Systematic review with network meta-analysis: comparative efficacy of pharmacologic therapies for fibrosis improvement and resolution of NASH

Targeting Metabolism: Innovative Therapies for MASLD Unveiled

The recent introduction of the term metabolic-dysfunction-associated steatotic liver disease (MASLD) has highlighted the critical role of metabolism in the disease's pathophysiology. This innovative nomenclature signifies a shift from the previous designation of non-alcoholic fatty liver disease (NAFLD), emphasizing the condition's progressive nature. Simultaneously, MASLD has become one of the most prevalent liver diseases worldwide, highlighting the urgent need for research to elucidate its etiology and develop effective treatment strategies. This review examines and delineates the revised definition of MASLD, exploring its epidemiology and the pathological changes occurring at various stages of the disease. Additionally, it identifies metabolically relevant targets within MASLD and provides a summary of the latest metabolically targeted drugs under development, including those in clinical and some preclinical stages. The review finishes with a look ahead to the future of targeted therapy for MASLD, with the goal of summarizing and providing fresh ideas and insights.

Comparison of Glucagon-Like Peptide-1 Receptor Agonists and Sodium-Glucose Cotransporter Protein-2 Inhibitors on Treating Metabolic Dysfunction-Associated Steatotic Liver Disease or Metabolic Dysfunction-Associated Steatohepatitis: Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

To assess glucagon-like peptide-1 receptor agonists (GLP-1 receptor agonists) and sodium-glucose cotransporter protein-2 inhibitors (SGLT-2 inhibitors) in patients with metabolic dysfunction-associated steatotic liver disease or metabolic dysfunction-associated steatohepatitis (previously known as nonalcoholic fatty liver disease [NAFLD] and nonalcoholic steatohepatitis [NASH]), we performed a systematic review and network meta-analysis of randomized controlled trials.

METHODS

The study searched Pubmed, Embase, the Cochrane Library, and Web of Science databases up to November 26, 2023. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias.

RESULTS

Thirty-seven studies were included in the analysis. GLP-1 receptor agonists were found to be more effective than placebo in resolving NASH (relative risk: 2.48, 95% CI:1.86 to 3.30). Both drugs were superior to placebo in reducing liver fat content, as well as decreasing levels of liver enzyme. Network meta-analysis indicated that SGLT-2 inhibitors were more effective than GLP-1 receptor agonists in reducing alanine aminotransferase and aspartate aminotransferase levels. According to the surface under the cumulative probability ranking curve values, GLP-1 receptor agonists and SGLT-2 inhibitors consistently ranked among the top 2 in terms of reducing anthropometric data compared to other included drugs.

CONCLUSIONS

GLP-1 receptor agonists and SGLT-2 inhibitors have significant effects on reducing liver fat content and liver enzymes in NAFLD or NASH patients compared to placebo. GLP-1 receptor agonists were found to be superior to placebo in resolving NASH. SGLT-2 inhibitors were more effective than GLP-1 receptor agonists in reducing alanine aminotransferase and aspartate aminotransferase levels.

Comparison of pharmacological therapies in metabolic dysfunction-associated steatohepatitis for fibrosis regression and MASH resolution: Systematic review and network meta-analysis

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) is a leading cause of liver disease. With the advent of multiple therapeutic targets in late-phase clinical drug development for MASH, there is a knowledge gap to better understand the comparative efficacy of various pharmacological agents. We conducted an updated network meta-analysis to evaluate the relative rank order of the different pharmacological agents for both fibrosis regression and MASH resolution.

APPROACH AND RESULTS

We searched PubMed and Embase databases from January 1, 2020 to December 1, 2024, for published randomized controlled trials comparing pharmacological interventions in patients with biopsy-proven MASH. The co-primary endpoints were fibrosis improvement ≥1 stage without MASH worsening and MASH resolution without worsening fibrosis. We conducted surface under the cumulative ranking curve (SUCRA) analysis. A total of 29 randomized controlled trials (n=9324) were included. Pegozafermin, cilofexor + firsocostat, denifanstat, survodutide, obeticholic acid, tirzepatide, resmetirom, and semaglutide were significantly better than placebo in achieving fibrosis regression without worsening MASH. Pegozafermin (SUCRA: 79.92), cilofexor + firsocostat (SUCRA: 71.38), and cilofexor + selonsertib (SUCRA: 69.11) were ranked the most effective interventions. Pegozafermin, survodutide, tirzepatide, efruxifermin, liraglutide, vitamin E + pioglitazone, resmetirom, semaglutide, pioglitazone, denifanstat, semaglutide, and lanifibranor were significantly better than placebo in achieving MASH resolution without worsening fibrosis. Pegozafermin (SUCRA: 91.75), survodutide (SUCRA: 90.87), and tirzepatide (SUCRA: 84.70) were ranked the most effective interventions for achieving MASH resolution without worsening fibrosis.

CONCLUSIONS

This study provides updated rank-order efficacy of MASH pharmacological therapies for fibrosis regression and MASH resolution. These data are helpful to inform practice and clinical trial design.

Current Status of Glucagon-like Peptide-1 Receptor Agonists in Metabolic Dysfunction-associated Steatotic Liver Disease: A Clinical Perspective

Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently a pressing public health issue associated with adverse outcomes such as cirrhosis, malignancy, transplantation, and mortality. Lifestyle modifications constitute the most effective and fundamental management approach, but they often pose challenges in sustaining long-term clinical benefits. Hence, there is a critical need to enhance our understanding through pharmacological management, which unfortunately remains limited. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as a leading treatment in the fields of diabetes and obesity, with recent preclinical and clinical studies indicating significant benefits in the management and treatment of MASLD. Our article begins by reviewing the beneficial therapeutic components of GLP-1RAs in MASLD. Subsequently, from a clinical research perspective, we concluded with the liver outcomes of current primary GLP-1RAs and co-agonists. Finally, we presented our insights on clinical concerns such as appropriate trial endpoints, management of comorbidities, and future developments. In conclusion, the benefits of GLP-1RAs in MASLD are promising, and background therapy involving metabolic modulation may represent one of the future therapeutic paradigms.

Cardiovascular Risk Reduction in Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Dysfunction-Associated Steatohepatitis

PURPOSE OF REVIEW

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease, characterized by hepatic steatosis with at least one cardiometabolic risk factor. Patients with MASLD are at increased risk for the occurrence of cardiovascular events. Within this review article, we aimed to provide an update on the pathophysiology of MASLD, its interplay with cardiovascular disease, and current treatment strategies.

RECENT FINDINGS

Given their high burden of cardiovascular comorbidities, patients with MASLD or MASH should undergo regular cardiovascular risk assessment using established risk models. In the absence of liver-specific therapies, therapeutic strategies should focus on improving cardiometabolic risk factors. Patients require a multimodal and multi-stakeholder treatment approach, including optimization of lifestyle, dysglycemia, obesity, and dyslipidemia. Statin treatment represents a safe and effective but often underused therapy in the management of at-risk patients with MASLD and MASH. Novel promising approaches include the use of GLP-1 receptor agonists, especially in, but not limited to, patients with cardiovascular disease and obesity. Patients with MASLD and MASH are at high cardiovascular risk requiring a multi-modal therapeutic approach including regular cardiovascular risk assessment, as well as lifestyle and pharmacological interventions. Statin therapy represents an inexpensive, safe and effective therapy across the spectrum of non-alcohol related steatotic liver diseases without major safety concerns. More prospective, randomized trials in patients with MASLD and MASH are needed.

Comparative efficacy of THR-β agonists, FGF-21 analogues, GLP-1R agonists, GLP-1-based polyagonists, and Pan-PPAR agonists for MASLD: A systematic review and network meta-analysis

AIMS

To compare the efficacy of thyroid hormone receptor beta (THR-β) agonists, fibroblast growth factor 21 (FGF-21) analogues, glucagon-like peptide-1 receptor agonists (GLP-1RAs), GLP-1-based polyagonists, and pan-peroxisome proliferator-activated receptor (Pan-PPAR) agonists in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

A database search for relevant randomized double-blind controlled trials published until July 11, 2024, was conducted. Primary outcomes were the relative change in hepatic fat fraction (HFF) and liver stiffness assessed non-invasively by magnetic resonance imaging proton density fat fraction and elastography. Secondary outcomes included histology, liver injury index, lipid profile, glucose metabolism, blood pressure, and body weight.

