Therapies for non-alcoholic fatty liver disease: A 2022 update

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly increasing and lifestyle interventions to treat this disease by addressing the underlying metabolic syndrome are often limited. Many pharmacological interventions are being studied to slow or even reverse NAFLD progression. This review for hepatologists aims to provide an updated understanding of the pathogenesis of NAFLD, current recommended therapies, and the most promising treatment options that are currently under development.     

MicroRNAs as controlled systems and controllers in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multi-faceted condition including simple steatosis alone or associated with inflammation and ballooning (non-alcoholic steatohepatitis) and eventually fibrosis. The NAFLD incidence has increased over the last twenty years becoming the most frequent chronic liver disease in industrialized countries. Obesity, visceral adiposity, insulin resistance, and many other disorders that characterize metabolic syndrome are the major predisposing risk factors for NAFLD. Furthermore, different factors, including genetic background, epigenetic mechanisms and environmental factors, such as diet and physical exercise, contribute to NAFLD development and progression. Several lines of evidence demonstrate that specific microRNAs expression profiles are strongly associated with several pathological conditions including NAFLD. In NAFLD, microRNA deregulation in response to intrinsic genetic or epigenetic factors or environmental factors contributes to metabolic dysfunction. In this review we focused on microRNAs role both as controlled and controllers molecules in NAFLD development and/or their eventual value as non-invasive biomarkers of disease.     

Serum autotaxin levels are correlated with hepatic fibrosis and ballooning in patients with non-alcoholic fatty liver disease

AIM To examine the relationship between serum autotaxin(ATX) concentrations and clinicopathological findings in non-alcoholic fatty liver disease(NAFLD) patients.METHODS One hundred eighty-six NAFLD patients who had undergone liver biopsy between 2008 and 2017 were retrospectively enrolled.Serum samples were collected at the time of biopsy and ATX was measured by enzyme immunoassays.Sera obtained from 160 healthy,nonobese individuals were used as controls.Histological findings were graded according to an NAFLD scoring system and correlations with serum ATX were calculated by Spearman's test.Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve(AUC).Cut-off values were identified by the Youden index,and the nearest clinically applicable value to the cutoff was considered the optimal threshold for clinical convenience.RESULTS Serum ATX levels were significantly higher in NAFLD patients than in controls(0.86 mg/L vs 0.76 mg/L,P 0.001) and correlated significantly with ballooning score and fibrosis stage(r = 0.36,P 0.001 and r = 0.45,P 0.001,respectively).Such tendencies were stronger in female patients.There were no remarkable relationships between ATX and serum alanine aminotransferase,lipid profiles,or steatosis scores.The AUC values of ATX for predicting the presence of fibrosis(≥ F1),significant fibrosis(≥ F2),severe fibrosis(≥ F3),and cirrhosis(F4),were all more than 0.70 in respective analyses.CONCLUSION Serum ATX levels may at least partially reflect histological severity in NAFLD.     

Focus on emerging drugs for the treatment of patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)has become the most common liver disorder in Western countries and is increasingly being recognized in developing nations.Fatty liver disease encompasses a spectrum of hepatic pathology,ranging from simple steatosis to non-alcoholic steatohepatitis,cirrhosis,hepatocellular carcinoma and end-stage liver disease.Moreover,NAFLD is often associated with other metabolic conditions,such as diabetes mellitus type 2,dyslipidemia and visceral obesity.The most recent guidelines suggest the management and treatment of patients with NAFLD considering both the liver disease and the associated metabolic co-morbidities.Diet and physical exercise are considered the first line of treatment for patients with NAFLD,but their results on therapeutic efficacy are often contrasting.Behavior therapy is necessary most of the time to achieve a sufficient result.Pharmacological therapy includes a wide variety of classes of molecules with different therapeutic targets and,often,little evidence supporting the real efficacy.Despite the abundance of clinical trials,NAFLD therapy remains a challenge for the scientific community,and there are no licensed therapies for NAFLD.Urgently,new pharmacological approaches are needed.Here,we will focus on the challenges facing actual therapeutic strategies and the most recent investigated molecules.     

