Effects of Novel Dual GIP and GLP-1 Receptor Agonist Tirzepatide on Biomarkers of Nonalcoholic Steatohepatitis in Patients With Type 2 Diabetes

Beyond obesity: lean metabolic dysfunction-associated steatohepatitis from unveiling molecular pathogenesis to therapeutic advancement

Nonalcoholic fatty liver disease (NAFLD), now known by the name of metabolic dysfunction-associated fatty liver disease (MAFLD), with increased global incidence, has been recognized as a significant metabolic disorder. NAFLD includes a spectrum liver disease from hepatocellular fat accumulation (isolated steatosis) to an advanced form of liver injury known as nonalcoholic steatohepatitis (NASH), which refers to distinct histologic features, including hepatocellular steatosis and injury, necroinflammation, and eventually fibrosis. Nonobese or lean individuals associated with metabolic dysregulation usually demonstrated diverse risk factors compared to obese MAFLD. The presence of normal range body mass index (BMI) and excess visceral adiposity with increased cardiometabolic and renal comorbidities, along with sarcopenia, has been evidenced to be associated with lean MASH. Genetic predispositions accompanying lifestyle and environmental factors contribute to disease initiation and progression. The genetic influence in pathophysiology indicated the significant contributions of the following genes: PNPLA3, TM6SF2, APOB, LIPA, MBOAT7, and HSD17B13, and the impact of their disease-specific variants in the development of obesity-independent MASH. The epigenetic modifications exhibited differential DNA methylation patterns in the genes involved in lipid metabolism, particularly hypomethylation of PEMT. Diet-induced and genetic animal models of lean MASH, including Slc: Wistar/ST rats, PPAR-α, PTEN, and MAT1A knockout mice models, are indicated to be pivotal in the exploration of disease progression and observing the effect of therapeutic interventions. This comprehensive review comprises the molecular and genetic pathophysiology, molecular diagnostics, and therapeutic aspects of lean MASH to enunciate a diagnostic approach that combines detailed clinical phenotyping regarding genomic analysis.

Mechanism of liver x receptor alpha in intestine, liver and adipose tissues in metabolic associated fatty liver disease

Metabolism associated fatty liver disease (MAFLD) has emerged as a growing global health challenge with limited effective treatments. Research on nuclear receptors offers promising new therapeutic avenues for MAFLD. The liver X receptor (LXR) has gained attention for its roles in tumors and metabolic and inflammatory diseases; However, its effects on MAFLD treatment remain a subject of debate. This review explores the therapeutic role of LXRα in MAFLD, focusing on its functions in the intestine, hepatic and adipose tissue, and summarizes recent advancements in LXRα ligands over the past five years. In the intestine, LXRα activation enhances the efflux of non-biliary cholesterol and reduces inflammation in the gut-liver axis by regulating intestinal high-density lipoprotein synthesis and its interaction with lipopolysaccharide. In the liver, LXRα activation facilitates cholesterol transport, influences hepatic lipid synthesis, and exerts anti-inflammatory effects. In adipose tissue, LXRα helps delay MAFLD progression by managing lipid autophagy and insulin resistance. Ligands that modulate LXRα transcriptional activity show considerable promise for MAFLD treatment.

Reasons for discontinuing tirzepatide in randomized controlled trials: A systematic review and meta-analysis

BACKGROUND

Despite therapeutic benefits, discontinuation of tirzepatide is common in randomized controlled trials (RCTs) due to adverse events (AEs) and other causes. No previous systematic reviews have explored the reasons for discontinuing tirzepatide in the RCTs.

AIM

To explore the reasons for permanent discontinuation of tirzepatide vs controls [placebo, insulin, and glucagon-like peptide-1 receptor agonists (GLP-1Ras)] in RCTs.

METHODS

Relevant RCTs were systematically searched using related terms through multiple databases such as MEDLINE (via PubMed), Scopus, Cochrane Central Register, and ClinicalTrials.gov from their inception until June 20, 2024. RevMan web was used to conduct meta-analysis using random-effects models. Outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

Seventeen RCTs (n = 14645), mostly having low risks of bias, were analyzed. Compared to placebo, the risk of permanent discontinuation of the study drug was substantially lower with tirzepatide 10 mg (RR: 0.69, 95%CI: 0.51-0.93, P = 0.02) and similar with tirzepatide 5 mg (RR: 0.74, 95%CI: 0.47-1.17, P = 0.20) and 15 mg (RR: 0.94, 95%CI: 0.68-1.31, P = 0.71). Tirzepatide had identical discontinuation risks when compared to insulin at 5 mg (RR: 0.96, 95%CI: 0.75-1.24, P = 0.77) and 10 mg (RR: 1.19, 95%CI: 0.77-1.82, P = 0.44) doses, whereas such risk was higher with tirzepatide 15 mg than insulin (RR: 1.31, 95%CI: 1.03-1.67, P = 0.03). Compared to GLP-1RA, the permanent discontinuation risk was similar with tirzepatide 5 mg (RR: 0.98, 95%CI: 0.70-1.37, P = 0.90) but was higher with tirzepatide 10 mg (RR: 1.40, 95%CI: 1.03-1.90, P = 0.03) and 15 mg (RR: 1.70, 95%CI: 1.27-2.27, P = 0.0004). Tirzepatide, at all doses, had higher risks of AE-related discontinuation than insulin; such risks were only greater with higher doses of tirzepatide than with placebo or GLP-1RA. Discontinuation risk due to withdrawal by the study subjects was lower with tirzepatide than with placebo or insulin. Compared to the placebo, tirzepatide (all doses) conferred a lower risk of study drug discontinuation due to other causes not specifically mentioned.

CONCLUSION

The discontinuation risk is not higher in tirzepatide group than in the placebo arm. Many factors other than AEs led to drug discontinuation in the included RCTs.

Hidden in the Fat: Unpacking the Metabolic Tango Between Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Syndrome

Metabolic syndrome (MetS) and metabolic dysfunction-associated steatotic liver disease (MASLD) are closely related, with rapidly increasing prevalence globally, driving significant public health concerns. Both conditions share common pathophysiological mechanisms such as insulin resistance (IR), adipose tissue dysfunction, oxidative stress, and gut microbiota dysbiosis, which contribute to their co-occurrence and progression. While the clinical implications of this overlap, including increased cardiovascular, renal, and hepatic risk, are well recognized, current diagnostic and therapeutic approaches remain insufficient due to the clinical and individuals' heterogeneity and complexity of these diseases. This review aims to provide an in-depth exploration of the molecular mechanisms linking MetS and MASLD, identify critical gaps in our understanding, and highlight existing challenges in early detection and treatment. Despite advancements in biomarkers and therapeutic interventions, the need for a comprehensive, integrated approach remains. The review also discusses emerging therapies targeting specific pathways, the potential of precision medicine, and the growing role of artificial intelligence in enhancing research and clinical management. Future research is urgently needed to combine multi-omics data, precision medicine, and novel biomarkers to better understand the complex interactions between MetS and MASLD. Collaborative, multidisciplinary efforts are essential to develop more effective diagnostic tools and therapies to address these diseases on a global scale.