RESULTS

Twenty-seven trials (5357 patients with MASLD) were identified. For HFF reduction, GLP-1-based polyagonists were most potentially effective (mean difference [MD] -51.47; 95 % confidence interval [CI]: -68.25 to -34.68; surface under the cumulative ranking curve [SUCRA] 84.9) vs. placebo, followed by FGF-21 analogues (MD -47.08; 95 % CI: -58.83 to -35.34; SUCRA 75.5), GLP-1R agonists (MD -37.36; 95 % CI: -69.52 to -5.21; SUCRA 52.3) and THR-β agonists (MD -33.20; 95 % CI: -43.90 to -22.51; SUCRA 36.9). For liver stiffness, FGF-21 analogues were most potentially effective (MD -9.65; 95 % CI: -19.28 to -0.01; SUCRA 82.2) vs. placebo, followed by THR-β agonists (MD -5.79; 95 % CI: -9.50 to -2.09; SUCRA 58.2), and GLP-1RAs (MD -5.58; 95 % CI: -15.02 to 3.86; SUCRA 54.7). For fibrosis improvement in histology, GLP-1-based polyagonists were most potentially effective, followed by FGF-21 analogues, THR-β agonists, Pan-PPAR agonists, and GLP-1R agonists; For MASH resolution in histology, GLP-1-based polyagonists were most potentially effective, followed by THR-β agonists, GLP-1R agonists, FGF-21 analogues, and Pan-PPAR agonists. THR-β agonists are well-balanced in liver steatosis and fibrosis, and excel at improving lipid profiles; FGF-21 analogues are effective at improving steatosis and particularly exhibit strong antifibrotic abilities. GLP-1R agonists showed significant benefits in improving liver steatosis, glucose metabolism, and body weight. GLP-1-based polyagonists have demonstrated the most potential efficacy overall in terms of comprehensive curative effect. Pan-PPAR agonists showed distinct advantages in improving liver function and glucose metabolism.

CONCLUSION

These results illustrate the relative superiority of the five classes of therapy in the treatment of MASLD and may serve as guidance for the development of combination therapies.

The effect of vitamin E and docosahexaenoic acid ethyl ester on Metabolic Dysfunction-Associated steatotic Liver Disease (MASLD)-A randomised, double-blind, placebo-controlled, parallel-group clinical trial (PUVENAFLD)

AIMS

We conducted a clinical trial to determine the efficacy of the combination of vitamin E and/or docosahexaenoic acid (DHA) versus placebo in reducing liver fat content after 6 months of intervention in adults with MASLD.

METHODS

Adults with MASLD were randomised to one of four treatment arms (vitamin E 1000 mg/daily + DHA 1.89 g/daily or combination arm, vitamin E 1000 mg alone, DHA 1.89 g alone or placebo) following a 2:1:1:2 randomisation. The primary objective was to determine the efficacy of DHA + vitamin E versus placebo in reducing hepatic fat fraction (%) relative to baseline after 6 months of intervention. Secondary objectives were to determine the effect of vitamin E or DHA alone versus placebo on reducing liver fat at 6 months.

RESULTS

Our cohort consisted of 203 subjects with a mean age of 51 years, 53% female, 91% White, 59% Hispanic ethnicity. The combination of vitamin E + DHA had no effect on the primary endpoint of reducing hepatic steatosis as determined by MRI-PDFF (p = 0.98). Neither vitamin E alone (p = 0.91) nor DHA alone (p = 0.14) significantly reduced hepatic steatosis compared to placebo. However, the trial was not powered adequately for this analysis. Compared with placebo, no statistically significant differences were detected in the 3-month or 6-month levels for ALT (U/L) or AST (U/L) in all three intervention groups.

CONCLUSIONS

The combination of DHA + vitamin E or either agent alone did not demonstrate efficacy on reducing liver fat or aminotransferases in the studied population.

Comparative efficacy of pharmacologic therapies for MASH in reducing liver fat content: Systematic review and network meta-analysis

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) is a leading cause of liver disease. Dynamic changes in MRI proton-density-fat fraction (PDFF) are associated with MASH resolution. We aimed to determine the relative efficacy of therapeutic agents for reducing hepatic fat, assessed by MRI-PDFF.

APPROACH AND RESULTS

In this systematic review and network meta-analysis, we searched MEDLINE and Embase from inception until December 26, 2023, for published randomized controlled trials comparing pharmacological interventions in patients with MASH that assessed changes in MRI-PDFF. The primary outcome was the absolute change in MRI-PDFF. The secondary outcome was a ≥30% decline in MRI-PDFF. A surface under-the-curve cumulative ranking probabilities (SUCRA) analysis was performed. Of 1550 records, a total of 39 randomized controlled trials (3311 participants) met the inclusion criteria. For MRI-PDFF decline at 24 weeks, aldafermin (SUCRA: 83.65), pegozafermin (SUCRA: 83.46), and pioglitazone (SUCRA: 71.67) were ranked the most effective interventions. At 24 weeks, efinopegdutide (SUCRA: 67.02), semaglutide + firsocostat (SUCRA: 62.43), and pegbelfermin (SUCRA: 61.68) were ranked the most effective interventions for achieving a ≥30% decline in MRI-PDFF.

CONCLUSIONS

This study provides an updated, relative rank-order efficacy of therapies for MASH in reducing hepatic fat. These data may help inform the design and sample size calculation of future clinical trials and assist in the selection of combination therapy.

Efficacy of pharmacologic interventions on magnetic resonance imaging biomarkers in patients with nonalcoholic fatty liver disease: systematic review and network meta-analysis

BACKGROUND AND AIM

Several agents are under investigation for nonalcoholic fatty liver disease (NAFLD). We assessed the comparative efficacy of pharmacologic interventions for patients with NAFLD focusing on magnetic resonance imaging (MRI) biomarkers.

METHODS

We searched Medline, Embase, and CENTRAL. We included randomized controlled trials of more than 12 weeks of intervention that recruited patients with biopsy-confirmed or MRI-confirmed NAFLD and assessed the efficacy of interventions on liver fat content (LFC) and fibrosis by means of MRI. We performed random-effects frequentist network meta-analyses and assessed confidence in our estimates using the CINeMA (Confidence in Network Meta-Analysis) approach.

RESULTS

We included 47 trials (8583 patients). Versus placebo, thiazolidinediones were the most efficacious for the absolute change in LFC, followed by vitamin E, fibroblast growth factor (FGF) analogs, and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with mean differences ranging from -7.46% (95% confidence interval [-11.0, -3.9]) to -4.36% (-7.2, -1.5). No differences between drug classes were evident. Patients receiving GLP-1 RAs or glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RAs were more likely to achieve ≥30% relative reduction in LFC. Among agents, efruxifermin produced the largest reduction in LFC compared to placebo [-13.5% (-18.5, -8.5)], followed by pioglitazone, while being superior to most interventions. The effect of interventions on magnetic resonance elastography assessed fibrosis was small and insignificant. The confidence in our estimates was low to very low.

CONCLUSIONS

Several drug classes may reduce LFC in patients with NAFLD without a significant effect on fibrosis; nevertheless, trial duration was small, and confidence in the effect estimates was low.

Efficacy and safety of aldafermin in non-alcoholic steatohepatitis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is an advanced subtype of non-alcoholic fatty liver disease (NAFLD). NASH prevalence is increasing exponentially and carries a high risk for disease progression, cirrhosis, and liver-related mortality. Aldafermin, a fibroblast growth factor 19 (FGF19) analog, is one of the evolving therapeutic agents with the potential to regulate multiple pathways involved in the pathogenesis of NASH. We aimed to investigate the efficacy and safety of aldafermin in patients with NASH.

METHODS

PubMed, Scopus, Cochrane Library, and Web of Science were searched till November 2023 to identify eligible randomized controlled trials (RCTs). Continuous data were pooled as mean difference (MD), while dichotomous data were pooled as risk ratios (RR) with a 95 % confidence interval. A subgroup meta-analysis was conducted to evaluate the efficacy of the two doses (1 mg and 3 mg) of aldafermin.

RESULTS

Four RCTs with a total of 491 patients were included. Aldafermin showed a dose-dependent improvement in the ≥30 % reduction in the liver fat content (RR: 2.16, 95 % CI [1.41 to 3.32]) and (RR: 5.00, 95 % CI [1.34 to 18.64]), alanine aminotransferase levels (MD: -19.79, 95 % CI [-30.28 to -9.3]) and (MD: -21.91, 95 % CI [-29.62 to -14.21]), aspartate aminotransferase levels (MD: -11.79, 95 % CI [-18.06 to -5.51]) and (MD: -13.9, 95 % CI [-18.59 to -9.21]), and enhanced liver fibrosis score (ELF) (MD: -0.13, 95 % CI [-0.29 to 0.02]) and (MD: -0.33, 95 % CI [-0.50 to -0.17]), in the 1 mg and 3 mg subgroups respectively. No significant differences were detected in the aldafermin group regarding histologic endpoints, lipid profile, metabolic parameters, and overall adverse effects, except for the increased occurrence of diarrhea in the aldafermin 3 mg subgroup.

