Non-obese histologically confirmed NASH patients with abnormal liver biochemistry have more advanced fibrosis

Proportion and clinical characteristics of metabolic-associated fatty liver disease and associated liver fibrosis in an urban Chinese population

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is the predominant form of chronic liver disease worldwide. This study was designed to investigate the proportion and characteristics of MAFLD within the general Chinese population and to identify the contributory risk factors for liver fibrosis among MAFLD individuals.

METHODS

The participants were recruited from a cohort undergoing routine health evaluations at the Third Hospital of Hebei Medical University between May 2019 and March 2023. The diagnosis of MAFLD was based on the established clinical practice guidelines. The fibrosis-4 index score (FIB-4) was employed to evaluate hepatic fibrosis, with a FIB-4 score of ≥1.3 indicating significant fibrosis. Binary logistic regression analyses were used to determine risk factors associated with significant hepatic fibrosis in MAFLD.

RESULTS

A total of 22,970 participants who underwent comprehensive medical examinations were included in the analysis. The overall proportion of MAFLD was 28.77% (6608/22,970), with 16.87% (1115/6608) of these patients showing significant fibrosis as assessed using FIB-4. Independent risk factors for significant liver fibrosis in MAFLD patients were male (odds ratio [OR] = 0.676, 95% confidence interval [CI]: 0.558-0.821), hepatitis B surface antigen (HBsAg) positivity (OR = 2.611, 95% CI: 1.557-4.379), body mass index ≥23.00 kg/m 2 (OR = 0.632, 95% CI: 0.470-0.851), blood pressure ≥130/85 mmHg (OR = 1.885, 95% CI: 1.564-2.272), and plasma glucose ≥5.6 mmol/L (OR = 1.815, 95% CI: 1.507-2.186) (all P <0.001).

CONCLUSIONS

The proportion of MAFLD in an urban Chinese population is 28.77%. About 16.87% of MAFLD patients presented with significant liver fibrosis. Independent risk factors for significant liver fibrosis in MAFLD patients should be noticed.

Delicate and thin fibrous septa indicate a regression tendency in metabolic dysfunction-associated steatohepatitis patients with advanced fibrosis

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatohepatitis (MASH)-related fibrosis is reversible. However, the dynamic morphology change in fibrosis regression remains unclear. We aim to explore the morphological characteristics of fibrosis regression in advanced MASH patients.

METHODS

Clinical and histological data of 79 biopsy-proved MASH patients with advanced fibrosis (F3-F4) were reviewed. The second harmonic generation/two-photon excitation fluorescence (SHG/TPEF) image technology was used to quantitatively identify the R (regressive) septa from P (progressive) septa and PS (perisinusoidal) fibrosis. Non-invasive tests were used to compare the fibrosis level with and without R septa groups. Transcriptomics was used to explore hub genes and the underlying mechanism of the formation of R septa.

RESULTS

The R septa were different from the P septa and PS fibrosis in detail collagen quantitation identified by SHG/TPEF technology. The R septa were found in MASH fibrosis-regressed patients, which met the definition of the "Beijing classification". Therefore, patients were divided into two groups according to septa morphology: with R septa (n = 10, 12.7%), and without R septa (n = 69, 87.3%). Patients with R septa had lower values in most non-invasive tests, especially for liver stiffness assessed by TE (12.3 vs. 19.4 kPa, p = 0.010) and FAST (FibroScan®-AST) score (0.43 vs. 0.70, p = 0.003). Transcriptomics analysis showed that the expressions of five hub fibrogenic genes, including Col3A1, BGN, Col4A1, THBS2, and Col4A2 in the R septa group, were significantly lower.

CONCLUSIONS

The R septa can be differentiated from the P septa and PS fibrosis by quantitative assessment of SHG/TPEF, and it represents a tendency of fibrosis regression in MASH patients.

TRIAL REGISTRATION

NCT03386890, 29/12/2017.

Diabetes as a risk factor for MASH progression

Non-alcoholic (now: metabolic) steatohepatitis (MASH) is the progressive inflammatory form of metabolic dysfunction-associated steatotic liver disease (MASLD), which often coexists and mutually interacts with type 2 diabetes (T2D), resulting in worse hepatic and cardiovascular outcomes. Understanding the intricate mechanisms of diabetes-related MASH progression is crucial for effective therapeutic strategies. This review delineates the multifaceted pathways involved in this interplay and explores potential therapeutic implications. The synergy between adipose tissue, gut microbiota, and hepatic alterations plays a pivotal role in disease progression. Adipose tissue dysfunction, particularly in the visceral depot, coupled with dysbiosis in the gut microbiota, exacerbates hepatic injury and insulin resistance. Hepatic lipid accumulation, oxidative stress, and endoplasmic reticulum stress further potentiate inflammation and fibrosis, contributing to disease severity. Dietary modification with weight reduction and exercise prove crucial in managing T2D-related MASH. Additionally, various well-known but also novel anti-hyperglycemic medications exhibit potential in reducing liver lipid content and, in some cases, improving MASH histology. Therapies targeting incretin receptors show promise in managing T2D-related MASH, while thyroid hormone receptor-β agonism has proven effective as a treatment of MASH and fibrosis.

Metabolic dysfunction associated fatty liver disease in healthy weight individuals

Metabolic dysfunction associated fatty liver disease (MAFLD) is an increasing public health problem, affecting one third of the global population. Contrary to conventional wisdom, MAFLD is not exclusive to obese or overweight individuals. Epidemiological studies have revealed a remarkable prevalence among healthy weight individuals, leading investigations into the genetic, lifestyle, and dietary factors that contribute to the development of MAFLD in this population. This shift in perspective requires reconsideration of preventive strategies, diagnostic criteria and therapeutic approaches tailored to address the unique characteristics of MAFLD healthy weight individuals. It also underscores the importance of widespread awareness and education, within the medical community and among the general population, to promote a more inclusive understanding of liver metabolic disorders. With this review, we aim to provide a comprehensive exploration of MAFLD in healthy weight individuals, encompassing epidemiological, pathophysiological, and clinical aspects.