MASLD: Prevalence, Mechanisms, and Sex-Based Therapies in Postmenopausal Women

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease influenced by genetic, lifestyle, and environmental factors. While MASLD is more prevalent in men, women are at increased risk after menopause, highlighting the critical pathogenetic role of sex hormones. The complex interplay between estrogen deficiency, visceral fat accumulation, metabolic syndrome (MetS), and inflammation accelerates disease progression, increases cardiovascular (CV) risk, and triggers a cycle of worsening adiposity, metabolic dysfunction, and psychological problems, including eating disorders. Weight loss in postmenopausal women can significantly improve both metabolic and psychological outcomes, helping to prevent MASLD and related conditions. This review examines the prevalence of MASLD, its comorbidities (type 2 diabetes T2D, CV, mental disorders), pathogenetic mechanisms, and pharmacological treatment with GLP-1 receptor agonists (GLP1-RAs), with a focus on postmenopausal women. Given the use of GLP1-RAs in the treatment of obesity and T2D in MASLD patients, and the increase in MetS and MASLD after menopause, this review analyzes the potential of a stable GLP-1-estrogen conjugate as a therapeutic approach in this subgroup. By combining the synergistic effects of both hormones, this dual agonist has been shown to increase food intake and food reward suppression, resulting in greater weight loss and improved insulin sensitivity, glucose, and lipid metabolism. Therefore, we hypothesize that this pharmacotherapy may provide more targeted therapeutic benefits than either hormone alone by protecting the liver, β-cells, and overall metabolic health. As these effects are only supported by preclinical data, this review highlights the critical need for future research to evaluate and confirm the mechanisms and efficacy in clinical settings, particularly in postmenopausal women.

Genetic Evidence for GLP-1 and GIP Receptors as Targets for Treatment and Prevention of MASLD/MASH

BACKGROUND AND AIMS

Glucagon-like peptide-1 receptor (GLP1R) agonists and glucose-dependent insulinotropic polypeptide receptor (GIPR) agonists may help treat metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). However, their definitive effects are still unclear. Our study aims to clarify this uncertainty.

METHODS

We utilised conventional Mendelian randomisation (MR) analysis to explore potential causal links between plasma GLP-1/GIP concentrations and MASLD and its related traits. Next, we conducted drug-target MR analysis using highly expressed tissue data to assess the effects of corresponding drug perturbation on these traits. Finally, mediation analysis was performed to ascertain whether the potential causal effect is direct or mediated by other MASLD-related traits.

RESULTS

Circulating 2-h GLP-1 and GIP concentrations measured during an oral glucose tolerance test showed hepatoprotective effects on MASLD risk (ORGLP-1 = 0.168 [95% CI 0.033-0.839], p = 0.030; ORGIP = 0.331 [95% CI 0.222-0.494], p = 6.31 × 10-8). GLP1R expression in the blood had a minimal causal effect on MASLD risk, whereas GIPR expression significantly affected MASLD risk (OR = 0.671 [95% CI 0.531-0.849], p = 9.07 × 10-4). Expression levels of GLP1R or GIPR in the blood significantly influenced MASLD-related clinical traits. Mediation analysis revealed that GIPR expression protected against MASLD, even after adjusting for type 2 diabetes or body mass index.

CONCLUSIONS

GLP-1/GIP receptor agonists offer promise in lowering MASLD/MASH risk. GIP receptor agonists can exert direct and indirect effects on MASLD mediated by weight reduction or glycemic control improvement.

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.

Effects of Tirzepatide on the Clinical Trajectory of Patients With Heart Failure, Preserved Ejection Fraction, and Obesity

BACKGROUND

Patients with heart failure with preserved ejection fraction and obesity have significant disability and frequent exacerbations of heart failure. We hypothesized that tirzepatide, a long-acting agonist of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors, would improve a comprehensive suite of clinical end points, including measures of health status, functional capacity, quality of life, exercise tolerance, patient well-being, and medication burden, in these patients.

METHODS

We randomized (double-blind) 731 patients with class II to IV heart failure, ejection fraction ≥50%, and body mass index ≥30 kg/m2 to tirzepatide (titrated up to 15 mg SC weekly; n=364) or placebo (n=367) added to background therapy for a median of 104 weeks (quartile 1, 66; quartile 3, 126 weeks). The primary end points were whether tirzepatide reduced the combined risk of cardiovascular death or worsening heart failure and improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score. The current expanded analysis included sensitivity analyses of the primary end points, 6-minute walk distance, EQ-5D-5L health state index, Patient Global Impression of Severity Overall Health score, New York Heart Association class, use of heart failure medications, and a hierarchical composite based on all-cause death, worsening heart failure, and 52-week changes in Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and 6-minute walk distance.

RESULTS

Patients were 65.2±10.7 years of age; 53.8% (n=393) were female; body mass index was 38.2±6.7 kg/m2; Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was 53.5±18.5; 6-minute walk distance was 302.8±81.7 m; and 53% (n=388) had a worsening heart failure event in the previous 12 months. Compared with placebo, tirzepatide produced a consistent beneficial effect across all composites of death and worsening heart failure events, analyzed as time to first event (hazard ratios, 0.41-0.67). At 52 weeks, tirzepatide increased the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score by 6.9 points (95% CI, 3.3-10.6; P<0.001), 6-minute walk distance 18.3 meters (95% CI, 9.9-26.7; P<0.001), and EQ-5D-5L 0.06 (95% CI, 0.03-0.09; P<0.001). The tirzepatide group shifted to a more favorable Patient Global Impression of Severity Overall Health score (proportional odds ratio, 1.99 [95% CI, 1.44-2.76]) and New York Heart Association class (proportional odds ratio, 2.26 [95% CI, 1.54-3.31]; both P<0.001) and required fewer heart failure medications (P=0.015). The broad spectrum of effects was reflected in benefits on the hierarchical composite (win ratio, 1.63 [95% CI, 1.17-2.28]; P=0.004).

CONCLUSIONS

Tirzepatide produced a comprehensive, meaningful improvement in heart failure across multiple complementary domains; enhanced health status, quality of life, functional capacity, exercise tolerance, and well-being; and reduced symptoms and medication burden in patients with heart failure with preserved ejection fraction and obesity.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04847557.

Pharmacological treatment for metabolic dysfunction-associated steatotic liver disease and related disorders: Current and emerging therapeutic options

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as nonalcoholic fatty liver disease) is a chronic liver disease affecting over a billion individuals worldwide. MASLD can gradually develop into more severe liver pathologies, including metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and liver malignancy. Notably, although being a global health problem, there are very limited therapeutic options against MASLD and its related diseases. While a thyroid hormone receptor agonist (resmetirom) is recently approved for MASH treatment, other efforts to control these diseases remain unsatisfactory. Given the projected rise in MASLD and MASH incidence, it is urgent to develop novel and effective therapeutic strategies against these prevalent liver diseases. In this article, the pathogenic mechanisms of MASLD and MASH, including insulin resistance, dysregulated nuclear receptor signaling, and genetic risk factors (eg, patatin-like phospholipase domain-containing 3 and hydroxysteroid 17-β dehydrogenase-13), are introduced. Various therapeutic interventions against MASH are then explored, including approved medication (resmetirom), drugs that are currently in clinical trials (eg, glucagon-like peptide 1 receptor agonist, fibroblast growth factor 21 analog, and PPAR agonist), and those failed in previous trials (eg, obeticholic acid and stearoyl-CoA desaturase 1 antagonist). Moreover, given that the role of gut microbes in MASLD is increasingly acknowledged, alterations in the gut microbiota and microbial mechanisms in MASLD development are elucidated. Therapeutic approaches that target the gut microbiota (eg, dietary intervention and probiotics) against MASLD and related diseases are further explored. With better understanding of the multifaceted pathogenic mechanisms, the development of innovative therapeutics that target the root causes of MASLD and MASH is greatly facilitated. The possibility of alleviating MASH and achieving better patient outcomes is within reach. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, and it can progress to more severe pathologies, including steatohepatitis, cirrhosis, and liver cancer. Better understanding of the pathogenic mechanisms of these diseases has facilitated the development of innovative therapeutic strategies. Moreover, increasing evidence has illustrated the crucial role of gut microbiota in the pathogenesis of MASLD and related diseases. It may be clinically feasible to target gut microbes to alleviate MASLD in the future.