Epigenetic mechanisms in non-alcoholic fatty liver disease: An emerging field

Non-alcoholic fatty liver disease (NAFLD) is an emerging health concern in both developed and non-developed world, encompassing from simple steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis and liver cancer. Incidence and prevalence of this disease are increasing due to the socioeconomic transition and change to harmful diet. Currently, gold standard method in NAFLD diagnosis is liver biopsy, despite complications and lack of accuracy due to sampling error. Further, pathogenesis of NAFLD is not fully understood, but is well-known that obesity, diabetes and metabolic derangements played a major role in disease development and progression. Besides, gut microbioma and host genetic and epigenetic background could explain considerable interindividual variability. Knowledge that epigenetics, heritable events not caused by changes in DNA sequence, contribute to development of diseases has been a revolution in the last few years. Recently, evidences are accumulating revealing the important role of epigenetics in NAFLD pathogenesis and in NASH genesis. Histone modifications, changes in DNA methylation and aberrant profiles or microRNAs could boost development of NAFLD and transition into clinical relevant status. PNPLA3 genotype GG has been associated with a more progressive disease and epigenetics could modulate this effect. The impact of epigenetic on NAFLD progression could deserve further applications on therapeutic targets together with future non-invasive methods useful for the diagnosis and staging of NAFLD.     

Clinical approaches to non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)ranges from simple steatosis to nonalcoholic steatohepatitis(NASH),leading to fibrosis and potentially cirrhosis,and it is one of the most common causes of liver disease worldwide.NAFLD is associated with other medical conditions such as metabolic syndrome,obesity,cardiovascular disease and diabetes.NASH can only be diagnosed through liver biopsy,but noninvasive techniques have been developed to identify patients who are most likely to have NASH or fibrosis,reducing the need for liver biopsy and risk to patients.Disease progression varies between individuals and is linked to a number of risk factors.Mechanisms involved in the pathogenesis are associated with diet and lifestyle,influx of free fatty acids to the liver from adipose tissue due to insulin resistance,hepatic oxidative stress,cytokines production,reduced very low-density lipoprotein secretion and intestinal microbiome.Weight loss through improved diet and increased physical activity has been the cornerstone therapy of NAFLD.Recent therapies such as pioglitazone and vitamin E have been shown to be beneficial.Omega 3 polyunsaturated fatty acids and statins may offer additional benefits.Bariatric surgery should be considered in morbidly obese patients.More research is needed to assess the impact of these treatments on a long-term basis.The objective of this article is to briefly review the diagnosis,management and treatment of this disease in order to aid clinicians in managing these patients.     

Clinical validation of the FLIP algorithm and the SAF score in patients with non-alcoholic fatty liver disease

1. Download : Download high-res image (135KB)
2. Download : Download full-size image

     

Lipidomics in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disorder in Western countries, comprises steatosis to nonalcoholic steatohepatitis (NASH), with the latter having the potential to progress to cirrhosis. The transition from isolated steatosis to NASH is still poorly understood, but lipidomics approach revealed that the hepatic lipidome is extensively altered in the setting of steatosis and steatohepatitis and these alterations correlate with disease progression. Recent data suggest that both quantity and quality of the accumulated lipids are involved in pathogenesis of NAFLD. Changes in glycerophospholipid, sphingolipid, and fatty acid composition have been described in both liver biopsies and plasma of patients with NAFLD, implicating that specific lipid species are involved in oxidative stress, inflammation, and cell death. In this article, we summarize the findings of main human lipidomics studies in NAFLD and delineate the currently available information on the pathogenetic role of each lipid class in lipotoxicity and disease progression.     

