Natural history of nonalcoholic fatty liver disease: A prospective follow-up study with serial biopsies

Natural history and progression of metabolic dysfunction-associated steatotic liver disease

The natural history of metabolic dysfunction-associated steatotic liver disease (MASLD), previously referred to as non-alcoholic fatty liver disease (NAFLD), is complex and long. A minority of patients develop inflammation and risk progressive fibrosis that can result in cirrhosis. Progression to cirrhosis occurs in 3-5% of patients and often takes more than 20 years. This narrative review presents an update on the natural history of MASLD, discussing studies and risk estimates for progression to severe outcomes, such as decompensated cirrhosis or hepatocellular carcinoma. We highlight the dynamic progression of liver damage, how to identify patients whose disease progresses over time, and how risk factors might be mitigated to reduce the risk for disease progression.

Liver stiffness predicts progression to liver-related events in patients with chronic liver disease - A cohort study of 14 414 patients

BACKGROUND & AIMS

Liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) is a non-invasive diagnostic biomarker of liver fibrosis. It is uncertain if LSM can predict risk for future liver-related outcomes in large, heterogenous populations.

METHODS

This Swedish multi-centre cohort study included patients (n = 14 414) from 16 sites who underwent LSM by VCTE between 2008 and 2020. Outcomes were ascertained from national registers. We investigated progression to cirrhosis with portal hypertension or hepatocellular carcinoma (HCC), separately. Cox regression was used to obtain hazard ratios (HRs). Harrel's C-index was used to measure discrimination of VCTE.

RESULTS

Included patients had a median age of 46 (interquartile range 34-57), median LSM of 5.9 kPa (4.6-8.0), 59% were male, and the majority had hepatitis C (50.1%). During a median follow-up of 5.9 (4.3-8.0) years, 402 patients (2.7%) developed cirrhosis with portal hypertension. In patients with an LSM ≥25 kPa, 28.7% developed cirrhosis with portal hypertension within 5 years of follow-up, while only .6% of patients with an LSM <10 kPa did. This translated to a HR of 48.3 (95% confidence interval = 37.6-62.0). VCTE had a high discriminative ability, with C-indices above .80 for most liver diseases, including .82 for MASLD. Similar findings were seen for incident HCC.

CONCLUSIONS

Increased LSM by VCTE was associated with an increased risk of progression to both cirrhosis with portal hypertension, and to HCC, and had a high discriminative ability across different aetiologies of chronic liver diseases. These results support the use of VCTE to guide follow-up and treatment decisions.

Association between Lifestyle Modification and All-Cause, Cardiovascular, and Premature Mortality in Individuals with Non-Alcoholic Fatty Liver Disease

BACKGROUND

This study is designed to explore the correlation between multiple healthy lifestyles within the framework of "lifestyle medicine", and the mortality risk of nonalcoholic fatty liver disease (NAFLD).

METHODS

The National Health and Nutrition Examination Survey (NHANES) database was employed. The analysis consisted of 5542 participants with baseline NAFLD and 5542 matched non-NAFLD participants from the database. Lifestyle information, including five low risk factors advocated by lifestyle medicine (healthy diet, vigorous physical activity, healthy sleep duration, avoiding smoking, and maintaining a non-depressed psychological status), was collected through a baseline questionnaire. Cox proportional hazards regression models and Kaplan-Meier survival curve were used to evaluate risk of mortality. In addition, subgroups were analyzed according to gender, age, body mass index and waist circumference.

RESULTS

In total, 502 deaths (n = 181 deaths from cardiovascular disease (CVD)) were recorded among NAFLD participants after the median follow up duration of 6.5 years. In the multivariate-adjusted model, compared to participants with an unfavorable lifestyle (scoring 0-1), NAFLD participants with a favorable lifestyle (scoring 4-5) experienced a 56% reduction in all-cause mortality and a 66% reduction in CVD mortality. Maintaining an undepressed psychological state and adhering to vigorous exercise significantly reduced CVD mortality risk in NAFLD participants (HR, 0.64 [95% CI, 0.43-0.95]; HR, 0.54 [95% CI, 0.33-0.88]) while maintaining healthy sleep reduced premature mortality due to CVD by 31%.

CONCLUSIONS

Healthy lifestyle, characterized by maintaining an undepressed mental state and healthy sleep, significantly mitigates the risk of all-cause, CVD, and premature mortality risk among NAFLD patients, with a particularly pronounced effect observed in female and obese subpopulations.

Activin A levels in metabolic dysfunction-associated steatotic liver disease associates with fibrosis and the PNPLA3 I148M variant

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver condition worldwide. There is an urgent need to develop new biomarkers to assess disease severity and to define patients with a progressive phenotype. Activin A is a new promising biomarker with conflicting results about liver fibrosis. In this study we investigate levels of Activin A in patients with biopsy proven MASLD. We assess levels of Activin A in regard to fibrosis stage and genetic variant I148M in the patatin-like phospholipase domain-containing protein 3 (PNPLA3).

METHODS

Activin A levels were assessed in plasma samples from patients with biopsy-proven MASLD in a cross-sectional study. All patients were clinically evaluated and the PNPLA3 I148M genotype of the cohort was assessed.

FINDINGS

41 patients were included and 27% of these had advanced fibrosis. In MASLD patients with advanced fibrosis, Activin A levels was higher (p < 0.001) and could classify advanced fibrosis with an AUROC for activin A of 0.836 (p < 0.001). Patients homozygous for PNPLA3 I148M G/G had higher levels of activin A than non-homozygotes (p = 0.027).

CONCLUSIONS

Circulating activin A levels were associated with advanced fibrosis and could be a potential blood biomarker for identifying advanced fibrosis in MASLD. Patients with the risk genotype PNPLA3 I148M G/G had higher levels of activin A proposing activin A as a contributor of the transition from simple steatosis to a fibrotic phenotype.

Vitamin D and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Novel Mechanistic Insights

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly prevalent condition characterized by abnormal fat accumulation in the liver, often associated with metabolic disorders. Emerging evidence suggests a potential link between vitamin D deficiency and the development and progression of MASLD. The current review provides a concise overview of recent studies uncovering novel mechanistic insights into the interplay between vitamin D and MASLD. Several epidemiological studies have highlighted a significant association between low vitamin D levels and an increased risk of MASLD. Vitamin D, traditionally known for its role in bone health, has now been recognized as a key player in various physiological processes, including immune regulation and inflammation. Experimental studies using animal models have demonstrated that vitamin D deficiency exacerbates liver steatosis and inflammation, suggesting a potential protective role against MASLD. Mechanistically, vitamin D appears to modulate MASLD through multiple pathways. Firstly, the vitamin D receptor (VDR) is abundantly expressed in liver cells, indicating a direct regulatory role in hepatic function. Activation of the VDR has been shown to suppress hepatic lipid accumulation and inflammation, providing a mechanistic basis for the observed protective effects. Additionally, vitamin D influences insulin sensitivity, a critical factor in MASLD pathogenesis. Improved insulin sensitivity may mitigate the excessive accumulation of fat in the liver, thus attenuating MASLD progression. In parallel, vitamin D exhibits anti-inflammatory properties by inhibiting pro-inflammatory cytokines implicated in MASLD pathophysiology. Experimental evidence suggests that the immunomodulatory effects of vitamin D extend to the liver, reducing inflammation and oxidative stress, key drivers of MASLD, and the likelihood of hepatocyte injury and fibrosis. Understanding the complex interplay between vitamin D and MASLD provides a basis for exploring targeted therapeutic strategies and preventive interventions. As vitamin D deficiency is a modifiable risk factor, addressing this nutritional concern may prove beneficial in mitigating the burden of MASLD and associated metabolic disorders.

Development of non-alcoholic steatohepatitis is associated with gut microbiota but not with oxysterol enzymes CH25H, EBI2, or CYP7B1 in mice

Liver steatosis is the most frequent liver disorder and its advanced stage, non-alcoholic steatohepatitis (NASH), will soon become the main reason for liver fibrosis and cirrhosis. The "multiple hits hypothesis" suggests that progression from simple steatosis to NASH is triggered by multiple factors including the gut microbiota composition. The Epstein Barr virus induced gene 2 (EBI2) is a receptor for the oxysterol 7a, 25-dihydroxycholesterol synthesized by the enzymes CH25H and CYP7B1. EBI2 and its ligand control activation of immune cells in secondary lymphoid organs and the gut. Here we show a concurrent study of the microbial dysregulation and perturbation of the EBI2 axis in a mice model of NASH.We used mice with wildtype, or littermates with CH25H-/-, EBI2-/-, or CYP7B1-/- genotypes fed with a high-fat diet (HFD) containing high amounts of fat, cholesterol, and fructose for 20 weeks to induce liver steatosis and NASH. Fecal and small intestinal microbiota samples were collected, and microbiota signatures were compared according to genotype and NASH disease state.We found pronounced differences in microbiota composition of mice with HFD developing NASH compared to mice did not developing NASH. In mice with NASH, we identified significantly increased 33 taxa mainly belonging to the Clostridiales order and/ or the family, and significantly decreased 17 taxa. Using an Elastic Net algorithm, we suggest a microbiota signature that predicts NASH in animals with a HFD from the microbiota composition with moderate accuracy (area under the receiver operator characteristics curve = 0.64). In contrast, no microbiota differences regarding the studied genotypes (wildtype vs knock-out CH25H-/-, EBI2-/-, or CYP7B1-/-) were observed.In conclusion, our data confirm previous studies identifying the intestinal microbiota composition as a relevant marker for NASH pathogenesis. Further, no link of the EBI2 - oxysterol axis to the intestinal microbiota was detectable in the current study.

