Estimating global prevalence, incidence, and outcomes of non-alcoholic fatty liver disease from 2000 to 2021: systematic review and meta-analysis

The current findings on the gut-liver axis and the molecular basis of NAFLD/NASH associated with gut microbiome dysbiosis

Recent research has highlighted the complex relationship between gut microbiota, metabolic pathways, and nonalcoholic fatty liver disease (NAFLD) progression. Gut dysbiosis, commonly observed in NAFLD patients, impairs intestinal permeability, leading to the translocation of bacterial products like lipopolysaccharides, short-chain fatty acids, and ethanol to the liver. These microbiome-associated mechanisms contribute to intestinal and hepatic inflammation, potentially advancing NAFLD to NASH. Dietary habits, particularly those rich in saturated fats and fructose, can modify the microbiome composition, leading to dysbiosis and fatty liver development. Metabolomic approaches have identified unique profiles in NASH patients, with specific metabolites like ethanol linked to disease progression. While bariatric surgery has shown promise in preventing NAFLD progression, the role of gut microbiome and metabolites in this improvement remains to be proven. Understanding these microbiome-related pathways may provide new diagnostic and therapeutic targets for NAFLD and NASH. A comprehensive review of current literature was conducted using multiple medical research databases, including PubMed, Scopus, Web of Science, Embase, Cochrane Library, ClinicalTrials.gov, ScienceDirect, Medline, ProQuest, and Google Scholar. The review focused on studies that examine the relationship between gut microbiota composition, metabolic pathways, and NAFLD progression. Key areas of interest included microbial dysbiosis, endotoxin production, and the influence of diet on gut microbiota. The analysis revealed that gut dysbiosis contributes to NAFLD through several mechanisms, diet significantly influences gut microbiota composition, which in turn affects liver function through the gut-liver axis. High-fat diets can lead to dysbiosis, altering microbial metabolic activities and promoting liver inflammation. Specifically, gut microbiota-mediated generation of saturated fatty acids, such as palmitic acid, can activate liver macrophages and increase TNF-α expression, contributing to NASH development. Different dietary components, including cholesterol, fiber, fat, and carbohydrates, can modulate the gut microbiome and influence NAFLD progression. This gut-liver axis plays a crucial role in maintaining immune homeostasis, with the liver responding to gut-derived bacteria by activating innate and adaptive immune responses. Microbial metabolites, such as bile acids, tryptophan catabolites, and branched-chain amino acids, regulate adipose tissue and intestinal homeostasis, contributing to NASH pathogenesis. Additionally, the microbiome of NASH patients shows an elevated capacity for alcohol production, suggesting similarities between alcoholic steatohepatitis and NASH. These findings indicate that targeting the gut microbiota may be a promising approach for NASH treatment and prevention. Recent research highlights the potential of targeting gut microbiota for managing nonalcoholic fatty liver disease (NAFLD). The gut-liver axis plays a crucial role in NAFLD pathophysiology, with dysbiosis contributing to disease progression. Various therapeutic approaches aimed at modulating gut microbiota have shown promise, including probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and dietary interventions. Probiotics have demonstrated efficacy in human randomized controlled trials, while other interventions require further investigation in clinical settings. These microbiota-targeted therapies may improve NAFLD outcomes through multiple mechanisms, such as reducing inflammation and enhancing metabolic function. Although lifestyle modifications remain the primary recommendation for NAFLD management, microbiota-focused interventions offer a promising alternative for patients struggling to achieve weight loss targets.

Incidence rate and associated patient characteristics of liver disease in Wales 2004-2022: a retrospective population-scale observational study

OBJECTIVE

To describe the incidence and key demographic, socioeconomic and clinical characteristics of individuals with liver disease in Wales.

DESIGN AND SETTING

This study is designed as a retrospective observational study that linked data of anonymised identified individuals from primary, secondary care and mortality data from the Secure Anonymised Information Linkage (SAIL) Databank in Wales.

PARTICIPANTS

All Welsh residents who registered with a SAIL-contributing general practitioner (GP) and diagnosed with liver disease from 2004 to 2022.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome is the annual age-standardised incidence rate of liver disease. Secondary outcome is the numbers and frequencies of underlying aetiology and the associated comorbidities.