Management of non-alcoholic fatty liver disease in 2015

There is no single pharmacologic therapy that has been approved to treat nonalcoholic fatty liver disease in the general population. The backbone of therapy currently includes intensive lifestyle modification with established targets for diet and weight loss. The use of unsweetened, unfiltered coffee along with limiting high fructose corn syrup have emerged as beneficial dietary recommendations. The use of empiric oral hypoglycemic agents and vitamin E, however, has not been widely accepted. Developing bariatric surgical techniques are promising, but additional studies with long-term follow up are needed before it can be widely recommended. Finally, liver transplantation is an increasingly frequent consideration once complications of end-stage disease have developed. The future treatment of those with nonalcoholic fatty liver disease will likely involve a personalized approach. The importance of the gut microbiome in mediating hepatocyte inflammation and intestinal permeability is emerging and may offer avenues for novel treatment. The study of anti-fibrotic agents such as pentoxifylline and FXR agonists hold promise and new pathways, such as hepatocyte cannabinoid receptor antagonists are being studied. With the incidence of obesity and the metabolic syndrome increasing throughout the developed world, the future will continue to focus on finding novel agents and new applications of existing therapies to help prevent and to mediate the progression of nonalcoholic fatty liver disease.     

Pediatric non-alcoholic fatty liver disease: Recent solutions,unresolved issues,and future research directions

Non-alcoholic fatty liver disease(NAFLD) in children is becoming a major health concern. A "multiple-hit" pathogenetic model has been suggested to explain the progressive liver damage that occurs among children with NAFLD. In addition to the accumulation of fat in the liver, insulin resistance(IR) and oxidative stress due to genetic/epigenetic background, unfavorable lifestyles, gut microbiota and gut-liver axis dysfunction, and perturbations of trace element homeostasis have been shown to be critical for disease progression and the development of more severe inflammatory and fibrotic stages [non-alcoholic steatohepatitis(NASH)]. Simple clinical and laboratory parameters, such as age, history, anthropometrical data(BMI and waist circumference percentiles), blood pressure, surrogate clinical markers of IR(acanthosis nigricans), abdominal ultrasounds, and serum transaminases, lipids and glucose/insulin profiles, allow a clinician to identify children with obesity and obesity-related conditions, including NAFLD and cardiovascular and metabolic risks. A liver biopsy(the "imperfect" gold standard) is required for a definitive NAFLD/NASH diagnosis, particularly to exclude other treatable conditions or when advanced liver disease is expected on clinical and laboratory grounds and preferably prior to any controlled trial of pharmacological/surgical treatments. However, a biopsy clearly cannot represent a screening procedure. Advancements in diagnostic serum and imaging tools, especially for the non-invasive differentiation between NAFLD and NASH, have shown promising results, e.g., magnetic resonance elastography. Weight loss and physical activity should be the first option of intervention.Effective pharmacological treatments are still under development; however, drugs targeting IR, oxidative stress, proinflammatory pathways, dyslipidemia, gut microbiota and gut liver axis dysfunction are an option for patients who are unable to comply with the recommended lifestyle changes. When morbid obesity prevails, bariatric surgery should be considered.     

Microbial metabolites in non-alcoholic fatty liver disease

The prevalence of non-alcoholic fatty liver disease(NAFLD) is rising exponentially worldwide. The spectrum of NAFLD includes non-alcoholic fatty liver, non-alcoholic steatohepatitis, liver cirrhosis, and even hepatocellular carcinoma. Evidence shows that microbial metabolites play pivotal roles in the onset and progression of NAFLD. In this review, we discuss how microbederived metabolites, such as short-chain fatty acids, endogenous ethanol, bile acids and so forth, contribute to the pathogenesis of NAFLD.     

Combination drug treatment in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) includes simple steatosis, a benign condition, and non-alcoholic steatohepatitis, a condition that beyond TG accumulation also includes necroinflammation and fibrosis. An association between NAFLD and cardiovascular disease (CVD) has been recently suggested. NAFLD patients usually have an increased CVD risk profile. NAFLD is also associated with metabolic syndrome (MetS) and is considered as the hepatic component of MetS by some authors. Currently, the only established treatment of NAFLD is gradual weight loss. However, multifactorial treatment of NAFLD risk factors may be needed to reduce the increased CVD risk of NALFD patients. Drug combinations that include antiobesity drugs (such as orlistat and sibutramine) and target CVD risk factors may be a good approach to NAFLD patients. Our group has investigated the orlistat-fenofibrate combination treatment in obese patients with MetS and the orlistat-ezetimibe and sibutramine-antihypertensive combination treatment in obese patients with hyperlipidaemia with promising results in CVD risk factor reduction and improvement of liver function tests. Small studies give promising results but double-blind, randomized trials examining the effects of such multifactorial treatment in hard CVD endpoints in NAFLD patients are missing.     

Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice

With the increasing number of individuals with diabetes and obesity,nonalcoholic fatty liver disease(NAFLD) is becoming increasingly prevalent,affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver(NAFL) to nonalcoholic steatohepatitis(NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden,and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD,including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.     

Bariatric surgery in patients with non-alcoholic fatty liver disease-from pathophysiology to clinical effects

Non-alcoholic fatty liver disease(NAFLD) is increasingly recognized as a significant liver disease,and it covers the disease spectrum from simple steatosis with a risk of development of non-alcoholic steatohepatitis(NASH) to fibrosis,subsequent cirrhosis,end-stage liver failure,and liver cancer with a potential need for liver transplantation.NAFLD and NASH are closely related to obesity,metabolic syndrome,and type 2 diabetes(T2 D).The role of gut hormones,especially glucagon-like peptide 1(GLP-1),is important in NAFLD.Bariatric surgery has the potential for inducing great weight loss and may improve the symptoms of metabolic syndrome and T2 D.Recent data demonstrated significant effects of bariatric surgery on GLP-1 and other gut hormones and important lipid metabolic and inflammatory abnormalities in the pathophysiology of NAFLD.Therefore,bariatric surgery may reverse the pathological liver changes in NAFLD and NASH patients.In the present review,we describe NAFLD and NASH pathophysiology and the primary effects of bariatric surgery on metabolic pathways.We performed a systematic review of the beneficial and harmful effects and focused on changes in liver disease severity in NAFLD and NASH patients.The specific focus was liver histopathology as assessed by the invasive liver biopsy.Additionally,we reviewed several non-invasive methods used for the assessment of liver disease severity following bariatric surgery.     

血清AST水平与非酒精性脂肪性肝病的进展性肝纤维化有关

目的探讨我国成人非酒精性脂肪性肝病（NAFLD）进展性肝纤维化的预测因素。方法通过分析2005年1月—2009年3月经病理学证实的NAFLD患者的人口学、生化学及病理学资料,研究与组织学进展性肝纤维化相关的危险因素。非酒精性脂肪性肝炎（NASH）定义为肝组织G2以上炎症或出现BruntNASH病理标准中的肝纤维化,进展性肝纤维化定义为2期以上肝纤维化。结果总计有108例NAFLD患者纳入研究,其中单纯性脂肪肝、NASH、NASH相关肝硬化分别有67例（62.04%）、39例（36.11%）、2例（1.85%）。男性90.7%、平均年龄（36.6±11.1）岁、体质量指数（BMI）（26.34±3.38）kg/m^2、收缩压（120.13±11.17）mmHg、舒张压（76.61±8.93）mmHg。肝脏病理学结果显示,肝纤维化分期S055例（50.5%）、S128例（25.9%）、S215例（13.9%）、S38例（7.4%）、S42例（1.9%）,与S0-1组（83例）患者相比,S2-4组（25例）BMI、血清ALT和AST水平更高（P〈0.05）,年龄、血清总胆红素水平更低（P〈0.05）。Logistic逐步回归分析表明,仅血清AST增高与进展性肝纤维化相关（P=0.027,OR=3.536,CI=1.159～10.790）,ROC曲线下面积为0.724（CI=0.600～0.849,P=0.002）。结论血清AST水平增高是NAFLD出现进展性肝纤维化的重要预测因素,但准确性欠佳。     

Urea cycle dysregulation in non-alcoholic fatty liver disease

1. Download high-res image (174KB)
2. Download full-size image

     

