Old and new classes of glucose-lowering agents as treatments for non-alcoholic fatty liver disease: A narrative review

The Triad of Risk: Linking MASLD, Cardiovascular Disease and Type 2 Diabetes; From Pathophysiology to Treatment

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an emerging global health concern, and it is not only the keystone precursor of eventual liver-related morbidity, but it also places patients at considerably higher cardiovascular risk, which is still a leading cause of death in these patients. The most important common underlying pathophysiological mechanisms in these diseases are primarily related to insulin resistance, chronic inflammation and oxidative stress. The presence of MASLD with cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) elevates the risk for poor outcomes, thus this review highlights a method to the therapeutic approaches. Given the intertwined nature of MASLD, T2DM, and CVD, there is an urgent need for therapeutic strategies that address all three conditions. Although lifestyle changes are important as treatment, medication plays a crucial role in managing hyperglycemia, enhancing liver function and lowering cardiovascular risk. The onset and progression of MASLD should be addressed through a multifaceted therapeutic approach, targeting inflammatory, immune, metabolic, oxidative stress, hormonal and gutaxis pathways, alongside the treatment strategies for T2DM. In this review, we discuss the effects of antidiabetic drugs with an impact on both liver outcomes and cardiovascular risk in patients affected by MASLD, T2DM and CDV.

Protective Effects of Plum on Liver and Gut Injury in Metabolic Dysfunction-Associated Fatty Liver Disease

Metabolic dysfunction-associated fatty liver disease (MASLD), a persistent liver condition associated with metabolic syndrome, is primarily caused by excessive fructose intake and a typical Western diet. Because there is currently only one approved treatment, lifestyle and dietary interventions are crucial. This study assessed the effects of dietary intervention involving freeze-dried plum (FDP), a natural source of antioxidants containing diverse polyphenols. This study aimed to assess its potential as a protective agent against the gut-liver axis and its therapeutic effects on liver injury and gut permeability issues associated with MASLD. We indicate that 10% FDP intake restored gut barrier proteins and reduced serum endotoxin levels in the MASLD mouse models. Additionally, 10% FDP intake significantly reduced hepatic oxidative stress, lipid metabolism, and fibrosis marker levels. Interestingly, FDP intake significantly reduced the levels of inflammatory cytokine tumor necrosis factor-α and markers of liver damage, such as serum alanine aminotransferase/aspartate aminotransferase and hepatic triglycerides. These results highlight that dietary intervention with FDP that acts as a natural antioxidant may be a significant protective and therapeutic agent against liver and gut damage caused by MASLD.

AI-based digital pathology provides newer insights into lifestyle intervention-induced fibrosis regression in MASLD: An exploratory study

BACKGROUND AND AIMS

Lifestyle intervention is the mainstay of therapy for metabolic dysfunction-associated steatohepatitis (MASH), and liver fibrosis is a key consequence of MASH that predicts adverse clinical outcomes. The placebo response plays a pivotal role in the outcome of MASH clinical trials. Second harmonic generation/two-photon excitation fluorescence (SHG/TPEF) microscopy with artificial intelligence analyses can provide an automated quantitative assessment of fibrosis features on a continuous scale called qFibrosis. In this exploratory study, we used this approach to gain insight into the effect of lifestyle intervention-induced fibrosis changes in MASH.

METHODS

We examined unstained sections from paired liver biopsies (baseline and end-of-intervention) from MASH individuals who had received either routine lifestyle intervention (RLI) (n = 35) or strengthened lifestyle intervention (SLI) (n = 17). We quantified liver fibrosis with qFibrosis in the portal tract, periportal, transitional, pericentral, and central vein regions.

RESULTS

About 20% (7/35) and 65% (11/17) of patients had fibrosis regression in the RLI and SLI groups, respectively. Liver fibrosis tended towards no change or regression after each lifestyle intervention, and this phenomenon was more prominent in the SLI group. SLI-induced liver fibrosis regression was concentrated in the periportal region.

CONCLUSION

Using digital pathology, we could detect a more pronounced fibrosis regression with SLI, mainly in the periportal region. With changes in fibrosis area in the periportal region, we could differentiate RLI and SLI patients in the placebo group in the MASH clinical trial. Digital pathology provides new insight into lifestyle-induced fibrosis regression and placebo responses, which is not captured by conventional histological staging.

Metabolic dysfunction-associated fatty liver disease: bridging cardiology and hepatology

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases, affecting approximately 30% of the global adult population, with a rise largely attributed to increasing rates of obesity and diabetes worldwide. Historically, the term “NAFLD” did not explicitly link the condition to its most common causes, such as obesity and diabetes, or its principal pathophysiological mechanisms, including insulin resistance and low-grade chronic metabolic inflammation. This semantic laxity has potentially reduced attempts at screening, diagnosis, and management. The shift to using the terms metabolic-associated fatty liver disease (MAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) reflects a more accurate understanding of the condition’s metabolic origins and highlights its broader implications, particularly its link to cardiovascular diseases. MAFLD/MASLD represents a convergence point between hepatology and cardiology, with metabolic dysfunction serving as the bridge between liver pathology and increased cardiovascular risk. Growing clinical evidence reveals a strong association between MAFLD/MASLD and cardiovascular morbidity and mortality. Despite this, cardiovascular risks associated with MAFLD/MASLD are often underestimated, especially among cardiologists. This narrative review explores the potential clinical implications of MAFLD/MASLD for cardiology practice, examining diagnostic criteria, cardiovascular risk assessment, adjustments in clinical practice, collaborative care strategies, treatment options, and directions for future research.