CONCLUSION

Aldafermin is a promising well-tolerated therapeutic agent for NASH with evidence supporting its ability to reduce liver fat content, fibrosis serum biomarkers, and liver enzymes. However, its effectiveness in improving histologic fibrosis, while showing numerical trends, still lacks statistical significance. Larger and longer NASH trials are warranted to enhance the robustness of the evidence.

New and emerging treatments for metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is a leading etiology of chronic liver disease worldwide, with increasing incidence and prevalence in the setting of the obesity epidemic. MASH is also a leading indication for liver transplantation, given its associated risk of progression to end-stage liver disease. A key challenge in managing MASH is the lack of approved pharmacotherapy. In its absence, lifestyle interventions with a focus on healthy nutrition and regular physical activity have been the cornerstone of therapy. Real-world efficacy and sustainability of lifestyle interventions are low, however. Pharmacotherapy development for MASH is emerging with promising data from several agents with different mechanisms of action (MOAs) in phase 3 clinical trials. In this review, we highlight ongoing challenges and potential solutions in drug development for MASH and provide an overview of available data from emerging therapies across multiple MOAs.

Metabolic dysfunction-associated steatotic liver disease: An opportunity for collaboration between cardiology and hepatology

Altered metabolic function has many detrimental effects on the body that can manifest as cardiovascular and liver diseases. Traditional approaches to understanding and treating metabolic dysfunction-associated disorders have been organ-centered, leading to silo-type disease care. However, given the broad impact that systemic metabolic dysfunction has on the human body, approaches that simultaneously involve multiple medical specialists need to be developed and encouraged to optimize patient outcomes. In this review, we highlight how several of the treatments developed for cardiac care may have a beneficial effect on the liver and vice versa, suggesting that there is a need to target the disease process, rather than specifically target the cardiovascular or liver specific sequelae of metabolic dysfunction.

Tyrosol attenuates NASH features by reprogramming the hepatic immune milieu

Nonalcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease, and no drugs have been approved for its therapy. Among plant-derived molecules, phenolic compounds of extra virgin olive oil like tyrosol (Tyr) had demonstrated multiple beneficial actions for liver health, including the modulation of inflammation in fibrosis. This study aims at assessing the protective effect and mechanism of Tyr in invitro and in vivo models of NASH, with a focus on the hepatic immune microenvironment and extrahepatic manifestations. The effect of Tyr was evaluated in cellular models of NASH, obtained by co-culturing palmitic and oleic acid-treated HepG2 cells with THP1-derived M1 macrophages and LX2 cells, and in a mouse model of NASH induced by a high fructose-high fat diet combined to CCl4 treatment. In vitro Tyr reduced fatty acid (FA) accumulation in HepG2 cells and displayed a beneficial effect on LX2 activation and macrophage differentiation. In vivo, beside reducing steatosis and fibrosis in NASH animals, Tyr prevented inflammation, as demonstrated by the reduction of hepatic inflammatory foci, and immune cells like CD86+ macrophages (p < 0.05), CD4+ (p < 0.05) and T helper effector CD4+ FoxP3- CD62L-lymphocytes (p < 0.05). Also, the prooxidant enzyme NOX1 and the mRNA expression of TGF-β1 and IL6 (p < 0.05) were reduced by Tyr. Notably, in Tyr-treated animals, a significant increase of CD4+ FoxP3+ Treg cells (p < 0.05) was observed, involved in regenerative pathways. Moreover, Tyr attenuated the fatigue and anxious behavior observed in NASH mice. In conclusion, Tyr effectively reduced NASH-related steatosis, fibrosis, oxidative stress, and inflammation, displaying a beneficial effect on the hepatic immune infiltrate, indicating its possible development as a therapeutic agent for NASH due to its multifaceted mechanism.

Meta-analysis: Efficacy and safety of fibroblast growth factor 21 analogues for the treatment of non-alcoholic steatohepatitis and non-alcoholic steatohepatitis-related fibrosis

BACKGROUND

Fibroblast growth factor 21 (FGF21) analogues have emerged as promising therapeutic targets for non-alcoholic steatohepatitis (NASH). However, the effects and safety of these analogues on NASH and NASH-related fibrosis remain unexplored.

AIMS

To estimate the efficacy and safety of FGF21 analogues for treating NASH and NASH-related fibrosis.

METHODS

PubMed, Embase, and the Cochrane Library were searched for relevant studies up to 11 October 2023. Primary outcomes were defined as the fibrosis improvement ≥1 stage without worsening of NASH and NASH resolution without worsening fibrosis. Secondary outcomes included biomarkers of fibrosis, liver injury, and metabolism. Treatment-related adverse events were also analysed.

RESULTS

Nine studies, including 1054 patients with biopsy-proven NASH and stage F1-F4 fibrosis, were identified. Seven studies reported histological outcomes. The relative risk (RR) for obtaining fibrosis improvement ≥1 stage efficacy was 1.79 (95% CI 1.29-2.48, I2  = 37%, p < 0.001) with FGF21 analogues relative to placebo. Although no statistically significant difference was observed between FGF21 analogues in NASH resolution, sensitivity analyses and fragility index suggest that this result is unstable. The drugs improved hepatic fat fraction (HFF), along with other biomarkers of fibrosis, liver injury, and metabolism (MRE, LSM, Pro-C3, ELF, ALT, AST, TG, HDL-C, and LDL-C). Additionally, no significant difference in serious adverse event incidence rate was observed (RR = 1.26, 95% CI 0.82-1.94, I2  = 24%, p = 0.3).

CONCLUSIONS

FGF21 analogues appear as promising agents for the treatment of NASH and NASH-related fibrosis, and they generally seem to be safe and well tolerated.

Management of cardiovascular risk in patients with metabolic dysfunction-associated steatotic liver disease

The novel term Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is proposed to replace non-alcoholic fatty liver disease (NAFLD) to highlight the close association with the metabolic syndrome. MASLD encompasses patients with liver steatosis and at least one of five cardiometabolic risk factors which implies that these patients are at increased risk of cardiovascular disease (CVD). Indeed, the prevalence of CVD in MASLD patients is increased and CVD is recognized as the most common cause of death in MASLD patients. We here present an update on the pathophysiology of CVD in MASLD, discuss the risk factors, and suggest screening for CVD in patients with MASLD. Currently, there is no FDA-approved pharmacological treatment for MASLD, and no specific treatment recommended for CVD in patients with MASLD. Thus, the treatment strategy is based on weight loss and a reduction and treatment of CVD risk factors. We recommend screening of MASLD patients for CVD using the SCORE2 system with guidance to specific treatment algorithms. In all patients with CVD risk factors, lifestyle intervention to induce weight loss through diet and exercise is recommended. Especially a Mediterranean diet may improve hyperlipidemia and if further treatment is needed, statins should be used as first-line treatment. Further, anti-hypertensive drugs should be used to treat hypertension. With the epidemic of obesity and type 2 diabetes mellitus (T2DM) the risk of MASLD and CVD is expected to increase, and preventive measures, screening, and effective treatments are highly needed to reduce morbidity and mortality in MASLD patients.

The effect and safety of obeticholic acid for patients with nonalcoholic steatohepatitis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NASH) is one of the primary causes of chronic liver disease worldwide. Obeticholic acid (OCA), a potent farnesoid X nuclear receptor activator, has shown promise for treating NASH-related fibrosis due to its anti-fibrotic effects. This study aimed to examine the efficacy of OCA for patients with NASH as well as to investigate its impact on dyslipidemia.

METHOD

A search of databases including PubMed, Embase, and Cochrane Library from January 1, 2010, to November 1, 2022, was conducted to identify systematic reviews of randomized controlled trials involving NASH patients. Inclusion criteria comprised randomized controlled trials that specifically addressed NASH as diagnosed through magnetic resonance imaging, computed tomography, or histology. The results were then categorized, with consideration given to both biochemical and histological outcomes.