CEUS and Fibroscan in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

AIM: To determine intra-hepatic blood flow and liver stiffness in patients with non-alcoholic fatty liver disease(NAFLD) and non-alcoholic steatohepatitis (NASH) using contrast-enhanced ultrasound and fibroscan.METHODS: This prospective study included 15 patients with NAFLD, 17 patients with NASH and 16 healthy controls.In each patient, real-time ultrasound was used to locate the portal vein (PV) and the right liver lobe, and 5 mL of SonoVue? was then injected intravenous in a peripheral vein of the left arm over a 4-s span. Digital recording was performed for 3 min thereafter. The recording was subsequently retrieved to identify an area of interest in the PV area and in the right liver parenchyma(LP) to assess the blood flow by processing the data using dedicated software (Qontrast?, Bracco, Italy).The following parameters were evaluated: percentage of maximal contrast activity (Peak%), time to peak (TTP, s), regional blood volume (RBV, cm3), regional blood flow (RBF, cm3/s) and mean transit time (MTT, s).At 24-48 h post-injection, liver stiffness was evaluated using Fibroscan and measured in kPa. The statistical evaluation was performed using Student’s t test.RESULTS: In the PV, the Peak%, RBV and RBF were significantly reduced in the NAFLD and NASH patientscompared with the controls (Peak%: NAFLD 26.3 ± 6.6,NASH 28.1 ± 7.3 vs controls 55.8 ± 9.9, P 0.001;RBV: NAFLD 4202.3 ± 3519.7, NASH 3929.8 ± 1941.3vs controls 7473 ± 3281, P 0.01; RBF: NAFLD 32.5± 10.8, NASH 32.7 ± 12.1 vs controls 73.1 ± 13.9, P 0.001). The TTP in the PV was longer in both patient groups but reached statistical significance only in the NASH patients compared with the controls (NASH 79.5± 37.8 vs controls 43.2 ± 30, P 0.01). In the LP,the Peak%, RBV and RBF were significantly reduced in the NAFLD and NASH patients compared with the controls (Peak%: NAFLD 43.2 ± 7.3, NASH 41.7 ± 7.7 vs controls 56.6 ± 6.3, P 0.001; RBV: NAFLD 4851.5± 2009, NASH 5069.4 ± 2292.5 vs controls 6922.9 ±2461.5, P 0.05; RBF: NAFLD 55.7 ± 10.1, NASH 54.5 ± 12.1 vs controls 75.9 ± 10.5, P 0.001). The TTP was longer in both patient groups but did not reach statistical significance. The MTT in both the PV and LP in the NAFLD and NASH patients was not different from that in the controls. Liver stiffness was significantly increased relative to the controls only in the NASH patients(NASH: 6.4 ± 2.2 vs controls 4.6 ± 1.5, P 0.05).CONCLUSION: Blood flow derangement within the liver present not only in NASH but also in NAFLD suggests that a vascular flow alteration precedes liver fibrosis development.     

关注2型糖尿病合并非酒精性脂肪性肝病的肝脏结局

<正>2型糖尿病(type 2 diabetes mellitus,T2DM)和非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)作为代谢综合征的组分常相伴存在,NAFLD影响糖尿病患者血糖控制难以达标,进而促进慢性并发症的发生。同时,2型糖尿病促使NAFLD向非酒精性脂肪性肝炎(NASH)、肝纤维化、甚至肝细胞癌发展,增加肝脏相关死亡率。就诊内     

A non-invasive prediction model for non-alcoholic steatohepatitis in paediatric patients with non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease encompasses a spectrum of diseases that range from simple steatosis to the aggressive form of non-alcoholic steatohepatitis. Non-alcoholic steatohepatitis is currently diagnosed through liver biopsy.

Aim

To develop a non-invasive predictive model of non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease.

Methods

Anthropometric, laboratory, and histologic data were obtained in a cohort of children with biopsy-proven non-alcoholic fatty liver disease. Multivariable logistic regression analysis was employed to create a nomogram predicting the risk of non-alcoholic steatohepatitis. Internal validation was performed by bootstrapping.

Results

Three hundred and two children were included in this analysis with a mean age of 12.3 ± 3.1 years, a mean body mass index percentile of 94.3 ± 6.9, and non-alcoholic steatohepatitis was present in 67%. Following stepwise variable selection, total cholesterol, waist circumference percentile, and total bilirubin were included as variables in the model, with good discrimination with an area under the receiver operating characteristic curve of 0.737.

Conclusions

A nomogram was constructed with reasonable accuracy that can predict the risk of non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease. If validated externally, this tool could be utilized as a non-invasive method to diagnose non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease.