Risk for hepatic and extra-hepatic outcomes in nonalcoholic fatty liver disease

Temporal relationship between hepatic steatosis and blood pressure elevation and the mediation effect in the development of cardiovascular disease

The temporal relationship between non-alcoholic fatty liver disease (NAFLD) and hypertension remains highly controversial, with ongoing debates on whether NAFLD induces hypertension or vice versa. We employed cross-lagged panel models to investigate the temporal relationship between hepatic steatosis (assessed by Fatty Liver Index [FLI] in the main analysis, and by Proton Density Fat Fraction [PDFF] in the validation study) and blood pressure (systolic and diastolic blood pressure [SBP/ DBP]). Subsequently, we employed causal mediation models to explore the mediation effect in CVD development, including ischemic heart disease and stroke. The main analysis incorporated repeated measurement data of 5,047 participants from the China Multi-Ethnic Cohort (CMEC) and 5,685 participants from the UK Biobank (UKB). In both cohorts, the path coefficients from FLI to blood pressure were significant and greater than the path from blood pressure to FLI, with βFLI→SBP = 0.081, P < 0.001 versus βSBP→FLI = 0.020, P = 0.031; βFLI→DBP = 0.082, P < 0.001 versus βDBP→FLI = -0.006, P = 0.480 for CEMC, and βFLI→SBP = 0.057, P < 0.001 versus βSBP→FLI = -0.001, P = 0.727; βFLI→DBP = 0.061, P < 0.001, versus βDBP→FLI = -0.006, P = 0.263 for UKB. The validation study with 962 UKB participants using PDFF consistently supported these findings. In the mediation analyses encompassing 11,108 UKB participants, SBP and DBP mediated 12.2% and 5.2% of the hepatic steatosis-CVD association, respectively. The proportions were lower for ischemic heart disease (SBP: 6.1%, DBP: non-statistically significant -6.8%), and relatively stronger for stroke (SBP: 19.4%, DBP: 26.1%). In conclusion, hepatic steatosis more strongly contributes to elevated blood pressure than vice versa. Blood pressure elevation positively mediates the hepatic steatosis-CVD association, particularly in stroke compared to ischemic heart disease.

RNF31 alleviates liver steatosis by promoting p53/BNIP3-related mitophagy in hepatocytes

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is one of the liver illnesses that may be affected by mitophagy, which is the selective removal of damaged mitochondria. RNF31, an E3 ubiquitin ligase, is carcinogenic in many malignancies. However, the influence of RNF31 on mitochondrial homeostasis and NAFLD development remains unknown.

METHODS

Oleic-palmitic acid treated hepatocytes and high-fat diet (HFD)-fed mice were established to observe the effect of RNF31 on hepatocyte mitophagy and steatosis. Mitophagy processes were comprehensively assessed by mt-Keima fluorescence imaging, while global changes in hepatic gene expression were measured by RNA-seq.

RESULTS

The present study discovered a reduction in RNF31 expression in lipotoxic hepatocytes with mitochondrial dysfunction. The observed decrease in RNF31 expression was associated with reduced mitochondrial membrane potential, disturbed mitophagy, and increased steatosis. Additionally, the findings indicated that RNF31 is a pivotal factor in the initiation of mitophagy and the facilitation of mitochondrial homeostasis, resulting in a decrease in steatosis in lipotoxic hepatocytes. Mechanistically, RNF31 enhanced p53 ubiquitination and subsequent proteasomal degradation. Down-regulation of p53 led to increased expression of the mitophagy receptor protein BCL2 and adenovirus E1B 19 kDa-interacting protein 3 (BNIP3), thereby promoting mitophagy in hepatocytes. Furthermore, it was demonstrated that the transportation of RNF31 via small extracellular vesicles derived from mesenchymal stem cells (referred to as sEV) had a substantial influence on reducing hepatic steatosis and restoring liver function in HFD-fed mice.

CONCLUSIONS

The findings highlight RNF31's essential role in the regulation of mitochondrial homeostasis in hepatocytes, emphasizing its potential as a therapeutic target for NAFLD.