RESULT

Five NASH studies were ultimately selected for further analysis. In terms of biochemical indicators, patients receiving OCA treatment showed improvements in alanine transaminase (mean difference: -19.48, 95% confidence interval [CI]: -24.39 to 14.58; P < .05) and aspartate aminotransferase (mean difference: -9.22, 95% CI: -12.70 to 5.74; P < .05). As for histological improvement, OCA treatment reduced fibrosis (odds ratio [OR]: 1.95, 95% CI: 1.47-2.59; P = .001) and steatosis (OR: 1.95, 95% CI: 1.47-2.59; P = .001). No significant differences were observed regarding adverse events (1.44, 95% CI: 0.57-3.62; P > .001). Regarding dyslipidemia, mean differences between total cholesterol and low-density lipoprotein were found to be high (0.33, 95% CI: 0.01-0.64, P < .05; 0.39, 95% CI: 0.04-0.73, P < .05). In the case of pruritus, OCA achieved a high OR (3.22, 95% CI: 2.22-4.74) compared with placebo.

CONCLUSION

OCA also reduced several liver test markers compared to placebo, including the biochemical indicators alanine transaminase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase, and improved hepatocellular ballooning, fibrosis, steatosis, and lobular inflammation. Although the incidence of adverse events did not significantly differ between OCA and placebo groups among NASH patients, OCA treatment was found to elevate total cholesterol and low-density lipoprotein levels, and the reported severity of pruritus increased with higher doses of OCA.

New insights into metabolic dysfunction-associated steatotic liver disease and oxidative balance score

Background

The relationship between oxidative stress and metabolic dysfunction-associated steatotic liver disease (MASLD) has not been studied, which remains inadequately recognized. This is a cross-sectional study in a US adult population to explore the relationship between MASLD and oxidative balance scores (OBS), which containing integrating dietary nutrition and lifestyle factors.

Methods

We analyzed data from National Health and Nutrition Examination Survey during 2017-2018. Multivariate logistic regression, restricted cubic spline curve (RCS) and subgroup analysis were used to investigate the association between OBS and MASLD. Cox regression analysis was utilized to assess the association between OBS and all-cause mortality among individuals.

Results

The multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI) for the highest quartile of OBS (Q4) was 0.30 (0.12, 0.77) (p = 0.012) compared to the lowest quartile of OBS (Q1). The RCS regression and subgroup analysis indicated an inverted relationship between OBS and the development of MASLD. The OBS Q4 group (HR: 0.15, 95% CI: 0.03-0.87; p = 0.035) exhibited a lower risk of all-cause death than the Q1 group.

Conclusion

OBS is statistically significantly and negatively correlated with the risk of MASLD and all-cause mortality in US adults. More prospective investigations are required to substantiate our findings.

[Diagnosis and evaluation of metabolic dysfunction associated steatotic liver disease (MASLD)]

Non-alcoholic fatty liver disease (NAFLD) or recently called Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD), is the leading cause of liver disease, with an estimated worldwide prevalence of 25%. MASLD is suspected, in a metabolic condition, in the presence of hepatic steatosis, moderate hepatic cytolysis or hyperferritinemia. The severity of the disease depends on the stage of liver fibrosis, which can be suspected in clinical practice by simple blood tests such as the FIB-4 or NAFLD fibrosis Score. The treatment is based on lifestyle intervention combining weight loss, increased physical activity and a Mediterranean-style diet. Only a small minority of patients with MASLD will develop advanced liver disease and require liver specialist. Given the high prevalence of MASLD, the identification of these patients cannot be envisaged without the taking part in the screening of all physicians (general practitioners and specialists).

The role of anti-diabetic drugs in NAFLD. Have we found the Holy Grail? A narrative review

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of liver disease, affecting 30% of the global population. NAFLD prevalence is particularly high in obese individuals and patients with type 2 diabetes mellitus (T2DM). NAFLD ranges from simple fat deposition in the liver to necroinflammation and fibrosis (non-alcoholic steatohepatitis (NASH)), NASH-cirrhosis, and/or hepatocellular carcinoma. Insulin resistance plays a key role in NAFLD pathogenesis, alongside dysregulation of adipocytes, mitochondrial dysfunction, genetic factors, and changes in gut microbiota. Since insulin resistance is also a major predisposing factor of T2DM, the administration of anti-diabetic drugs for the management of NAFLD seems reasonable.

METHODS

In this review we provide the NAFLD-associated mechanisms of action of some of the most widely used anti-diabetic drugs, namely metformin, pioglitazone, sodium-glucose transport protein-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor analogs (GLP1 RAs), and dipeptyl-peptidase-4 inhibitors (DPP4i) and present available data regarding their use in patients with NAFLD, with and without T2DM.

RESULTS

Both metformin and DPP4i have shown rather contradictory results, while pioglitazone seems to benefit patients with NASH and is thus the only drug approved for NASH with concomitant significant liver fibrosis by all major liver societies. On the other hand, SGLT2i and GLP1 RAs seem to be beneficiary in patients with NAFLD, showing both remarkable results, with SGLT2i proving to be more efficient in the only head-to-head study so far.

CONCLUSION

In patients with NAFLD and diabetes, pioglitazone, GLP1 RAs, and SGLT2i seem to be logical treatment options. Larger studies are needed before these drugs can be recommended for non-diabetic individuals.

Potential therapeutic targets for nonalcoholic fatty liver disease: Glucagon-like peptide 1

Nonalcoholic fatty liver disease (NAFLD) is the most rapidly growing contributor to liver mortality and morbidity. Hepatocellular injury in nonalcoholic steatohepatitis (NASH) is caused by an increase in metabolic substrates (glucose, fructose, and fatty acids), leading fatty acids to participate in pathways that cause cellular injury and a poor response to injury. The pathogenesis of this disease is largely associated with obesity, type 2 diabetes, and increasing age. To date, there are no Food and Drug Administration-approved treatments for NAFLD/NASH or its associated fibrosis. Since one of the pathogenic drivers of NASH is insulin re-sistance, therapies approved for the treatment of type 2 diabetes are being evaluated in patients with NASH. Currently, the glucagon-like peptide-1 receptor agonist (GLP-1RA) semaglutide is a safe, well-studied therapeutic for NAFLD/ NASH patients. Existing research demonstrates that semaglutide can increase the resolution of NASH but not improve fibrosis. However, improving the fibrosis of NAFLD is the only way to improve the long-term prognosis of NAFLD. Given the complex pathophysiology of NASH, combining therapies with complementary mechanisms may be beneficial. Researchers have conducted trials of semaglutide in combination with antifibrotic drugs. However, the results have not fully met expectations, and it cannot be ruled out that the reason is the short trial time. We should continue to pay increasing attention to GLP-1RAs.

Comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging in patients with type 2 diabetes mellitus: systematic review and network meta-analysis

PURPOSE

To assess the comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging (MRI) in patients with T2D.

METHODS

We searched several databases and grey literature sources. Eligible trials had at least 12 weeks of intervention, included patients with T2D, and assessed the efficacy of glucose-lowering drugs as monotherapies. The primary outcome of interest was absolute reduction in liver fat content (LFC), assessed by means of MRI. Secondary efficacy outcomes were reduction in visceral and subcutaneous adipose tissue. We performed random effects frequentist network meta-analyses to estimate mean differences (MDs) with 95% confidence intervals (CIs). We ranked treatments based on P-scores.

RESULTS

We included 29 trials with 1906 patients. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors (P-score 0.84) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) (0.71) were the most efficacious in terms of liver fat content reduction. Among individual agents, empagliflozin was the most efficacious (0.86) and superior to pioglitazone (MD -5.7, 95% CI -11.2 to -0.3) (very low confidence). GLP-1 RAs had also the most favorable effects on visceral and subcutaneous adipose tissue.

CONCLUSIONS

GLP-1 RAs and SGLT-2 inhibitors seem to be the most efficacious glucose-lowering drugs for liver steatosis in patients with T2D. Assessment of their efficacy on NAFLD in patients irrespective of presence of T2D is encouraged.

Dietary and lifestyle oxidative balance scores are independently and jointly associated with nonalcoholic fatty liver disease: a 20 years nationally representative cross-sectional study

BACKGROUND

Oxidative stress is an important contributor to the progression of nonalcoholic fatty liver disease (NAFLD), but whether dietary and lifestyle pro- and antioxidants may have combined or independent effects on NAFLD, and advanced liver fibrosis (AHF) remains unclear. We aimed to elucidate the relationship between a well-established oxidative balance score (OBS) and NAFLD/AHF.