NAFLD Fibrosis Progression and Type 2 Diabetes: The Hepatic-Metabolic Interplay

The bidirectional relationship between type 2 diabetes and (non-alcoholic fatty liver disease) NAFLD is indicated by the higher prevalence and worse disease course of one condition in the presence of the other, but also by apparent beneficial effects observed in one, when the other is improved. This is partly explained by their belonging to a multisystemic disease that includes components of the metabolic syndrome and shared pathogenetic mechanisms. Throughout the progression of NAFLD to more advanced stages, complex systemic and local metabolic derangements are involved. During fibrogenesis, a significant metabolic reprogramming occurs in the hepatic stellate cells, hepatocytes, and immune cells, engaging carbohydrate and lipid pathways to support the high-energy-requiring processes. The natural history of NAFLD evolves in a variable and dynamic manner, probably due to the interaction of a variable number of modifiable (diet, physical exercise, microbiota composition, etc.) and non-modifiable (genetics, age, ethnicity, etc.) risk factors that may intervene concomitantly, or subsequently/intermittently in time. This may influence the risk (and rate) of fibrosis progression/regression. The recognition and control of the factors that determine a rapid progression of fibrosis (or its regression) are critical, as the fibrosis stages are associated with the risk of liver-related and all-cause mortality.

Metabolic Disorders in Liver Transplant Recipients: The State of the Art

Liver transplantation represents a chief therapeutic approach for acute liver failure, end-stage liver disease and hepatocellular carcinoma. Despite witnessing advancements in short- and medium-term survival over recent decades, attributed to refinements in surgical techniques and immunosuppressive protocols, long-term mortality remains impervious to modification. Notably, cardiovascular disease emerges as a predominant cause of mortality among liver transplant recipients. This trend is accentuated by the increasing prominence of non-alcoholic steatohepatitis-related cirrhosis as an indication for liver transplantation. Moreover, the administration of immunosuppressive agents is intricately linked to the degradation of the metabolic profile in liver transplant recipients, thereby contributing to the initiation or exacerbation of cardiovascular risk factors, such as hypertension, diabetes, and dyslipidaemia. In addition, the post-liver transplantation period is marked by a decline in lifestyle quality and a failure to acknowledge the psychological distress experienced by patients throughout the transplant process. These factors can precipitate a deterioration in the patient's metabolic profile, exacerbated by suboptimal therapeutic compliance. This narrative review aims to comprehensively address the principal metabolic disorders intricately associated with liver transplantation.

Phase 2, open-label, rollover study of cenicriviroc for liver fibrosis associated with metabolic dysfunction-associated steatohepatitis

BACKGROUND

Cenicriviroc (CVC) is a novel, orally administered antagonist of chemokine receptor types 2/5 that has demonstrated antifibrotic activity in a phase 2b study of patients with NASH. This phase 2, open-label, rollover study investigated the long-term safety and tolerability of CVC in patients with NASH and stage 0-4 liver fibrosis.

METHODS

Eligible patients who completed the phase 2 CENTAUR study or reached a predefined endpoint in the phase 3 AURORA study were rolled over and received open-label CVC 150 mg once daily. Safety assessments were conducted at the start of the study, and patients were seen in the clinic every 3 months until the study sponsor terminated CVC development. Safety endpoints included treatment-emergent adverse events (TEAEs), treatment-related TEAEs, adverse event severity, and clinical laboratory assessments.

RESULTS

A total of 167 patients were enrolled, with a median treatment duration of 33.6 months. Before study termination, 36 patients (21.6%) prematurely discontinued the study. Treatment-related TEAEs were reported in 28 patients (16.8%). The most common treatment-related TEAEs were 4 cases of diarrhea (2.4%) and 2 cases each (1.2%) of abdominal pain, nausea, alanine aminotransferase increased, aspartate aminotransferase increased, hypertriglyceridemia, myalgia, pruritus, and rash. The majority of these treatment-related events were mild in intensity, and none were life-threatening. There were no clinically meaningful changes in hepatic function, chemistry, or liver parameters from baseline to the end of the study.

CONCLUSIONS

In this rollover study, CVC 150 mg once daily was well tolerated in patients with NASH and stage 0-4 liver fibrosis. No new safety signals were reported, and these data further support the safety and tolerability of CVC.

Association between body roundness index and risk of ultrasound-defined non-alcoholic fatty liver disease

Objectives

While several indicators have been studied, the association of body roundness index (BRI) with non-alcoholic fatty liver disease (NAFLD) remains unclear. We aimed to explore the association between BRI and ultrasound-defined NAFLD.

Methods

The sample dataset was extracted from the National Health and Nutrition Examination Survey (NHANES) during the period of 2017-2018. The diagnosis of NAFLD was determined based on the controlled attenuated parameter (CAP≥248 dB/m) score of liver ultrasound transient elastography (LUTE). Participants with excessive alcohol use and viral hepatitis were excluded. To delve deeper into the relationship, Multivariable logistic regression with adjustment for confounding variables and smoothing curve analysis was used to investigate the association and nonlinear relationships between BRI and NAFLD.

Results

Among 4210 individuals aged 20 years or older included in the study, 28.2 % had NAFLD. Compared to the first tertile, BRI notably increased the risk of NAFLD 3.53-fold [95 % confidence interval (CI) = 2.73-4.57] in the second tertile and 7.00-fold (95%CI = 5.29-9.27) in the third tertile after adjusting for multiple covariates (P for trend <0.001). Furthermore, when BRI was treated as a continuous variable, one unit of increment in BRI was associated with 41 % higher odds of NAFLD [adjusted odds ratio (aOR) = 1.41; 95%CI = 1.34-1.48; P < 0.001]. The associations of BRI with NAFLD persisted in all subgroup analyses. A smoothing curve fitting demonstrated that the relationship between BRI and NAFLD was a nonlinear connection. The risk of NAFLD increased significantly when BRI was lower than 4.82, after which the curve showed a modest ascent.

Conclusion

Higher BRI was consistently associated with an increased risk of NAFLD in US adults. BRI is a risk factor for NAFLD, and there is an imperative to give more attention to lowering the BRI.

Immunology of gut microbiome and liver in non-alcoholic fatty liver disease (NAFLD): mechanisms, bacteria, and novel therapeutic targets

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Most important contributors to its development are diet and obesity. Gut microbiome's importance for immune system and inflammatory pathways more widely accepted as an important component in NAFLD and other liver diseases' pathogenesis. In this article we review potential mechanisms of microbiome alteration of local and systemic immune responses leading to NAFLD's development, and how can modulate them for the treatment. Our review mentions different immune system pathways and microorganisms regulating metabolism, liver inflammation and fibrosis. We specifically point out TLR-4 as a potential key immune pathway activated by bacterial lipopolysaccharides producing pro-inflammatory cytokines in NAFLD. Also, we discuss three endotoxin-producing strains (Enterobacter cloacae B29, Escherichia coli PY102, Klebsiella pneumoniae A7) that can promote NAFLD development via TLR4-dependent immune response activation in animal models and how they potentially contribute to disease progression in humans. Additionally, we discuss their other immune and non-immune mechanisms contributing to NAFLD pathogenesis. In the end we point out gut microbiome researches' future perspective in NAFLD as a potential new target for both diagnostic and treatment.

A Markov model of fibrosis development in nonalcoholic fatty liver disease predicts fibrosis progression in clinical cohorts

Disease progression in nonalcoholic steatohepatitis (NASH) is highly heterogenous and remains poorly understood. Fibrosis stage is currently the best predictor for development of end-stage liver disease and mortality. Better understanding and quantifying the impact of factors affecting NASH and fibrosis is essential to inform a clinical study design. We developed a population Markov model to describe the transition probability between fibrosis stages and mortality using a unique clinical nonalcoholic fatty liver disease cohort with serial biopsies over 3 decades. We evaluated covariate effects on all model parameters and performed clinical trial simulations to predict the fibrosis progression rate for external clinical cohorts. All parameters were estimated with good precision. Age and diagnosis of type 2 diabetes (T2D) were found to be significant predictors in the model. Increase in hepatic steatosis between visits was the most important predictor for progression of fibrosis. Fibrosis progression rate (FPR) was twofold higher for fibrosis stages 0 and 1 (F0-1) compared to fibrosis stage 2 and 3 (F2-3). A twofold increase in FPR was observed for T2D. A two-point steatosis worsening increased the FPR 11-fold. Predicted fibrosis progression was in good agreement with data from external clinical cohorts. Our fibrosis progression model shows that patient selection, particularly initial fibrosis stage distribution, can significantly impact fibrosis progression and as such the window for assessing drug efficacy in clinical trials. Our work highlights the increase in hepatic steatosis as the most important factor in increasing FPR, emphasizing the importance of well-defined lifestyle advise for reducing variability in NASH progression during clinical trials.