EASL-EASD-EASO Clinical Practice Guidelines on the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

Prognostic value of liver stiffness in metabolic dysfunction-associated steatotic liver disease: a systematic review and meta-analysis

BACKGROUND AND AIMS

Liver stiffness measurement, assessed by vibration-controlled transient elastography, has been recognized as a powerful tool for liver fibrosis assessment. The potential of liver stiffness measurement to predict clinically relevant outcomes in fatty liver disease has received considerable attention. This study aimed to investigate the prediction of liver-related events in metabolic dysfunction-associated steatotic liver disease patients by liver stiffness measurement value on transient elastography.

METHODS

We systematically searched the Electronic databases including PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov until 6 September 2023. The hazard ratios adjusted for confounders were extracted and pooled by random-effects model analysis.

RESULTS

A total of 20587 individuals from 7 studies were included. The pooled HRs were 18.65 (95% CI 9.95-34.95, P < 0.01, I2 = 0%) in the stratification analysis of the highest versus lowest liver stiffness measurement categories. In 1-kPa analysis, the risk of liver-related events was increased with 1 kPa increment (HR 1.05, 95% CI 1.03-1.07, P < 0.01, I2 = 74.47%).

CONCLUSIONS

Metabolic dysfunction-associated steatotic liver disease patients with high liver stiffness measurement values were at an increased risk of liver-related events. Liver stiffness measurement can be used as a prognostic tool to achieve risk stratification in fatty liver patients.

Endpoints in NASH Clinical Trials: Are We Blind in One Eye?

This narrative review aims to illustrate the notion that nonalcoholic steatohepatitis (NASH), recently renamed metabolic dysfunction-associated steatohepatitis (MASH), is a systemic metabolic disorder featuring both adverse hepatic and extrahepatic outcomes. In recent years, several NASH trials have failed to identify effective pharmacological treatments and, therefore, lifestyle changes are the cornerstone of therapy for NASH. with this context, we analyze the epidemiological burden of NASH and the possible pathogenetic factors involved. These include genetic factors, insulin resistance, lipotoxicity, immuno-thrombosis, oxidative stress, reprogramming of hepatic metabolism, and hypoxia, all of which eventually culminate in low-grade chronic inflammation and increased risk of fibrosis progression. The possible explanations underlying the failure of NASH trials are also accurately examined. We conclude that the high heterogeneity of NASH, resulting from variable genetic backgrounds, exposure, and responses to different metabolic stresses, susceptibility to hepatocyte lipotoxicity, and differences in repair-response, calls for personalized medicine approaches involving research on noninvasive biomarkers. Future NASH trials should aim at achieving a complete assessment of systemic determinants, modifiers, and correlates of NASH, thus adopting a more holistic and unbiased approach, notably including cardiovascular-kidney-metabolic outcomes, without restricting therapeutic perspectives to histological surrogates of liver-related outcomes alone.

Validation of a Clinical Risk-based Classification System in a Large Nonalcoholic Fatty Liver Disease Real-world Cohort

BACKGROUND & AIMS

There is an unmet need to validate simple and easily available methods that can be used in routine practice to identify those at risk of adverse outcomes from nonalcoholic fatty liver disease (NAFLD). A retrospective-prospective analysis of NAFLD patients enrolled in a longitudinal noninterventional study (TARGET-NASH) was performed to validate the prognostic utility of the following risk-categories: (A) Fibrosis-4 (FIB-4) <1.3 and/or liver-stiffness measurement (LSM) measured by Fibroscan <8 kp, (B) FIB-4 1.31‒2.6 and/or LSM 8.1-12.5 kp, and (C) FIB-4 >2.6 and/or LSM >12.5 kp.

METHODS

Those in class A with aspartate transaminase:alanine transaminase ratio >1 or platelets <150,000/mm3, or class B with aspartate transaminase:alanine transaminase ratio >1 or platelets <150,000/mm3 were upstaged by one class. Fine-Gray competing risk analyses were performed for all outcomes.