METHODS

This was a cross-sectional study. We included adult participants with complete data from the National Health and Nutrition Examination Survey 1999-2018. Survey-weighted adjusted multivariate regression analyses were used to examine the association of all OBS with NAFLD/AHF. A combination of restricted cubic splines, mediation analysis, stratified analysis, and sensitivity analysis were used to further elucidate these associations.

RESULTS

We included 6,341 eligible adult participants with prevalence of NAFLD and AHF of 30.2 and 13.9%, respectively. In the fully adjusted model, the highest quartile of OBS, dietary OBS, and lifestyle OBS were associated with 65, 55, and 77% reduced risk of NAFLD, respectively, compared with the reference population, respectively. However, all OBS were not associated with the risk of AHF. All OBS were nonlinearly associated with risk of NAFLD and had a more pronounced reduced risk for OBS, dietary OBS, and lifestyle OBS after exceeding 26, 21, and 5 points, respectively. OBS may exert a protective effect indirectly through inflammation, oxidative stress, and glycolipid metabolism markers. Stratification and sensitivity analyses demonstrate the robustness of our findings.

CONCLUSION

All OBS were nonlinearly and negatively associated with NAFLD risk. These effects may exert indirectly through inflammation, oxidative stress, and glycolipid metabolism markers.

The metabolic influence of duodenal mucosal resurfacing for nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease worldwide with decreased life expectancy. Duodenal mucosal resurfacing (DMR) has been associated with metabolic improvement in glycemic and hepatic parameters of type 2 diabetes, but the metabolic impact of DMR for NAFLD/NASH remains inconclusive. We conducted a meta-analysis to investigate metabolic effects of DMR in patients with NAFLD/NASH.

METHODS

Three major bibliographic databases were reviewed for enrollment of trials prior to January 28, 2022. We included adults with biopsy-proven NAFLD/NASH or liver magnetic resonance imaging proton density fat fraction (MRI-PDFF) >5% at baseline and focused on the metabolic difference of MRI-PDFF at 12 weeks, and HbA1c or homeostatic model assessment index for insulin resistance (HOMA-IR) at 24 weeks.

RESULTS

Two studies involved a total of 67 participants for analysis. When compared with pre-intervention status, mean difference of MRI-PDFF, HbA1c, and HOMA-IR after DMR were -2.22 (95% CI: -12.79~8.34), -0.32% (95% CI: -0.80~0.16), and 0.15 (95% CI: -5.11~5.41) without statistical significance.

CONCLUSIONS

For patients with NAFLD/NASH, DMR has the trend to improve liver fat at 12 weeks, and glycemic control in terms of HbA1c level at 24 weeks based on a very low quality of evidence.

The emerging significance of mitochondrial targeted strategies in NAFLD treatment

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, ranging from liver steatosis to nonalcoholic steatohepatitis, which ultimately progresses to fibrosis, cirrhosis, and hepatocellular carcinoma. Individuals with NAFLD have a higher risk of developing cardiovascular and extrahepatic cancers. Despite the great progress being made in understanding the pathogenesis and the introduction of new pharmacological targets for NAFLD, no drug or intervention has been accepted for its management. Recent evidence suggests that NAFLD may be a mitochondrial disease, as mitochondrial dysfunction is involved in the pathological processes that lead to NAFLD. In this review, we describe the recent advances in our understanding of the mechanisms associated with mitochondrial dysfunction in NAFLD progression. Moreover, we discuss recent advances in the efficacy of mitochondria-targeted compounds (e.g., Mito-Q, MitoVit-E, MitoTEMPO, SS-31, mitochondrial uncouplers, and mitochondrial pyruvate carrier inhibitors) for treating NAFLD. Furthermore, we present some medications currently being tested in clinical trials for NAFLD treatment, such as exercise, mesenchymal stem cells, bile acids and their analogs, and antidiabetic drugs, with a focus on their efficacy in improving mitochondrial function. Based on this evidence, further investigations into the development of mitochondria-based agents may provide new and promising alternatives for NAFLD management.

Vitamin E and Pioglitazone: A Comprehensive Systematic Review of Their Efficacy in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent worldwide, especially in people with obesity, dyslipidemia, type 2 diabetes mellitus (T2DM), and metabolic syndrome. Weight loss and dietary modifications are established first-line treatments for NAFLD. Currently, there is no approved drug for NAFLD; however, pioglitazone and vitamin E have shown some beneficial effects. This systematic review covers the comparative efficacies of vitamin E, pioglitazone, and vitamin E plus pioglitazone. As of December 2022, the sources for prior literature review included PubMed, PubMed Central, and Medline. We included studies assessing the efficacy of pioglitazone, vitamin E, and vitamin E plus pioglitazone in improving liver histology, liver markers, and lipid profile when compared to other interventions in patients with NAFLD/non-alcoholic steatohepatitis (NASH). Review materials include randomized control trials (RCTs), traditional reviews, systematic reviews, meta-analyses, and observational studies on human participants published within the last five years in the English language. Studies on animals, pediatric populations, and with insufficient data were excluded from the review. Two authors scanned and filtered articles independently and later performed quality checks. A third reviewer resolved any conflicts. The risk of bias was assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines for systematic reviews, the Cochrane Risk of Bias Tool for RCTs, and the Scale for the Assessment of Narrative Review Articles for Traditional Reviews. A total of 21 articles were shortlisted. The results showed that pioglitazone and vitamin E are effective in reducing steatosis, inflammation, and ballooning, reducing liver markers, but there seem to be conflicting data on fibrosis resolution. Pioglitazone decreases triglycerides and increases high-density lipoproteins. One study has suggested that pioglitazone has superior efficacy to vitamin E in fibrosis reduction and vitamin E plus pioglitazone has superior efficacy than pioglitazone alone for NASH resolution. However, these conclusions require further validation through extensive analysis and additional research. In conclusion, diabetic patients with NAFLD can be given pioglitazone, and non-diabetic patients with NAFLD can be given vitamin E.

The role of glucagon-like peptide-1 receptor agonists in nonalcoholic fatty liver disease

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent disease, associated with obesity, type 2 diabetes mellitus and dyslipidemia, which can lead to liver cirrhosis and hepatocellular carcinoma in some patients. Apart from lifestyle modifications, which are the cornerstone for its management, several drugs are under evaluation, including glucagon-like peptide-1 receptor agonists (GLP-R1RAs). In this review, we summarized major clinical data concerning the effects of GLP-1RAs on NAFLD, trying to highlight existing knowledge and to elucidate areas of uncertainty, thus providing clues to potential clinical implications and research.

AREAS COVERED

Selected clinical studies on GLP-R1As in NAFLD are presented in this narrative review.

EXPERT OPINION

There is evidence that treatment with GLP-R1As in NAFLD has beneficial effects on NAFLD, i.e. improvement in liver function tests and histological improvement in hepatic steatosis and inflammation, but not fibrosis. Further research is required toward the early use of GLP-R1Αs, i.e. in NAFLD patients without fibrosis to evaluate whether they may prevent the progression to fibrosis, or in patients with advanced disease in combination with other medications, which may have additive or even synergistic effects on NAFLD.

Comparison of glucagon-like peptide-1 receptor agonists and thiazolidinediones on treating nonalcoholic fatty liver disease: A network meta-analysis

BACKGROUND/AIMS

Previous studies have revealed that glucagon-like peptide-1 receptor agonist (GLP-1RA) and thiazolidinedione (TZD) can improve nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH). However, comprehensive research comparing the effects of GLP-1RA and TZD is limited. Thus, this study aimed to compare the effects of GLP-1RA and TZD on NAFLD or NASH through a network meta-analysis.

METHODS

The PubMed, Embase, Web of Science, and Scopus databases were searched for randomized controlled trials (RCTs) that explored the efficacy of GLP-1RAs or TZDs in adult patients with NAFLD or NASH. The outcomes were liver biopsy-based (NAFLD activity score [NAS], fibrosis stage, and NASH resolution), noninvasive technique-based (liver fat content on proton magnetic resonance spectroscopy [1H-MRS] and controlled attenuation parameter [CAP]), biological, and anthropometric indicators. A random effects model was used to calculate the mean difference (MD) and relative risk with 95% confidence interval (CI).

RESULTS

Twenty-five RCTs with 2,237 overweight or obese patients were included. GLP-1RA was significantly superior in reducing liver fat content evaluated using 1H-MRS (MD -2.42, 95% CI -3.84 to -1.00), body mass index (MD -1.60, 95% CI -2.41 to -0.80), and waist circumference (MD -4.89, 95% CI -8.17 to -1.61) than TZD. In liver biopsy-based evaluation and liver fat content assessment using CAP, GLP-1RA tended to surpass TZD, albeit not significantly. Sensitivity analysis showed consistent results with the main results.