Identification of key genes and functional enrichment analysis of liver fibrosis in nonalcoholic fatty liver disease through weighted gene co-expression network analysis

Nonalcoholic fatty liver disease (NAFLD) is a common type of chronic liver disease, with severity levels ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis (NASH). The extent of liver fibrosis indicates the severity of NASH and the risk of liver cancer. However, the mechanism underlying NASH development, which is important for early screening and intervention, remains unclear. Weighted gene co-expression network analysis (WGCNA) is a useful method for identifying hub genes and screening specific targets for diseases. In this study, we utilized an mRNA dataset of the liver tissues of patients with NASH and conducted WGCNA for various stages of liver fibrosis. Subsequently, we employed two additional mRNA datasets for validation purposes. Gene set enrichment analysis (GSEA) was conducted to analyze gene function enrichment. Through WGCNA and subsequent analyses, complemented by validation using two additional datasets, we identified five genes (BICC1, C7, EFEMP1, LUM, and STMN2) as hub genes. GSEA analysis indicated that gene sets associated with liver metabolism and cholesterol homeostasis were uniformly downregulated. BICC1, C7, EFEMP1, LUM, and STMN2 were identified as hub genes of NASH, and were all related to liver metabolism, NAFLD, NASH, and related diseases. These hub genes might serve as potential targets for the early screening and treatment of NASH.

Insights into the role of vitamin D in targeting the culprits of non-alcoholic fatty liver disease

Vitamin D (VD) is a secosteroid hormone that is renowned for its crucial role in phospho-calcium homeostasis upon binding to the nuclear vitamin D receptor (VDR). Over and above, the pleiotropic immunomodulatory, anti-inflammatory, and metabolic roles VD plays in different disease settings started to surface in the past few decades. On the other hand, a growing body of evidence suggests a correlation between non-alcoholic fatty liver disease (NAFLD) and its progressive inflammatory form non-alcoholic steatohepatitis (NASH) with vitamin D deficiency (VDD) owing to the former's ingrained link with obesity and metabolic syndrome. Accordingly, a better understanding of the contribution of disrupted VDR signalling to NAFLD incidence and progression would provide further insights into its diagnosis, treatment modalities, and prognosis. This is especially significant as, hitherto, no drug for NAFLD has been approved. This review, therefore, sought to set forth the likely contribution of VDR signalling in NAFLD and how it might influence its multiple drivers.

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.

Trajectories of Liver Fibrosis and Gene Expression Profiles in Nonalcoholic Fatty Liver Disease Associated With Diabetes

Understanding the mechanisms linking steatosis to fibrosis is needed to establish a promising therapy against nonalcoholic fatty liver disease (NAFLD). The aim of this study was to clarify clinical features and hepatic gene expression signatures that predict and contribute to liver fibrosis development during the long-term real-world histological course of NAFLD in subjects with and without diabetes. A pathologist scored 342 serial liver biopsy samples from 118 subjects clinically diagnosed with NAFLD during a 3.8-year (SD 3.45 years, maximum 15 years) course of clinical treatment. At the initial biopsy, 26 subjects had simple fatty liver, and 92 had nonalcoholic steatohepatitis (NASH). In the trend analysis, the fibrosis-4 index (P < 0.001) and its components at baseline predicted the future fibrosis progression. In the generalized linear mixed model, an increase in HbA1c, but not BMI, was significantly associated with fibrosis progression (standardized coefficient 0.17 [95% CI 0.009-0.326]; P = 0.038) for subjects with NAFLD and diabetes. In gene set enrichment analyses, the pathways involved in zone 3 hepatocytes, central liver sinusoidal endothelial cells (LSECs), stellate cells, and plasma cells were coordinately altered in association with fibrosis progression and HbA1c elevation. Therefore, in subjects with NAFLD and diabetes, HbA1c elevation was significantly associated with liver fibrosis progression, independent of weight gain, which may be a valuable therapeutic target to prevent the pathological progression of NASH. Gene expression profiles suggest that diabetes-induced hypoxia and oxidative stress injure LSECs in zone 3 hepatocytes, which may mediate inflammation and stellate cell activation, leading to liver fibrosis.

ARTICLE HIGHLIGHTS

It remains uncertain how diabetes and obesity contribute to histological courses of nonalcoholic fatty liver disease (NAFLD). Clinical features and gene expression signatures that predict or are associated with future liver fibrosis development were assessed in a serial liver biopsy study of subjects with NAFLD. An increase in HbA1c, but not BMI, was associated with liver fibrosis progression in the generalized linear mixed model. Considering hepatic gene set enrichment analyses, diabetes may enhance liver fibrosis via injuring central liver sinusoidal endothelial cells that mediate inflammation and stellate cell activation during NAFLD development.

Nonalcoholic liver disease: Epidemiology, risk factors, natural history, and management strategies

Nonalcoholic fatty liver disease (NAFLD) is now the most common chronic liver disease worldwide and a leading indication for liver transplantation in the United States. NAFLD encompasses a heterogeneous clinicopathologic spectrum, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis, and progressive fibrosis, which can lead to end-stage liver disease including cirrhosis and hepatocellular cancer. Predictive models suggest that over 100 million adults in the United States will have NAFLD by 2030, representing over a third of the population. In this manuscript, we provide an overview of NAFLD risk factors, natural history (including hepatic and extra-hepatic outcomes), diagnosis, and current management strategies.

The efficacy of L-carnitine in patients with nonalcoholic steatohepatitis and concomitant obesity

BACKGROUND

In light of the high prevalence of nonalcoholic fatty liver disease and obesity, treatment options for nonalcoholic steatohepatitis are of particular interest. The purpose of the study is to assess the efficacy of L-carnitine and its effects on the functional state of the liver, as well as on lipid and carbohydrate metabolism in patients with nonalcoholic steatohepatitis and concomitant obesity.

METHODS

People in the control group followed a hypocaloric diet and received 1 tablet of simvastatin 20 mg once a day and 2 capsules of essential phospholipids 600 mg three times a day for 90 days. People in the experimental group followed a hypocaloric diet and received 1 tablet of simvastatin 20 mg once a day and L-carnitine 10 mL orally two times a day for 90 days.

RESULTS

L-carnitine normalized the blood lipid profile of subjects, as demonstrated by a significant decrease in the blood levels of total cholesterol, triglycerides, low-density lipoproteins, atherogenic index, and insulin resistance. The use of L-carnitine in patients with nonalcoholic steatohepatitis and concomitant obesity contributes to the steady reduction of the main clinical and biochemical symptoms of nonalcoholic steatohepatitis.

CONCLUSIONS

L-carnitine produces positive effects on the blood lipid profile and carbohydrate metabolism.

Innovative Therapeutic Approaches in Non-Alcoholic Fatty Liver Disease: When Knowing Your Patient Is Key

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disorders ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic steatosis may result from the dysfunction of multiple pathways and thus multiple molecular triggers involved in the disease have been described. The development of NASH entails the activation of inflammatory and fibrotic processes. Furthermore, NAFLD is also strongly associated with several extra-hepatic comorbidities, i.e., metabolic syndrome, type 2 diabetes mellitus, obesity, hypertension, cardiovascular disease and chronic kidney disease. Due to the heterogeneity of NAFLD presentations and the multifactorial etiology of the disease, clinical trials for NAFLD treatment are testing a wide range of interventions and drugs, with little success. Here, we propose a narrative review of the different phenotypic characteristics of NAFLD patients, whose disease may be triggered by different agents and driven along different pathophysiological pathways. Thus, correct phenotyping of NAFLD patients and personalized treatment is an innovative therapeutic approach that may lead to better therapeutic outcomes.

Non-alcoholic fatty liver disease is associated with an increased risk of type 2 diabetes

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease worldwide and represents the leading cause of liver-related morbidity and mortality. Its all-cause mortality is often driven by co-existing metabolic diseases such as type 2 diabetes (T2DM), which share many pathophysiological characteristics. The risk of developing T2DM among NAFLD patients in Germany is only poorly described.

METHODS

A cohort of 17 245 NAFLD patients and a propensity score-matched cohort of equal size were identified from the Disease Analyzer database (IQVIA) between 2005 and 2020. The incidence of T2DM was evaluated as a function of NAFLD during a 5-year study period using Cox-regression models.

RESULTS

Within 5 years of the index date, 18.8% and 11.7% of individuals with and without NAFLD were diagnosed with T2DM ( P  < 0.001). Regression analysis revealed a hazard ratio of 1.77 [95% confidence interval (CI), 1.68-1.88] for the development of T2DM among NAFLD patients. Subgroup analyses confirmed this association for all age groups (18-50, 51-60, 61-70 and >70 years), male and female patients, as well as normal weight (BMI < 25 kg/m 2 ), overweighted (BMI 25-30 kg/m 2 ) and obese (BMI > 30 kg/m 2 ) patients.

CONCLUSION

Our data revealed a significantly increased incidence of T2DM among NAFLD patients in Germany. Given the dramatically increasing global relevance of NAFLD, we believe that prevention and regular screening programs for T2DM in NAFLD patients could help to reduce its high mortality and morbidity in the future.

Outcomes of fatty liver disease with and without metabolic comorbidities and risk factors for mortality

Background and Aim

As the clinical course of metabolic-associated fatty liver disease (MAFLD) is unclear, we compared the clinical courses of MAFLD and non-alcoholic FLD (NAFLD).

Methods

Asian FLD patients (n = 987) from 1991 to 2021 (biopsy-proven in 939) were enrolled. The patients were divided into NAFLD (N-alone, n = 92), both MAFLD and N (M&N, n = 785), and M-alone (n = 90) groups. Clinical features, complications, and survival rates were compared among the three groups. Risk factors of mortality were subjected to Cox regression analysis.

Results

The N-alone group patients were significantly younger (N alone, M&N, and M alone: 50, 53, and 57 years, respectively), more frequently male (54.3%, 52.6%, and 37.8%), and had a low body mass index (BMI, 23.1, 27.1, and 26.7 kg/m²) and FIB-4 index (1.20, 1.46, and 2.10). Hypopituitarism (5.4%) and hypothyroidism (7.6%) were significantly observed in the N-alone group. Hepatocellular carcinoma (HCC) developed in 0.0%, 4.2%, and 3.5% of the cases, and extrahepatic malignancies in 6.8%, 8.4%, and 4.7% of the cases, respectively, with no significant differences. The cardiovascular event rate was significantly higher in the M-alone group (1, 37, and 11 cases, P < 0.01). Survival rates were similar among the three groups. Risk factors for mortality were age and BMI in the N-alone group; age, HCC, alanine transaminase, and FIB-4 in the M&N group; and FIB-4 in the M-alone group.

Conclusion

Different risk factors for mortality may exist among the FLD groups.

Disease State Transition Probabilities Across the Spectrum of NAFLD: A Systematic Review and Meta-Analysis of Paired Biopsy or Imaging Studies

BACKGROUND & AIMS

We conducted a meta-analysis to summarize the rates of progression to and regression of nonalcoholic fatty liver (NAFL), nonalcoholic steatohepatitis (NASH), and fibrosis in adults with nonalcoholic fatty liver disease (NAFLD).

METHODS

We searched PubMed/Medline and 4 other databases from 1985 through 2020. We included observational studies and randomized controlled trials in any language that used liver biopsy or imaging to diagnose NAFLD in adults with a follow-up period ≥48 weeks. Rates were calculated as incident cases per 100 person-years and pooled using the random-effects Poisson distribution model. Heterogeneity was assessed using the I2 statistic.

RESULTS

We screened 9744 articles and included 54 studies involving 26,738 patients. Among observational studies, 20% of healthy adults developed NAFL (incidence rate, 4.8/100 person-years) while 21% of people with fatty liver had resolution of NAFL (incidence rate, 2.4/100 person-years) after a median of approximately 4.5 years. In addition, 31% of patients developed NASH after 4.7 years (incidence rate, 7.4/100 person-years), whereas in 29% of those with NASH, resolution occurred after a median of 3.5 years (incidence rate, 5.1/100 person-years). Time to progress by 1 fibrosis stage was 9.9, 10.3, 13.3, and 22.2 years for F0, F1, F2, and F3, respectively. Time to regress by 1 stage was 21.3, 12.5, 20.4, and 40.0 years for F4, F3, F2, and F1, respectively. Rates estimated from randomized controlled trials were higher than those from observational studies.

CONCLUSIONS

In our meta-analysis, progression to NASH was more common than regression from NASH. Rates of fibrosis progression were similar across baseline stage, but patients with advanced fibrosis were more likely to regress than those with mild fibrosis.

The utility of non-invasive tests to assess advanced fibrosis in Asian subjects with chronic hepatitis B and concomitant hepatic steatosis

BACKGROUND

Chronic hepatitis B (CHB) is endemic to Asia and is a leading cause of liver-related morbidity. The prevalence of concomitant CHB and hepatic steatosis (HS) is increasing in Asia. Non-invasive tests (NITs) including FIB-4, NFS and APRI assess fibrosis in populations with a single aetiology, but not in subjects with concomitant CHB and HS.

AIM

To explore the accuracy of NITs in predicting advanced fibrosis in patients with concomitant CHB and HS.

METHODOLOGY

This multicentre study of CHB patients who underwent liver biopsy explored clinical characteristics of these subjects, stratified by presence of HS. Fibrosis scores from NITs were compared against histological fibrosis stage in CHB subjects with and without HS.

RESULTS

2262 subjects were enrolled, 74.5% were males, and the mean age was 39.5 years ±11.8 SD. 984 (44.4%) had HS, 824 (36.4%) had advanced fibrosis. In the CHB group, the AUROC for advanced fibrosis were 0.65 (95% CI 0.62-0.69) for FIB-4 and 0.63 (95% CI 0.60-0.66) for APRI. The specificities were 0.94 for FIB-4 greater than 3.25 and 0.81 for APRI greater than 1.5. In the CHBHS group, the AUROC for advanced fibrosis were 0.67 (95% CI 0.63-0.71) for FIB-4, 0.60 (95% CI 0.56-0.64) for APRI and 0.65 (95% CI 0.61-0.69) for NFS. The specificities were 0.95 for FIB-4 greater than 3.25, 0.88 for APRI greater than 1.5 and 0.99 for NFS greater than 0.675.

CONCLUSION

The performance of NITs to exclude advanced fibrosis did not differ greatly regardless of HS. FIB-4 and NFS have the best negative predictive values of 0.80 and 0.78, respectively, to exclude advanced fibrosis in CHBHS subjects.

Comparative Analysis of Global Hepatic Gene Expression in Adolescents and Adults with Non-alcoholic Fatty Liver Disease

Introduction

To gain insights into the mechanisms underlying distinct nonalcoholic fatty liver disease (NAFLD) histological phenotypes between children and adults, we compared hepatic gene expression profiles associated with NAFLD phenotypes between the two age groups.

Methods

Histological characteristics of intra-operative liver biopsies from adolescents and adults undergoing bariatric surgery were assessed by the same pathologist using the non-alcoholic steatohepatitis (NASH) Clinical Research Network scoring system. Hepatic gene expression was measured by microarray analysis. Transcriptomic signatures of histological phenotypes between the two groups were compared, with significance defined as p-value <0.05 and a fold change >1.5.

Results

In 67 adolescents and 76 adults, distribution of histological phenotypes was: not-NAFLD (controls) 51% vs 39%, NAFL 39% vs 37%, and NASH 10% vs 24%, respectively. There were 279 differentially expressed genes in adolescents and 213 in adults with NAFLD vs controls. In adolescents, transcriptomes for NAFL vs controls, and borderline vs definite NASH were undifferentiable, whereas in adults, NAFL and borderline NASH demonstrated a transcriptomic gradient between controls and definite NASH. When applied to adolescents, significant adult genes discriminated borderline and definite NASH from control and NAFL, but the majority of significant pediatric genes were not portable to adults. Genes associated with NASH in adolescents and adults showed some ontological consistency but notable differences.

Conclusions

There is some similarity but major differences in the transcriptomic profiles associated with NAFLD between adolescents and adults with severe obesity. These data suggest different mechanisms contribute to the pathogenesis of NAFLD severity at different stages in life.

Association between Cardiovascular Disease and Liver Disease, from a Clinically Pragmatic Perspective as a Cardiologist

Cardiovascular diseases and liver diseases are closely related. Non-alcoholic fatty liver disease has the same risk factors as those for atherosclerotic cardiovascular disease and may also be a risk factor for atherosclerotic cardiovascular disease on its own. Heart failure causes liver fibrosis, and liver fibrosis results in worsened cardiac preload and congestion. Although some previous reports regard the association between cardiovascular diseases and liver disease, the management strategy for liver disease in patients with cardiovascular diseases is not still established. This review summarized the association between cardiovascular diseases and liver disease. In patients with non-alcoholic fatty liver disease, the degree of liver fibrosis progresses with worsening cardiovascular prognosis. In patients with heart failure, liver fibrosis could be a prognostic marker. Liver stiffness assessed with shear wave elastography, the fibrosis-4 index, and non-alcoholic fatty liver disease fibrosis score is associated with both liver fibrosis in patients with liver diseases and worse prognosis in patients with heart failure. With the current population ageing, the importance of management for cardiovascular diseases and liver disease has been increasing. However, whether management and interventions for liver disease improve the prognosis of cardiovascular diseases has not been fully understood. Future investigations are needed.

Incidence and Predictors of Liver-Related Events in Patients With Nonalcoholic Fatty Liver Disease

Background

Nonalcoholic fatty liver disease (NAFLD) is the commonest type of liver disease worldwide. We aimed to assess the incidence and predictors of liver-related events (LREs) and mortality in NAFLD patients.