Current status and future trends of the global burden of MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most common chronic liver disease globally, affecting more than a third of the world's adult population. This comprehensive narrative review summarizes the global incidence and prevalence rates of MASLD and its related adverse hepatic and extrahepatic outcomes. We also discuss the substantial economic burden of MASLD on healthcare systems, thus further highlighting the urgent need for global efforts to tackle this common and burdensome liver condition. We emphasize the clinical relevance of early interventions and a holistic approach that includes public health strategies to reduce the global impact of MASLD.

Mechanism of Action of Dihydroquercetin in the Prevention and Therapy of Experimental Liver Injury

Liver disease is a global health problem that affects the well-being of tens of thousands of people. Dihydroquercetin (DHQ) is a flavonoid compound derived from various plants. Furthermore, DHQ has shown excellent activity in the prevention and treatment of liver injury, such as the inhibition of hepatocellular carcinoma cell proliferation after administration, the normalization of oxidative indices (like SOD, GSH) in this tissue, and the down-regulation of pro-inflammatory molecules (such as IL-6 and TNF-α). DHQ also exerts its therapeutic effects by affecting molecular pathways such as NF-κB and Nrf2. This paper discusses the latest research progress of DHQ in the treatment of various liver diseases (including viral liver injury, drug liver injury, alcoholic liver injury, non-alcoholic liver injury, fatty liver injury, and immune liver injury). It explores how to optimize the application of DHQ to improve its effectiveness in treating liver diseases, which is valuable for preparing potential therapeutic drugs for human liver diseases in conjunction with DHQ.

MAFLD Pandemic: Updates in Pharmacotherapeutic Approach Development

With around one billion of the world's population affected, the era of the metabolic-associated fatty liver disease (MAFLD) pandemic has entered the global stage. MAFLD is a chronic progressive liver disease with accompanying metabolic disorders such as type 2 diabetes mellitus and obesity which can progress asymptomatically to liver cirrhosis and subsequently to hepatocellular carcinoma (HCC), and for which to date there are almost no approved pharmacologic options. Because MAFLD has a very complex etiology and it also affects extrahepatic organs, a multidisciplinary approach is required when it comes to finding an effective and safe active substance for MAFLD treatment. The optimal drug for MAFLD should diminish steatosis, fibrosis and inflammation in the liver, and the winner for MAFLD drug authorisation seems to be the one that significantly improves liver histology. Saroglitazar (Lipaglyn®) was approved for metabolic-dysfunction-associated steatohepatitis (MASH) in India in 2020; however, the drug is still being investigated in other countries. Although the pharmaceutical industry is still lagging behind in developing an approved pharmacologic therapy for MAFLD, research has recently intensified and many molecules which are in the final stages of clinical trials are expected to be approved in the coming few years. Already this year, the first drug (Rezdiffra™) in the United States was approved via accelerated procedure for treatment of MAFLD, i.e., of MASH in adults. This review underscores the most recent information related to the development of drugs for MAFLD treatment, focusing on the molecules that have come furthest towards approval.

Optimized strategy among diet, exercise, and pharmacological interventions for nonalcoholic fatty liver disease: A network meta-analysis of randomized controlled trials

BACKGROUND

Emerging treatment methods, including exercise, diet, and drugs, for nonalcoholic fatty liver disease have been proposed. However, the differences in their efficacy have not been determined. We aimed to compare the effects of these treatments excluding surgery via a systematic review and network meta-analysis of randomized controlled trials.

DATA SOURCE

The data sources included PubMed, Embase, Web of Science and Cochrane up to February 1st, 2023. The endpoints consisted of body mass index (BMI), serum markers of metabolism and liver injury markers, liver fat content, and stiffness.

RESULTS

A total of 174 studies with 10,183 patients were included in this meta-analysis. In terms of improving BMI, Pan-agonist of peroxisome proliferator-activated receptors (PPAR) is the best treatment with the highest SUCRA (surface under the cumulative ranking) of 84.8% (mean = -3.40, 95% CI -5.55, -1.24) by the comparative effectiveness ranking. GLP-1 (glucagon-like peptide-1) has the best effect in improving the liver fat content based on the MRI-PDFF, steatosis score (SUCRA 99.7%, mean = -2.19, 95% CI -2.90, -1.48) and ballooning score (SUCRA 61.2%, mean = -0.82, 95% CI -4.46, 2.83).

CONCLUSIONS

Pan-agonist of PPAR was the most efficacious regimen in lowering BMIs, whereas GLP-1R agonists achieved the highest efficacy of steatosis improvement in this network meta-analysis.

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.