Linking Cardiovascular Disease and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): The Role of Cardiometabolic Drugs in MASLD Treatment

The link between cardiovascular disease (CVD) and metabolic dysfunction-associated steatotic liver disease (MASLD) is well-established at both the epidemiological and pathophysiological levels. Among the common pathophysiological mechanisms involved in the development and progression of both diseases, oxidative stress and inflammation, insulin resistance, lipid metabolism deterioration, hepatokines, and gut dysbiosis along with genetic factors have been recognized to play a pivotal role. Pharmacologic interventions with drugs targeting common modifiable cardiometabolic risk factors, such as T2DM, dyslipidemia, and hypertension, are a reasonable strategy to prevent CVD development and progression of MASLD. Recently, a novel drug for metabolic dysfunction-associated steatohepatitis (MASH), resmetirom, has shown positive effects regarding CVD risk, opening new opportunities for the therapeutic approach of MASLD and CVD. This review provides current knowledge on the epidemiologic association of MASLD to CVD morbidity and mortality and enlightens the possible underlying pathophysiologic mechanisms linking MASLD with CVD. The role of cardiometabolic drugs such as anti-hypertensive drugs, hypolipidemic agents, glucose-lowering medications, acetylsalicylic acid, and the thyroid hormone receptor-beta agonist in the progression of MASLD is also discussed. Metformin failed to prove beneficial effects in MASLD progression. Studies on the administration of thiazolinediones in MASLD suggest effectiveness in improving steatosis, steatohepatitis, and fibrosis, while newer categories of glucose-lowering agents such as GLP-1Ra and SGLT-2i are currently being tested for their efficacy across the whole spectrum of MASLD. Statins alone or in combination with ezetimibe have yielded promising results. The conduction of long-duration, large, high-quality, randomized-controlled trials aiming to assess by biopsy the efficacy of cardiometabolic drugs to reverse MASLD progression is of great importance.

Renal effects and safety of tirzepatide in subjects with and without diabetes: A systematic review and meta-analysis

BACKGROUND

Type 2 diabetes (T2D), as well as obesity, are risk factors for chronic kidney disease (CKD) and end-stage renal disease. The renal impacts of glucose-lowering and weight-lowering drugs and their potential benefits in preventing CKD often guide clinicians in choosing them appropriately. Only limited data based on randomized controlled trials (RCTs) is currently available on the renal effects and safety profile of tirzepatide.

AIM

To explore the renal benefits and safety of tirzepatide vs controls.

METHODS

RCTs involving patients receiving tirzepatide for any indication in the intervention arm and placebo or active comparator in the control arm were searched through multiple electronic databases. The co-primary outcomes were percent change from baseline (CFB) in urine albumin-to-creatinine ratio (UACR) and absolute CFB in estimated glomerular filtration rate (eGFR; in mL/min/1.73 m2); the secondary outcome was tirzepatide's renal safety profile. RevMan web was used to conduct meta-analysis using random-effects models. Outcomes were presented as mean differences (MD) or risk ratios with 95% confidence intervals.

RESULTS

Fifteen RCTs (n = 14471) with mostly low risk of bias (RoB) were included. Over 26-72 weeks, tirzepatide 10 mg [MD -26.95% (-40.13, -13.76), P < 0.0001] and 15 mg [MD -18.03% (-28.58, -7.47), P = 0.0008] were superior to placebo in percent reductions of UACR. Tirzepatide, at all doses, outperformed insulin in percent reductions of UACR. Compared to the placebo, the percent UACR reduction was greater in subjects with T2D than those with obesity but without T2D (MD -33.25% vs -7.93%; P = 0.001). The CFB in eGFR with all doses of tirzepatide was comparable [5 mg: MD 0.36 (-1.41, 2.14); 10 mg: MD 1.17 (-0.22, 2.56); 15 mg: MD 1.42 (-0.04, 2.88)]; P > 0.05 for all] vs insulin. Tirzepatide (pooled and separate doses) did not increase the risks of adverse renal events, urinary tract infection, nephrolithiasis, acute kidney injury, and renal cancer compared to the placebo, insulin, and glucagon-like peptide-1 receptor agonists.

CONCLUSION

Short-term data from RCTs with low RoB suggests that tirzepatide positively impacts UACR without detrimental effects on eGFR in subjects with T2D and obesity without T2D, with a reassuring renal safety profile. Larger RCTs are warranted to prove the longer-term renal benefits of tirzepatide, which might also prevent eGFR decline and worsening of CKD.

Dual GIP and GLP-1 receptor agonist tirzepatide alleviates hepatic steatosis and modulates gut microbiota and bile acid metabolism in diabetic mice

Tirzepatide is a dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors and is a promising therapeutic option for type 2 diabetes mellitus (T2DM). Nevertheless, its effect and underlying mechanism on hepatic steatosis remain ambiguous. Herein, we explored the impact of tirzepatide on improving hepatic steatosis in diabetic mice, with a particular focus on the gut microbiota and bile acids (BAs) using animal models. The tirzepatide effectively reduced body weight, improved insulin resistance, decreased serum and hepatic lipid levels, and mitigated liver injury. Compared to semaglutide, tirzepatide exhibited superior efficacy in reducing hepatic lipid accumulation. 16S rRNA gene sequencing and targeted metabolomics of BAs revealed that tirzepatide ameliorated gut microbiota dysbiosis and BAs metabolism in diabetic mice. Notably, tirzepatide observably increased the abundance of beneficial genera such as Akkermansia, elevated the ratio of farnesoid X receptor (FXR) antagonists (glycoursodeoxycholic acid: GUDCA, β-muricholic acid: β-MCA, hyodeoxycholic acid: HDCA, ursodeoxycholic acid: UDCA) to natural agonists (cholic acid: CA, lithocholic acid: LCA, chenodeoxycholic acid: CDCA, glycocholic acid: GCA, taurodeoxycholic acid: TDCA), and reduced FXR expression in intestinal tissues. In conclusion, tirzepatide attenuated hepatic steatosis in diabetic mice and regulated the gut microbiota and BAs metabolism, which may help to provide a novel therapeutic approach and therapeutic target for metabolic dysfunction-associated steatotic liver disease (MASLD).

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.

Clinical study on the effect of jejunoileal side-to-side anastomosis on metabolic parameters in patients with type 2 diabetes

BACKGROUND

At present, the existing internal medicine drug treatment can alleviate the high glucose toxicity of patients to a certain extent, to explore the efficacy of laparoscopic jejunoileal side to side anastomosis in the treatment of type 2 diabetes, the report is as follows.