Methods

NAFLD patients (n = 957) evaluated between January 2000 and November 2021 were included. Patients were categorised as noncirrhosis (NC), compensated cirrhosis (CC) and decompensated cirrhosis (DC), and the incidence of LRE and mortality were estimated and compared.

Results

The proportions of NC, CC and DC were 87.8% (n = 840), 8.8% (n = 84) and 3.4% (n = 33), respectively. The median follow-up duration was 3.9 (3.0-5.7) years, and the total cumulative duration was 4633 person-years. The incidence of LRE per 100 person-years was 0.14, 2.72 and 10.24 in patients with NC, CC and DC, respectively. The incidence of mortality was 0.12, 1.05 and 4.24 per 100 person-years, respectively, in the 3 groups. The causes of mortality in the 3 groups were liver related in 1/5 (20%), 3/4 (75%) and 6/9 (66.7%), respectively. Overall, the mortality rate was higher in those with diabetes than those without diabetes (log-rank P value = 0.005). On further analysis, diabetes was associated with poor outcomes only in NC group (log-rank P value = 0.036), and not in CC (log-rank P value = 0.353) or DC groups (log-rank P value = 0.771). On multivariate Cox proportional hazard analysis, age (hazard ratio [HR] 1.070), hypertension (HR 4.361) and DC (HR 15.036) were independent predictors of poor outcomes. Liver stiffness measurement, bilirubin, CC and DC were independent predictors of LRE.

Conclusion

In our study of NAFLD from India, the incidence of LRE was found to be similar to that seen in Western studies. In NC NAFLD, diabetes was associated with poor outcomes.

The effects of electronic-based lifestyle interventions on nonalcoholic fatty liver disease: A systematic review

Objective

Lifestyle interventions are increasingly becoming an integrated part of nonalcoholic fatty liver disease (NAFLD) management. Electronic lifestyle interventions may be able to expand the access and utility of this approach. This study aimed to synthesize the evidence for the effects of electronic-based lifestyle interventions on weight, anthropometric, and liver enzyme measurements in patients with NAFLD.

Methods

Medline, Scopus, and Web of Science were searched up to February 2023. Clinical trials investigating the effects of electronic lifestyle interventions on weight, body mass index (BMI), waist circumference (WC), and liver enzymes in NAFLD patients were reviewed. After reviewing full-text articles, seven clinical trials were included in the systematic review.

Results

Two articles included telephone calls, one was based on text messaging, two studies were based on web-based lifestyle modifications, and two used mobile apps. Except for one, all other six studies indicated a significant impact on weight loss. BMI was reported in six of seven studies. Except for one, BMI was significantly reduced in the group receiving e-health. WC was reported in four studies, which indicated a significant reduction in the e-health intervention group. Alanine transaminase (ALT) was reported in all the included studies. Except for two, others demonstrated a significant improvement in ALT in the e-health intervention groups. As reported in four studies, Aspartate transaminase (AST) significantly decreased in the group receiving e-health interventions, except in one study.

Conclusions

The results support applying electronic lifestyle interventions in NAFLD patients to reduce weight, BMI, WC, AST, and ALT.

Multi-Channel Metabolomics Analysis Identifies Novel Metabolite Biomarkers for the Early Detection of Fatty Liver Disease in Dairy Cows

Fatty liver disease, a type of metabolic disorder, frequently occurs in dairy cows during the parturition period, causing a high culling rate and, therefore, considerable economic losses in the dairy industry owing to the lack of effective diagnostic methods. Here, metabolite biomarkers were identified and validated for the diagnosis of metabolic disorders. A total of 58 participant cows, including severe fatty liver disease and normal control groups, in the discovery set (liver biopsy tested, n = 18), test set (suspected, n = 20) and verification set (liver biopsy tested, n = 20), were strictly recruited and a sample collected for their feces, urine, and serum. Non-targeted GC-MS-based metabolomics methods were used to characterize the metabolite profiles and to screen in the discovery set. Eventually, ten novel biomarkers involved in bile acid, amino acid, and fatty acid were identified and validated in the test set. Each of them had a higher diagnostic ability than the traditional serum biochemical indicators, with an average area under the receiver operating characteristic curve of 0.830 ± 0.0439 (n = 10) versus 0.377 ± 0.182 (n = 9). Especially, combined biomarker panels via different metabolic pipelines had much better diagnostic sensitivity and specificity than every single biomarker, suggesting their powerful utilization potentiality for the early detection of fatty liver disease. Intriguingly, the serum biomarkers were confirmed perfectly in the verification set. Moreover, common biological pathways were found to be underlying the pathogenesis of fatty liver syndrome in cattle via different metabolic pipelines. These newly-discovered and non-invasive metabolic biomarkers are meaningful in reducing the high culling rate of cows and, therefore, benefit the sustainable development of the dairy industry.

Non-invasive diagnosis and staging of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic manifestation of the metabolic syndrome and is characterized by ectopic accumulation of triglycerides in the cytoplasm of hepatocytes, i.e., steatosis. NAFLD has become the most common chronic liver disease, with an estimated global prevalence of 25%. Although the majority of NAFLD patients will never experience liver-related complications, the progressive potential of NAFLD is indisputable, with 5-10% of subjects progressing to cirrhosis, end-stage liver disease, or hepatocellular carcinoma. NAFLD patients with advanced fibrosis are at the highest risk of developing cardiovascular and cirrhosis-related complications. Liver biopsy has hitherto been considered the reference method for evaluation of hepatic steatosis and fibrosis stage. Given the limitations of biopsy for widescale screening, non-invasive tests (NITs) for assessment of steatosis and fibrosis stage, including serum-based algorithms and ultrasound- and magnetic resonance-based methods, will play an increasing role in the management of NAFLD patients. This comprehensive review presents the advantages and limitations of NITs for identification of steatosis and advanced fibrosis in NAFLD. The clinical implications of using NITs to identify and manage NAFLD patients are also discussed.

Increased Adherence to the Mediterranean Diet after Lifestyle Intervention Improves Oxidative and Inflammatory Status in Patients with Non-Alcoholic Fatty Liver Disease

Background: A Mediterranean diet (MedDiet) is recommended as a therapy for non-alcoholic fatty liver disease (NAFLD) because there is no specific pharmacological treatment for this disease. Objective: To assess the relationship between the adherence to the Mediterranean diet and the intrahepatic fat content (IFC), levels of oxidative stress, and inflammation biomarkers after a 6-month lifestyle intervention in NAFLD patients. Methods: Patients diagnosed with NAFLD (n = 60 adults; 40–60 years old) living in the Balearic Islands, Spain, were classified into two groups, according to the adherence to the MedDiet after 6 months of lifestyle intervention. Anthropometry, blood pressure, IFC, maximal oxygen uptake, and pro/antioxidant and inflammatory biomarkers were measured in plasma and in PBMCs before and after the intervention. Results: Reductions in weight, body mass index, IFC, blood pressure levels, circulating glucose, glycosylated hemoglobin, and markers of liver damage—aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and cytokeratin 18 (CK-18)—were observed after the intervention. The highest reductions were observed in the group with the best adherence to the MedDiet. A significant improvement in cardiorespiratory fitness was also observed in the group with a higher adherence. The activities of catalase in plasma and catalase and superoxide dismutase in blood mononuclear cells increased only in the group with a higher adherence, as well as the catalase gene expression in the blood mononuclear cells. The plasma levels of malondialdehyde and myeloperoxidase decreased, and resolvin-D1 increased in both groups after the intervention, whereas interleukin-6 levels decreased only in the group with a higher adherence to the MedDiet. Conclusions: A greater adherence to the MedDiet is related to greater improvements in IFC, cardiorespiratory fitness, and pro-oxidative and proinflammatory status in NAFLD patients after a 6-month nutritional intervention based on the MedDiet.

Hepatic patatin-like phospholipase domain-containing 3 levels are increased in I148M risk allele carriers and correlate with NAFLD in humans

In nonalcoholic fatty liver disease (NAFLD) the patatin‐like phospholipase domain‐containing 3 (PNPLA3) rs738409 variant is a contributor. In mice, the Pnpla3 148M variant accumulates on lipid droplets and probably leads to sequestration of a lipase cofactor leading to impaired mobilization of triglycerides. To advance our understanding of the localization and abundance of PNPLA3 protein in humans, we used liver biopsies from patients with NAFLD to investigate the link to NAFLD and the PNPLA3 148M genotype. We experimentally qualified an antibody against human PNPLA3. Hepatic PNPLA3 protein fractional area and localization were determined by immunohistochemistry in biopsies from a well‐characterized NAFLD cohort of 67 patients. Potential differences in hepatic PNPLA3 protein levels among patients related to degree of steatosis, lobular inflammation, ballooning, and fibrosis, and PNPLA3 I148M gene variants were assessed. Immunohistochemistry staining in biopsies from patients with NAFLD showed that hepatic PNPLA3 protein was predominantly localized to the membranes of small and large lipid droplets in hepatocytes. PNPLA3 protein levels correlated strongly with steatosis grade (p = 0.000027) and were also significantly higher in patients with lobular inflammation (p = 0.009), ballooning (p = 0.022), and significant fibrosis (stage 2–4, p = 0.014). In addition, PNPLA3 levels were higher in PNPLA3 rs738409 148M (CG, GG) risk allele carriers compared to 148I (CC) nonrisk allele carriers (p = 0.0029). Conclusion: PNPLA3 protein levels were associated with increased hepatic lipid content and disease severity in patients with NAFLD and were higher in PNPLA3 rs738409 (148M) risk allele carriers. Our hypothesis that increased hepatic levels of PNPLA3 may be part of the pathophysiological mechanism of NAFLD is supported.

The role of microbiota in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most frequent liver disease worldwide. Gut microbiota can play a role in the pathogenesis of NAFLD since dysbiosis is associated with reduced bacterial diversity, altered Firmicutes/Bacteroidetes ratio, a relative abundance of alcohol-producing bacteria, or other specific genera. Changes can promote disrupted intestinal barrier and hyperpermeability, filtration of bacterial products, activation of the immune system, and pro-inflammatory changes in the intestine, in the liver, and at a systemic level. Microbiota-derived molecules can contribute to the steatogenic effects. The link between gut dysbiosis and NAFLD, however, is confused by several factors which include age, BMI, comorbidities, dietary components, and lifestyle. The role of toxic chemicals in food and water requires further studies in both gut dysbiosis and NAFLD. We can anticipate that gut microbiota manipulation will represent a potential therapeutic tool to delay or reverse the progression of NAFLD, paving the way to primary prevention measures.

Repeated measurements of non-invasive fibrosis tests to monitor the progression of non-alcoholic fatty liver disease: A long-term follow-up study

BACKGROUND AND AIMS

The presence of advanced hepatic fibrosis is the prime marker for the prediction of liver-related complications in non-alcoholic fatty liver disease (NAFLD). Blood-based non-invasive tests (NITs) have been developed to evaluate fibrosis and identify patients at risk. Current guidelines propose monitoring the progression of NAFLD using repeated NITs at 2-3-year intervals. The aim of this study was to evaluate the association of changes in NITs measured at two time points with the progression of NAFLD.

METHODS

We retrospectively included NAFLD patients with NIT measurements in whom the baseline hepatic fibrosis stage had been assessed by biopsy or transient elastography (TE). Subjects underwent follow-up visits at least 1 year from baseline to evaluate the progression of NAFLD. NAFLD progression was defined as the development of end-stage liver disease or fibrosis progression according to repeat biopsy or TE. The following NITs were calculated at baseline and follow-up: Fibrosis-4 (FIB-4), NAFLD fibrosis score (NFS), aspartate aminotransferase to platelet ratio index (APRI) and dynamic aspartate-to-alanine aminotransferase ratio (dAAR).

RESULTS

One hundred and thirty-five patients were included with a mean follow-up of 12.6 ± 8.5 years. During follow-up, 41 patients (30%) were diagnosed with progressive NAFLD. Change in NIT scores during follow-up was significantly associated with disease progression for all NITs tested except for NFS. However, the diagnostic precision was suboptimal with area under the receiver operating characteristics 0.56-0.64 and positive predictive values of 0.28-0.36 at sensitivity fixed at 90%.

CONCLUSIONS

Change of FIB-4, NFS, APRI, and dAAR scores is only weakly associated with disease progression in NAFLD. Our findings do not support repeated measurements of these NITs for monitoring the course of NAFLD.

Clinical outcome of non-alcoholic fatty liver disease: an 11-year follow-up study

OBJECTIVES

To clarify non-alcoholic fatty liver disease (NAFLD) prevalence, risk factors and clinical outcome in an exemplary Chinese population, a cohort of company employees was followed up for 11 years.

DESIGN

Retrospective cohort study.

SETTING

Between 2006 and 2016 in Ning bo, China.

PARTICIPANTS

13 032 company employees.

RESULTS

Over 11 years, the prevalence of NAFLD increased from 17.2% to 32.4% (men 20.5%-37% vs women 9.8%-22.2%). Male peak prevalence was between 40 and 60 years of age, whereas highest prevalence in women was at an age of 60 years and older. Logistic and Cox regression revealed 16 risk factors, including body mass index (BMI), albumin, white blood cell, triglycerides (TG), high-density lipoprotein, glutamyl transpeptidase, alanine transaminase, creatinine, urea acid, glucose, systolic blood pressure, diastolic blood pressure, blood sedimentation, haemoglobin, platelet and apolipoprotein B2 (p<0.05 for all factors). The area under the curve of these variables for NAFLD is 0.88. However, cause-effect analyses showed that only BMI, gender and TG directly contributed to NAFLD development. Over an 11-year follow-up period, 12.6%, 37.7% and 14.2% of male patients with NAFLD and 11.6%, 44.7% and 22.6% of female patients with NAFLD developed diabetes, hypertension and hyperuricaemia, respectively. Except one male patient who developed cirrhosis, no patients with NAFLD progressed into severe liver disease.

CONCLUSION

Diabetes, hypertension and hyperuricaemia are the main clinical outcomes of NAFLD. Eleven years of NAFLD are not sufficient to cause severe liver disease. Age and obesity are direct risk factors for NAFLD. BMI, gender and TG are three parameters directly reflecting the occurrence of NAFLD.

Influence of Type 2 Diabetes in the Association of PNPLA3 rs738409 and TM6SF2 rs58542926 Polymorphisms in NASH Advanced Liver Fibrosis

Nonalcoholic steatohepatitis (NASH) is a leading cause of cirrhosis in western countries. Insulin resistance (IR), type 2 diabetes (T2D), and the polymorphisms patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 and transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 are independent risk factors of NASH. Nevertheless, little is known about the interaction between IR and T2D with these polymorphisms in the pathogenesis of NASH and the development of advanced fibrosis. Thus, our study aimed to investigate this relationship. This is a cross-sectional study including NASH patients diagnosed by liver biopsy, at the Vall d’Hebron University Hospital. A total of 140 patients were included (93 T2D, 47 non-T2D). T2D (OR = 4.67; 95%CI 2.13−10.20; p < 0.001), PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphisms (OR = 3.94; 95%CI 1.63−9.54; p = 0.002) were independently related with advanced liver fibrosis. T2D increased the risk of advance fibrosis on top of the two polymorphisms (OR = 14.69; 95%CI 3.03−77.35; p = 0.001 for PNPLA3 rs738409 and OR = 11.45; 95%CI 3.16−41.55; p < 0.001 for TM6SF2 rs58542926). In non-T2D patients, the IR (HOMA-IR ≥ 5.2, OR = 14.33; 95%CI 2.14−18.66; p = 0.014) increased the risk of advanced fibrosis when the polymorphisms were present (OR = 19.04; 95%CI 1.71−650.84; p = 0.042). The T2D and IR status increase the risk of advanced fibrosis in patients with NASH carrying the PNPLA3 rs738409 and/or TM6SF2 rs58542926 polymorphisms, respectively.

Healthcare practitioners' diagnostic and treatment practice patterns of nonalcoholic fatty liver disease in Poland: a cross-sectional survey

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) awareness is low. NAFLD diagnosis and management by gastroenterologists (GEs) and general practitioners (GPs) in Poland were evaluated.

METHODS

RESTORE was an observational, noninterventional, retrospective cross-sectional survey performed among GEs and GPs with at least 3 years' experience. Computer-assisted web interviews were completed. GEs provided information from patient records.

RESULTS

Mean experience was 14.2 (95 GEs) and 22.6 (115 GPs) years. Mean patient numbers with liver disorders consulted per month were 36 (13%; GEs) and 51 (6%; GPs); ~50% were patients with NAFLD. All GEs/GPs used ultrasound; most evaluated transaminases and gamma-glutamyl transferase. More GEs used other imaging techniques and a larger spectrum of laboratory tests than GPs. Physician-identified NAFLD key symptoms were similar for GEs/GPs. GEs noticed less obvious symptoms (abdominal discomfort, drowsiness, fatigability, lack of energy) vs. GPs (abdominal pain/discomfort, dyspepsia). Common comorbidities in NAFLD were similar in GE/GP responses. NAFLD interventions by GEs/GPs (% patients) were diet/lifestyle/pharmacological interventions (54%/59%), diet/lifestyle changes alone (41%/31%) or pharmacological interventions alone (5%/10%). The top three criteria for supportive pharmacological selection were efficacy, tolerability and quality of life improvement for GEs/GPs. The five supportive treatments most commonly prescribed by GEs/GPs were essential phospholipids, ursodeoxycholic acid, timonacic, silybinin/silymarin and ornithine + choline. Information from patient records (n = 380) confirmed GEs responses.

CONCLUSIONS

NAFLD is not a silent disease as physicians and patients reported many, albeit nonspecific, symptoms. This cross-sectional survey provides important insights into clinical management of NAFLD by GEs and GPs in Poland.