RESULTS

A total of 2523 individuals (class A = 555, B = 879, C = 1089) were followed for a median duration of 3.74 years. Adverse outcomes increased from class A to C in all-cause mortality (0.07 vs 0.3 vs 2.5/100 person-years [PY], hazard ratio [HR], 3.0 and 16.3 class B and C vs A), liver-associated clinical events (0.2 vs 1 vs 8/100 PY, HR, 4.3 and 36.6 B and C vs A), major adverse cardiovascular events (0.69 vs 0.87 vs 2.02/100 PY, HR, 0.78 and 1.55 B and C vs A), hepatocellular carcinoma (0 vs 0.09 vs 0.88/100 PY, HR, 8.32 C vs B), and chronic kidney disease (1.24 vs 2.48 vs 3.51/100 PY). Those who were upstaged had outcome rates similar to the lower class defined by their FIB-4.

CONCLUSIONS

These data support a FIB-4-based risk-stratification of NAFLD that can be used in routine clinical practice.

CLINICALTRIALS

gov Identifier: NCT02815891.

Comparison of liver fibrosis scores for predicting mortality and morbidity in heart failure with preserved ejection fraction

AIMS

Liver fibrosis scores (LFSs) are non-invasive and effective tools for estimating cardiovascular risks. To better understand the advantages and limitations of currently available LFSs, we determined to compare the predictive values of LFSs in heart failure with preserved ejection fraction (HFpEF) for primary composite outcome, atrial fibrillation (AF), and other clinical outcomes.

METHODS AND RESULTS

This was a secondary analysis of the TOPCAT trial, and 3212 HFpEF patients were enrolled. Five LFSs, namely, non-alcoholic fatty liver disease fibrosis score (NFS), fibrosis-4 score (FIB-4), BARD, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio, and Health Utilities Index (HUI) scores were adopted. Cox proportional hazard model and competing risk regression model were performed to assess the associations between LFSs and outcomes. The discriminatory power of each LFS was evaluated by calculating the area under the curves (AUCs). During a median follow-up of 3.3 years, a 1-point increase in the NFS [hazard ratio (HR) 1.10; 95% confidence interval (CI) 1.04-1.17], BARD (HR 1.19; 95% CI 1.10-1.30), and HUI (HR 1.44; 95% CI 1.09-1.89) scores was associated with an increased risk of primary outcome. Patients with high levels of NFS (HR 1.63; 95% CI 1.26-2.13), BARD (HR 1.64; 95% CI 1.25-2.15), AST/ALT ratio (HR 1.30; 95% CI 1.05-1.60), and HUI (HR 1.25; 95% CI 1.02-1.53) were at an increased risk of primary outcome. Subjects who developed AF were more likely to have high NFS (HR 2.21; 95% CI 1.13-4.32). High levels of NFS and HUI scores were a significant predictor of any hospitalization and hospitalization for heart failure. The AUCs for the NFS in predicting primary outcome (0.672; 95% CI 0.642-0.702) and incident of AF (0.678; 95% CI 0.622-0.734) were higher than other LFSs.

CONCLUSIONS

In light of these findings, NFS appears to have superior predictive and prognostic utility compared with AST/ALT ratio, FIB-4, BARD, and HUI scores.

CLINICAL TRIAL REGISTRATION

(https://clinicaltrials.gov). Unique identifier: NCT00094302.

Risk of cardiovascular disease and loss in life expectancy in NAFLD

BACKGROUND AND AIMS

Conflicting evidence exists on cardiovascular disease (CVD) risk in patients with NAFLD, and data are lacking on whether NAFLD increases mortality after a CVD event. Moreover, life expectancy in NAFLD has not been studied. We therefore examined CVD risk and life expectancy in patients with NAFLD compared with the general population.