RESULTS

Between 2004 and 2022, 111 098 individuals received a diagnosis of liver disease in Wales and were included in this study. The incidence of liver disease increased threefold during the study period (97.7 per 100 000 inhabitants in 2004 to 316.2 per 100 000 inhabitants in 2022). A total of 79 992 individuals (72%) entered the cohort with the underlying aetiology of liver disease, including alcohol-related liver disease, non-alcoholic fatty liver disease (NAFLD), viral hepatitis, metabolic, haemochromatosis and autoimmune liver diseases. NAFLD has contributed to most of the change in incidence.

CONCLUSIONS

We observed increasing incidence rates of liver disease in Wales, with NAFLD showing a particularly sharp increase and frequently identified as an underlying condition. A better understanding of the incidence of liver disease is the first step towards effective prevention, early detection and targeted intervention to improve patient outcomes.

Global burden of adult non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) has been steadily increasing over the past decades and is expected to persist in the future

BACKGROUND

At present, there is a dearth of comprehensive data at the global, national, and regional levels regarding the adult non-alcoholic fatty liver disease (NAFLD) prevalence. This cross-sectional study aims at ascertaining the prevalence of NAFLD and non-alcoholic steatohepatitis (NASH), utilizing body mass index (BMI) as a determining factor.

METHODS

Based on the NHANES database, sigmoidal fitting curves were generated to establish the relationship between BMI and the risk of NAFLD/NASH. Utilizing BMI data from the NCD Risk Factor Collaboration (NCD-RisC) database at both global and regional levels, the prevalence of NAFLD/NASH among adults was estimated from 1975 to 2016, encompassing global, regional, and national perspectives. Additionally, projections were made to forecast the prevalence of adult NAFLD/NASH from 2017 to 2030.

RESULTS

In 2016, the global prevalence of NAFLD was 41.12% for males and 37.32% for females, while the global prevalence of NASH was 15.79% for males and 16.48% for females. The prevalence of NAFLD/NASH increased with higher BMI in both genders. Over the period from 1975 to 2016, there has been a gradual increase in the global prevalence of NAFLD/NASH in adults, and this trend is expected to continue between 2017 and 2030. In males, the prevalence of adult NAFLD/NASH was found to be highest in High-income Western countries, while it was highest in Central Asia, Middle East, and North African countries after 1995.

CONCLUSIONS

The prevalence of adult NAFLD/NASH has been observed to increase annually, with significant variations in burden across different countries and regions.

Prevalence of Sarcopenia and Its Defining Components in Non-alcoholic Fatty Liver Disease Varies According to the Method of Assessment and Adjustment: Findings from the UK Biobank

Sarcopenia may increase non-alcoholic fatty liver disease (NAFLD) risk, but prevalence likely varies with different diagnostic criteria. This study examined the prevalence of sarcopenia and its defining components in adults with and without NAFLD and whether it varied by the method of muscle mass assessment [bioelectrical impedance (BIA) versus dual-energy X-ray absorptiometry (DXA)] and adjustment (height2 versus BMI). Adults (n = 7266) in the UK Biobank study (45-79 years) with and without NAFLD diagnosed by MRI, were included. Sarcopenia was defined by the 2018 European Working Group on Sarcopenia in Older People definition, with low appendicular skeletal muscle mass (ASM) assessed by BIA and DXA and adjusted for height2 or BMI. Overall, 21% of participants had NAFLD and the sex-specific prevalence of low muscle strength (3.6-7.2%) and sarcopenia (0.1-1.4%) did not differ by NAFLD status. However, NAFLD was associated with 74% (males) and 370% (females) higher prevalence of low ASM when adjusted for BMI but an 82% (males) to 89% (females) lower prevalence when adjusted for height2 (all P < 0.05). The prevalence of impaired physical function was 40% (males, P = 0.08) to 123% (females, P < 0.001) higher in NAFLD. In middle-aged and older adults, NAFLD was not associated with a higher prevalence of low muscle strength or sarcopenia but was associated with an increased risk of impaired physical function and low muscle mass when adjusted for BMI. These findings support the use of adiposity-based adjustments when assessing low muscle mass and the assessment of physical function in NAFLD.

Unveiling the mitophagy puzzle in non-alcoholic fatty liver disease (NAFLD): Six hub genes for early diagnosis and immune modulatory roles

Background

Non-alcoholic fatty liver disease (NAFLD) stands as a predominant chronic liver ailment globally, yet its pathogenesis remains elusive. This study aims to identify Hub mitophagy-related genes (MRGs), and explore the underlying pathological mechanisms through which these hub genes regulate NAFLD.

Methods

A total of 3 datasets were acquired from the GEO database and integrated to identify differentially expressed genes (DEGs) in NAFLD and perform Gene Set Enrichment Analysis (GSEA). By intersecting DEGs with MRGs, mitophagy-related differentially expressed genes (MRDEGs) were obtained. Then, hub MRGs with diagnostic biomarker capability for NAFLD were screened and a diagnostic prediction model was constructed and assessed using Nomogram, Decision Curve Analysis (DCA), and ROC curves. Functional enrichment analysis was conducted on the identified hub genes to explore their biological significance. Additionally, regulatory networks were constructed using databases. NAFLD was stratified into high and low-risk groups based on the Riskscore from the diagnostic prediction model. Furthermore, single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT algorithms were employed to analyze immune cell infiltration patterns and the relationship between Hub MRGs and immune cells.

Results

The integrated dataset comprised 122 NAFLD samples and 31 control samples. After screening, 18 MRDEGs were identified. Subsequently, six hub MRGs (NR4A1, PPP2R2A, P4HA1, TUBB6, DUSP1, NAMPT) with diagnostic potential were selected through WGCNA, logistic regression, SVM, RF, and LASSO models, all significantly downregulated in NAFLD samples compared to the control group. A diagnostic prediction model based on these six genes demonstrated robust predictive performance. Functional enrichment analysis of the six hub genes revealed involvement in processes such as protein phosphorylation or dephosphorylation. Correlation analysis demonstrated a significant association between hub MRGs and infiltrating immune cells.

Conclusion

We identified six hub MRGs in NAFLD and constructed a diagnostic prediction model based on these six genes, applicable for early NAFLD diagnosis. These genes may participate in regulating NAFLD progression through the modulation of mitophagy and immune activation. Our findings may contribute to subsequent clinical and basic research on NAFLD.

Namodenoson at the Crossroad of Metabolic Dysfunction-Associated Steatohepatitis and Hepatocellular Carcinoma

Namodenoson (CF102) is a small, orally available, anti-inflammatory, and anti-cancer drug candidate currently in phase 2B trial for the treatment of metabolic dysfunction-associated steatohepatitis (MASH; formerly known as non-alcoholic steatohepatitis (NASH)) and in phase 3 pivotal clinical trial for the treatment of hepatocellular carcinoma (HCC). In both MASH and HCC, the mechanism-of-action of namodenoson involves targeting the A3 adenosine receptor (A3AR), resulting in deregulation of downstream signaling pathways and leading to inhibition of inflammatory cytokines (TNF-α, IL-1, IL-6, and IL-8) and stimulation of positive cytokines (G-CSF and adiponectin). Subsequently, inhibition of liver inflammation, steatosis, and fibrosis were documented in MASH experimental models, and inhibition of HCC growth was observed in vitro, in vivo, and in clinical studies. This review discusses the evidence related to the multifaceted mechanism of action of namodenoson, and how this mechanism is reflected in the available clinical data in MASH and HCC.

Association of NAFLD/NASH, and MAFLD/MASLD with chronic kidney disease: an updated narrative review

Chronic kidney disease (CKD) and nonalcoholic fatty liver disease (NAFLD), metabolic dysfunction-associated fatty liver disease (MAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) account for substantial financial burden worldwide. These alarming features call for enhanced efforts to prevent and manage the development and progression of CKD. Accumulating evidence supporting a causal role of NAFLD/MAFLD/MASLD-in CKD opens new horizons to achieve this aim. Recent epidemiological studies and meta-analyses exploring the association of NAFLD/MAFLD/MASLD with CKD and the characteristics of NAFLD/MAFLD/MASLD associated with the odds of incident CKD are discussed. The involved pathomechanisms, including the common soil hypothesis, genetics, gut dysbiosis, and portal hypertension, are examined in detail. Finally, lifestyle changes (diet and physical exercise), direct manipulation of gut microbiota, and drug approaches involving statins, renin-angiotensin-aldosterone system inhibitors, GLP-1 Receptor Agonists, Sodium-glucose cotransporter-2, pemafibrate, and vonafexor are examined within the context of prevention and management of CKD among those with NAFLD/MAFLD/MASLD. The evolving NAFLD/MAFLD/MASLD nomenclature may generate confusion among practicing clinicians and investigators. However, comparative studies investigating the pros and contra of different nomenclatures may identify the most useful definitions among NAFLD/MAFLD/MASLD and strategies to identify, prevent, and halt the onset and progression of CKD.

Hypertension and NAFLD risk: Insights from the NHANES 2017-2018 and Mendelian randomization analyses

BACKGROUND

Hypertension and non-alcoholic fatty liver disease (NAFLD) share several pathophysiologic risk factors, and the exact relationship between the two remains unclear. Our study aims to provide evidence concerning the relationship between hypertension and NAFLD by analyzing data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 and Mendelian randomization (MR) analyses.

METHODS

Weighted multivariable-adjusted logistic regression was applied to assess the relationship between hypertension and NAFLD risk by using data from the NHANES 2017-2018. Subsequently, a two-sample MR study was performed using the genome-wide association study (GWAS) summary statistics to identify the causal association between hypertension, systolic blood pressure (SBP), diastolic blood pressure (DBP), and NAFLD. The primary inverse variance weighted (IVW) and other supplementary MR approaches were conducted to verify the causal association between hypertension and NAFLD. Sensitivity analyses were adopted to confirm the robustness of the results.

RESULTS

A total of 3144 participants were enrolled for our observational study in NHANES. Weighted multivariable-adjusted logistic regression analysis suggested that hypertension was positively related to NAFLD risk (odds ratio [OR] = 1.677; 95% confidence interval [CI], 1.159-2.423). SBP ≥130 mmHg and DBP ≥80 mmHg were also significantly positively correlated with NAFLD. Moreover, hypertension was independently connected with liver steatosis ( β = 7.836 [95% CI, 2.334-13.338]). The results of MR analysis also supported a causal association between hypertension (OR = 7.203 [95% CI, 2.297-22.587]) and NAFLD. Similar results were observed for the causal exploration between SBP (OR = 1.024 [95% CI, 1.003-1.046]), DBP (OR = 1.047 [95% CI, 1.005-1.090]), and NAFLD. The sensitive analysis further confirmed the robustness and reliability of these findings (all P >0.05).

CONCLUSION

Hypertension was associated with an increased risk of NAFLD.

Development of a prediction model for predicting the prevalence of nonalcoholic fatty liver disease in Chinese nurses: the first-year follow data of a web-based ambispective cohort study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is gradually becoming a huge threat to public health. With complex working characteristics, female nurses had been found with high risk of NAFLD. To develop and validate a prediction model to predict the prevalence of NAFLD based on demographic characteristics, work situation, daily lifestyle and laboratory tests in female nurses.

METHODS

This study was a part of the Chinese Nurse Cohort Study (The National Nurse Health Study, NNHS), and data were extracted from the first-year follow data collected from 1st June to 1st September 2021 by questionnaires and physical examination records in a comprehensive tertiary hospital. The questionnaires included demographic characteristics, work situation and daily lifestyle. Logistic regression and a nomogram were used to develop and validate the prediction model.

RESULTS

A total of 824 female nurses were included in this study. Living situation, smoking history, monthly night shift, daily sleep time, ALT/AST, FBG, TG, HDL-C, UA, BMI, TBil and Ca were independent risk factors for NAFLD occurance. A prediction model for predicting the prevalence of NAFLD among female nurses was developed and verified in this study.

CONCLUSION

Living situation, smoking history, monthly night shift, daily sleep time, ALT/AST, FBG, TG, UA, BMI and Ca were independent predictors, while HDL-C and Tbil were independent protective indicators of NAFLD occurance. The prediction model and nomogram could be applied to predict the prevalence of NAFLD among female nurses, which could be used in health improvement.

TRIAL REGISTRATION

This study was a part of the Chinese Nurse Cohort Study (The National Nurse Health Study, NNHS), which was a ambispective cohort study contained past data and registered at Clinicaltrials.gov ( https://clinicaltrials.gov/ct2/show/NCT04572347 ) and the China Cohort Consortium ( http://chinacohort.bjmu.edu.cn/project/102/ ).