MAFLD: an ideal framework for understanding disease phenotype in individuals of normal weight

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is significant, impacting almost one-third of the global population. MAFLD constitutes a primary cause of end-stage liver disease, liver cancer and the need for liver transplantation. Moreover, it has a strong association with increased mortality rates due to various extrahepatic complications, notably cardiometabolic diseases. While MAFLD is typically correlated with obesity, not all individuals with obesity develop the disease and a significant percentage of MAFLD occurs in patients without obesity, termed lean MAFLD. The clinical features, progression and underlying physiological mechanisms of patients with lean MAFLD remain inadequately characterized. The present review aims to provide a comprehensive summary of current knowledge on lean MAFLD and offer a perspective on defining MAFLD in individuals with normal weight. Key to this process is the concept of metabolic health and flexibility, which links states of dysmetabolism to the development of lean MAFLD. This perspective offers a more nuanced understanding of MAFLD and its underlying mechanisms and highlights the importance of considering the broader metabolic context in which the disease occurs. It also bridges the knowledge gap and offers insights that can inform clinical practice.

Exploring the role of genetic variations in NAFLD: implications for disease pathogenesis and precision medicine approaches

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases, affecting more than one-quarter of people worldwide. Hepatic steatosis can progress to more severe forms of NAFLD, including NASH and cirrhosis. It also may develop secondary diseases such as diabetes and cardiovascular disease. Genetic and environmental factors regulate NAFLD incidence and progression, making it a complex disease. The contribution of various environmental risk factors, such as type 2 diabetes, obesity, hyperlipidemia, diet, and sedentary lifestyle, to the exacerbation of liver injury is highly understood. Nevertheless, the underlying mechanisms of genetic variations in the NAFLD occurrence or its deterioration still need to be clarified. Hence, understanding the genetic susceptibility to NAFLD is essential for controlling the course of the disease. The current review discusses genetics' role in the pathological pathways of NAFLD, including lipid and glucose metabolism, insulin resistance, cellular stresses, and immune responses. Additionally, it explains the role of the genetic components in the induction and progression of NAFLD in lean individuals. Finally, it highlights the utility of genetic knowledge in precision medicine for the early diagnosis and treatment of NAFLD patients.

Accuracy of prognostic serological biomarkers in predicting liver fibrosis severity in people with metabolic dysfunction-associated steatotic liver disease: a meta-analysis of over 40,000 participants

Introduction

A prognostic model to predict liver severity in people with metabolic dysfunction-associated steatotic liver disease (MASLD) is very important, but the accuracy of the most commonly used tools is not yet well established.

Objective

The meta-analysis aimed to assess the accuracy of different prognostic serological biomarkers in predicting liver fibrosis severity in people with MASLD.

Methods

Adults ≥18 years of age with MASLD were included, with the following: liver biopsy and aspartate aminotransferase-to-platelet ratio (APRI), fibrosis index-4 (FIB-4), non-alcoholic fatty liver disease fibrosis score (NFS), body mass index, aspartate aminotransferase/alanine aminotransferase ratio, diabetes score (BARD score), FibroMeter, FibroTest, enhanced liver fibrosis (ELF), Forns score, and Hepascore. Meta-analyses were performed using a random effects model based on the DerSimonian and Laird methods. The study's risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2.

Results

In total, 138 articles were included, of which 86 studies with 46,514 participants met the criteria for the meta-analysis. The results for the summary area under the receiver operating characteristic (sAUROC) curve, according to the prognostic models, were as follows: APRI: advanced fibrosis (AF): 0.78, any fibrosis (AnF): 0.76, significant fibrosis (SF): 0.76, cirrhosis: 0.72; FIB-4: cirrhosis: 0.83, AF: 0.81, AnF: 0.77, SF: 0.75; NFS: SF: 0.81, AF: 0.81, AnF: 0.71, cirrhosis: 0.69; BARD score: SF: 0.77, AF: 0.73; FibroMeter: SF: 0.88, AF: 0.84; FibroTest: SF: 0.86, AF: 0.78; and ELF: AF: 0.87.

Conclusion

The results of this meta-analysis suggest that, when comparing the scores of serological biomarkers with liver biopsies, the following models showed better diagnostic accuracy in predicting liver fibrosis severity in people with MASLD: FIB-4 for any fibrosis, FibroMeter for significant fibrosis, ELF for advanced fibrosis, and FIB-4 for cirrhosis.Clinical trial registration: [https://clinicaltrials.gov/], identifier [CRD 42020180525].

Triglycerides Mediate the Influence of Body Mass Index on Non-Alcoholic Fatty Liver Disease in a Non-Obese Chinese Population with Normal Low-Density Lipoprotein Cholesterol Levels

INTRODUCTION

Over 25% of the world's population has non-obese or lean non-alcoholic fatty liver disease (NAFLD), and the prevalence is higher than average in Asia. The present study focused on the relationship between body mass index (BMI) and non-obese NAFLD in non-overweight people in China, particularly the influence of triglycerides (TG) in the pathogenesis of non-obese NAFLD. The findings suggest new treatments for NAFLD patients with normal BMI, as well as provide an early warning system for the understanding and prevention of NAFLD in non-obese patients.