APPROACH AND RESULTS

In this nationwide population-based cohort, all patients with NAFLD diagnosis and without baseline CVD (ascertaining from the Swedish National Patient Register from 1987 to 2016, n = 10,023) were matched 10:1 on age, sex, and municipality to individuals from the general population (controls, n = 96,313). CVD diagnosis and mortality were derived from national registers. Multistate models and flexible parametric survival models were used to estimate adjusted hazard ratios (aHRs) for CVD risk and loss in life expectancy due to NAFLD. We identified 1037 (10.3%) CVD events in patients with NAFLD and 4041 (4.2%) in controls. CVD risk was 2.6-fold higher in NAFLD compared with controls (aHR = 2.61, 95% CI = 2.36-2.88) and was strongest for nonfatal CVD (aHR = 3.71, 95% CI = 3.29-4.17). After a nonfatal CVD event, the risk for all-cause mortality was similar between patients with NAFLD and controls (aHR = 0.89, 95% CI = 0.64-1.25). Life expectancy in patients with NAFLD was, on average, 2.8 years lower than controls, with the highest loss of life-years when NAFLD was diagnosed in middle age (40-60 years).

CONCLUSIONS

NAFLD was associated with a higher risk of nonfatal CVD but did not affect post-CVD mortality risk. Patients diagnosed with NAFLD have a lower life expectancy than the general population.

Nonalcoholic Fatty Liver Disease and Risk of Dementia: A Population-Based Cohort Study

BACKGROUND AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) and dementia share common risk factors including metabolic disorders. However, whether NAFLD is associated with dementia risk is unclear. We investigated the association between NAFLD and dementia risk as well as the role of cardiovascular complications including heart disease and stroke.

METHODS

In this population-based matched cohort study, we identified all Swedish patients aged 65 years or older with NAFLD identified from the National Patient Register (NPR) between 1987 and 2016. These were matched with up to 10 reference individuals from the general population on age, sex, and municipality at the year of diagnosis. Incident dementia diagnosis was derived from the NPR or the Cause of Death Register until 2016. Adjusted hazard ratios (aHRs) and 95% CIs were estimated with Cox regression models.

RESULTS

A total of 2,898 patients with NAFLD and 28,357 matched controls were identified (median age at entry, interquartile range [IQR], 70 [8]; 55.1% female). During a median follow-up of 5.5 years (IQR: 8.5 years), 145 (5.0%) patients with NAFLD and 1,291 (4.6%) reference individuals were diagnosed with dementia. Compared with the reference individuals, patients with NAFLD had higher rates of dementia (aHR 1.38, 95% CI 1.10-1.72) and vascular dementia (aHR 1.44, 95% CI 0.96-2.23, p = 0.07). Comorbid NAFLD and either heart disease (aHR 1.50 95% 1.08-2.05) or stroke (aHR 2.60 95% CI 1.95-3.47) conferred a greater risk of dementia.

DISCUSSION

NAFLD had a modest association with increased rates of dementia. This was stronger among patients with NAFLD diagnosed with cardiovascular comorbidities.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that nonalcoholic fatty liver disease is associated with the development of vascular and nonvascular dementia.

Association between the severity of metabolic dysfunction-associated fatty liver disease and the risk of colorectal neoplasm: a systematic review and meta-analysis

Background

The severity of metabolic dysfunction-associated fatty liver disease (MAFLD) reportedly plays a part in the etiology of colorectal tumors. However, there is no consensus.

Methods

Studies relevant with the impact of MAFLD severity on the risk of colorectal neoplasms published before 24th April 2022 were screened. The pooled odds ratio (OR) with corresponding 95% confidence intervals (95% CI) was obtained using standard and cumulative meta-analyses. Subgroup, meta-regression, and sensitivity analyses were carried out to identify heterogeneity.

Results

Fourteen studies with data from 37,824 MAFLD patients were included. The prevalence of colorectal neoplasms escalated with the progression of MAFLD compared to simple steatosis (OR = 1.93; 95% CI = 1.42–2.62). The magnitude and direction of the effect on these outcomes remained largely constant over time. Even after limiting the meta-analysis to 8 studies with available adjusted OR (aOR), the findings still suggested that MAFLD severity was positively related to colorectal neoplasms (aOR = 3.03; 95% CI = 2.02–4.53). Severe MAFLD was more likely to cause left colon tumors (OR = 3.86, 95% CI = 2.16–6.91) than right colon neoplasms (OR = 1.94, 95% CI = 1.15–3.28).

Conclusion

The severity of MAFLD was independently related to colorectal neoplasms and severe MAFLD was more likely to cause left colon tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01659-1.