CONCLUSION

Compared with TZD, GLP-1RA had better effects on liver fat content, body mass index, and waist circumference in overweight or obese patients with NAFLD or NASH.

Efruxifermin, an investigational treatment for fibrotic or cirrhotic non-alcoholic steatohepatitis (NASH)

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease and strongly associated with metabolic disorders: obesity, type 2 diabetes (T2D), cardiovascular disease. Persistent metabolic injury results in inflammatory processes leading to nonalcoholic steatohepatitis (NASH), liver fibrosis and ultimately cirrhosis. To date, no pharmacologic agent is approved for the treatment of NASH. Fibroblast growth factor 21 (FGF21) agonism has been linked to beneficial metabolic effects ameliorating obesity, steatosis and insulin resistance, supporting its potential as a therapeutic target in NAFLD.

AREAS COVERED

Efruxifermin (EFX, also AKR-001 or AMG876) is an engineered Fc-FGF21 fusion protein with an optimized pharmacokinetic and pharmacodynamic profile, which is currently tested in several phase 2 clinical trials for the treatment of NASH, fibrosis and compensated liver cirrhosis. EFX improved metabolic disturbances including glycemic control, showed favorable safety and tolerability, and demonstrated antifibrotic efficacy according to FDA requirements for phase 3 trials.

EXPERT OPINION

While some other FGF-21 agonists (e.g. pegbelfermin) are currently not further investigated, available evidence supports the development of EFX as a promising anti-NASH drug in fibrotic and cirrhotic populations. However, antifibrotic efficacy, long-term safety and benefits (i.e. cardiovascular risk, decompensation events, disease progression, liver transplantation, mortality) remain to be determined.

AGER1 deficiency-triggered ferroptosis drives fibrosis progression in nonalcoholic steatohepatitis with type 2 diabetes mellitus

Hyperglycemia is an independent risk factor for the rapid progression of nonalcoholic steatohepatitis (NASH) to liver fibrosis with an incompletely defined mechanism. Ferroptosis is a novel form of programmed cell death that has been identified as a pathogenic mechanism in various diseases. However, the role of ferroptosis in the development of liver fibrosis in NASH with type 2 diabetes mellitus (T2DM) is unclear. Here, we observed the histopathological features of the progression of NASH to liver fibrosis as well as hepatocyte epithelial-mesenchymal transition (EMT) in a mouse model of NASH with T2DM and high-glucose-cultured steatotic human normal liver (LO2) cells. The distinctive features of ferroptosis, including iron overload, decreased antioxidant capacity, the accumulation of reactive oxygen species, and elevated lipid peroxidation products, were confirmed in vivo and in vitro. Liver fibrosis and hepatocyte EMT were markedly alleviated after treatment with the ferroptosis inhibitor ferrostatin-1. Furthermore, a decrease in the gene and protein levels of AGE receptor 1 (AGER1) was detected in the transition from NASH to liver fibrosis. Overexpression of AGER1 dramatically reversed hepatocyte EMT in high-glucose-cultured steatotic LO2 cells, whereas the knockdown of AGER1 had the opposite effect. The mechanisms underlying the phenotype appear to be associated with the inhibitory effects of AGER1 on ferroptosis, which is dependent on the regulation of sirtuin 4. Finally, in vivo adeno-associated virus-mediated AGER1 overexpression effectively relieved liver fibrosis in a murine model. Collectively, these findings suggest that ferroptosis participates in the pathogenesis of liver fibrosis in NASH with T2DM by promoting hepatocyte EMT. AGER1 could reverse hepatocyte EMT to ameliorate liver fibrosis by inhibiting ferroptosis. The results also suggest that AGER1 may be a potential therapeutic target for the treatment of liver fibrosis in patients with NASH with T2DM. Chronic hyperglycemia is associated with increased advanced glycation end products, resulting in the downregulation of AGER1. AGER1 deficiency downregulates Sirt4, which disturbs key regulators of ferroptosis (TFR-1, FTH, GPX4, and SLC7A11). These lead to increased iron uptake, decreasing the antioxidative capacity and enhanced lipid ROS production, ultimately leading to ferroptosis, which further promotes hepatocyte epithelial-mesenchymal transition and fibrosis progression in NASH with T2DM.

Exercise Is Medicine for Nonalcoholic Fatty Liver Disease: Exploration of Putative Mechanisms

Exercise remains a key component of nonalcoholic fatty liver disease (NAFLD) treatment. The mechanisms that underpin improvements in NAFLD remain the focus of much exploration in our attempt to better understand how exercise benefits patients with NAFLD. In this review, we summarize the available scientific literature in terms of mechanistic studies which explore the role of exercise training in modulating fatty acid metabolism, reducing hepatic inflammation, and improving liver fibrosis. This review highlights that beyond simple energy expenditure, the activation of key receptors and pathways may influence the degree of NAFLD-related improvements with some pathways being sensitive to exercise type, intensity, and volume. Importantly, each therapeutic target of exercise training in this review is also the focus of previous or ongoing drug development studies in patients with nonalcoholic steatohepatitis (NASH), and even when a regulatory-agency-approved drug comes to market, exercise will likely remain an integral component in the clinical management of patients with NAFLD and NASH.

Current Treatment Options, Including Diet, Exercise, and Medications: The Impact on Histology

Paralleling the rise in obesity and diabetes, nonalcoholic fatty liver disease (NAFLD) is now the most prevalent chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH), the progressive form of NAFLD, may progress to cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Despite its public health treat, no approved pharmacotherapies for NAFLD/NASH currently exist. Although the armamentarium of therapies for NASH is limited, current treatment options include life-style modification and the use of medications to treat metabolic comorbidities. This review addresses current approaches to the treatment of NAFLD/NASH, including the impact of diet, exercise, and available pharmacotherapies on the histologic features of liver injury.

An integrated view of anti-inflammatory and antifibrotic targets for the treatment of NASH

Successful development of treatments for non-alcoholic fatty liver disease (NAFLD) and its progressive form, non-alcoholic steatohepatitis (NASH) has been challenging. Because NASH and fibrosis lead to NAFLD progression towards cirrhosis and to clinical outcomes, approaches have either sought to attenuate metabolic dysregulation and cell injury, or directly target the inflammation and fibrosis that ensue. Targets for reducing the activation of inflammatory cascades include nuclear receptor agonists (thyroid hormone receptor-beta, e.g. resmetirom, peroxisome proliferator-activated receptor [PPAR], e.g. lanifibranor, farnesoid X receptor [FXR], e.g. obeticholic acid), modulators of lipotoxicity (e.g. aramchol, acetyl-CoA carboxylase inhibitors) or modification of genetic variants (e.g. PNPLA3 gene silencing). Extrahepatic inflammatory signals from circulation, adipose tissue or gut are targets of hormonal agonists (e.g. glucagon-like peptide-1 [GLP-1] like semaglutide, fibroblast growth factor [FGF]-19 or FGF21), microbiota or lifestyle (weight loss, diet, exercise) interventions. Stress signals and hepatocyte death activate immune responses engaging innate (macrophages, lymphocytes) and adaptive (auto-aggressive T-cells) mechanisms. Therapies seek to blunt immune cell activation, recruitment (chemokine receptor inhibitors) and responses (e.g. galectin 3 inhibition, anti-platelet drugs). The disease-driving pathways of NASH converge to elicit fibrosis, which is reversible. The activation of hepatic stellate cells (HSC) into matrix-producing myofibroblasts can be inhibited by antagonizing soluble factors (e.g. integrins, cytokines), cellular crosstalk (e.g. with macrophages), and agonizing nuclear receptor signaling (e.g. FXR or PPAR agonists). In advanced fibrosis, cell therapy with restorative macrophages or reprogrammed T-cells (e.g., CAR T) may accelerate repair through HSC deactivation or killing, or by enhancing matrix degradation. Heterogeneity of disease - either due to genetics or divergent disease drivers - is an obstacle to defining effective drugs for all patients with NASH that will be incrementally overcome.

Pharmacotherapeutic efficacy on noninvasive fibrosis progression in nonalcoholic fatty liver disease: a systematic review and network meta-analysis

BACKGROUND

Fibrosis impacts long-term outcomes among patients with nonalcoholic fatty liver disease (NAFLD). Due to well-documented flaws associated with liver biopsy, there has been a recent emphasis on prioritizing noninvasive testing over liver biopsy for the assessment of fibrosis.