AIM

To investigate the effect of jejunoileal side-to-side anastomosis on metabolic parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

We retrospectively analyzed the clinical data of 78 patients with T2DM who were treated via jejunoileal lateral anastomosis. Metabolic indicators were collected preoperatively, as well as at 3 and 6 months postoperative. The metabolic indicators analyzed included body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), 2-hour blood glucose (PBG), glycated hemoglobin (HbA1c), fasting C-peptide, 2-hour C-peptide (PCP), fasting insulin (Fins), 2-hour insulin (Pins), insulin resistance index (HOMA-IR), β Cellular function index (HOMA-β), alanine aminotransferase, aspartate aminotransferase, serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), high-density lipoprotein, and uric acid (UA) levels.

RESULTS

SBP, DBP, PBG, HbA1c, LDL-C, and TG were all significantly lower 3 months postoperative vs preoperative values; body weight, BMI, SBP, DBP, FBG, PBG, HbA1c, TC, TG, UA, and HOMA-IR values were all significantly lower 6 months postoperative vs at 3 months; and PCP, Fins, Pins, and HOMA-β were all significantly higher 6 months postoperative vs at 3 months (all P < 0.05).

CONCLUSION

Side-to-side anastomosis of the jejunum and ileum can effectively treat T2DM and improve the metabolic index levels associated with it.

Inter-organ metabolic interaction networks in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multisystem metabolic disorder, marked by abnormal lipid accumulation and intricate inter-organ interactions, which contribute to systemic metabolic imbalances. NAFLD may progress through several stages, including simple steatosis (NAFL), non-alcoholic steatohepatitis (NASH), cirrhosis, and potentially liver cancer. This disease is closely associated with metabolic disorders driven by overnutrition, with key pathological processes including lipid dysregulation, impaired lipid autophagy, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and local inflammation. While hepatic lipid metabolism in NAFLD is well-documented, further research into inter-organ communication mechanisms is crucial for a deeper understanding of NAFLD progression. This review delves into intrahepatic networks and tissue-specific signaling mediators involved in NAFLD pathogenesis, emphasizing their impact on distal organs.

Influence of glucagon-like peptide-1 receptor agonists on hepatic events in type 2 diabetes: a systematic review and meta-analysis

BACKGROUND AND AIM

Type 2 diabetes mellitus (T2DM) is intrinsically linked to various etiologies of liver disease, with 69% of patients having concomitant metabolic dysfunction-associated steatotic liver disease (MASLD). Studies suggest glucagon-like peptide-1 receptor agonists (GLP-1RAs) can ameliorating liver disease. With this analysis, we address the gap in knowledge about the effectiveness of these agents in preventing different major adverse liver outcomes (MALOs).

METHODS

PubMed, Embase, and The Cochrane Central of Trials were searched for articles reporting MALOs in T2DM patients. Publication bias-identifying methods, quality assessment and sensitivity analyses (subgroup analyses, leave-one-out meta-analyses, and meta-regression) were employed. Statistical analyses were performed in R using the "meta" and "metafor" packages.

RESULTS

Nine cohort studies from 535 identified articles encompassing 579 256 T2DM patients were included in the main analyses. GLP-1RA use was associated with reduced risks of hepatocellular carcinoma (HR 0.74, 95% CI 0.56-0.96) and cirrhosis decompensation (HR 0.68, 95% CI 0.65-0.72). Within the latter, variceal bleeding and hepatic encephalopathy prevention were found to be significantly reduced. Egger's test, Begg's test, and funnel-plot analysis yielded no publication bias. No significant differences were observed in preventing cirrhosis or hepatic failure. Meta-regression analysis revealed a positive correlation between hepatocellular carcinoma incidence and both male sex and longer follow-up duration.

CONCLUSIONS

This meta-analysis improves our understanding of the hepatoprotective effects of GLP-1RAs in T2DM patients and supports existing research, exhibiting superiority over other antidiabetic medications for hepatoprotection in this subgroup. Additional long-term follow-up studies are necessary to further validate these findings.

Effect of pemvidutide, a GLP-1/glucagon dual receptor agonist, on MASLD: A randomized, double-blind, placebo-controlled study

BACKGROUND & AIMS

This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

Patients with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus. The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment.

RESULTS

Ninety-four patients were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of patients had type 2 diabetes mellitus. At week 12, relative reductions in LFC from baseline were 46.6% (95% CI -63.7 to -29.6), 68.5% (95% CI -84.4 to -52.5), and 57.1% (95% CI -76.1 to -38.1) for the pemvidutide 1.2 mg, 1.8 mg, and 2.4 mg groups, respectively, vs. 4.4% (95% CI -20.2 to 11.3) for the placebo group (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of patients achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events.

CONCLUSIONS

In patients with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo.

IMPACT AND IMPLICATIONS

Metabolic dysfunction-associated steatotic liver disease, and its progressive form steatohepatitis, are strongly associated with overweight/obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/glucagon receptor agonist, to significantly reduce liver fat content, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both metabolic dysfunction-associated steatohepatitis and obesity.

CLINICAL TRIAL NUMBER

NCT05006885.

Charting New Territories in Obesity Management- Traditional Techniques to Tirzepatide

BACKGROUND

Obesity, a pervasive global health challenge affecting more than 2 billion people, requires comprehensive interventions. Traditional approaches, including lifestyle modification, and diverse drugs targeting a gastrointestinal hormone, including glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (Liraglutide, Semaglutide, Exenatide, Albiglutide, Dulaglutide, Lixisenatide, Orlistat, Phentermine/Topiramate, Lorcaserin, Sibutramine, and Rimonabant) offer tailored strategies; yet their effectiveness is limited and some drugs were taken off the market. Moreover, various surgical modalities, such as Roux-en-Y Bypass surgery, sleeve gastrectomy, intragastric balloons, biliopancreatic diversion with duodenal switch, laparoscopic adjustable gastric band, and vagal nerve blockade can be considered but are associated with numerous side effects and require careful monitoring. Consequently, there is a pressing need for novel anti-obesity treatments.

METHODS

This comprehensive review was based on the available data to discuss the traditional pharmaceutical and surgical therapeutical strategies for obesity, going further to discuss tirzepatide's mode of action, its outcomes for obesity, and the associated side effects.

RESULTS

In this landscape, tirzepatide, initially designed for type 2 diabetes management, emerges as a potential game-changer. Functioning as a dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, it not only addresses control but also introduces a fresh perspective on weight reduction. This review intricately explores tirzepatide's mechanism, dissecting insights from clinical studies and positioning it as a major force in obesity treatment.

CONCLUSIONS

In the middle of significant shifts in obesity management, tirzepatide presents itself as a promising and cost-effective intervention. Its Food and Drug Administration approval marks a milestone in the realm of obesity therapeutics. Going beyond a recapitulation of findings, the conclusion emphasizes the imperative for ongoing exploration and vigilant safety monitoring in tirzepatide's application.

Pharmacological management of pediatric metabolic dysfunction-associated steatotic liver disease

Pediatric obesity, characterized by a body mass index (BMI) at or above the 95th percentile for age, affects a substantial number of children and adolescents worldwide. Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease, represents a prominent hepatic manifestation of obesity and metabolic syndrome, emerging as the most prevalent hepatic disorder among pediatric patients and a significant contributor to liver transplantation in adults. The escalating prevalence of pediatric MASLD mirrors the alarming rise in childhood obesity rates over recent decades. While lifestyle modifications focusing on dietary changes and increased physical activity constitute the cornerstone of MASLD management, achieving and maintaining significant weight reduction remains challenging. Moreover, disease progression often persists despite standard-of-care interventions, warranting exploration into alternative therapeutic strategies. Pharmacological interventions, particularly, glucagon-like peptide-1 receptor agonists (GLP-1RA), have shown promise in addressing pediatric obesity and its associated comorbidities, including MASLD. Recent studies have demonstrated the efficacy of GLP-1RA in inducing weight loss and improving liver enzyme levels, suggesting a potential role in halting disease progression, and reducing the risk of major adverse liver outcomes. This review provides a comprehensive overview of the current pharmacotherapy landscape for pediatric MASLD, with a focus on novel agents such as GLP-1RA. Furthermore, the manuscript proposes a practical algorithm to assist in integrating GLP-1RA into the clinical management of pediatric patients with obesity and MASLD. Despite promising results, further research is warranted to elucidate the long-term efficacy and safety of GLP-1RA in pediatric populations.

The effect and application of adiponectin in hepatic fibrosis

Hepatic fibrosis, a degenerative liver lesion, significantly contributes to the deterioration and mortality among patients with chronic liver diseases. The condition arises from various factors including toxins, such as alcohol, infections like different types of viral hepatitis, and metabolic diseases. Currently, there are no effective treatments available for liver fibrosis. Recent research has shown that adiponectin (ADPN) exhibits inhibitory effects on hepatic fibrosis. ADPN, an adipocytokine secreted by mature adipocytes, features receptors that are widely distributed across multiple tissues, especially the liver. In the liver, direct effects of ADPN on liver fibrosis include reducing inflammation and regulating hepatic stellate cell proliferation and migration. And its indirect effects include alleviating hepatic endoplasmic reticulum stress and reducing inflammation in hepatic lobules, thereby mitigating hepatic fibrosis. This review aims to elucidate the regulatory role of ADPN in liver fibrosis, explore how ADPN and its receptors alleviate endoplasmic reticulum stress, summarize ADPN detection methods, and discuss its potential as a novel marker and therapeutic agent in combating hepatic fibrosis.

Metabolic disorders, inter-organ crosstalk, and inflammation in the progression of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a global health concern, affecting over 30 % of adults. It is a principal driver in the development of cirrhosis and hepatocellular carcinoma. The complex pathogenesis of MASLD involves an excessive accumulation of lipids, subsequently disrupting lipid metabolism and prompting inflammation within the liver. This review synthesizes the recent research progress in understanding the mechanisms contributing to MASLD progression, with particular emphasis on metabolic disorders and interorgan crosstalk. We highlight the molecular mechanisms linked to these factors and explore their potential as novel targets for pharmacological intervention. The insights gleaned from this article have important implications for both the prevention and therapeutic management of MASLD.

Resmetirom and Metabolic Dysfunction-Associated Steatohepatitis: Perspectives on Multidisciplinary Management from Global Healthcare Professionals

PURPOSE OF REVIEW

The approval of resmetirom brings great hope to patients with metabolic dysfunction-associated steatohepatitis (MASH). The purpose of this review is to explore its impact on the global health environment. The implementation of multidisciplinary management MASH is proposed.

RECENT FINDINGS

Resmetirom has benefits in the treatment of MASH, and its safety and effectiveness have been studied. The adverse events (AEs) need to be noticed. To improve patient outcomes, a multimodal approach with medication such as resmetirom, combined with metabolic and bariatric surgery (MBS) and lifestyle interventions can be conducted. MASH, a liver disease linked with obesity, is a challenging global healthcare burden compounded by the absence of any approved pharmacotherapy. The recent conditional approval by the Food and Drug Administration (FDA) in the United States of resmetirom, an oral, liver-directed, thyroid hormone receptor beta-selective agonist, marks a significant milestone, offering a treatment option for adults with non-cirrhotic MASH and who have moderate to advanced liver fibrosis. This narrative review discusses the efficacy and safety of resmetirom and its role in the therapeutic landscape of MASH treatment. Despite the promising hepatoprotective effect of resmetirom on histological liver endpoints, its use need further research, particularly regarding ethnic differences, effectiveness and cost-effectiveness, production scalability, social acceptance and accessibility. In addition, integrating resmetirom with other multidisciplinary therapeutic approaches, including lifestyle changes and MBS, might further improve clinical liver-related and cardiometabolic outcomes of individuals with MASH. This review highlights the importance of a comprehensive treatment strategy, supporting continued innovation and collaborative research to refine treatment guidelines and consensus for managing MASH, thereby improving clinical patient outcomes in the growing global epidemic of MASH. Studies done to date have been relatively short and ongoing, the course of the disease is highly variable, the conditions of various patients vary, and given this complex clinical phenotype, it may take many years of clinical trials to show long-term benefits.

Incretin-based therapy: a new horizon in diabetes management

Diabetes mellitus, a metabolic syndrome characterized by hyperglycemia and insulin dysfunction, often leads to serious complications such as neuropathy, nephropathy, retinopathy, and cardiovascular disease. Incretins, gut peptide hormones released post-nutrient intake, have shown promising therapeutic effects on these complications due to their wide-ranging biological impacts on various body systems. This review focuses on the role of incretin-based therapies, particularly Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, in managing diabetes and its complications. We also discuss the potential of novel agents like semaglutide, a recently approved oral compound, and dual/triple agonists targeting GLP-1/GIP, GLP-1/glucagon, and GLP-1/GIP/glucagon receptors, which are currently under investigation. The review aims to provide a comprehensive understanding of the beneficial impacts of natural incretins and the therapeutic potential of incretin-based therapies in diabetes management.

Guideline for the Prevention and Treatment of Metabolic Dysfunction-associated Fatty Liver Disease (Version 2024)

With the rising epidemic of obesity, metabolic syndrome, and type 2 diabetes mellitus in China, metabolic dysfunction-associated non-alcoholic fatty liver disease has become the most prevalent chronic liver disease. This condition frequently occurs in Chinese patients with alcoholic liver disease and chronic hepatitis B. To address the impending public health crisis of non-alcoholic fatty liver disease and its underlying metabolic issues, the Chinese Society of Hepatology and the Chinese Medical Association convened a panel of clinical experts to revise and update the "Guideline of prevention and treatment of non-alcoholic fatty liver disease (2018, China)". The new edition, titled "Guideline for the prevention and treatment of metabolic dysfunction-associated fatty liver disease (Version 2024)", offers comprehensive recommendations on key clinical issues, including screening and monitoring, diagnosis and evaluation, treatment, and follow-up for metabolic dysfunction-associated fatty liver disease and metabolic dysfunction-associated steatotic liver disease. Metabolic dysfunction-associated fatty liver disease is now the preferred English term and is used interchangeably with metabolic dysfunction-associated steatotic liver disease. Additionally, the guideline emphasizes the importance of multidisciplinary collaboration among hepatologists and other specialists to manage cardiometabolic disorders and liver disease effectively.

GLP-1 and GIP agonism has no direct actions in human hepatocytes or hepatic stellate cells

The use of incretin agonists for managing metabolic dysfunction-associated steatohepatitis (MASH) is currently experiencing considerable interest. However, whether these compounds have a direct action on MASH is still under debate. This study aims to investigate whether GLP-1R/GIPR agonists act directly in hepatocytes and hepatic stellate cells (HSCs). For this, human hepatocyte and HSCs lines, as well as primary human hepatocytes and HSCs treated with Liraglutide, Acyl-GIP or the GLP-1/GIP dual agonist (MAR709) were used. We show that the concentrations of each compound, which were effective in insulin release, did not induce discernible alterations in either hepatocytes or HSCs. In hepatocytes displaying elevated fatty acid content after the treatment with oleic acid and palmitic acid, none of the three compounds reduced lipid concentration. Similarly, in HSCs activated with transforming growth factor-β (TGFb), Liraglutide, Acyl-GIP and MAR709 failed to ameliorate the elevated expression of fibrotic markers. The three compounds were also ineffective in phosphorylating CREB, which mediates insulinotropic actions, in both hepatocytes and HSCs. These findings indicate that incretin agonists have no direct actions in human hepatocytes or hepatic stellate cells, suggesting that their beneficial effects in patients with MASH are likely mediated indirectly, potentially through improvements in body weight, insulin resistance and glycemic control.

Pharmacologic Treatment of Obesity in adults and its impact on comorbidities: 2024 Update and Position Statement of Specialists from the Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

Pharmacological treatment of obesity is passing through many changes in the last decades; different agents have been approved, and newer options are leaning towards higher efficacy and a more favourable safety profile; however, medications approved for a longer time are still available and useful for many patients. This document is an 2024 Update Position Statement of Specialists from the Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso) and the Brazilian Society of Endocrinology and Metabolism (SBEM), with the aim of reviewing all the approved medications for the management of obesity in Brazil (sibutramine, orlistat, liraglutide, semaglutide and bupropion/naltrexone fixed dose), with the addition of tirzepatide, that is approved in other countries and likely approved soon in Brazil. The review is focused on efficacy, safety profile and the impact of drugs (based on existing studies) on different comorbidities.

Drug treatment for metabolic dysfunction-associated steatotic liver disease: Progress and direction

Metabolic dysfunction-associated steatotic liver disease (MASLD), also called non-alcoholic fatty liver disease, is the most epidemic chronic liver disease worldwide. Metabolic dysfunction-associated steatohepatitis (MASH) is the critical stage of MASLD, and early diagnosis and treatment of MASH are crucial for reducing the incidence of intrahepatic and extrahepatic complications. So far, pharmacotherapeutics for the treatment of MASH are still a major challenge, because of the complexity of the pathogenesis and heterogeneity of MASH. Many agents under investigation have shown impressive therapeutic effects by targeting different key pathways, including the attenuation of steatohepatitis or fibrosis or both. It is notable that thyroid hormone receptor-β agonist, resmetirom has become the first officially approved drug for treating MASH with fibrosis. Other agents such as peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 analogs, and fibroblast growth factor 21 analogs are awaiting approval. This review focuses on the current status of drug therapy for MASH and summarizes the latest results of new medications that have completed phase 2 or 3 clinical trials, and presents the future directions and difficulties of new drug research for MASH.

Metabolic Dysfunction-Associated Steatotic Liver Disease in Type 2 Diabetes Mellitus: A Review and Position Statement of the Fatty Liver Research Group of the Korean Diabetes Association

Since the role of the liver in metabolic dysfunction, including type 2 diabetes mellitus, was demonstrated, studies on non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) have shown associations between fatty liver disease and other metabolic diseases. Unlike the exclusionary diagnostic criteria of NAFLD, MAFLD diagnosis is based on the presence of metabolic dysregulation in fatty liver disease. Renaming NAFLD as MAFLD also introduced simpler diagnostic criteria. In 2023, a new nomenclature, steatotic liver disease (SLD), was proposed. Similar to MAFLD, SLD diagnosis is based on the presence of hepatic steatosis with at least one cardiometabolic dysfunction. SLD is categorized into metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-related/-associated liver disease, alcoholrelated liver disease, specific etiology SLD, and cryptogenic SLD. The term MASLD has been adopted by a number of leading national and international societies due to its concise diagnostic criteria, exclusion of other concomitant liver diseases, and lack of stigmatizing terms. This article reviews the diagnostic criteria, clinical relevance, and differences among NAFLD, MAFLD, and MASLD from a diabetologist's perspective and provides a rationale for adopting SLD/MASLD in the Fatty Liver Research Group of the Korean Diabetes Association.

Hepatokines and MASLD: The GLP1-Ras-FGF21-Fetuin-A Crosstalk as a Therapeutic Target

The introduction of the term "Metabolic Steatotic Liver Disease" (MASLD) underscores the critical role of metabolic dysfunction in the development and progression of chronic liver disease and emphasizes the need for strategies that address both liver disease and its metabolic comorbidities. In recent years, a liver-focused perspective has revealed that altered endocrine function of the fatty liver is a key contributor to the metabolic dysregulation observed in MASLD. Due to its secretory capacity, the liver's increased production of proteins known as "hepatokines" has been linked to the development of insulin resistance, explaining why MASLD often precedes dysfunction in other organs and ultimately contributes to systemic metabolic disease. Among these hepatokines, fibroblast growth factor 21 (FGF21) and fetuin-A play central roles in regulating the metabolic abnormalities associated with MASLD, explaining why their dysregulated secretion in response to metabolic stress has been implicated in the metabolic abnormalities of MASLD. This review postulates why their modulation by GLP1-Ras may mediate the beneficial metabolic effects of these drugs, which have increased attention to their emerging role as pharmacotherapy for MASLD. By discussing the crosstalk between GLP1-Ras-FGF21-fetuin-A, this review hypothesizes that the possible modulation of fetuin-A by the novel GLP1-FGF21 dual agonist pharmacotherapy may contribute to the management of metabolic and liver diseases. Although research is needed to go into the details of this crosstalk, this topic may help researchers explore the mechanisms by which this type of pharmacotherapy may manage the metabolic dysfunction of MASLD.

An insight into the updated pharmacotherapy of metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals: a review

Metabolic-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatohepatitis (MASH) in lean individuals represents a distinctive subset of MASH. Current pharmacotherapies, for MASH as demonstrated in clinical trials, predominantly target obese patients with limited consideration for lean MASH. We aimed to systematically review the literature on the pharmacotherapy of lean MASH. We searched standard medical databases, such as PubMed, Embase, Scopus, Cochrane CENTRAL, and ClinicalTrials.gov to identify eligible studies published in English up to 31 December 2023 regarding the effect of pharmacological interventions in individuals with lean MASH. We have summarized the role of various drug classes including peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, vitamin E, farnesoid X receptor agonists, selective thyroid hormone receptor-β agonists, and selective cholesterol absorption inhibitors. Consequently, lifestyle interventions, encompassing dietary modifications, exercise, and weight loss particularly directed at visceral obesity or achieving a reduction in body weight are recommended for all non-obese individuals with MASH. A highlight on the only available treatment recommendation for lean MASH is also presented. The available evidence regarding the efficacy of various drugs for the treatment of lean MASH is limited. Conclusive evidence is warranted from clinical trials exclusively involving lean individuals with MASH.

Potential therapeutic strategies for MASH: from preclinical to clinical development

Current treatment paradigms for metabolic dysfunction-associated steatohepatitis (MASH) are based primarily on dietary restrictions and the use of existing drugs, including anti-diabetic and anti-obesity medications. Given the limited number of approved drugs specifically for MASH, recent efforts have focused on promising strategies that specifically target hepatic lipid metabolism, inflammation, fibrosis, or a combination of these processes. In this review, we examined the pathophysiology underlying the development of MASH in relation to recent advances in effective MASH therapy. Particularly, we analyzed the effects of lipogenesis inhibitors, nuclear receptor agonists, glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists, fibroblast growth factor mimetics, and combinatorial therapeutic approaches. We summarize these targets along with their preclinical and clinical candidates with the ultimate goal of optimizing the therapeutic prospects for MASH.

Metabolic Dysfunction-associated Steatotic Liver Disease and Type 2 Diabetes: A Deadly Synergy

Type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD) are both facets of the metabolic syndrome, associated with obesity and insulin resistance. MASLD, a term that replaces non-alcoholic fatty liver disease (NAFLD), occurs in up to 70% of people with T2D. Not only do T2D and MASLD commonly co-occur, but there is a synergistic, bidirectional relationship between these conditions, meaning that each affects the natural disease course of the other. As such, it is important for those caring for people with T2D to recognize the importance of this co-diagnosis. In this summary, we detail the synergistic relationship between T2D and MASLD, explain the current challenges in recognizing this common co-diagnosis and suggest practical approaches for those caring for people with T2D to improve the diagnosis and treatment of MASLD.

The role of incretin receptor agonists in the treatment of obesity

INTRODRODUCTION

Obesity and its associated metabolic conditions have become a significant global health problem in recent years, with many people living with obesity fulfilling criteria for pharmacological treatment. The development of the glucagon-like peptide-1 receptor agonists for chronic weight management has triggered new interest in the incretins and other hormones as targets for obesity, and investigations into dual and triple co-agonists.

METHODS

The objective of this narrative review was to summarize the available data on approved and emerging incretin-based agents for the treatment of obesity.

RESULTS

In clinical trials of currently available agents in people with overweight or obesity, weight loss of between 6% and 21% of baseline body weight has been observed, with between 23% and 94% of participants achieving 10% or higher weight loss, depending on the study and the agent used. Favourable outcomes have also been seen with regard to cardiovascular risk and outcomes, diabetes prevention, metabolic dysfunction-associated steatotic liver disease/steatohepatitis and prevention of weight regain after metabolic surgery. Limitations associated with these agents include high costs, the potential for weight regain once treatment is stopped, the potential loss of lean body mass and gastrointestinal adverse events; potential issues with respect to gallbladder and biliary diseases require further investigation.

CONCLUSIONS

Many dual and triple co-agonists are still in development, and more data are needed to assess the efficacy, safety and tolerability of these emerging therapies versus the established incretin-based therapies; however, data are promising, and further results are eagerly awaited.

Review of current and new drugs for the treatment of metabolic-associated fatty liver disease

In the past 3 decades, metabolic-associated fatty liver disease (MAFLD) has emerged as a widespread liver condition, with its global prevalence on the rise. It ranks as a leading contributor to hepatocellular carcinoma (HCC) and necessitates liver transplantation. Under the multiple parallel hits model, the pathogenesis of MAFLD stems from various liver stressors, notably nutrient overload and sedentary lifestyles. While medical management for MAFLD is well-established, encompassing non-pharmaceutical and pharmaceutical interventions, determining the most effective pharmaceutical therapy has remained elusive. This review discusses diabetic medications for MAFLD treatment, emphasizing recent studies and emerging drugs while reviewing other nondiabetic agents. Emerging evidence suggests that combination therapies hold promise for resolving MAFLD and metabolic steatohepatitis (MASH) while managing side effects. Ongoing trials play a pivotal role in elucidating the effects of mono, dual, and triple receptor agonists in individuals with MASH. With the rising burden of MAFLD/MASH and its severe consequences, the need for effective treatments is more pressing than ever. This review provides a comprehensive overview of the current landscape of pharmaceutical interventions for MAFLD and MASH, shedding light on the potential of newer drugs especially diabetic medications and the importance of ongoing research in this field.

The Pathophysiological Associations Between Obesity, NAFLD, and Atherosclerotic Cardiovascular Diseases

Obesity, non-alcoholic fatty liver disease (NAFLD), and atherosclerotic cardiovascular diseases are common and growing public health concerns. Previous epidemiological studies unfolded the robust correlation between obesity, NAFLD, and atherosclerotic cardiovascular diseases. Obesity is a well-known risk factor for NAFLD, and both of them can markedly increase the odds of atherosclerotic cardiovascular diseases. On the other hand, significant weight loss achieved by lifestyle modification, bariatric surgery, or medications, such as semaglutide, can concomitantly improve NAFLD and atherosclerotic cardiovascular diseases. Therefore, certain pathophysiological links are involved in the development of NAFLD in obesity, and atherosclerotic cardiovascular diseases in obesity and NAFLD. Moreover, recent studies indicated that simultaneously targeting several mechanisms by tirzepatide and retatrutide leads to greater weight loss and markedly improves the complications of metabolic syndrome. These findings remind the importance of a mechanistic viewpoint for breaking the association between obesity, NAFLD, and atherosclerotic cardiovascular diseases. In this review article, we mainly focus on shared pathophysiological mechanisms, including insulin resistance, dyslipidemia, GLP1 signaling, inflammation, oxidative stress, mitochondrial dysfunction, gut dysbiosis, renin-angiotensin-aldosterone system (RAAS) overactivity, and endothelial dysfunction. Most of these pathophysiological alterations are primarily initiated by obesity. The development of NAFLD further exacerbates these molecular and cellular alterations, leading to atherosclerotic cardiovascular disease development or progression as the final manifestation of molecular perturbation. A better insight into these mechanisms makes it feasible to develop new multi-target approaches to simultaneously unhinge the deleterious chain of events linking obesity and NAFLD to atherosclerotic cardiovascular diseases.

Modern Management of Cardiometabolic Continuum: From Overweight/Obesity to Prediabetes/Type 2 Diabetes Mellitus. Recommendations from the Eastern and Southern Europe Diabetes and Obesity Expert Group

The increasing global incidence of obesity and type 2 diabetes mellitus (T2D) underscores the urgency of addressing these interconnected health challenges. Obesity enhances genetic and environmental influences on T2D, being not only a primary risk factor but also exacerbating its severity. The complex mechanisms linking obesity and T2D involve adiposity-driven changes in β-cell function, adipose tissue functioning, and multi-organ insulin resistance (IR). Early detection and tailored treatment of T2D and obesity are crucial to mitigate future complications. Moreover, personalized and early intensified therapy considering the presence of comorbidities can delay disease progression and diminish the risk of cardiorenal complications. Employing combination therapies and embracing a disease-modifying strategy are paramount. Clinical trials provide evidence confirming the efficacy and safety of glucagon-like peptide 1 receptor agonists (GLP-1 RAs). Their use is associated with substantial and durable body weight reduction, exceeding 15%, and improved glucose control which further translate into T2D prevention, possible disease remission, and improvement of cardiometabolic risk factors and associated complications. Therefore, on the basis of clinical experience and current evidence, the Eastern and Southern Europe Diabetes and Obesity Expert Group recommends a personalized, polymodal approach (comprising GLP-1 RAs) tailored to individual patient's disease phenotype to optimize diabetes and obesity therapy. We also expect that the increasing availability of dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) agonists will significantly contribute to the modern management of the cardiometabolic continuum.

