff values (7.9, 8.7 and 9.6kPa) THE presented the highest sensitivity values (95%, 90% and 85% respectively), and the highest NPV (98%, 96.4% and 95.1% respectively) for the diagnosis of advanced fibrosis. It also presented the highest AUROC (0.87; CI 95% 0.78-0.97).

CONCLUSION

When compared to the gold standard, transient hepatic elastography presented the best performance for the diagnosis and exclusion of advanced fibrosis in patients with NAFLD, overcoming APRI, FIB4 and NAFLD score.

Fibromax and inflamatory markers cannot replace liver biopsy in the evaluation of non-alcoholic fatty liver disease

BACKGROUND

To evaluate the performance of a non-invasive test (Fibromax™, Ferring Pharmaceutical, Saint-Prex, Switzerland) and inflamatory markers (IL-1β, IL-6, IL-8, TNF-α, MCP-1) in the diagnosis and staging of patients with non-alcoholic fatty liver disease.

METHODS

Patients older than 18 years with steatosis were prospectively evaluated at a tertiary hospital in southern Brazil. Liver biopsy, Fibromax™ test and inflamatory markers (IL-1β, IL-6, IL-8, TNF-α, MCP-1) were performed. Measures of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were used, considering liver biopsy as the gold standard.

RESULTS

Seventy-three Fibromax™ tests were analyzed. SteatoTest presented a sensitivity of 95.5% and PPV of 97.0% for the diagnosis of steatosis. NashTest obtained a sensitivity of 83.3%, specificity of 37.5%, PPV of 90.9% and NPV of 23.1% for the diagnosis of non-alcoholic steatohepatitis (NASH). FibroTest presented a sensitivity of 38.9%, specificity of 92.7%, PPV of 63.6% and NPV of 82.3% to evaluate advanced fibrosis. In the evaluation of patients with grade 2 and 3 steatosis, ROC analyses showed an area under the curve (AUROC) for SteatoTest of 0.68 (P=0.015). NashTest AUROC was 0.59 (P=0.417) for the evaluation of NASH. FibroTest AUROC was 0.79 (P<0.001) for advanced fibrosis. Kappa coefficient values for SteatoTest, NashTest and FibroTest were not statistically significant. Thirty-seven patients performed also analysis of the inflamatory markers, showing that patients with inflammatory activity grade 2-3 on liver biopsy had significantly higher levels of IL6 (P=0.016) and lower TNF-α (P=0.034), but there was no other difference when analysed fibrosis or steatosis.

CONCLUSIONS

The Fibromax™ test and the inflamatory markers (IL-1β, IL-6, IL-8, TNF-α, MCP-1) did not present a satisfactory performance to be considered a good alternative to replace liver biopsy in the evaluation of non-alcoholic fatty liver disease.

The Prevalence of NAFLD and Fibrosis in Bariatric Surgery Patients and the Reliability of Noninvasive Diagnostic Methods

Background

Bariatric surgery patients have a higher prevalence of nonalcoholic fatty liver (NAFL) than the general population; however, its assessment and the accurate staging of fibrosis are often complicated because noninvasive tests are not very accurate in patients with morbid obesity, and liver biopsy cannot be performed as a routine exam. The aim of this study was to evaluate (A) the histological prevalence of NAFL, nonalcoholic steatohepatitis (NASH), and fibrosis in patients undergoing bariatric surgery; (B) the reliability of ultrasound (US) in diagnosing NAFL; and (C) the reliability of various fibrosis scoring systems for defining fibrosis.

Methods

US and intraoperative liver biopsy results were reviewed in 57 bariatric surgery patients. NAFL, NASH, and fibrosis were diagnosed according to the Kleiner scoring system. US diagnosis of liver steatosis was based on the bright liver. Fibrosis scores used were (i) the BMI, AST/ALT Ratio, Diabetes (BARD) scoring system; (ii) the nonalcoholic fatty liver disease (NAFLD) fibrosis score; and (iii) the fibrosis-4 (FIB-4) index.

Results

The prevalence of NAFL was 81%, NASH 61.4%, and fibrosis 94% (F3 5.7%, cirrhosis 2.8%). The sensitivity of US was 95%, specificity 50%, and likelihood ratio (LR+, LR-) 1.91 and 0.1. The reliability of fibrosis scores for F ≥ 2 were as follows: BARD score: sensitivity 46%, specificity 54%, and area under the receiver-operating characteristics (AUROC) curve 0.5; NAFLD score: sensitivity 30%, specificity 89%, and AUROC 0.5; and FIB-4: sensitivity 68%, specificity 67%, and AUROC 0.7.