METHODS

This cross-sectional study enrolled 159,959 Chinese subjects with BMI <24 kg/m2 and normal levels of low-density lipoprotein cholesterol (LDL-c). The average age was 40.21 ± 13.88 years, and males accounted for 45.7%. A total of 15,907 (9.94%) patients with NAFLD were diagnosed by ultrasonography. Biochemical indicators were measured using an automated analyzer (Abbott AxSYM). The BMI (kg/m2) was calculated from the weight (kg)/height in square meters (m2). The BMI quartile was used as the column-stratified variable to determine the baseline distribution, and logistic regression analysis was used to assess the relationship between NAFLD and its risk factors, with multiple logistic regression used to assess the relationships between BMI or TG and NAFLD and multivariate linear regression used to analyze the association between BMI and TG, while mediation analysis was used to assess the mediation effect of TG.

RESULTS

After adjustment of all covariates, the odds ratios were 1.788 (95% CI: 1.749-1.829; p < 0.00001) and 1.491 (95% CI: 1.451-1.532; p < 0.00001) for the association between BMI and TG with NAFLD incidence. The multivariate linear regression coefficient of BMI and TG was β = 0.027 (95% CI: 0.023-0.030; p < 0.00001). Mediation analysis showed that BMI contributed to 10.81% of lean NAFLD with a mediation effect of 2.98%.

CONCLUSION

In a Chinese population with BMI <24 kg/m2 and normal LDL-c levels, BMI and TG were found to be independent predictors of NAFLD. The direct effect of BMI on non-obese NAFLD was 10.41%. The TG level was found to partially mediate the association.

Clinical Classification of Obesity and Implications for Metabolic Dysfunction-Associated Fatty Liver Disease and Treatment

Obesity,and metabolic dysfunction-associated fatty liver disease (MAFLD) have reached epidemic proportions globally. Obesity and MAFLD frequently coexist and act synergistically to increase the risk of adverse clinical outcomes (both hepatic and extrahepatic). Type 2 diabetes mellitus (T2DM) is the most important risk factor for rapid progression of steatohepatitis and advanced fibrosis. Conversely, the later stages of MAFLD are associated with an increased risk of T2DM incident. According to the proposed criteria, MAFLD is diagnosed in patients with liver steatosis and in at least one in three: overweight or obese, T2DM, or signs of metabolic dysregulation if they are of normal weight. However, the clinical classification and correlation between obesity and MAFLD is more complex than expected. In addition, treatment for obesity and MAFLD are associated with a reduced risk of T2DM, suggesting that liver-based treatments could reduce the risk of developing T2DM. This review describes the clinical classification of obesity and MAFLD, discusses the clinical features of various types of obesity and MAFLD, emphasizes the role of visceral obesity and insulin resistance (IR) in the development of MAFLD,and summarizes the existing treatments for obesity and MAFLD that reduce the risk of developing T2DM.

Epidemiological characteristics and management of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis in China: A narrative review

AIM

With industrialization and spread of the westernized lifestyle, the number of people affected by non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is growing rapidly in China; this has become a major public health concern. To better understand the burden and characteristics of NAFLD/NASH in China, we aim to perform a narrative review of the literature published in this field.

MATERIALS AND METHODS

We carried out a comprehensive electronic search of five English-language and three Chinese-language databases, to identify studies regarding NAFLD or NASH published from inception to November 30, 2022. Epidemiological studies of NAFLD/NASH in China were particularly noticed and summarized. We also searched the www.

CLINICALTRIALS

gov and www.chictr.org.cn websites for the registered trials on the treatment of the disease led by Chinese investigators or located in China.

RESULTS

The increasing rate of NAFLD prevalence in China is strikingly high, reaching more than twice that in western countries. The prevalence of NAFLD is nearly 30% of the general Chinese population, making it the leading cause of chronic liver diseases. The prevalence of NAFLD/NASH varies between provinces/regions, age groups, sexes, and individuals with different metabolic profiles. NAFLD co-exists in many Chinese patients with chronic hepatitis B. Since 2020, more Chinese studies have used the term metabolic-associated fatty liver disease (MAFLD), emphasizing the underlying metabolic disorders that occur concurrently with this disease. Several clinical trials involving lifestyle interventions, antidiabetic drugs, or traditional Chinese medicines, registered by Chinese investigators, have been completed or are ongoing. Moreover, several innovative targeted therapies developed in China are revolutionizing the treatment of NAFLD/NASH.

CONCLUSIONS

NAFLD has cast a heavy burden on the Chinese healthcare system. Chinese scholars are making efforts to achieve the optimal management of this disease.

Epidemiologic, Genetic, Pathogenic, Metabolic, Epigenetic Aspects Involved in NASH-HCC: Current Therapeutic Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is the sixth most frequent cancer in the world, being the third cause of cancer-related deaths. Nonalcoholic steatohepatitis (NASH) is characterized by fatty infiltration, oxidative stress and necroinflammation of the liver, with or without fibrosis, which can progress to advanced liver fibrosis, cirrhosis and HCC. Obesity, metabolic syndrome, insulin resistance, and diabetes exacerbates the course of NASH, which elevate the risk of HCC. The growing prevalence of obesity are related with increasing incidence of NASH, which may play a growing role in HCC epidemiology worldwide. In addition, HCC initiation and progression is driven by reprogramming of metabolism, which indicates growing appreciation of metabolism in the pathogenesis of this disease. Although no specific preventive pharmacological treatments have recommended for NASH, dietary restriction and exercise are recommended. This review focuses on the molecular connections between HCC and NASH, including genetic and risk factors, highlighting the metabolic reprogramming and aberrant epigenetic alterations in the development of HCC in NASH. Current therapeutic aspects of NASH/HCC are also reviewed.