METHODS

A comprehensive systematic review and frequentist random effects network meta-analysis was performed among randomized controlled trials reporting pharmacologic intervention in NAFLD. The primary endpoint was the absolute change in liver stiffness measurement (LSM) via elastography. Secondary endpoints included changes in noninvasive serologic tests including APRI, fibrosis-4 index, NAFLD fibrosis score, enhanced liver fibrosis (ELF) and FibroTest (FibroSure in the USA).

RESULTS

Forty-five randomized controlled trials enrolling 6932 patients were identified for this network meta-analysis. Across the primary endpoint, firsocostat, semaglutide, montelukast, cilofexor plus firsocostat, obeticholic acid and diacerein (change in LSM via vibration controlled transient elastography), in addition to lubiprostone and pemafibrate (change in LSM via magnetic resonance elastography) were found to be the most effective and statistically significant treatment interventions. Similarly, the following interventions were determined to be most effective as compared to placebo among secondary endpoints: saroglitazar, lubiprostone, and obeticholic acid (change in APRI); saroglitazar, semaglutide, firsocostat and cilofexor plus firsocostat (change in ELF); obeticholic acid and belapectin [change in FibroTest/FibroSure].

CONCLUSION

This is the first systematic review and network meta-analysis reporting pharmacologic efficacy in the progression of fibrosis based on noninvasive testing among patients with NAFLD. Semaglutide, obeticholic acid, firsocostat, cilofexor plus firsocostat and lubiprostone were found to be the most effective treatments based on their consistent efficacy reproduced across multiple endpoints, both via elastography and noninvasive blood tests.

Side effect profile of pharmacologic therapies for liver fibrosis in nonalcoholic fatty liver disease: a systematic review and network meta-analysis

Several studies have found that antifibrosis treatment for nonalcoholic fatty liver disease (NAFLD) can cause a variety of side effects. No network meta-analysis (NMA) analyzes the adverse events of antifibrotic drugs for NAFLD. This NMA aimed to systematically compare the drug-related side effects when using different pharmacological agents for the treatment of liver fibrosis in NAFLD. PubMed, EMBASE, Web of Science and Cochrane Library were systematically searched to select related studies published in English from the database inception until 30 June 2022. We conducted Bayesian fixed-effects NMA using data from randomized controlled trials (RCTs) to derive relative risks (RRs). The surface under the cumulative ranking (SUCRA) probabilities was used to assess ranking. A total of 26 RCTs with 19 interventions met the inclusion criteria. SUCRA analysis suggested that the lanifibranor group had the highest risk of diarrhea (SUCRA, 94), whereas the liraglutide group had the highest risk of constipation (SUCRA, 92.9). The semaglutide group showed the highest incidence of nausea (SUCRA, 81.2) and abdominal pain (SUCRA, 90.5), respectively. The cenicriviroc group showed the highest risk in the incidence of fatigue (SUCRA, 82.4). The MSDC-0602K group had the highest risk of headache (SUCRA, 76.4), whereas the obeticholic acid group had the highest risk of pruritus (SUCRA, 80.1). The risk of side effects significantly varied among different pharmacologic regimens, and evidence showed that lanifibranor, liraglutide, semaglutide, cenicriviroc, MSDC-0602K and obeticholic acid were the pharmacological interventions with the highest risk in patients with NAFLD. This study may guide clinicians and support further research.

Non-alcoholic fatty liver disease screening in type 2 diabetes mellitus: A cost-effectiveness and price threshold analysis

Introduction: The cost-effectiveness of screening asymptomatic non-alcoholic fatty liver disease (NAFLD) patients remains debatable, with current studies assuming lifelong benefits of NAFLD screening while neglecting cardiovascular outcomes. This study aims to assess the cost-effectiveness of NAFLD screening among type 2 diabetes mellitus (T2DM) patients, and to establish a price threshold for NAFLD treatment, when it becomes available. Method: A Markov model was constructed comparing 4 screening strategies (versus no screening) to identify NAFLD with advanced fibrosis among T2DM patients: fibrosis-4 (FIB-4), vibration-controlled transient elastography (VCTE), FIB-4 and VCTE (simultaneous), and FIB-4 and VCTE (sequential). Sensitivity analyses and price threshold analyses were performed to assess parameter uncertainties in the results. Results: VCTE was the most cost-effective NAFLD screening strategy (USD24,727/quality-adjusted life year [QALY]), followed by FIB-4 (USD36,800/QALY), when compared to no screening. Probabilistic sensitivity analysis revealed a higher degree of certainty for VCTE as a cost-effective strategy compared to FIB-4 (90.7% versus 73.2%). The duration of expected screening benefit is the most influential variable based on incremental cost-effectiveness ratio tornado analysis. The minimum duration of screening benefit for NAFLD screening to be cost-effective was at least 2.6 years. The annual cost of NAFLD treatment should be less than USD751 for NAFLD screening to be cost-effective. Conclusion: Both VCTE and FIB-4 are cost-effective NAFLD screening strategies among T2DM patients in Singapore. However, given the lack of access to VCTE at primacy care and potential budget constraints, FIB-4 can also be considered for NAFLD screening among T2DM patients in Singapore. Keywords: Cost-effectiveness analysis, fatty liver, screening, liver fibrosis, population health

Exosomal microRNAs and Progression of Nonalcoholic Steatohepatitis (NASH)

Nonalcoholic fatty liver disease (NAFLD)/metabolic associated fatty liver disease (MAFLD) is becoming a public health problem worldwide. Steatosis as the simple form and nonalcoholic steatohepatitis (NASH) as its progression form are commonly seen in liver biopsy specimens from patients with obesity, diabetes, hyperlipidemia, hypertension, and the use of certain drugs. Patients with NASH and advanced fibrosis were associated with increased risks of liver-related complications, including hepatocellular carcinoma (HCC). However, the mechanisms regarding the progression from simple steatosis to NASH fibrosis remain incompletely understood. Because NASH-caused liver injury is a complex process and multiple cell types are involved, intercellular communication is likely mediated by extracellular vesicles. Exosomes are a type of small extracellular vesicles and contain various cellular molecules, including proteins, messenger RNAs (mRNAs), and microRNAs (miRNAs). MiRNAs are short, non-coding RNA species that are important post-transcriptional regulators of gene expression and may play an important role in the pathogenesis of NALFD/NASH. In this article, we review the articles about NASH and exosomal miRNAs published in the most recent English literature through PubMed search and discuss the most recent criteria for histological diagnosis, pathogenesis from steatosis to NASH, roles of exosomal miRNAs in NASH pathogenesis and progression, as well as their potential in future clinical diagnosis and treatment for patients with NASH.

NAFLD in Cardiovascular Diseases: A Contributor or Comorbidity?

Nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases are both highly prevalent conditions around the world, and emerging data have shown an association between them. This review found several longitudinal and cross-sectional studies showing that NAFLD was associated with coronary artery disease, cardiac remodeling, aortic valve remodeling, mitral annulus valve calcifications, diabetic cardiomyopathy, diastolic cardiac dysfunction, arrhythmias, and stroke. Although the specific underlying mechanisms are not clear, many hypotheses have been suggested, including that metabolic syndrome might act as an upstream metabolic defect, leading to end-organ manifestations in both the heart and liver. Management of NAFLD includes weight loss through lifestyle interventions or bariatric surgery, and pharmacological interventions, often targeting comorbidities. Although there are no Food and Drug Administration-approved nonalcoholic steatohepatitis-specific therapies, several drug candidates have demonstrated effect in the improvement in fibrosis or nonalcoholic steatohepatitis resolution. Further studies are needed to assess the effect of those interventions on cardiovascular outcomes, the major cause of mortality in patients with NAFLD. In conclusion, a more comprehensive, multidisciplinary approach to diagnosis and management of patients with NAFLD and cardiovascular diseases is needed to optimize clinical outcomes.