Conclusions

In bariatric surgery patients, the prevalence of NAFL was 81%, NASH 61.4%, and fibrosis 94%. US is able to rule out the presence of NAFL, while the commonly used scores may be inaccurate in defining fibrosis in patients with morbid obesity.

A Structured Literature Review of the Epidemiology and Disease Burden of Non-Alcoholic Steatohepatitis (NASH)

INTRODUCTION

Non-Alcoholic Steatohepatitis (NASH) is a chronic, progressive disease characterized by fatty liver and liver cell injury, advancing to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Diagnosis involves liver biopsy; however, as a result of its high cost and invasiveness, NASH remains underdiagnosed, and accurate burden of disease (BoD) data are lacking. Our aim was to understand the epidemiological and BoD landscape in NASH and identify knowledge gaps.

METHODS

The Ovid search engine was used to conduct a structured review, following quality systematic principles. It included publications that reported on epidemiology, quality of life (QoL) and BoD outcomes in NASH adults. Searches were limited to English language studies published between January 2007 and September 2017. Additional grey literature searches were conducted. A total of 53 references were selected; 38 were peer-reviewed and 15 were grey literature sources.

RESULTS

NASH is estimated to affect 3-5% of the global population, most suffering from several comorbidities. Advancing fibrosis drives clinical outcomes, with approximately 20% of patients developing cirrhosis and/or HCC, the latter being a leading cause of death in NASH. A recent model predicted the 15-year survival of advanced fibrosis patients at F3 and F4 as 51.0% and 28.4%, respectively. The limited data consistently show that NASH patients experience significantly poorer QoL and higher costs compared to non-NASH patients.

CONCLUSION

This first broad-ranging examination of NASH literature revealed a paucity of evidence, with poor-quality, small studies found. The overwhelming impact of NASH and its patient and healthcare burden is evident. Further evidence is needed to improve our understanding of NASH, especially as fibrosis stages advance.

FUNDING

Gilead Science Inc.

Nonalcoholic fatty liver disease and the gut microbiome: Are bacteria responsible for fatty liver?

IMPACT STATEMENT

This invited minireview for the upcoming thematic issue on the microbiome addresses the role of the microbiome in nonalcoholic fatty liver disease (NAFLD). The incidence of NAFLD has increased greatly in recent years in parallel with the rise in obesity and is now believed to have a population prevalence of 20-40%. It is anticipated to soon become the primary cause of liver-related morbidity and mortality, and unfortunately, there are few treatment options. Therefore, there is a critical need for improved understanding of NAFLD pathophysiology to provide new avenues for therapeutic intervention. In this paper, we have reviewed evidence from human and animal model studies that have associated microbiome composition and microbial metabolites with development and progression of NAFLD. We have also discussed proposed mechanisms by which the microbiome could contribute to NAFLD pathogenesis and addressed future directions for this field.

Association between dietary total antioxidant capacity and hepatocellular ballooning in nonalcoholic steatohepatitis: a cross-sectional study

PURPOSE

Nonalcoholic steatohepatitis (NASH) is characterized by steatosis, lobular inflammation, ballooning, and in some cases, fibrosis, which can progress to cirrhosis and carcinoma. The progression of NASH is closely related to oxidative stress. Dietary intake of antioxidants has been suggested in protection against oxidative damage and related clinical complications. Thus, we evaluated the potential association of dietary total antioxidant capacity (TAC) with disease severity in NASH patients, as well as with anthropometric and body composition markers and biochemical parameters.

METHODS

Thirty-three outpatients with a mean age of 48.4 ± 1.9 years were evaluated. Dietary TAC was estimated from a quantitative food frequency questionnaire. NASH severity, determined by liver biopsy, lifestyle characteristics, occurrence of comorbidities, anthropometry, body composition, and biochemical parameters were assessed.

RESULTS

NASH patients who had a higher dietary TAC had fewer ballooned hepatocytes compared to those with a lower TAC (p = 0.024). The patients with the highest dietary TAC had a reduction of approximately 20% in the risk of having many ballooned hepatocytes (OR 0.791; 95% CI 0.643-0.974; p = 0.027). There was no association of steatosis, lobular inflammation, and fibrosis with dietary TAC. The same occurred for lifestyle characteristics, occurrence of comorbidities, anthropometry, body composition, and biochemical parameters.

CONCLUSION

Dietary TAC is higher in patients with lower hepatic injury (ballooning), suggesting a possible role of food intake naturally high in its antioxidant capacity in reducing free radical production and, consequently, oxidative stress.

Impact of Diabetes Mellitus and Insulin on Nonalcoholic Fatty Liver Disease in the Morbidly Obese

INTRODUCTION AND AIM

The prevalence of obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease are increasing. Type 2 diabetes mellitus may aggravate non-alcoholic fatty liver disease, increasing the risk of developing cirrhosis and hepatocellular carcinoma. This study aims to determine the effect of type 2 diabetes mellitus and insulin therapy on non-alcoholic fatty liver disease in the patients with morbid obesity.

MATERIAL AND METHODS

Clinical, anthropometric and laboratory data were analyzed together with intraoperative liver biopsies from morbidly obese patients undergoing bariatric surgery.

RESULTS

219 patients with morbid obesity were evaluated. Systemic arterial hypertension (55.9% vs. 33.8%, p = 0.004) and dyslipidemia (67.1% vs. 39.0%, p &lt; 0.001) were more prevalent in patients with diabetes when compared to patients without diabetes. In multivariate analysis, type 2 diabetes mellitus was an independent risk factor for severe steatosis (RR = 2.04, p = 0.023) and severe fibrosis (RR = 4.57, p = 0.013). Insulin therapy was significantly associated with non-alcoholic steatohepatitis (RR = 1.89, p = 0.001) and fibrosis (RR = 1.75, p = 0.050) when all patients were analysed, but when only patients with diabetes were analysed, insulin therapy was not associated with non-alcoholic steatohepatitis or fibrosis.

CONCLUSION

Type 2 diabetes mellitus plays an important role in the progression of non-alcoholic fatty liver disease as an independent risk factor for severe fibrosis.

Influence of gut microbiota on the development and progression of nonalcoholic steatohepatitis

INTRODUCTION

Nonalcoholic steatohepatitis (NASH) is characterized by the presence of steatosis, inflammation, and ballooning degeneration of hepatocytes, with or without fibrosis. The prevalence of NASH has increased with the obesity epidemic, but its etiology is multifactorial. The current studies suggest the role of gut microbiota in the development and progression of NASH. The aim is to review the studies that investigate the relationship between gut microbiota and NASH. These review also discusses the pathophysiological mechanisms and the influence of diet on the gut-liver axis.

RESULT

The available literature has proposed mechanisms for an association between gut microbiota and NASH, such as: modification energy homeostasis, lipopolysaccharides (LPS)-endotoxemia, increased endogenous production of ethanol, and alteration in the metabolism of bile acid and choline. There is evidence to suggest that NASH patients have a higher prevalence of bacterial overgrowth in the small intestine and changes in the composition of the gut microbiota. However, there is still a controversy regarding the microbiome profile in this population. The abundance of Bacteroidetes phylum may be increased, decreased, or unaltered in NASH patients. There is an increase in the Escherichia and Bacteroides genus. There is depletion of certain taxa, such as Prevotella and Faecalibacterium.

CONCLUSION

Although few studies have evaluated the composition of the gut microbiota in patients with NASH, it is observed that these individuals have a distinct gut microbiota, compared to the control groups, which explains, at least in part, the genesis and progression of the disease through multiple mechanisms. Modulation of the gut microbiota through diet control offers new challenges for future studies.

Pharmacotherapy for NASH: Current and emerging

Non-alcoholic fatty liver disease (NAFLD) has become one of the most prominent forms of chronic liver disease worldwide, reflecting the epidemic of global obesity. Those with the progressive variant of NAFLD, non-alcoholic steatohepatitis (NASH), are at significantly increased risk of multisystem morbidity and mortality. However, there are currently no approved pharmacologic therapies for NASH. Given the disease burden, there is an important unmet need for pharmacologic treatment options for this patient population. The underlying pathophysiologic mechanisms that contribute to the development and progression of NAFLD and NASH are complex and reflected by the myriad of therapies, with different targets, currently under investigation. In broad strokes, drug development has focused on modulation of metabolic pathways, inflammatory cascades, and/or mechanisms impacting fibrosis. Although much progress has been made in enhancing our understanding of NAFLD pathogenesis, development of pharmacologic treatments has been hindered by challenges in clinical trial enrollment and complexities in clinical trial design. The compounds in phase IIa have provided promising results in terms of potential benefits on various aspects of histopathology. Agents in later stages of development have shown fairly modest results in terms of reduction of hepatic steatosis, necroinflammation and fibrosis. If longer term safety and efficacy are established among heterogeneous cohorts, these medications may help mitigate potential morbidity and mortality for this burgeoning patient population.

