Comparison of the Efficacy of Glucagon-Like Peptide-1 Receptor Agonists in Patients With Metabolic Associated Fatty Liver Disease: Updated Systematic Review and Meta-Analysis

Underuse of GLP-1 receptor agonists in the management of type 2 diabetes despite a favorable benefit-safety profile

INTRODUCTION

Patients with type 2 diabetes (T2DM) are at high risk of atherosclerotic cardiovascular disease (ASCVD) and cardiovascular death. Cardiovascular protection is a key objective in T2DM.

AREAS COVERED

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have proven their efficacy in reducing major cardiovascular events in high-risk patients with T2DM in placebo-controlled trials, a finding confirmed in observational studies compared with other glucose-lowering agents. Overall, GLP-1RAs have a good safety profile associated with a favorable benefit/risk ratio for the management of T2DM, even if their cost-effectiveness might be questionable. International guidelines recommend GLP-1RAs as preferred glucose-lowering agents in patients with ASCVD and as a valuable alternative in overweight/obese patients with T2DM. However, real-life studies worldwide revealed that only a minority of patients receive a GLP-1RA, despite a positive trend for increased prescriptions in recent years. Surprisingly, however, fewer patients with established ASCVD are treated with these cardioprotective antihyperglycemic agents versus patients without ASCVD.

EXPERT OPINION

The reasons for GLP-1RA underuse in clinical practice are multiple. Multifaceted and coordinated interventions targeting all actors of the health-care system must be implemented to stimulate the adoption of GLP-1RAs as part of routine cardiovascular care among patients with T2DM, especially in those with ASCVD.

Role of gut-liver axis and glucagon-like peptide-1 receptor agonists in the treatment of metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a hepatic manifestation of the metabolic syndrome. It is one of the most common liver diseases worldwide and shows increasing prevalence rates in most countries. MAFLD is a progressive disease with the most severe cases presenting as advanced fibrosis or cirrhosis with an increased risk of hepatocellular carcinoma. Gut microbiota play a significant role in the pathogenesis and progression of MAFLD by disrupting the gut-liver axis. The mechanisms involved in maintaining gut-liver axis homeostasis are complex. One critical aspect involves preserving an appropriate intestinal barrier permeability and levels of intestinal lumen metabolites to ensure gut-liver axis functionality. An increase in intestinal barrier permeability induces metabolic endotoxemia that leads to steatohepatitis. Moreover, alterations in the absorption of various metabolites can affect liver metabolism and induce liver steatosis and fibrosis. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a class of drugs developed for the treatment of type 2 diabetes mellitus. They are also commonly used to combat obesity and have been proven to be effective in reversing hepatic steatosis. The mechanisms reported to be involved in this effect include an improved regulation of glycemia, reduced lipid synthesis, β-oxidation of free fatty acids, and induction of autophagy in hepatic cells. Recently, multiple peptide receptor agonists have been introduced and are expected to increase the effectiveness of the treatment. A modulation of gut microbiota has also been observed with the use of these drugs that may contribute to the amelioration of MAFLD. This review presents the current understanding of the role of the gut-liver axis in the development of MAFLD and use of members of the GLP-1 RA family as pleiotropic agents in the treatment of MAFLD.

Obesity medications: A narrative review of current and emerging agents

The aim of this narrative review is to synthesize the available data describing the efficacy and safety of medications approved for obesity management and to provide an overview of upcoming agents in development. A literature search of PubMed, Medline, and Embase databases identified relevant articles describing medications approved in the U.S., Australia, U.K., and/or Europe. Papers were selected based on relevance and originality, with phase 3 clinical trials and meta-analyses preferentially included. Six medications are widely approved for long-term weight management in conjunction with lifestyle interventions in people with body mass index (BMI) ≥30 ​kg/m2 or BMI ≥27 ​kg/m2 and at least one medical condition related to excess weight. Compared with lifestyle interventions alone, all medications approved for obesity management are more effective for long-term weight loss and improvements in cardiometabolic risk factors. Older obesity medications are associated with mean weight losses in the range of 5-10%. The new generation of agents, including the injectable incretin analogues semaglutide and tirzepatide are associated with sustained mean weight reductions of 15-20%, along with substantial benefits on a range of health outcomes. Several novel agents are under development, with multi-hormone receptor agonists and oral formulations likely to become available in the coming years. As effective treatment options expand, cost and availability will need to be addressed to enable equitable access to treatment. Other important challenges for clinical practice and research include the need for long-term strategies to prevent and manage weight regain and loss of lean muscle and bone mineral density.

Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity: A joint position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM), Brazilian Society of Hepatology (SBH), and Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso)

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Nonalcoholic fatty liver disease (NAFLD), is one of the most common hepatic diseases in individuals with overweight or obesity. In this context, a panel of experts from three medical societies was organized to develop an evidence-based guideline on the screening, diagnosis, treatment, and follow-up of MASLD.

Material and methods

A MEDLINE search was performed to identify randomized clinical trials, meta-analyses, cohort studies, observational studies, and other relevant studies on NAFLD. In the absence of studies on a certain topic or when the quality of the study was not adequate, the opinion of experts was adopted. Classes of Recommendation and Levels of Evidence were determined using prespecified criteria.

Results

Based on the literature review, 48 specific recommendations were elaborated, including 11 on screening and diagnosis, 9 on follow-up,14 on nonpharmacologic treatment, and 14 on pharmacologic and surgical treatment.

Conclusion

A literature search allowed the development of evidence-based guidelines on the screening, diagnosis, treatment, and follow-up of MASLD in individuals with overweight or obesity.

Effects of once-weekly glucagon-like peptide-1 receptor agonists on type 2 diabetes mellitus complicated with coronary artery disease: Potential role of the renin-angiotensin system

AIM

To investigate the potential mechanism of once-weekly glucagon-like peptide-1 receptor agonists (GLP-1 RA) in the treatment of type 2 diabetes mellitus (T2DM) complicated with coronary artery disease (CAD).

METHODS

We searched both Chinese and English databases for randomized controlled trials related to once-weekly GLP-1 RA for T2DM complicated with CAD to verify the safety and efficacy of GLP-1 RA. The underlying mechanism was analysed by network pharmacology.

RESULTS

In total, 13 studies with 35 563 participants were included in the analysis. The pooled analysis found that dulaglutide, exenatide and semaglutide outperformed placebo in cardiovascular outcomes in patients with T2DM, with a significant reduction in the incidence of non-fatal stroke (p < .00). Levels of cardiovascular risk factors were significantly reduced in the once-weekly GLP-1 RA group compared with the conventional treatment group (glycated haemoglobin: p < .00; fasting blood glucose: p < .00; weight: p < .00; systolic blood pressure: p < .00; total cholesterol: p < .00; low-density lipoprotein cholesterol: p < .00). Network pharmacology results were enriched to the renin-angiotensin system, and matrix metalloproteinase 2 and renin (REN) may be the key targets. In addition, four key targets of dulaglutide, five key targets of exenatide and two key targets of semaglutide were enriched.

CONCLUSIONS

Our study suggests that once-weekly GLP-1 RA may have a potential protective effect on cardiovascular events in patients with T2DM combined with CAD, possibly through the renin-angiotensin system. However, further research is needed to confirm these findings and determine cause and effect.

Role of semaglutide in the treatment of nonalcoholic fatty liver disease or non-alcoholic steatohepatitis: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis was conducted to evaluate the efficacy and safety of 24 weeks of semaglutide treatment in patients with non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH).

METHODS

PubMed, Embase, Scopus, Cochrane CENTRAL, and ClinicalTrials.gov databases were searched for relevant studies. The primary outcome was the change in the serum alanine transaminase level. The secondary outcomes were changes in liver stiffness, liver function test parameters, metabolic parameters, and safety. Pooled mean differences and relative risks were calculated using random-effects models.

RESULTS

Six hundred studies were screened and eight were included (n = 2413). Semaglutide treatment showed a reduction in serum alanine transaminase [mean difference: 14.07 U/L (95% CI: 19.39 to -8.75); p < 0.001] and aspartate transaminase [mean difference: 6.89 U/L (95% CI: 9.14 to -4.63); p < 0.001] levels. There was a significant improvement in liver fat content [mean difference: 4.97% (95% CI: 6.65 to -3.29); p < 0.001] and liver stiffness [mean difference: 0.96 kPa (95% CI: 1.87 to -0.04); p = 0.04]. There were significant improvements in the glycated hemoglobin level and the lipid profile. However, the risk of serious adverse events [relative risk: 1.54 (95% CI: 1.02 to 2.34); p = 0.04] was high following semaglutide treatment as compared to placebo; the most common ones were gastrointestinal (nausea and vomiting, dyspepsia, decreased appetite, constipation, and diarrhea) and gallbladder-related diseases.

CONCLUSION

Treatment with 24 weeks of semaglutide could significantly improve liver enzymes, reduce liver stiffness, and improve metabolic parameters in patients with NAFLD/NASH. However, the gastrointestinal adverse effects could be a major concern.

Cardiorenal syndrome and diabetes: an evil pairing

Cardiorenal syndrome (CRS) is a pathology where the heart and kidney are involved, and the deterioration of one of them leads to the malfunction of the other. Diabetes mellitus (DM) carries a higher risk of HF and a worse prognosis. Furthermore, almost half of people with DM will have chronic kidney disease (CKD), which means that DM is the main cause of kidney failure. The triad of cardiorenal syndrome and diabetes is known to be associated with increased risk of hospitalization and mortality. Cardiorenal units, with a multidisciplinary team (cardiologist, nephrologist, nursing), multiple tools for diagnosis, as well as new treatments that help to better control cardio-renal-metabolic patients, offer holistic management of patients with CRS. In recent years, the appearance of drugs such as sodium-glucose cotransporter type 2 inhibitors, have shown cardiovascular benefits, initially in patients with type 2 DM and later in CKD and heart failure with and without DM2, offering a new therapeutic opportunity, especially for cardiorenal patients. In addition, glucagon-like peptide-1 receptor agonists have shown CV benefits in patients with DM and CV disease in addition to a reduced risk of CKD progression.

Risk Prevention and Health Promotion for Non-Alcoholic Fatty Liver Diseases (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a serious clinicopathological condition that is recognized as the most frequent chronic liver disease, affecting 14–30% of the world’s population. The prevalence of NAFLD has rapidly grown and is correlated with the growth in obesity and type 2 diabetes, among other factors. NAFLD often results in long-term complications including cardiovascular disease, liver cirrhosis, and liver fibrosis. This paper provides an updated overview of NAFLD with a focus on epidemiology, etiology, pathophysiology, screening, complications, and pharmacological therapies to identify effective risk prevention and health promotion.

How Far beyond Diabetes Can the Benefits of Glucagon-like Peptide-1 Receptor Agonists Go? A Review of the Evidence on Their Effects on Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is characterized by poor survival rate and quality of life, while available treatments remain generally limited. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) originally emerged as drugs for the management of diabetes, but have also been shown to alleviate cardiorenal risk. Furthermore, they have demonstrated a wide range of extraglycemic effects that led to their evaluation as potential therapies for a variety of diseases beyond diabetes, such as obesity, neurogenerative disorders and nonalcoholic fatty liver disease. Given the presence of the GLP-1 receptor in hepatocytes, animal data suggest that GLP-1 RAs could regulate molecular pathways that are deeply involved in the genesis and progression of HCC, including inflammatory responses, tumor cell proliferation and oxidative stress, through direct and indirect effects on liver cells. However, future studies must assess several aspects of the benefit-to-risk ratio of the use of GLP-1 RAs in patients with HCC, including co-administration with approved systemic therapies, the incidence of gastrointestinal side effects in a high-risk population, and weight loss management in individuals with poor nutritional status and high rates of cancer cachexia. In this narrative review, we discuss the potential role of GLP-1 analogs in the treatment of HCC, focusing on the molecular mechanisms that could justify a possible benefit, but also referring to the potential clinical implications and areas for future research.

Renin–Angiotensin System in Liver Metabolism: Gender Differences and Role of Incretins

The impaired hepatic lipids and carbohydrates metabolism result in various metabolic disorders, including obesity, diabetes, insulin resistance, hyperlipidemia and metabolic syndrome. The renin–angiotensin system (RAS) has been identified in the liver and it is now recognized as an important modulator of body metabolic processes. This review is intended to provide an update of the impact of the renin–angiotensin system on lipid and carbohydrate metabolism, regarding gender difference and prenatal undernutrition, specifically focused on the role of the liver. The discovery of angiotensin-converting enzyme 2 (ACE2) has renewed interest in the potential therapeutic role of RAS modulation. RAS is over activated in non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma. Glucagon-like peptide-1 (GLP-1) has been shown to modulate RAS. The GLP-I analogue liraglutide antagonizes hepatocellular steatosis and exhibits liver protection. Liraglutide has a negative effect on the ACE/AngII/AT1R axis and a positive impact on the ACE2/Ang(1-7)/Mas axis. Activation of the ACE2/Ang(1-7)/Mas counter-regulatory axis is able to prevent liver injuries. Angiotensin(1-7) and ACE2 shows more favorable effects on lipid homeostasis in males but there is a need to do more investigation in female models. Prenatal undernutrition exerts long-term effects in the liver of offspring and is associated with a number of metabolic and endocrine alterations. These findings provide a novel therapeutic regimen to prevent and treat many chronic diseases by accelerating the effect of the ACE2/Ang1-7/Mas axis and inhibiting the ACE/AngII/AT1R axis.

Metabolic syndrome and cardiovascular diseases: Going beyond traditional risk factors

Metabolic syndrome (MS) is a chronic non-infective syndrome characterised clinically by a set of vascular risk factors that include insulin resistance, hypertension, abdominal obesity, impaired glucose metabolism, and dyslipidaemia. These risk factors are due to a pro-inflammatory state, oxidative stress, haemodynamic dysfunction, and ischaemia, which overlap in 'dysmetabolic' patients. This review aimed to evaluate the relationship between the traditional components of MS with cardiovascular disease (CVD), inflammation, and oxidative stress. MEDLINE-PubMed, EMBASE, and Cochrane databases were searched. Chronic low-grade inflammatory states and metaflammation are often accompanied by metabolic changes directly related to CVD incidence, such as diabetes mellitus, hypertension, and obesity. Moreover, the metaflammation is characterised by an increase in the serum concentration of pro-inflammatory cytokines, mainly interleukin-1 β (IL-1β), IL-6, and tumour necrosis factor-α (TNF-α), originating from the chronically inflamed adipose tissue and associated with oxidative stress. The increase of reactive oxygen species overloads the antioxidant systems causing post-translational alterations of proteins, lipids, and DNA leading to oxidative stress. Hyperglycaemia contributes to the increase in oxidative stress and the production of advanced glycosylation end products (AGEs) which are related to cellular and molecular dysfunction. Oxidative stress and inflammation are associated with cellular senescence and CVD. CVD should not be seen only as being triggered by classical MS risk factors. Atherosclerosis is a multifactorial pathological process with several triggering and aetiopathogenic mechanisms. Its medium and long-term repercussions, however, invariably constitute a significant cause of morbidity and mortality. Implementing preventive and therapeutic measures against oxy-reductive imbalances and metaflammation states has unquestionable potential for favourable clinical outcomes in cardiovascular medicine.

Therapeutic effects and mechanism of liraglutide on rats with type 2 diabetes and metabolic-associated fatty liver disease

• Background SREBP-1c/Insig/SCAP acts as a lipid de novo synthesis pathway, and its factors are highly expressed in the endoplasmic reticulum[4]. At present, this pathway has become a research hotspot in the development of metabolic-associated fatty liver disease. However, there are few studies on how various factors in this pathway change after endoplasmic reticulum stress; in particular, the role of the insulin-inducing gene-1 (Insig-1) has not been elucidated in detail. • Objective To investigate whether liraglutide has a therapeutic effect on rats with T2DM and MAFLD and to further study its possible mechanism. • Method rats in the control group and modeling group were fed with normal diet and high-sugar and high-fat diet, respectively . After one month, the mice in the modeling group were injected with 35mg/kg STZ intraperitoneally to establish the model of type 2 diabetes mellitus. T2DM and MAFLD rats were randomly divided into three groups: model group, low dose liraglutide group, and high dose liraglutide group. Fasting blood glucose ,fasting insulin, blood lipid profile, alanine aminotransferase, and aspartate aminotransferase were measured at the end of the 8th week. Paraffin sections were obtained from the same part of the liver of rats in each group and observed by electron microscope after HE staining. Western blot was used to detect the expression of endoplasmic reticulum stress index (GRP78) and negative feedback index of lipid synthesis (Insig-1) in each group. • Results of Liver tissue from the drug intervention groups caused a decrease in lipid droplet vacuoles, and the hepatocytes were arranged neatly again. While the expression of GRP78 rose, Insig-1 declined. There were differences with different doses of liraglutide; the higher the dose was, the more obvious the effect. No such changes were observed in T2DM and MAFLD rats after injection of saline. • Conclusion, we show that liraglutide may have a therapeutic effect on rats with T2DM and MAFLD by reducing endoplasmic reticulum stress in the liver and increasing the expression of Insig-1.

Drosophila melanogaster: A Powerful Tiny Animal Model for the Study of Metabolic Hepatic Diseases

Animal experimentation is limited by unethical procedures, time-consuming protocols, and high cost. Thus, the development of innovative approaches for disease treatment based on alternative models in a fast, safe, and economic manner is an important, yet challenging goal. In this paradigm, the fruit-fly Drosophila melanogaster has become a powerful model for biomedical research, considering its short life cycle and low-cost maintenance. In addition, biological processes are conserved and homologs of ∼75% of human disease-related genes are found in the fruit-fly. Therefore, this model has been used in innovative approaches to evaluate and validate the functional activities of candidate molecules identified via in vitro large-scale analyses, as putative agents to treat or reverse pathological conditions. In this context, Drosophila offers a powerful alternative to investigate the molecular aspects of liver diseases, since no effective therapies are available for those pathologies. Non-alcoholic fatty liver disease is the most common form of chronic hepatic dysfunctions, which may progress to the development of chronic hepatitis and ultimately to cirrhosis, thereby increasing the risk for hepatocellular carcinoma (HCC). This deleterious situation reinforces the use of the Drosophila model to accelerate functional research aimed at deciphering the mechanisms that sustain the disease. In this short review, we illustrate the relevance of using the fruit-fly to address aspects of liver pathologies to contribute to the biomedical area.

Perspectives on Precision Medicine Approaches to NAFLD Diagnosis and Management

Precision medicine defines the attempt to identify the most effective approaches for specific subsets of patients based on their genetic background, clinical features, and environmental factors. Nonalcoholic fatty liver disease (NAFLD) encompasses the alcohol-like spectrum of liver disorders (steatosis, steatohepatitis with/without fibrosis, and cirrhosis and hepatocellular carcinoma) in the nonalcoholic patient. Recently, disease renaming to MAFLD [metabolic (dysfunction)-associated fatty liver disease] and positive criteria for diagnosis have been proposed. This review article is specifically devoted to envisaging some clues that may be useful to implementing a precision medicine-oriented approach in research and clinical practice. To this end, we focus on how sex and reproductive status, genetics, intestinal microbiota diversity, endocrine and metabolic status, as well as physical activity may interact in determining NAFLD/MAFLD heterogeneity. All these factors should be considered in the individual patient with the aim of implementing an individualized therapeutic plan. The impact of considering NAFLD heterogeneity on the development of targeted therapies for NAFLD subgroups is also extensively discussed.