The association of exposure to polychlorinated biphenyls with lipid profile and liver enzymes in umbilical cord blood samples

Evidence on prenatal exposure to polychlorinated biphenyls (PCBs) and its effects on newborns and potential biological mechanisms is not well defined yet. Therefore, this study aimed to examine whether PCBs are associated with lipid profile and non-invasive markers of hepatocyte injuries in samples of blood obtained from the umbilical cord. This study included 450 mothers-newborn pairs. Umbilical levels of PCBs were measured using Gas Chromatography/Mass Spectrophotometry (GC/MS). Lipid profile including low-density lipoprotein (LDL-C), total cholesterol (TC), triglycerides (TG), and high-density lipoprotein (HDL-C), as well as liver enzymes i.e., alanine amino transferase (ALT), aspartate amino transferase (AST), γ-glutamyl-transferase (GGT) and alkaline phosphatase (ALP) were determined from umbilical cord blood samples. Quantile g-computation analysis was applied to evaluate the collective influence of PCBs on both lipid profiles and liver enzymes, along with the impact of lipid profiles on liver enzymes. Exposure to the mixture of PCBs was significantly associated with increases in ALP, AST, ALT, and GGT levels in cord blood samples, with increments of 90.38 U/L (95%CI: 65.08, 115.70, p < 0.01), 11.88 U/L (95%CI: 9.03, 14.74, p < 0.01), 2.19 U/L (95%CI:1.43, 2.94, p < 0.01), and 50.67 U/L (95%CI: 36.32, 65.03, p < 0.01), respectively. Additionally, combined PCBs exposure was correlated with significant increases in umbilical TG, TC, and LDL-C levels, with values of 3.97 mg/dL (95%CI: 0.86, 7.09, p = 0.01), 6.30 mg/dL (95%CI: 2.98, 9.61, p < 0.01), and 4.63 mg/dL (95%CI: 2.04, 7.23, p < 0.01) respectively. Exposure to the mixture of lipids was linked to elevated levels of AST and GGT in umbilical cord blood samples. Furthermore, a noteworthy mediating role of TC and LDL-C was observed in the association between total PCBs exposure and umbilical cord blood liver enzyme levels. Overall our findings suggested that higher levels of umbilical cord blood PCBs and lipid profile could affect liver function in newborns.

Tailored Model of Care for Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is increasing globally, creating a growing public health concern. However, this disease is often not diagnosed, and accurate data on its epidemiology are limited in many geographical regions, making it challenging to provide proper care and implement effective national plans. To combat the increasing disease burden, screening and diagnosis must reach a significant number of high-risk subjects. Addressing MASLD as a health care challenge requires a multidisciplinary approach involving prevention, diagnosis, treatment, and care, with collaboration between multiple stakeholders in the health care system. This approach must be guided by national and global strategies, to be combined with efficient models of care developed through a bottom-up process. This review article highlights the pillars of the MASLD model of care (MoC), including screening, risk stratification, and establishing a clinical care pathway for management, in addition to discussing the impact of nomenclature change on the proposed MoC.

Prevalence of Non-alcoholic Fatty Liver Disease in Iran: A Systematic Review and Meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) has a benign course in several patients; however, a serious form of this disease can turn into liver failure, liver cirrhosis, and hepatocellular carcinoma.

Aim

This study aims to estimate the prevalence of NAFLD in Iran.

Method

We searched the following databases from January 2000 to December 2022: Scopus, Pubmed/Medline, Embase, Web of Sciences, the Cochrane Library, and Google Scholar also a number of Iranian databases, namely MagIran, SID, and Elmnet. Additionally, the quality of the included studies was evaluated through the Newcastle-Ottawa Scale. We estimated heterogeneity between studies using the I2 statistic. Furthermore, we performed a synthesis of prevalence estimates through the random-effects DerSimonian and Laird model across the included studies with a 95% confidence interval. To assess the publication bias, we also used Egger's test.

Results

Thirty-one studies were eligible for inclusion. The overall number of participants in the present study was 41,971. The overall prevalence of NAFLD in Iran was 33% [CI: 27-37%], with I2 = 99.7% (P < 0.01). The prevalence was 35% [CI: 27-43%] and 37% [CI: 27-47%] in males and females, respectively. We used Egger's test, and no significant publication bias was identified in the overall prevalence (P = 0.45).

Conclusion

According to the results of this study, the prevalence of NAFLD in Iran is not only high but alsoa growing trend. Effective strategies for changing lifestyles, changing eating habits, and encouraging physical activities among Iranians are recommended. Also, providing screening tests, especially among high-risk groups, has a significant effect on early diagnosis and NAFLD control.