Elevated liver enzymes predict morbidity and mortality despite antiviral cure in patients with chronic hepatitis C: Data from the German Hepatitis C-Registry

While direct‐acting antivirals (DAAs) cure chronic hepatitis C virus (HCV) infection in almost all patients, some patients remain at risk of liver disease despite HCV cure. In order to identify risk factors indicating liver‐related morbidity and death after viral cure, we included 6982 patients from the national multicenter real‐world German Hepatitis C Registry with regular follow‐up visits for up to 7 years after DAA therapy. Definitions for normal liver function tests (in women/men) were alanine aminotransferase (ALT; ≤35/≤50 U/L), ALT according to American Association for the Study of Liver Diseases (AASLD; ≤19/≤30 U/L), and gamma‐glutamyltransferase (GGT; ≤40/≤60 U/L). In our cohort, 97.4% of patients achieved sustained virologic response (SVR). At 24 weeks after SVR (SVR24), elevated ALT occurred in 657/6982 (9.4%), elevated ALT (AASLD) in 2609/6982 (37.4%), and elevated GGT in 1777/6982 (25.5%) patients. Risk factors for increased ALT at SVR24 were obesity, alcohol, cirrhosis, elevated baseline ALT, and non‐SVR. Increased GGT at SVR24 was significantly (p < 0.05) and independently associated with male sex (odds ratio [OR], 2.12), higher body mass index (OR, 1.04), age >50 years (OR, 1.60), liver cirrhosis (OR, 3.97), alcohol consumption (OR, 2.99), diabetes (OR, 1.63), non‐SVR (OR, 8.00), and elevated GGT at baseline (OR, 17.12). In multivariate regression analysis, elevated GGT at SVR24, particularly in combination with cirrhosis, was the best predictor for hepatic decompensation, hepatocellular carcinoma development, and death, followed by elevated ALT (AASLD) and standard ALT, which predicted hepatic decompensation. Despite successful HCV therapy, elevated GGT at SVR24 and to a lesser extent ALT are predictive of the future clinical outcome and linked with liver‐associated comorbidities. This may highlight the relevance of nonalcoholic fatty liver disease, diabetes mellitus, alcohol, and cirrhosis for the clinical outcome in a vulnerable population, even after HCV cure.

A nanodrug system overexpressed circRNA_0001805 alleviates nonalcoholic fatty liver disease via miR-106a-5p/miR-320a and ABCA1/CPT1 axis

Our study aimed to explore the function of circRNA_0001805 in the pathogenesis of NAFLD and the underlying mechanism. A nanodrug system (GA-RM/GZ/PL) was constructed to overexpress circRNA_0001805 specifically in hepatocytes for the treatment of NAFLD. Fat droplet accumulation in cultured cells and mouse hepatic tissues was detected using Oil Red O or H&E staining. The relative expression of circRNAs, genes associated with lipogenesis was quantified by qRT-PCR. Interactions between circRNA_0001805 and miR-106a-5p/miR-320a, between miR-106a-5p/miR-320a and ABCA1/CPT1 were confirmed by dual-luciferase reporter assay. A novel metalorganic framework nanocarrier (GZ) was prepared from glycyrrhizic acid and zinc ions (Zn²⁺), and this nanocarrier was loaded with the circRNA_0001805 plasmid to construct a nanocore (GZ/PL). Then, this GZ/PL was coated with a galactose-modified RBC membrane (GA-RM) to generate GA-RM/GZ/PL. CircRNA_0001805 expression was downregulated in FFA-challenged primary hepatocytes, HFD-fed mice and NAFLD patients. Overexpressed circRNA_0001805 attenuated NAFLD development by suppressing lipid metabolism disorder and inflammation. CircRNA_0001805 targeted miR-106a-5p/miR-320a, which served as an upstream inhibitor of ABCA1/CPT1 and collaboratively regulated NAFLD progression. GA-RM/GZ/PL targeted hepatocytes, overexpressed circRNA_0001805, released glycyrrhizic acid to reduce the accumulation of lipids in the liver and played a synergistic role against NAFLD-induced lipid metabolism disorder.