Metabolic (dysfunction)-associated fatty liver disease in individuals of normal weight

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) affects up to a third of the global population; its burden has grown in parallel with rising rates of type 2 diabetes mellitus and obesity. MAFLD increases the risk of end-stage liver disease, hepatocellular carcinoma, death and liver transplantation and has extrahepatic consequences, including cardiometabolic disease and cancers. Although typically associated with obesity, there is accumulating evidence that not all people with overweight or obesity develop fatty liver disease. On the other hand, a considerable proportion of patients with MAFLD are of normal weight, indicating the importance of metabolic health in the pathogenesis of the disease regardless of body mass index. The clinical profile, natural history and pathophysiology of patients with so-called lean MAFLD are not well characterized. In this Review, we provide epidemiological data on this group of patients and consider overall metabolic health and metabolic adaptation as a framework to best explain the pathogenesis of MAFLD and its heterogeneity in individuals of normal weight and in those who are above normal weight. This framework provides a conceptual schema for interrogating the MAFLD phenotype in individuals of normal weight that can translate to novel approaches for diagnosis and patient care.

Divergent trajectories of lean vs obese non-alcoholic steatohepatitis patients from listing to post-transplant: A retrospective cohort study

BACKGROUND

Non-alcoholic steatohepatitis (NASH) cirrhosis is the second most common indication for liver transplantation (LT). The role of body mass index (BMI) on outcomes of NASH cirrhosis has been conflicting.

AIM

To compare the longitudinal trajectories of patients with lean vs obese NASH cirrhosis, from listing up to post-transplant, having adjusted their BMI for ascites.

METHODS

We retrospectively reviewed all adult NASH patients listed for LT in our program from 2012 to 2019. Fine-Gray Competing Risk analyses and Cox Proportional-Hazard Models were performed to examine the cumulative incidence of transplant and survival outcomes respectively.

RESULTS

Out of 265 NASH cirrhosis listed patients, 176 were included. Median age was 61.0 years; 46% were females. 111 patients underwent LT. Obese robust patients had better waitlist survival [hazard ratio (HR): 0.12; 95%CI: 0.05–0.29, P < 0.0001] with higher instantaneous rate of transplant (HR: 5.71; 95%CI: 1.26–25.9, P = 0.02). Lean NASH patients had a substantially higher risk of graft loss within 90 d post-LT (1.2% vs 13.8%, P = 0.032) and death post-LT (2.4% vs 17.2%, P = 0.029). 1- 3- and 5-year graft survival was poor for lean NASH (78.6%, 77.3% and 41.7% vs 98.6%, 96% and 85% respectively). Overall patient survival post-LT was significantly worse in lean NASH (HR: 0.17; 95%CI: 0.03–0.86, P = 0.0142) with 83% lower instantaneous rate of death in obese group.

CONCLUSION

Although lean NASH is considered to be more benign than obese NASH, our study suggests a paradoxical correlation of lean NASH with waitlist outcomes, and graft and patient survival post-LT.

Macrophage SCAP Contributes to Metaflammation and Lean NAFLD by Activating STING-NF-κB Signaling Pathway

BACKGROUND & AIMS

Sterol regulatory element binding protein cleavage-activating protein (SCAP) is a cholesterol sensor that confers a broad range of functional effects in metabolic diseases. Lean nonalcoholic fatty liver disease (NAFLD) is characterized by a decrease in subcutaneous fat and ectopic fat deposition in the liver. SCAP may mediate the development of lean NAFLD, but the mechanism of action remains unclear.

METHODS

C57BL/6J wild-type and macrophage SCAP-specific knockout mice (SCAP^ΔMϕ) were subjected to Paigen diet (PD) feeding induced lean NAFLD. Inflammation and lipid metabolism of adipose and liver were evaluated. The STING-NF-κB signaling pathway was examined in vivo and in vitro to explore the underlying mechanism of macrophage SCAP on metaflammation.

RESULTS

The data showed heterogeneity of lipid metabolic processes in liver and epididymal white adipose tissue due to inflammation mediated by macrophage infiltration. Meanwhile, we found that the macrophage SCAP was abnormally increased in the adipose and liver tissues of PD-fed mice. Intriguingly, the SCAP^ΔMϕ mice attenuated PD-induced metaflammation and ectopic lipid deposition by reducing hepatic stimulator of interferon gene (STING)-nuclear factor kappa B (NF-κB) pathway activation. In-depth molecular analysis revealed that SCAP specifically recruits the STING and tank-binding kinase 1 onto the Golgi to activate the NF-κB in macrophages, thereby promoting the release of inflammatory factors. This process ultimately led to an increased lipolysis in adipocytes and lipid uptake and synthesis in hepatocytes.

CONCLUSIONS

Our findings suggest that SCAP acts as a novel regulator of the macrophage inflammatory response and the pathogenesis of lean NAFLD by activating the STING-NF-κB signaling pathway. Inhibition of macrophage SCAP may represent a new therapeutic strategy for the treatment of lean NAFLD.

Caucasian lean subjects with non-alcoholic fatty liver disease share long-term prognosis of non-lean: time for reappraisal of BMI-driven approach?

OBJECTIVE

The full phenotypic expression of non-alcoholic fatty liver disease (NAFLD) in lean subjects is incompletely characterised. We aimed to investigate prevalence, characteristics and long-term prognosis of Caucasian lean subjects with NAFLD.

DESIGN

The study cohort comprises 1339 biopsy-proven NAFLD subjects from four countries (Italy, UK, Spain and Australia), stratified into lean and non-lean (body mass index (BMI)

RESULTS

Lean patients represented 14.4% of the cohort and were predominantly of Italian origin (89%). They had less severe histological disease (lean vs non-lean: non-alcoholic steatohepatitis 54.1% vs 71.2% p<0.001; advanced fibrosis 10.1% vs 25.2% p<0.001), lower prevalence of diabetes (9.2% vs 31.4%, p<0.001), but no significant differences in the prevalence of the PNPLA3 I148M variant (p=0.57). During a median follow-up of 94 months (>10 483 person-years), 4.7% of lean vs 7.7% of non-lean patients reported liver-related events (p=0.37). No difference in survival was observed compared with non-lean NAFLD (p=0.069).