In praise of pioglitazone: An economically efficacious therapy for type 2 diabetes and other manifestations of the metabolic syndrome

Pioglitazone improves glycaemic control, not only by lowering insulin resistance, but also by improving beta cell function. Because of the improved beta cell function the glycaemic control that occurs with pioglitazone is prolonged. Pioglitazone has positive effects not only on cardiac risk factors and surrogate measures of cardiovascular disease, it also lowers the incidence of cardiac events in patients with diabetes. The recurrence of transient ischaemic attack and ischaemic stroke is also reduced in non-diabetic, insulin-resistant subjects. Utilized at preclinical stages (but not later) of heart failure, pioglitazone improves diastolic function and avoids progression to heart failure. Pioglitazone, through suppression of atrial remodelling, also decreases the incidence of atrial fibrillation. The manifestations of diseases associated with insulin resistance (non-alcoholic steatohepatitis and polycystic ovary disease) are also improved with pioglitazone. Pioglitazone may possibly improve psoriasis and other dermopathies. Pioglitazone is therefore an inexpensive and efficacious drug for the insulin-resistant subject with diabetes that is underutilized because of biases that have evolved from the toxicities of other thiazolidinediones.

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.

Association of Dipeptidyl Peptidase-4 Inhibitors Use with Reduced Risk of Hepatocellular Carcinoma in Type 2 Diabetes Patients with Chronic HBV Infection

Previous studies have indicated that HBV infection and T2DM are the factors that increase the risk of developing HCC. The experimental evidence has shown that antiglycemic agents may reduce the risk of HCC. However, the effect of dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) on the risk of HCC in T2DM patients with chronic HBV infection remains unclear. In this retrospective cohort study, we extracted patients with T2DM and chronic HBV infection from the National Health Insurance Research Database (NHIRD) in Taiwan. The cases were divided into DPP-4 inhibitors use and non-use groups, according to whether they received DPP-4 inhibitors treatment, and the risk of HCC was compared between the two groups. At the end of the follow-up, approximately 2.33% of DPP-4 inhibitors users had received an HCC diagnosis compared with 3.33% of non-DPP-4 inhibitors users (p < 0.0001). After multivariate adjustment, DPP-4 inhibitors users showed a significant reduction in HCC risk (adjusted hazard ratios (aHRs): 0.53; 95% confidence intervals (CIs): 0.44-0.65). In conclusion, this population-based retrospective cohort study indicated that, in T2DM patients with chronic HBV infection, the use of DPP-4 inhibitors significantly reduced the risk of developing HCC compared with non-DPP-4 inhibitors use.

Portal hypertension in nonalcoholic fatty liver disease: Challenges and perspectives

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. NAFLD‐related cirrhosis is often complicated by portal hypertension (PHT). Recent evidence showed that portal venous pressure (PVP) starts to rise in the early stages of NAFLD, even in absence of advanced fibrosis or cirrhosis. However, the precise pathological mechanisms of this process are still poorly understood. Lipid accumulation, hepatocellular ballooning, sinusoidal endothelial cell dysfunction, capillarization, microthrombosis, increased angiogenesis, and pericellular fibrosis may all be involved in the early development of increased PVP in NAFLD. Direct measurement of PHT is invasive and impractical in noncirrhotic NAFLD individuals and may also underestimate its severity. Thus, the development and validation of noninvasive and more accurate measurements, including new serum biomarkers, scoring models, and imaging techniques (such as ultrasonography, elastography, and magnetic resonance imaging), are urgently needed. Owing to the increasing morbidity, challenges in the prevention and management of PHT in NAFLD are unprecedented. This review article aims to briefly discuss these challenges and summarizes the mechanisms, diagnosis, and emerging therapies for PHT in people with NAFLD.

The effect of metformin usage on survival outcomes for hepatocellular carcinoma patients with type 2 diabetes mellitus after curative therapy

OBJECTIVE

Metformin has attracted more attention from researchers for its newly discovered antitumor effects. A meta-analysis was performed to reveal the efficacy of metformin on overall survival (OS) and recurrence-free survival (RFS) for HCC patients with type 2 diabetes mellitus (T2DM) after curative treatment.

METHODS

Databases including PubMed, the Cochrane Library, Web of Science, CNKI, Wangfang, and Weipu Database up until 31 May 2022 were searched for relevant studies. STATA 13.0 was used to perform the meta-analysis.

RESULTS

A total of six studies involving 5,936 patients were included in our study. The results from the current study revealed that metformin usage can significantly prolong the 3-year [odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.22-1.83, p = 0.000] and 5-year (OR = 1.88, 95% CI: 1.47-2.41, p = 0.000) OS and decrease the 1-year (OR = 1.31, 95% CI: 1.08-1.59, p = 0.007), 3-year (OR = 1.88, 95% CI: 1.48-2.37, p = 0.000), and 5-year (OR = 1.83, 95% CI: 1.40-2.40, p = 0.000) recurrence rates.

CONCLUSION

Metformin treatment significantly prolongs the OS and decreases the recurrence rate for HCC patients with T2DM after curative HCC therapy.