Nonalcoholic Fatty Liver Disease Incidence and Remission and Their Predictors During 7 Years of Follow-up Among Finns

CONTEXT

The incidence and remission of nonalcoholic fatty liver disease (NAFLD) are sparsely studied outside Asia.

OBJECTIVE

This prospective study aimed to investigate NAFLD incidence and remission, and their predictors among a general Finnish population.

METHODS

The applied cohort included 1260 repeatedly studied middle-aged participants with data on liver ultrasound and no excessive alcohol intake. Hepatic steatosis was assessed by liver ultrasound with a 7.2-year study interval. Comprehensive data on health parameters and lifestyle factors were available.

RESULTS

At baseline, 1079 participants did not have NAFLD, and during the study period 198 of them developed NAFLD. Of the 181 participants with NAFLD at baseline, 40 achieved NAFLD remission. Taking multicollinearity into account, key predictors for incident NAFLD were baseline age (odds ratio 1.07; 95% CI, 1.02-1.13; P = .009), waist circumference (WC) (2.77, 1.91-4.01 per 1 SD; P < .001), and triglycerides (2.31, 1.53-3.51 per 1 SD; P < .001) and alanine aminotransferase (ALAT) (1.90, 1.20-3.00 per 1 SD; P = .006) concentrations as well as body mass index (BMI) change (4.12, 3.02-5.63 per 1 SD; P < .001). Predictors of NAFLD remission were baseline aspartate aminotransferase (ASAT) concentration (0.23, 0.08-0.67 per 1 SD; P = .007) and WC change (0.38, 0.25-0.59 per 1 SD; P < .001).

CONCLUSION

During follow-up, NAFLD developed for every fifth participant without NAFLD at baseline, and one-fifth of those with NAFLD at baseline had achieved NAFLD remission. NAFLD became more prevalent during the follow-up period. From a clinical perspective, key factors predicting NAFLD incidence and remission were BMI and WC change independent of their baseline level.

Close association of PFASs exposure with hepatic fibrosis than steatosis: evidences from NHANES 2017-2018

Multiple animals and in vitro studies have demonstrated that perfluoroalkyl and polyfluoroalkyl substances (PFASs) exposure causes liver damage associated with fat metabolism. However, it is lack of population evidence for the correlation between PFAS exposure and nonalcoholic fatty liver disease (NAFLD). A cross-sectional analysis was performed of 1150 participants aged over 20 from the US. Liver ultrasound transient elastography was to identify the participants with NAFLD and multiple biomarkers were the indicators for hepatic steatosis and hepatic fibrosis. Logistics regression and restricted cubic splines models were used to estimate the association between PFASs and NAFLD. PFASs had not a significant association with NAFLD after adjustment. The hepatic steatosis indicators including fatty liver index, NAFLD liver fat score, and Framingham steatosis index were almost not significantly correlated with PFASs exposure respectively. But fibrosis indicators including fibrosis-4 index (FIB-4), NAFLD fibrosis score, and Hepamet fibrosis score were positively correlated with each type of PFASs exposure. After adjustment by gender, age, race, education, and poverty income rate, there was also a significant correlation between PFOS and FIB-4 with 0.07 (0.01, 0.13). The mixed PFASs were associated with FIB-4, with PFOS contributing the most (PIP = 1.000) by the Bayesian kernel machine regression model. The results suggested PFASs exposure appeared to be more closely associated with hepatic fibrosis than steatosis, and PFOS might be the main cause of PFASs associated with hepatic fibrosis.Key messagesCurrent exposure doses of PFAS did not significantly change the risk of developing NAFLD.PFASs exposure appeared to be more closely associated with hepatic fibrosis than steatosis.PFOS might be the main cause of PFASs associated with hepatic fibrosis.