NAFLD: Is There Anything New under the Sun?

Nonalcoholic fatty liver disease (NAFLD) is an "umbrella" definition that encompasses a spectrum of histological liver changes ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) with/without fibrosis, "cryptogenic" cirrhosis, and hepatocellular carcinoma (HCC), occurring in a dysmetabolic milieu, though in the absence of excessive alcohol consumption and other competing etiologies of chronic liver disease [1].[...].

Sarcopenia and non-alcoholic fatty liver disease: Is there a relationship? A systematic review

AIM

To perform a systematic review to evaluate the incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) in adult patients with sarcopenia.

METHODS

Randomized clinical trials, cross-sectional or cohort studies including adult patients (over 18 years) with sarcopenia were selected. The primary outcomes of interest were the prevalence or incidence of NAFLD in sarcopenic patients. In the screening process, 44 full-text articles were included in the review and 41 studies were excluded.

RESULTS

Three cross-sectional studies were included. The authors attempted to perform a systematic review, but due to the differences between the studies, a qualitative synthesis was provided. The diagnosis of NAFLD was made by non-invasive methods (image methods or any surrogate markers) in all three evaluated studies. All the studies suggested that there was an independent association between sarcopenia and NAFLD.

CONCLUSION

Sarcopenia is independently associated with NAFLD and possibly to an advanced fibrosis.

Drug-induced steatohepatitis

INTRODUCTION

Drug induced steatohepatitis (DISH), a form of drug induced liver injury (DILI) is characterized by intracellular accumulation of lipids in hepatocytes and subsequent inflammatory events, in some ways similar to the pathology seen with other metabolic, viral and genetic causes of non alcoholic fatty liver disease and steatohepatitis (NAFLD and NASH). Areas covered: This paper provides a comprehensive review of the main underlying mechanisms by which various drugs cause DISH, and outlines existing preclinical tools to predict it and study underlying pathways involved. The translational hurdles of these models are discussed, with the example of an organotypic liver system designed to address them. Finally, we describe the clinical assessment and management of DISH. Expert Opinion: The complexity of the interconnected mechanistic pathways underlying DISH makes it important that preclinical evaluation of drugs is done in a physiologically and metabolically relevant context. Advanced organotypic tissue models, coupled with translational functional biomarkers and next-generational pan-omic measurements, may offer the best shot at gathering mechanistic knowledge and potential of a drug causing steatohepatitis. Ultimately this information could also help predict, detect or guide the development of specific treatments for DISH, which is an unmet need as of today.

Characterization of long non-coding RNA transcriptome in high-energy diet induced nonalcoholic steatohepatitis minipigs

Today, obesity and nonalcoholic steatohepatitis are a worldwide epidemic, although how these syndromes are regulated with respect to lncRNAs remains largely unknown. Our previous studies have revealed important pathological features and molecular characteristics of nonalcoholic steatohepatitis in the minipig model, and in this study, we analyze the features of lncRNAs and their potential target genes. Minipig samples only from liver were analyzed using next-generation deep sequencing. In total, we obtained 585 million raw reads approximately 70.4 Gb of high quality data. After a strict five-step filtering process, 1,179 lncRNAs were identified, including 89 differentially expressed lncRNAs (P < 0.05) in the experiment group relative to the control group. The cis and trans analysis identified target genes that were enriched for specific GO terms (P < 0.01), including immune processes, chemokine activity, cytokine activity, and G-protein coupled receptor binding, which are closely related to nonalcoholic steatohepatitis. The predicted protein-coding targets of the differentially expressed lncRNAs were further analyzed, such as PPAR, FADS2, DGAT2, ACAA2, CYP2E1, ADH4, and Fos. This study reveals a wealth of candidate lncRNAs involved in NASH and their regulated pathways, which should facilitate further research into the molecular mechanisms of this disorder.