Fecal Microbiota Transplantation in NAFLD Treatment

Introduction: Gut microbiota is not only a taxonomic biologic ecosystem but is also involved in human intestinal and extra-intestinal functions such as immune system modulation, nutrient absorption and digestion, as well as metabolism regulation. The latter is strictly linked to non-alcoholic fatty liver disease (NAFLD) pathophysiology. Materials and methods: We reviewed the literature on the definition of gut microbiota, the concepts of “dysbiosis” and “eubiosis”, their role in NAFLD pathogenesis, and the data on fecal microbiota transplantation (FMT) in these patients. We consulted the main medical databases using the following keywords, acronyms, and their associations: gut microbiota, eubiosis, dysbiosis, bile acids, NAFLD, and FMT. Results: Gut microbiota qualitative and quantitative composition is different in healthy subjects vs. NALFD patients. This dysbiosis is associated with and involved in NAFLD pathogenesis and evolution to non-acoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma (HCC). In detail, microbial-driven metabolism of bile acids (BAs) and interaction with hepatic and intestinal farnesoid nuclear X receptor (FXR) have shown a determinant role in liver fat deposition and the development of fibrosis. Over the use of pre- or probiotics, FMT has shown preclinical and initial clinical promising results in NAFLD treatment through re-modulation of microbial dysbiosis. Conclusions: Promising clinical data support a larger investigation of gut microbiota dysbiosis reversion through FMT in NAFLD using randomized clinical trials to design precision-medicine treatments for these patients at different disease stages.

Pharmacotherapy for Non-alcoholic Fatty Liver Disease Associated with Diabetes Mellitus Type 2

Non-alcoholic fatty liver disease (NAFLD) and diabetes mellitus type 2 commonly coexist as a manifestation of metabolic syndrome. The presence of diabetes promotes the progression of simple fatty liver to non-alcoholic steatohepatitis (NASH) and cirrhosis, and the presence of NAFLD increases the risk of diabetic complications. This coexistence affects a large part of the population, imposing a great burden on health care systems worldwide. Apart from diet modification and exercise, recent advances in the pharmacotherapy of diabetes offer new prospects regarding liver steatosis and steatohepatitis improvement, enriching the existing algorithm and supporting a multifaceted approach to diabetic patients with fatty liver disease. These agents mainly include members of the families of glucagon-like peptide-1 analogues and the sodium-glucose co-transporter-2 inhibitors. In addition, agents acting on more than one receptor simultaneously are presently under study, in an attempt to further enhance our available options.

Effect of pharmacological interventions and placebo on liver Histology in nonalcoholic steatohepatitis: A network meta-analysis

BACKGROUND

The aims of this study were to quantify the histological improvement and its risk factors in patients with NASH enrolled in the placebo arms of randomized controlled trials (RCTs), and to indirectly compare the effect of several investigational drugs for NASH on validated histological outcomes.

DATA SYNTHESIS

A comprehensive search was conducted to detect phase 2 and 3 RCTs comparing pharmacological interventions in patients with NASH. According to Food and Drug Administration (FDA) recommendations, primary outcomes included: 1) NASH resolution without worsening of fibrosis; 2) At least 1-point reduction in fibrosis without worsening of NASH. Meta-analysis and meta-regressions were conducted on placebo arms, while network meta-analysis was performed on intervention arms. A total of 15 RCTs met the eligibility criteria. The meta-analysis on placebo arms showed a pooled estimate rate of 17% (95%C.I. 12%-23%;I2 = 86%; p < 0.01) for NASH resolution without worsening of fibrosis and of 21% (95%C.I. 13%-31%;I2 = 84%; p < 0.01) for ≥1stage improvement of fibrosis without worsening of NASH. Phase 3 (vs Phase 2)RCTs, older age and higher AST levels were significantly associated with progression of liver disease by univariate meta-regression. At network meta-analysis, Semaglutide (P-score 0.906), Pioglitazione alone (score 0.890) and plus Vitamin E (0.826) had the highest probability of being ranked the most effective intervention for NASH resolution without worsening of fibrosis, while Aldafermin (0.776), Lanifibranor (0.773) and Obeticholic acid (0.771) had the highest probability to achieve ≥1 stage of fibrosis improvement without worsening of NASH.

CONCLUSION

This study confirms the heterogeneity of histological progression of untreated patients with NASH and provides evidence to stratify patients according to identified risk factors in future RCTs of combination therapies. PROSPERO CRD42021287205.

Effects of Maternal Gut Microbiota-Targeted Therapy on the Programming of Nonalcoholic Fatty Liver Disease in Dams and Fetuses, Related to a Prenatal High-Fat Diet

Metabolic disorders can start in utero. Maternal transmission of metabolic phenotypes may increase the risks of adverse metabolic outcomes, such as nonalcoholic fatty liver disease (NAFLD); effective intervention is essential to prevent this. The gut microbiome plays a crucial role in fat storage, energy metabolism, and NAFLD. We investigated the therapeutic use of probiotic Lactobacillus reuteri and postbiotic butyrate gestation in the prevention of perinatal high-fat diet-induced programmed hepatic steatosis in the offspring of pregnant Sprague–Dawley rats who received regular chow or a high-fat (HF) diet 8 weeks before mating. L. reuteri or sodium butyrate was administered via oral gavage to the gestated rats until their sacrifice on day 21 of gestation. Both treatments improved liver steatosis in pregnant dams; L. reuteri had a superior effect. L. reuteri ameliorated obesity and altered the metabolic profiles of obese gravid dams. Maternal L. reuteri therapy prevented maternal HF diet-induced fetal liver steatosis, and reformed placental remodeling and oxidative injury. Probiotic therapy can restore lipid dysmetabolism in the fetal liver, modulate nutrient-sensing molecules in the placenta, and mediate the short-chain fatty acid signaling cascade. The therapeutic effects of maternal L. reuteri on maternal NAFLD and NAFLD reprogramming in offspring should be validated for further clinical translation.

Anti-obesity Medications for the Management of Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Obesity is closely associated with nonalcoholic fatty liver disease (NAFLD), a highly prevalent disease without any approved medication. The aim of this review was to summarize the evidence on the effect of anti-obesity medications on NAFLD, especially focusing on hepatic histology.

RECENT FINDINGS

Orlistat and some glucagon-like peptide-1 receptor analogs, including liraglutide and semaglutide, have beneficial effects on hepatic steatosis and inflammation, but not fibrosis. Other anti-obesity medications, including lorcaserin, setmelanotide, phentermine hydrochloric, phentermine/topiramate, and naltrexone/bupropion, have been minimally investigated in NAFLD. Furthermore, medications like sodium-glucose cotransporter-2 inhibitors and farnesoid X receptor have shown beneficial effects in both NAFLD and obesity, but they have not been licensed for either disease. Liraglutide, semaglutide, and orlistat may be currently used in selected patients with obesity and NAFLD. Further research is warranted, since targeting obesity may provide additional benefits on its comorbidities, including NAFLD.

Pharmacotherapeutic Impact on Nonalcoholic Steatohepatitis Histology: A Systematic Review and Network Meta-analysis

Background

Due to lack of targeted treatment options and inconsistent utilization of histologic endpoints among clinical trials, identifying efficacious pharmacotherapies for nonalcoholic steatohepatitis [NASH] has proven challenging.

Methods

A thorough systematic review and frequentist random-effects network meta-analysis was performed across all randomized clinical trials reporting a pharmacotherapeutic intervention on biopsy-proven NASH. Primary outcomes were based on the most current, up-to-date recommended histologic endpoints.

Results

A total of 40 RCTs were identified including 6593 total patients. The most effective and statistically significant treatment interventions for minimum two-point improvement in NAFLD Activity Score were aldafermin 1 mg [RR 7.69, 95% CI 2.00; 29.57], vitamin E 800 IU in combination with pioglitazone 45 mg [RR 3.38, 95% CI 1.88; 6.07], pioglitazone 45 mg [RR 3.29, 95% CI 1.74; 6.22], vitamin E 800 IU [RR 2.06, 95% CI 1.33; 3.18], resmetirom 80 mg [RR 1.74, 95% CI 1.03; 2.94], obeticholic acid 25 mg [RR 1.63, 95% CI 1.32; 2.01], and obeticholic acid 10 mg [RR 1.31, 95% CI 1.02; 1.67]). The most robust pharmacotherapies for NASH resolution without worsening fibrosis were found to be aldafermin 1 mg [RR 5.77, 95% CI 1.48; 22.51], pioglitazone 45 mg [RR 2.65, 95% CI 1.43; 4.91], vitamin E 800 IU in combination with pioglitazone 45 mg [RR 2.64, 95% CI 1.36; 5.12], pioglitazone 30 mg [RR 2.46, 95% CI 1.56; 3.88], vitamin E 800 IU [RR 1.90, 95% CI 1.20; 3.00], and obeticholic acid 25 mg [RR 1.52, 95% CI 1.03; 2.23]). Obeticholic acid had a significant improvement on fibrosis. Multiple interventions were found to improve individual histologic scores across secondary outcome analyses and are detailed below.

Conclusion

This novel systematic review and network meta-analysis represents the most comprehensive investigation to date regarding the pharmacotherapeutic options for biopsy-proven NASH using current recommended histologic endpoints.