Distinct ways to perform a liver biopsy: The core technique setups and updated understanding of these modalities

There is dramatically increased incidence of several liver diseases worldwide; thus, an unmet need to diagnose and stage these pathological entities heralds the wide application of liver biopsy (LB) techniques. The ways of LB are versatile, including percutaneous LB, transjugular LB, and more recently an approach of minimal invasiveness, that is, EUS-guided LB (EUS-LB). In this review article, we come to the conclusion that EUS-LB may serve as a feasible, reliable, and safe alternative to percutaneous LB and transjugular LB in terms of improved diagnostic yield, excellent sampling performance, and controlled adverse events among patients with focal, infiltrative, and parenchymal liver diseases. Furthermore, extensive efforts have been made to optimize and refine several technical pillars within EUS-LB modality such as the selection of needle size/type, priming manner of biopsy needle, and choice of pass/actuation technique, all of which aim at obtaining better specimen quantity and quality. Another advantageous aspect and unique property pertinent to EUS-guided modality indicate that multiple screening, surveillance, and intervention procedures can be combined into one single endoscopic session. Accordingly, some pilot studies have clarified the clinical usefulness by integrating EUS-LB with simultaneous measurement of portal pressure gradient or examination of liver stiffness. However, more studies, in particular, randomized controlled trials or real-world evidence, are practically warranted to elucidate the validity and safety of EUS-LB as a regular/routine part of managing liver diseases.

Interaction between mucus layer and gut microbiota in non-alcoholic fatty liver disease: Soil and seeds

ABSTRACT

The intestinal mucus layer is a barrier that separates intestinal contents and epithelial cells, as well as acts as the "mucus layer-soil" for intestinal flora adhesion and colonization. Its structural and functional integrity is crucial to human health. Intestinal mucus is regulated by factors such as diet, living habits, hormones, neurotransmitters, cytokines, and intestinal flora. The mucus layer's thickness, viscosity, porosity, growth rate, and glycosylation status affect the structure of the gut flora colonized on it. The interaction between "mucus layer-soil" and "gut bacteria-seed" is an important factor leading to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Probiotics, prebiotics, fecal microbiota transplantation (FMT), and wash microbial transplantation are efficient methods for managing NAFLD, but their long-term efficacy is poor. FMT is focused on achieving the goal of treating diseases by enhancing the "gut bacteria-seed". However, a lack of effective repair and management of the "mucus layer-soil" may be a reason why "seeds" cannot be well colonized and grow in the host gut, as the thinning and destruction of the "mucus layer-soil" is an early symptom of NAFLD. This review summarizes the existing correlation between intestinal mucus and gut microbiota, as well as the pathogenesis of NAFLD, and proposes a new perspective that "mucus layer-soil" restoration combined with "gut bacteria-seed" FMT may be one of the most effective future strategies for enhancing the long-term efficacy of NAFLD treatment.

Copper homeostasis dysregulation promoting cell damage and the association with liver diseases

ABSTRACT

Copper plays an important role in many metabolic activities in the human body. Copper level in the human body is in a state of dynamic equilibrium. Recent research on copper metabolism has revealed that copper dyshomeostasis can cause cell damage and induce or aggravate some diseases by affecting oxidative stress, proteasome, cuprotosis, and angiogenesis. The liver plays a central role in copper metabolism in the human body. Research conducted in recent years has unraveled the relationship between copper homeostasis and liver diseases. In this paper, we review the available evidence of the mechanism by which copper dyshomeostasis promotes cell damage and the development of liver diseases, and identify the future research priorities.

Precision diagnosis of hepatocellular carcinoma

ABSTRACT

Hepatocellular carcinoma (HCC) is the most common type of primary hepatocellular carcinoma (PHC). Early diagnosis of HCC remains the key to improve the prognosis. In recent years, with the promotion of the concept of precision medicine and more in-depth analysis of the biological mechanism underlying HCC, new diagnostic methods, including emerging serum markers, liquid biopsies, molecular diagnosis, and advances in imaging (novel contrast agents and radiomics), have emerged one after another. Herein, we reviewed and analyzed scientific advances in the early diagnosis of HCC and discussed their application and shortcomings. This review aimed to provide a reference for scientific research and clinical practice of HCC.

Current, emerging, and potential therapies for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) has been identified as the most common chronic liver disease worldwide, with a growing incidence. NAFLD is considered the hepatic manifestation of a metabolic syndrome that emerges from multiple factors (e.g., oxidative stress, metabolic disorders, endoplasmic reticulum stress, cell death, and inflammation). Non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, has been reported to be a leading cause of cirrhosis and hepatic carcinoma, and it is progressing rapidly. Since there is no approved pharmacotherapy for NASH, a considerable number of therapeutic targets have emerged with the deepening of the research on NASH pathogenesis. In this study, the therapeutic potential and properties of regulating metabolism, the gut microbiome, antioxidant, microRNA, inhibiting apoptosis, targeting ferroptosis, and stem cell-based therapy in NASH are reviewed and evaluated. Since the single-drug treatment of NASH is affected by individual heterogeneous responses and side effects, it is imperative to precisely carry out targeted therapy with low toxicity. Lastly, targeted therapeutic agent delivery based on exosomes is proposed in this study, such that drugs with different mechanisms can be incorporated to generate high-efficiency and low-toxicity individualized medicine.