Non-alcoholic fatty liver disease (NAFLD): a review of pathophysiology, clinical management and effects of weight loss

Given the increasing prevalence of diabetes and obesity worldwide, the deleterious effects of non-alcoholic fatty liver disease (NAFLD) are becoming a growing challenge for public health. NAFLD is the most common chronic liver disease in the Western world. NAFLD is closely associated with metabolic disorders, including central obesity, dyslipidaemia, hypertension, hyperglycaemia and persistent abnormalities of liver function tests.In general NAFLD is a common denominer for a broad spectrum of damage to the liver, which can be due to hepatocyte injury, inflammatory processes and fibrosis. This is normally seen on liver biopsy and can range from milder forms (steatosis) to the more severe forms (non-alcoholic steatohepatitis (NASH), advanced fibrosis, cirrhosis and liver failure). In these patients, advanced fibrosis is the major predictor of morbidity and liver-related mortality, and an accurate diagnosis of NASH and NAFLD is mandatory. Histologic evaluation with liver biopsy remains the gold standard to diagnose NAFLD. Diagnosis of NAFLD is defined as presence of hepatic steatosis, ballooning and lobular inflammation with or without fibrosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. Dietary recommendations and lifestyle interventions, weight loss, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established with promising results but are difficult to maintain. Pioglitazone and vitamin E are recommended by guidelines in selected patients. This review gives an overview of NAFLD and its treatment options.

The advantages of physical exercise as a preventive strategy against NAFLD in postmenopausal women

BACKGROUND

The prevalence and severity of nonalcoholic fatty liver disease (NAFLD) increase in women after menopause. This narrative review discusses the causes and consequences of NAFLD in postmenopausal women and describes how physical activity can contribute to its prevention.

METHODS

The authors followed the narrative review method to perform a critical and objective analysis of the current knowledge on the topic. The Medical Subject Heading keywords 'physical exercise', 'menopause', 'hormone replacement therapy', 'estradiol' and 'NAFLD' were used to establish a conceptual framework. The databases used to collect relevant references included Medline and specialized high-impact journals.

RESULTS

Higher visceral adiposity, higher rate of lipolysis in adipose tissue after oestrogen drop and changes in the expression of housekeeping proteins involved in hepatic lipid management are observed in women after menopause, contributing to NAFLD. Excessive liver steatosis leads to hepatic insulin resistance, oxidative stress and inflammation, accelerating NAFLD progression. Physical activity brings beneficial effects against several postmenopausal-associated complications, including NAFLD progression. Aerobic and resistance exercises partially counteract alterations induced by metabolic syndrome in sedentary postmenopausal women, impacting NAFLD progression and severity.

CONCLUSIONS

With the increased global obesity epidemic in developing countries, NAFLD is becoming a severe problem with increased prevalence in women after menopause. Evidence shows that physical activity may delay NAFLD development and severity in postmenopausal women, although the prescription of age-appropriate physical activity programmes is advisable to assure the health benefits.

Synergistic and Detrimental Effects of Alcohol Intake on Progression of Liver Steatosis

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the most common liver disorders worldwide and the major causes of non-viral liver cirrhosis in the general population. In NAFLD, metabolic abnormalities, obesity, and metabolic syndrome are the driving factors for liver damage with no or minimal alcohol consumption. ALD refers to liver damage caused by excess alcohol intake in individuals drinking more than 5 to 10 daily units for years. Although NAFLD and ALD are nosologically considered two distinct entities, they show a continuum and exert synergistic effects on the progression toward liver cirrhosis. The current view is that low alcohol use might also increase the risk of advanced clinical liver disease in NAFLD, whereas metabolic factors increase the risk of cirrhosis among alcohol risk drinkers. Therefore, special interest is now addressed to individuals with metabolic abnormalities who consume small amounts of alcohol or who binge drink, for the role of light-to-moderate alcohol use in fibrosis progression and clinical severity of the liver disease. Evidence shows that in the presence of NAFLD, there is no liver-safe limit of alcohol intake. We discuss the epidemiological and clinical features of NAFLD/ALD, aspects of alcohol metabolism, and mechanisms of damage concerning steatosis, fibrosis, cumulative effects, and deleterious consequences which include hepatocellular carcinoma.

Intestinal Barrier and Permeability in Health, Obesity and NAFLD

The largest surface of the human body exposed to the external environment is the gut. At this level, the intestinal barrier includes luminal microbes, the mucin layer, gastrointestinal motility and secretion, enterocytes, immune cells, gut vascular barrier, and liver barrier. A healthy intestinal barrier is characterized by the selective permeability of nutrients, metabolites, water, and bacterial products, and processes are governed by cellular, neural, immune, and hormonal factors. Disrupted gut permeability (leaky gut syndrome) can represent a predisposing or aggravating condition in obesity and the metabolically associated liver steatosis (nonalcoholic fatty liver disease, NAFLD). In what follows, we describe the morphological-functional features of the intestinal barrier, the role of major modifiers of the intestinal barrier, and discuss the recent evidence pointing to the key role of intestinal permeability in obesity/NAFLD.

Pathophysiological Mechanisms in Non-Alcoholic Fatty Liver Disease: From Drivers to Targets

Non-alcoholic fatty liver disease (NAFLD) is characterized by the excessive and detrimental accumulation of liver fat as a result of high-caloric intake and/or cellular and molecular abnormalities. The prevalence of this pathological event is increasing worldwide, and is intimately associated with obesity and type 2 diabetes mellitus, among other comorbidities. To date, only therapeutic strategies based on lifestyle changes have exhibited a beneficial impact on patients with NAFLD, but unfortunately this approach is often difficult to implement, and shows poor long-term adherence. For this reason, great efforts are being made to elucidate and integrate the underlying pathological molecular mechanism, and to identify novel and promising druggable targets for therapy. In this regard, a large number of clinical trials testing different potential compounds have been performed, albeit with no conclusive results yet. Importantly, many other clinical trials are currently underway with results expected in the near future. Here, we summarize the key aspects of NAFLD pathogenesis and therapeutic targets in this frequent disorder, highlighting the most recent advances in the field and future research directions.

The Combination of MR Elastography and Proton Density Fat Fraction Improves Diagnosis of Nonalcoholic Steatohepatitis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is rapidly increasing worldwide. It is subdivided into nonalcoholic fatty liver (NAFL) and the more aggressive form, nonalcoholic steatohepatitis (NASH), which carries a higher risk of developing fibrosis and cirrhosis. There is currently no reliable non-invasive method for differentiating NASH from NAFL.

PURPOSE

To investigate the ability of magnetic resonance imaging (MRI)-based imaging biomarkers to diagnose NASH and moderate fibrosis as well as assess their repeatability.

STUDY TYPE

Prospective.

SUBJECTS

Sixty-eight participants (41% women) with biopsy-proven NAFLD (53 NASH and 15 NAFL). Thirty participants underwent a second MRI in order to assess repeatability.

FIELD STRENGTH/SEQUENCE

3.0 T; MR elastography (MRE) (a spin-echo echo-planar imaging [SE-EPI] sequence with motion-encoding gradients), MR proton density fat fraction (PDFF) and R2* mapping (a multi-echo three-dimensional gradient-echo sequence), T1 mapping (a single-point saturation-recovery technique), and diffusion-weighted imaging (SE-EPI sequence).

ASSESSMENT

Quantitative MRI measurements were obtained and assessed alone and in combination with biochemical markers (cytokeratin-18 [CK18] M30, alanine transaminase [ALT], and aspartate transaminase [AST]) using logistic regression models. Models that could differentiate between NASH and NAFL and between moderate to advanced fibrosis (F2-4) and no or mild fibrosis (F0-1), based on the histopathological results, were identified.

STATISTICAL TESTS

Independent samples t-test, Pearson's chi-squared test, area under the receiver operating characteristic curve (AUROC), Spearman's correlation, intra-individual coefficient of variation, and intraclass correlation coefficient (ICC). Statistical significance was set at P < 0.05.

RESULTS

There was a significant difference between the NASH and NAFL groups with liver stiffness assessed with MRE, CK18 M30, and ALT, with an AUROC of 0.74, 0.76, and 0.70, respectively. Both MRE and PDFF contributed significantly to a bivariate model for diagnosing NASH (AUROC = 0.84). MRE could significantly differentiate between F2-4 and F0-1 (AUROC = 0.74). A model combining MRE with AST improved the diagnosis of F2-4 (AUROC = 0.83). The ICC for repeatability was 0.94 and 0.99 for MRE and PDFF, respectively.

DATA CONCLUSION

MRE can potentially diagnose NASH and differentiate between fibrosis stages. Combining MRE with PDFF improves the diagnosis of NASH.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Proteome analysis identified proteins associated with mitochondrial function and inflammation activation crucially regulating the pathogenesis of fatty liver disease

Background

Fatty liver disease prevalently occurs in commercial postpartum dairies, resulting in a worldwide high culling rate because of their subsequent limitations of production and reproduction performance.