CONCLUSIONS

Caucasian lean subjects with NAFLD may progress to advanced liver disease, develop metabolic comorbidities and experience cardiovascular disease (CVD) as well as liver-related mortality, independent of longitudinal progression to obesity and PNPLA3 genotype. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD where the disease manifests at lower overall BMI thresholds.

LAY SUMMARY

NAFLD may affect and progress in both obese and lean individuals. Lean subjects are predominantly males, have a younger age at diagnosis and are more prevalent in some geographic areas. During the follow-up, lean subjects can develop hepatic and extrahepatic disease, including metabolic comorbidities, in the absence of weight gain. These patients represent one end of a wide spectrum of phenotypic expression of NAFLD.

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Key Words

• fatty liver
• nonalcoholic steatohepatitis

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MESH Headings

• Adult
• Body Mass Index
• Cohort Studies
• Female
• Humans
• Male
• Middle Aged
• Non-alcoholic Fatty Liver Disease/complications
• Non-alcoholic Fatty Liver Disease/mortality
• Non-alcoholic Fatty Liver Disease/pathology
• Prognosis
• Survival Rate
• Thinness/complications
• Thinness/mortality
• Thinness/pathology
• White People

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Grants

• MR/N005872/1 Medical Research Council

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Affiliation(s)

Ramy Younes The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK Boehringer Ingelheim International GmbH, Ingelheim, Germany Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Olivier Govaere The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
Salvatore Petta Sezione di Gastroenterologia, PROMISE, Università di Palermo, Palermo, Italy
Luca Miele Dipartimento Universitario Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy Area Medicina Interna, Gastroenterologia e Oncologia Medica, Fondazione Policlinico A. Gemelli IRCCS, Rome, Italy
Dina Tiniakos The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK Dept of Pathology, Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
Alastair Burt The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
Ezio David Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Fabio Maria Vecchio Dipartimento Universitario Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy Area Anatomia Patologica, Fondazione Policlinico Gemelli IRCCS, Rome, Italy
Marco Maggioni Department of Pathology, Ca' Granda IRCCS Foundation, Milan, Italy
Daniela Cabibi Pathology Institute, PROMISE, University of Palermo, Palermo, Italy
Duncan McLeod Department of Anatomical Pathology, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, Sydney, New South Wales, Australia
Maria Jesus Pareja Pathology Unit, Hospital Universitario de Valme, Sevilla, Spain
Anna Ludovica Fracanzani Unit of Medicine and Metabolic Disease Ca' Granda IRCCS Foundation, Policlinico Hospital, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
Rocio Aller Gastroenterology, Hospital Clínico Universitario de Valladolid, Centro de Investigación de Endocrinología y Nutrición, Universidad de Valladolid, Valladolid, Spain
Chiara Rosso Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Javier Ampuero UCM Digestive Diseases and SeLiver Group, Virgen del Rocio University Hospital, Institute of Biomedicine of Seville, University of Seville, Seville, Spain
Rocío Gallego-Durán UCM Digestive Diseases and SeLiver Group, Virgen del Rocio University Hospital, Institute of Biomedicine of Seville, University of Seville, Seville, Spain
Angelo Armandi Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Gian Paolo Caviglia Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Marco Y W Zaki The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK Biochemistry Department, Faculty of Pharmacy, Minia University, El Minia, Egypt
Antonio Liguori Dipartimento Universitario Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
Paolo Francione Unit of Medicine and Metabolic Disease Ca' Granda IRCCS Foundation, Policlinico Hospital, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
Grazia Pennisi Sezione di Gastroenterologia, PROMISE, Università di Palermo, Palermo, Italy
Antonio Grieco Dipartimento Universitario Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy Area Medicina Interna, Gastroenterologia e Oncologia Medica, Fondazione Policlinico A. Gemelli IRCCS, Rome, Italy
Giovanni Birolo Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Piero Fariselli Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy
Mohammed Eslam Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, New South Wales, Australia
Luca Valenti Translational Medicine, Department of Transfusion Medicine and Hematology, Fondazione IRCCS C'a Granda Ospedale Maggiore Policlinico, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
Jacob George Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, New South Wales, Australia
Manuel Romero-Gómez UCM Digestive Diseases and SeLiver Group, Virgen del Rocio University Hospital, Institute of Biomedicine of Seville, University of Seville, Seville, Spain
Quentin Mark Anstee The Newcastle Liver Research Group, Translational & Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK Newcastle NIHR Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
Elisabetta Bugianesi Department of Medical Sciences, Division of Gastroenterology and Hepatology, A.O. Città della Salute e della Scienza di Torino, Università degli Studi di Torino, Torino, Italy

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Association of genetic variations with NAFLD in lean individuals

BACKGROUND & AIMS

How adiposity influences the effect of genetic variants on non-alcoholic fatty liver disease (NAFLD) in the Asian population remains unclear. We aimed to study the association between genetic risk variants and susceptibility/severity of NAFLD in the lean, overweight and obese individuals.

METHODS

Nine hundred and four community subjects underwent proton-magnetic resonance spectroscopy and transient elastography examination. Lean (<23 kg/m2 ), overweight (23-24.9 kg/m2 ) and obesity (≥25 kg/m2 ) were defined according to the body mass index cut-offs for Asians. NAFLD was defined as intrahepatic triglycerides ≥5%. PNPLA3, TM6SF2, MBOAT7 and 9 other gene polymorphisms were analysed by rhAMPTM SNP assays.

RESULTS

Five hundred and twenty-nine (58.5%), 162 (17.9%) and 213 (23.6%) subjects were lean, overweight and obese, respectively. The prevalence of NAFLD was 12.4%, 41.4% and 59.1% in the three groups (P < .001). Amongst those with NAFLD, lean subjects (30.3%) were more likely to carry the PNPLA3 rs738409 GG genotype than overweight (17.9%) and obese subjects (17.4%) (P = .003). Compared with the CC genotype, the GG genotype was associated with the greatest increase in the risk of NAFLD in lean subjects (odds ratio [OR] 6.04), compared with overweight (OR 3.43, 95% CI [1.06, 11.14]) and obese subjects (OR 2.51, 95% CI [0.93, 6.78]). Additionally, the TM6SF2 rs58542926 TT genotype was associated with reduced serum triglycerides only in lean subjects. A gene-BMI effect was not observed for the other gene polymorphisms.