Mapping global epidemiology of thyroid nodules among general population: A systematic review and meta-analysis

INTRODUCTION

An emerging public health issue is brought on by the worldwide increase of thyroid nodules (TNs). The goal of the current study is to determine the global prevalence of TNs among the general population.

METHODS

We screened articles published from January 2000 to May 2022. TN prevalence was calculated with the DerSimonian-Laird random effects model with arcsine transformation.

RESULTS

A total of 20,358 entries were found in our research, and 102 of them met our inclusion criteria. A total of 9,276,178 individuals have been diagnosed as TNs; the overall prevalence was 24.83% (95% CI 21.44-28.55), regardless of the diagnostic techniques. TNs have become more prevalent during 2012-2022 (29.29%) compared with 2000-2011 (21.53%, p = 0.02). In addition, we discovered that women (36.51%) were more likely to have TNs than men (23.47%, p < 0.01). Interestingly, we found that obesity was correlated with the prevalence of TNs. Additionally, age-specific-stratified TN prevalence was found in our results.

DISCUSSION

This meta-analysis shows that, regardless of country development and economic status, TNs are spreading more widely over the world. Our findings showed a strong correlation between rising TN prevalence and older age, female sex, and elevated weight. To stop the TN epidemic from spreading over the world, increased awareness, the understanding of the disease, and quick action are required.

The Role of Intermittent Fasting in the Management of Nonalcoholic Fatty Liver Disease: A Narrative Review

Intermittent fasting is a non-pharmacological dietary approach to management of obesity and metabolic syndrome, involving periodic intervals of complete or near-complete abstinence from food and energy-containing fluids. This dietary strategy has recently gained significant popularity in mainstream culture and has been shown to induce weight loss in humans, reduce gut and systemic inflammation, and improve gut microbial diversity and dysbiosis (largely in animal models). It has been hypothesized that intermittent fasting could be beneficial in the management of nonalcoholic fatty liver disease, given the condition's association with obesity. This review summarizes protocols, potential mechanisms of action, and evidence for intermittent fasting in nonalcoholic fatty liver disease. It also highlights practical considerations for implementing intermittent fasting in clinical practice. A search of the literature for English-language articles related to intermittent fasting or time-restricted feeding and liver disease was completed in PubMed and Google Scholar. Potential mechanisms of action for effects of intermittent fasting included modulation of circadian rhythm, adipose tissue and adipokines, gut microbiome, and autophagy. Preclinical, epidemiological, and clinical trial data suggested clinical benefits of intermittent fasting on metabolic and inflammatory markers in humans. However, there was a paucity of evidence of its effects in patients with nonalcoholic fatty liver disease. More clinical studies are needed to determine mechanisms of action and to evaluate safety and efficacy of intermittent fasting in this population.

The immune response as a therapeutic target in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a complex and heterogeneous disorder considered a liver-damaging manifestation of metabolic syndrome. Its prevalence has increased in the last decades due to modern-day lifestyle factors associated with overweight and obesity, making it a relevant public health problem worldwide. The clinical progression of NAFLD is associated with advanced forms of liver injury such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). As such, diverse pharmacological strategies have been implemented over the last few years, principally focused on metabolic pathways involved in NAFLD progression. However, a variable response rate has been observed in NAFLD patients, which is explained by the interindividual heterogeneity of susceptibility to liver damage. In this scenario, it is necessary to search for different therapeutic approaches. It is worth noting that chronic low-grade inflammation constitutes a central mechanism in the pathogenesis and progression of NAFLD, associated with abnormal composition of the intestinal microbiota, increased lymphocyte activation in the intestine and immune effector mechanisms in liver. This review aims to discuss the current knowledge about the role of the immune response in NAFLD development. We have focused mainly on the impact of altered gut-liver-microbiota axis communication on immune cell activation in the intestinal mucosa and the role of subsequent lymphocyte homing to the liver in NAFLD development. We further discuss novel clinical trials that addressed the control of the liver and intestinal immune response to complement current NAFLD therapies.