Results

Fatty liver-specific proteome and acetylome analysis revealed that energy metabolism suppression closely associated with mitochondrial dysfunction and inflammation activation were shown to be remarkable biological processes underlying the development of fatty liver disease, furthermore, acetylation modification of proteins could be one of the main means to modulate these processes. Twenty pivotal genetic factors/genes that differentially expressing and being acetylation modified in liver were identified and proposed to regulate the pathogenesis of fatty liver dairies. These proteins were confirmed to be differentially expressing in individual liver tissue, eight of which being validated via immunohistochemistry assay.

Conclusions

This study provided a comprehensive proteome and acetylome profile of fatty liver of dairy cows, and revealed potential important biological processes and essential regulators in the pathogenesis of fatty liver disease. Expectantly, understanding the molecular mechanisms of the pathogenesis of fatty liver disease in dairies, as an animal model of non-alcoholic fatty liver disease (NAFLD) in human beings, which is a clinico-pathologically defined process associated with metabolic syndrome, could inspire and facilitate the development of efficacious therapeutic drugs on NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07950-2.

Low hepatic manganese concentrations in patients with hepatic steatosis - A cohort study of copper, iron and manganese in liver biopsies

BACKGROUND AND AIMS

Hepatic steatosis is the most common histopathological finding on liver biopsy, with the most prevalent etiology being NAFLD. The pathogenesis of hepatic steatosis and NAFLD is multifactorial, however, studies on the importance of manganese in NAFLD are limited. We aimed to study hepatic manganese content, and other trace elements, in relation to hepatic steatosis in patients with chronic liver diseases of different etiology, mainly NAFLD.

METHODS

Patients with chronically elevated liver function tests underwent a diagnostic work-up, including routine blood tests and two liver biopsies. One of the biopsies was sent for histopathological evaluation, and the other for ultra-trace elemental determinations. Steatosis was graded using conventional histopathological methodology, and fat content was also quantitated in biopsy samples by measuring the steatotic area of the section using stereological point counting (SPC). Ultra-trace elemental analysis was utilized for determining manganese, iron, and copper using inductively coupled plasma sector field mass spectrometry (ICP-SFMS).

RESULTS

76 patients were included in the study. Hepatic manganese concentrations in patients with steatosis were lower than in patients without hepatic steatosis (3.8 ± 1.1 vs. 6.4 ± 1.8, P < 0.001). Similar results were seen for blood manganese levels and hepatic steatosis. We found a strong inverse correlation between steatosis grade and hepatic manganese content (ρ=-0.743, P < 0.001). Also, low levels of manganese independently predicted the presence of steatosis (aOR 0.07 [95%CI: 0.01-0.63]).

CONCLUSION

Patients with NAFLD, or other CLD and concomitant hepatic steatosis, showed lower levels of hepatic manganese content with increasing grade of steatosis.

The complex link between NAFLD and type 2 diabetes mellitus - mechanisms and treatments

Nonalcoholic fatty liver disease (NAFLD) has reached epidemic proportions worldwide. NAFLD and type 2 diabetes mellitus (T2DM) are known to frequently coexist and act synergistically to increase the risk of adverse (hepatic and extra-hepatic) clinical outcomes. T2DM is also one of the strongest risk factors for the faster progression of NAFLD to nonalcoholic steatohepatitis, advanced fibrosis or cirrhosis. However, the link between NAFLD and T2DM is more complex than previously believed. Strong evidence indicates that NAFLD is associated with an approximate twofold higher risk of developing T2DM, irrespective of obesity and other common metabolic risk factors. This risk parallels the severity of NAFLD, such that patients with more advanced stages of liver fibrosis are at increased risk of incident T2DM. In addition, the improvement or resolution of NAFLD (on ultrasonography) is associated with a reduction of T2DM risk, adding weight to causality and suggesting that liver-focused treatments might reduce the risk of developing T2DM. This Review describes the evidence of an association and causal link between NAFLD and T2DM, discusses the putative pathophysiological mechanisms linking NAFLD to T2DM and summarizes the current pharmacological treatments for NAFLD or T2DM that might benefit or adversely affect the risk of T2DM or NAFLD progression.

A Narrative Review on the Role of AMPK on De Novo Lipogenesis in Non-Alcoholic Fatty Liver Disease: Evidence from Human Studies

5′AMP-activated protein kinase (AMPK) is known as metabolic sensor in mammalian cells that becomes activated by an increasing adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratio. The heterotrimeric AMPK protein comprises three subunits, each of which has multiple phosphorylation sites, playing an important role in the regulation of essential molecular pathways. By phosphorylation of downstream proteins and modulation of gene transcription AMPK functions as a master switch of energy homeostasis in tissues with high metabolic turnover, such as the liver, skeletal muscle, and adipose tissue. Regulation of AMPK under conditions of chronic caloric oversupply emerged as substantial research target to get deeper insight into the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Evidence supporting the role of AMPK in NAFLD is mainly derived from preclinical cell culture and animal studies. Dysbalanced de novo lipogenesis has been identified as one of the key processes in NAFLD pathogenesis. Thus, the scope of this review is to provide an integrative overview of evidence, in particular from clinical studies and human samples, on the role of AMPK in the regulation of primarily de novo lipogenesis in human NAFLD.

Mitochondria Matter: Systemic Aspects of Nonalcoholic Fatty Liver Disease (NAFLD) and Diagnostic Assessment of Liver Function by Stable Isotope Dynamic Breath Tests

The liver plays a key role in systemic metabolic processes, which include detoxification, synthesis, storage, and export of carbohydrates, lipids, and proteins. The raising trends of obesity and metabolic disorders worldwide is often associated with the nonalcoholic fatty liver disease (NAFLD), which has become the most frequent type of chronic liver disorder with risk of progression to cirrhosis and hepatocellular carcinoma. Liver mitochondria play a key role in degrading the pathways of carbohydrates, proteins, lipids, and xenobiotics, and to provide energy for the body cells. The morphological and functional integrity of mitochondria guarantee the proper functioning of β-oxidation of free fatty acids and of the tricarboxylic acid cycle. Evaluation of the liver in clinical medicine needs to be accurate in NAFLD patients and includes history, physical exam, imaging, and laboratory assays. Evaluation of mitochondrial function in chronic liver disease and NAFLD is now possible by novel diagnostic tools. "Dynamic" liver function tests include the breath test (BT) based on the use of substrates marked with the non-radioactive, naturally occurring stable isotope 13C. Hepatocellular metabolization of the substrate will generate 13CO2, which is excreted in breath and measured by mass spectrometry or infrared spectroscopy. Breath levels of 13CO2 are biomarkers of specific metabolic processes occurring in the hepatocyte cytosol, microsomes, and mitochondria. 13C-BTs explore distinct chronic liver diseases including simple liver steatosis, non-alcoholic steatohepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug, and alcohol effects. In NAFLD, 13C-BT use substrates such as α-ketoisocaproic acid, methionine, and octanoic acid to assess mitochondrial oxidation capacity which can be impaired at an early stage of disease. 13C-BTs represent an indirect, cost-effective, and easy method to evaluate dynamic liver function. Further applications are expected in clinical medicine. In this review, we discuss the involvement of liver mitochondria in the progression of NAFLD, together with the role of 13C-BT in assessing mitochondrial function and its potential use in the prevention and management of NAFLD.

Fatty Acids Activate the Transcriptional Coactivator YAP1 to Promote Liver Fibrosis via p38 Mitogen-Activated Protein Kinase

BACKGROUND & AIMS

Patients with simple steatosis (SS) and nonalcoholic steatohepatitis can develop progressive liver fibrosis, which is associated with liver-related mortality. The mechanisms contributing to liver fibrosis development in SS, however, are poorly understood. SS is characterized by hepatocellular free fatty acid (FFA) accumulation without lobular inflammation seen in nonalcoholic steatohepatitis. Because the Hippo signaling transcriptional coactivator YAP1 (YAP) has previously been linked with nonalcoholic fatty liver disease (NAFLD)-related fibrosis, we sought to explore how hepatocyte FFAs activate a YAP-mediated profibrogenic program.

METHODS

We analyzed RNA sequencing data from a GEO DataSet (accession: GSE162694) consisting of 143 patients with NAFLD. We also performed immunohistochemical, immunofluorescence, immunoblot, and quantitative reverse-transcription polymerase chain reaction analyses (qRT-PCR) in liver specimens from NAFLD subjects, from a murine dietary NAFLD model, and in FFA-treated hepatic spheroids and hepatocytes.

RESULTS

YAP-target gene expression correlated with increasing fibrosis stage in NAFLD patients and was associated with fibrosis in mice fed a NAFLD-inducing diet. Hepatocyte-specific YAP deletion in the murine NAFLD model attenuated diet-induced fibrosis, suggesting a causative role of YAP in NAFLD-related fibrosis. Likewise, in hepatic spheroids composed of Huh7 hepatoma cells and primary human hepatic stellate cells, Huh7 YAP silencing reduced FFA-induced fibrogenic gene expression. Notably, inhibition of p38 mitogen-activated protein kinase could block YAP activation in FFA-treated Huh7 cells.

CONCLUSIONS

These studies provide further evidence for the pathological role of YAP in NAFLD-associated fibrosis and that YAP activation in NAFLD may be driven by FFA-induced p38 MAPK activation.