CONCLUSIONS

The PNPLA3 rs738409 gene polymorphism has a greater effect on liver fat in Asian lean individuals than in overweight or obese ones.

Clinical and sociodemographic determinants of disease progression in patients with nonalcoholic steatohepatitis in the United States

One fifth of patients with nonalcoholic fatty liver disease (NAFLD) may progress to nonalcoholic steatohepatitis (NASH), which can increase the risk of cirrhosis, cancer, and death. To date, reported predictors of NASH progression have been heterogeneous.We identified determinants of fibrosis progression in patients with NASH in the United States using physician-reported data from the real-world Global Assessment of the Impact of NASH (GAIN) study, including demographics and clinical characteristics, NASH diagnostic information, fibrosis stage, comorbidities, and treatment. We developed a logistic regression model to assess the likelihood of fibrosis progression since diagnosis, controlling for sociodemographic and clinical variables. An iterative nested model selection approach using likelihood ratio test determined the final model.A total of 989 patients from the GAIN US cohort were included; 46% were women, 58% had biopsy-proven NAFLD, and 74% had fibrosis stage F0-F2 at diagnosis. The final multivariable model included age, years since diagnosis, sex, employment status, smoking status, obesity, fibrosis stage, diagnostic biopsy, Vitamin E, and liver transplant proposed at diagnosis. Odds of progression were 17% higher (odds ratio, 1.17 [95% CI: 1.11-1.23]; P < .001) with each year since NASH diagnosis, 41% lower (0.59 [0.38-0.90]; P = .016) for women than men, 131% higher (2.31 [1.30-4.03]; P = .004) for smokers versus non-smokers, and 89% higher (1.89 [1.26-2.86]; P = .002) with obesity. Odds of progression were also higher with part-time, retired, unemployed, and unable to work due to NASH status versus full-time employment, and when a liver transplant was proposed at diagnosis.Disease duration and severity, obesity, smoking, and lack of full-time employment were significant determinants of fibrosis progression. These findings can support clinical and health-policy decisions to improve NASH management in the US.

Non-Alcoholic Fatty Liver Disease in Lean and Non-Obese Individuals: Current and Future Challenges

Non-alcoholic fatty liver disease (NAFLD), which approximately affects a quarter of the world’s population, has become a major public health concern. Although usually associated with excess body weight, it may also affect normal-weight individuals, a condition termed as lean/non-obese NAFLD. The prevalence of lean/non-obese NAFLD is around 20% within the NAFLD population, and 5% within the general population. Recent data suggest that individuals with lean NAFLD, despite the absence of obesity, exhibit similar cardiovascular- and cancer-related mortality compared to obese NAFLD individuals and increased all-cause mortality risk. Lean and obese NAFLD individuals share several metabolic abnormalities, but present dissimilarities in genetic predisposition, body composition, gut microbiota, and susceptibility to environmental factors. Current treatment of lean NAFLD is aimed at improving overall fitness and decreasing visceral adiposity, with weight loss strategies being the cornerstone of treatment. Moreover, several drugs including PPAR agonists, SGLT2 inhibitors, or GLP-1 receptor agonists could also be useful in the management of lean NAFLD. Although there has been an increase in research regarding lean NAFLD, there are still more questions than answers. There are several potential drugs for NAFLD therapy, but clinical trials are needed to evaluate their efficacy in lean individuals.

Development of a novel mouse model of diet-induced nonalcoholic steatohepatitis-related progressive bridging fibrosis

Nonalcoholic steatohepatitis (NASH) progresses to liver fibrosis and cirrhosis. Existing mouse models of NASH rarely develop diet-induced severe fibrosis. We aimed to establish a dietary model of NASH with rapid progression to fibrosis. Six-week-old male Tsumura-Suzuki obese diabetes (TSOD) mice (a model of spontaneous metabolic syndrome) and corresponding control Tsumura-Suzuki nonobese (TSNO) mice were fed a novel diet high in fat, cholesterol, and cholate (iHFC). Histologic steatohepatitis, including steatosis, inflammation, and fibrosis, were observed in both TSNO and TSOD iHFC diet-fed mice at 20 weeks of age. As compared with TSOD mice, TSNO mice developed much more severe fibrosis and reached stage 3 of bridging fibrosis within 14 weeks under the iHFC diet feeding. Perivenular/perisinusoidal pattern of fibrosis in TSNO mice resembled human NASH. Our model of NASH with advanced fibrosis by simple diet offers many advantages useful in studying the mechanism of liver fibrosis and preclinical drug testing.

PPARGC1A rs8192678 G>A polymorphism affects the severity of hepatic histological features and nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease

BACKGROUND

The association between PPARGC1A rs8192678 and nonalcoholic fatty liver disease (NAFLD) requires further confirmation. In addition, it is still unknown whether PPARGC1A rs8192678 is associated with hepatic histological features in NAFLD in the Chinese population.

AIM

To investigate the interaction between PPARGC1A rs8192678 and nonalcoholic steatohepatitis (NASH), and whether this polymorphism is associated with hepatic histological features.

METHODS

Fifty-nine patients with liver biopsy-proven NAFLD and 93 healthy controls were recruited to a cohort representing the Chinese Han population. The SAF (steatosis, activity, and fibrosis) scoring system was used for hepatic histopathological evaluation. The polymorphisms of PPARGC1A rs8192678 and patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 were genotyped. The intrahepatic mRNA expression of PPARGC1A was evaluated by real-time polymerase chain reaction.

RESULTS

Thirty-seven patients with NAFLD had NASH, of which 12 were nonobese. The PPARGC1A rs8192678 risk A allele (carrying GA and AA genotypes) had the lowest P value in the dominant model; the odds ratio (OR) for NAFLD was 2.321 [95% confidence interval (CI): 1.121-4.806]. After adjusting for age, sex, and the PNPLA3 rs738409 risk G allele, the PPARGC1A rs8192678 A allele was a risk factor for NAFLD (OR 2.202, 95%CI: 1.030-4.705, P = 0.042). The genetic analysis showed that patients with NAFLD, moderate-to-severe steatosis (S2-3), and Activity 2-4 (A ≥ 2) were more likely to carry A in PPARGC1A rs8192678 (OR 5.000, 95%CI: 1.343-18.620, P = 0.012; and OR 4.071, 95%CI: 1.076-15.402, P = 0.031). The multivariate logistic regression analysis showed that PPARGC1A rs8192678 risk A allele was also independently associated with S2-3, A ≥ 2, and NASH (OR 6.190, 95%CI: 1.508-25.410, P = 0.011; OR 4.506, 95%CI 1.070-18.978, P = 0.040; and OR 6.337, 95%CI: 1.135-35.392, P = 0.035, respectively) after adjusting for age, sex, body mass index, and PNPLA3 rs738409 risk G allele. The results also showed that this polymorphism was associated with nonobese NASH (OR 22.000, 95%CI: 1.540-314.292, P = 0.021). The intrahepatic expression of PPARGC1A mRNA was significantly lower in the group of patients who carried the risk A allele (P = 0.014).

CONCLUSION

The PPARGC1A rs8192678 risk A allele is associated with NAFLD, and with S2-3, A ≥ 2 and NASH in NAFLD patients, independent of PNPLA3 rs738409, and may be associated with nonobese NASH.

A review of non-alcoholic fatty liver disease in non-obese and lean individuals

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of hepatic disorders. It represents a wide range of chronic liver diseases in patients with no history of significant alcohol consumption, starting with simple steatosis and progressing towards non-alcoholic steatohepatitis, cirrhosis, and ultimately hepatocellular carcinoma. NAFLD is usually associated with type 2 diabetes mellitus, dyslipidemia, metabolic syndrome, and obesity. This disease has mostly been studied in obese individuals; however, it has been widely reported and studied among the lean/non-obese population in recent years. The pathogenesis of NAFLD in non-obese patients is associated with various genetic predispositions, particularly a patatin-like phospholipase domain-containing protein 3 G allele polymorphism, which results in the accumulation of triglyceride in the liver and resistance to insulin. Additionally, dietary factors such as high fructose consumption seem to play a substantial role in the pathology of non-obese NAFLD. Although there is not enough evidence on the treatment of NAFLD in non-obese patients, the standard approach is to advise altering one's lifestyle in order to diminish visceral adiposity. Dietary modification, weight loss, and increased physical activity are highly recommended. We aimed to review and summarize the existing information on the prevalence, pathogenesis, genetic predispositions, diagnosis, and treatment of NAFLD in non-obese patients according to the latest literature.

Circulating lipidomic alterations in obese and non-obese subjects with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) affects obese and non-obese individuals. However, mechanisms underlying non-obese non-alcoholic steatohepatitis (NASH) remain unclear.

AIMS

To attempt to identify metabolic perturbations associated with non-obese and obese NAFLD using a lipidomics approach.

METHODS

A cross-sectional analysis of 361 subjects with biopsy-proven NAFLD (157 NAFL and 138 NASH) and healthy controls (n = 66) was performed. Individuals were categorised as obese or non-obese based on the Asian cut-off for body mass index. Circulating lipidomic profiling of sera was performed based on the histological severity of NAFLD. Circulating lipidomic alterations were validated with an independent validation set (154 NAFLD subjects [93 NAFL and 61 NASH] and 21 healthy controls).

RESULTS

Saturated sphingomyelin (SM) species were significantly associated with visceral adiposity in non-obese NAFLD (SM d38:0; P < 0.001) but not in obese NAFLD. Additionally, SM levels were significantly associated with systemic and adipose tissue insulin resistance (SM d38:0; P = 0.002 and <0.001, respectively). Five potential lipid metabolites for non-obese subjects and seven potential lipids for obese subjects were selected to predict NAFLD and NASH. These lipid combinations showed good diagnostic performance for non-obese (area under the curve [AUC] for NAFLD/NASH = 0.916/0.813) and obese (AUC for NAFLD/NASH = 0.967/0.812) subjects. Moreover, distinctly altered patterns of diacylglycerol (DAG), triacylglycerol (TAG) and SM levels were confirmed in the validation set depending on the histological severity of NAFLD.

CONCLUSION

Non-obese and obese NAFLD subjects exhibit unique circulating lipidomic signatures, including DAGs, TAGs and SMs. These lipid combinations may be useful biomarkers for non-obese and obese NAFLD patients.

Clinical assessment and management of liver fibrosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is among the most frequent etiologies of cirrhosis worldwide, and it is associated with features of metabolic syndrome; the key factor influencing its prognosis is the progression of liver fibrosis. This review aimed to propose a practical and stepwise approach to the evaluation and management of liver fibrosis in patients with NAFLD, analyzing the currently available literature. In the assessment of NAFLD patients, it is important to identify clinical, genetic, and environmental determinants of fibrosis development and its progression. To properly detect fibrosis, it is important to take into account the available methods and their supporting scientific evidence to guide the approach and the sequential selection of the best available biochemical scores, followed by a complementary imaging study (transient elastography, magnetic resonance elastography or acoustic radiation force impulse) and finally a liver biopsy, when needed. To help with the selection of the most appropriate method a Fagan's nomogram analysis is provided in this review, describing the diagnostic yield of each method and their post-test probability of detecting liver fibrosis. Finally, treatment should always include diet and exercise, as well as controlling the components of the metabolic syndrome, +/- vitamin E, considering the presence of sleep apnea, and when available, allocate those patients with advanced fibrosis or high risk of progression into clinical trials. The final end of this approach should be to establish an opportune diagnosis and treatment of liver fibrosis in patients with NAFLD, aiming to decrease/stop its progression and improve their prognosis.

Naringin ameliorates type 2 diabetes mellitus-induced steatohepatitis by inhibiting RAGE/NF-κB mediated mitochondrial apoptosis

AIMS

Recent findings have instituted the role of hyperglycemia-related AGE/RAGE and NF-κB in instigating reactive oxygen species (ROS) mediated mitochondrial dysfunction and apoptosis of hepatocyte, which leads to steatohepatitis. Naringin, a flavanone glycoside found to possess myriads of pharmacological benefits along with its antioxidant and anti-inflammatory properties. Consequently, we aimed to decipher the effect of naringin on RAGE/NF-κB mediated mitochondrial apoptosis in type 2 diabetes mellitus (T2DM)-induced steatohepatitis.

MAIN METHODS

Hepatic HepG2 cells were cultured in palmitic acid medium with and without naringin. Lipid content was examined by Oil Red O and Nile Red staining. Cellular apoptosis was determined by Annexin V-FITC/PI staining. An experimental T2DM-induced steatohepatitis was developed in Sprague Dawley rats by high-fat diet (HFD) for 12 weeks. The naringin was administrated orally at a dose of 100 mg/kg, daily for eight weeks. Glucose and insulin tolerance test was performed. Liver sections were stained by hematoxylin-eosin and picrosirius red. The mRNA and protein expression of RAGE and NF-κB were determined by qPCR, Immunofluorescence, and Immunoblotting. Mitochondrial membrane potential (MMP), cellular and mitochondrial ROS were measured by FACS.

KEY FINDINGS

Palmitic acid encountered HepG2 cells and HFD fed rats exhibited hyperlipidemia, insulin resistance, abnormal aminotransferases, steatosis, and fibrosis. Besides, the level of AGEs, RAGE, NF-κB, and oxidative stress were exacerbated. Moreover, MMP, cellular and mitochondrial ROS were altered in diabetic rats. Nevertheless, the naringin treatment ameliorated the steatohepatitis by improving the levels of aforementioned parameters.

SIGNIFICANCE

Collectively, these findings suggested anti-steatohepatitis potential of naringin in diabetics.

Epidemiology of nonalcoholic fatty liver disease in non-obese populations: Meta-analytic assessment of its prevalence, genetic, metabolic, and histological profiles

OBJECTIVE

As a subgroup of nonalcoholic fatty liver disease (NAFLD), patients with non-obese NAFLD may also have an increased risk of adverse hepatic and metabolic outcomes. We aimed to estimate the prevalence and incidence of non-obese NAFLD and to describe its clinical characteristics in this systematic review and meta-analysis.

METHODS

We performed a systematic search of 1235 citations published up to Mar 2020. Meta-analyses, stratified analyses and meta-regression were all performed.

RESULTS

Of the 46 studies included, 28 cross-sectional and longitudinal studies of 155 846 non-obese participants reported a pooled NAFLD prevalence of 14.5% (95% confidence interval [CI] 12.3%-17.1%). A multivariate meta-regression analysis showed the trend that the prevalence varied by their geographical location. Further stratified analyses showed that NAFLD was relatively prevalent among people aged ≥45 years (16.2%; 95% CI 10.8-23.4) and those in South America (25.7%; 95% CI 24.4-27.0). The PNPLA3 rs738409 gene polymorphism was more frequently observed in non-obese NAFLD than in both obese NAFLD and non-obese controls, while the metabolic profiles of non-obese NAFLD were less severe than those of the obese NAFLD group. Patients with non-obese NAFLD had 4.81-fold and 5.43-fold higher risk of diabetes mellitus and metabolic syndrome, respectively, than the non-obese controls.

CONCLUSIONS

Non-obese NAFLD is common, particularly in South America and among people aged ≥45 years. Metabolic diseases and PNPLA3 rs738409 gene polymorphism are more frequent in the non-obese NAFLD group than in non-obese controls.

Paraoxonase-1 Serum Concentration and PON1 Gene Polymorphisms: Relationship with Non-Alcoholic Fatty Liver Disease

Background: Non-alcoholic fatty liver disease (NAFLD) is an important cause of chronic liver diseases around the world. Paraoxonase-1 (PON1) is an enzyme produced by the liver with an important antioxidant role. The aim of this study was to evaluate PON1 serum concentration and PON1 gene polymorphisms in patients with NAFLD. Materials and methods: We studied a group of 81 patients with NAFLD with persistently elevated aminotransferases and a control group of 81 patients without liver diseases. We collected clinical information and performed routine blood tests. We also measured the serum concentration of PON1 and evaluated the PON1 gene polymorphisms L55M, Q192R, and C-108T. Results: There was a significant difference (p < 0.001) in serum PON1 concentrations among the two groups. The heterozygous and the mutated homozygous variants (LM + MM) of the L55M polymorphism were more frequent in the NAFLD group (p < 0.001). These genotypes were found in a multivariate binary logistic regression to be independently linked to NAFLD (Odds ratio = 3.4; p = 0.04). In a multivariate linear regression model, the presence of NAFLD was associated with low PON1 concentration (p < 0.001). Conclusions: PON1 serum concentrations were diminished in patients with NAFLD, and the presence of NAFLD was linked with low PON1 concentration. The LM + MM genotypes of the PON1 L55M polymorphism were an independent predictor for NAFLD with persistently elevated aminotransferases.