Inhibition of sodium-glucose cotransporter-2 and liver-related complications in individuals with diabetes: a Mendelian randomization and population-based cohort study

BACKGROUND AND AIMS

No medication has been found to reduce liver-related events. We evaluated the effect of sodium-glucose cotransporter-2 inhibitor (SGLT2i) on liver-related outcomes.

APPROACH AND RESULTS

Single nucleotide polymorphisms associated with SGLT2 inhibition were identified, and a genetic risk score (GRS) was computed using the UK Biobank data (n=337,138). Two-sample Mendelian randomization (MR) was conducted using the FinnGen (n=218,792) database and the UK Biobank data. In parallel, a nationwide population-based study using the Korean National Health Insurance Service (NHIS) database was conducted. The development of liver-related complications (ie, hepatic decompensation, HCC, liver transplantation, and death) was compared between individuals with type 2 diabetes mellitus and steatotic liver diseases treated with SGLT2i (n=13,208) and propensity score-matched individuals treated with dipeptidyl peptidase-4 inhibitor (n=70,342). After computing GRS with 6 single nucleotide polymorphisms (rs4488457, rs80577326, rs11865835, rs9930811, rs34497199, and rs35445454), GRS-based MR showed that SGLT2 inhibition (per 1 SD increase of GRS, 0.1% lowering of HbA1c) was negatively associated with cirrhosis development (adjusted odds ratio=0.83, 95% CI=0.70-0.98, p =0.03) and this was consistent in the 2-sample MR (OR=0.73, 95% CI=0.60-0.90, p =0.003). In the Korean NHIS database, the risk of liver-related complications was significantly lower in the SGLT2i group than in the dipeptidyl peptidase-4 inhibitor group (adjusted hazard ratio=0.88, 95% CI=0.79-0.97, p =0.01), and this difference remained significant (adjusted hazard ratio=0.72-0.89, all p <0.05) across various sensitivity analyses.

CONCLUSIONS

Both MRs using 2 European cohorts and a Korean nationwide population-based cohort study suggest that SGLT2 inhibition is associated with a lower risk of liver-related events.

Network Pharmacological Analysis Combined with Experimental Verification to Explore the Effect of Ginseng Polypeptide on the Improvement of Diabetes Symptoms in db/db Mice

Diabetes mellitus is a typical metabolic disease that has become a major threat to human health worldwide. Ginseng polypeptide (GP), a small molecule active substance isolated from ginseng, has shown positive hypoglycemic effects in preliminary studies. However, its mechanism in ameliorating multiorgan damage in db/db mice is unclear. In this study, we utilized network pharmacology, molecular docking, and animal experiments to explore the targets and biological mechanisms of GP to ameliorate multiorgan damage in T2DM. The results showed that GP improves T2DM by inhibiting inflammation and oxidative damage, thereby alleviating hyperglycemia, insulin resistance, and multiorgan damage in db/db mice. These effects are potentially mediated through the PI3K-Akt signaling pathway and the MAPK signaling pathway. This study establishes GP's efficacy in alleviating T2DM and provides a robust theoretical basis for the development of new drugs or functional foods for treating this disease.

Glucagon-like peptide 1 agonists are potentially useful drugs for treating metabolic dysfunction-associated steatotic liver disease

In this editorial, we comment on Yin et al's recently published Letter to the editor. In particular, we focus on the potential use of glucagon-like peptide 1 receptor agonists (GLP-1RAs) alone, but even more so in combination therapy, as one of the most promising therapies in metabolic dysfunction-associated steatotic liver disease (MASLD), the new definition of an old condition, non-alcoholic fatty liver disease, which aims to better define the spectrum of steatotic pathology. It is well known that GLP-1RAs, having shown outstanding performance in fat loss, weight loss, and improvement of insulin resistance, could play a role in protecting the liver from progressive damage. Several clinical trials have shown that, among GLP-1RAs, semaglutide is a safe, well-studied therapeutic choice for MASLD patients; however, most studies demonstrate that, while semaglutide can reduce steatosis, including steatohepatitis histological signs (in terms of inflammatory cell infiltration and hepatocyte ballooning), it does not improve fibrosis. Combinations of therapies with different but complementary mechanisms of action are considered the best way to improve efficiency and slow disease progression due to the complex pathophysiology of the disease. In particular, GLP-1RAs associated with antifibrotic drug therapy, dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1RA or GLP-1 and glucagon RAs have promoted greater improvement in hepatic steatosis, liver biochemistry, and non-invasive fibrosis tests than monotherapy. Therefore, although to date there are no definitive indications from international drug agencies, there is the hope that soon the therapeutic lines in the most advanced phase of study will be able to provide a therapy for MASLD, one that will certainly include the use of GLP-1RAs as combination therapy.

Metabolic dysfunction-associated liver disease and diabetes: Matrix remodeling, fibrosis, and therapeutic implications

Metabolic dysfunction-associated liver disease (MASLD) and steatohepatitis (MASH) are becoming the most common causes of chronic liver disease in the United States and worldwide due to the obesity and diabetes epidemics. It is estimated that by 2030 close to 100 million people might be affected and patients with type 2 diabetes are especially at high risk. Twenty to 30% of patients with MASLD can progress to MASH, which is characterized by steatosis, necroinflammation, hepatocyte ballooning, and in advanced cases, fibrosis progressing to cirrhosis. Clinically, it is recognized that disease progression in diabetic patients is accelerated and the role of various genetic and epigenetic factors, as well as cell-matrix interactions in fibrosis and stromal remodeling, have recently been recognized. While there has been great progress in drug development and clinical trials for MASLD/MASH, the complexity of these pathways highlights the need to improve diagnosis/early detection and develop more successful antifibrotic therapies that not only prevent but reverse fibrosis.

Tirzepatide for Metabolic Dysfunction-Associated Steatohepatitis with Liver Fibrosis

BACKGROUND

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive liver disease associated with liver-related complications and death. The efficacy and safety of tirzepatide, an agonist of the glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors, in patients with MASH and moderate or severe fibrosis is unclear.

METHODS

We conducted a phase 2, dose-finding, multicenter, double-blind, randomized, placebo-controlled trial involving participants with biopsy-confirmed MASH and stage F2 or F3 (moderate or severe) fibrosis. Participants were randomly assigned to receive once-weekly subcutaneous tirzepatide (5 mg, 10 mg, or 15 mg) or placebo for 52 weeks. The primary end point was resolution of MASH without worsening of fibrosis at 52 weeks. A key secondary end point was an improvement (decrease) of at least one fibrosis stage without worsening of MASH.

RESULTS

Among 190 participants who had undergone randomization, 157 had liver-biopsy results at week 52 that could be evaluated, with missing values imputed under the assumption that they would follow the pattern of results in the placebo group. The percentage of participants who met the criteria for resolution of MASH without worsening of fibrosis was 10% in the placebo group, 44% in the 5-mg tirzepatide group (difference vs. placebo, 34 percentage points; 95% confidence interval [CI], 17 to 50), 56% in the 10-mg tirzepatide group (difference, 46 percentage points; 95% CI, 29 to 62), and 62% in the 15-mg tirzepatide group (difference, 53 percentage points; 95% CI, 37 to 69) (P<0.001 for all three comparisons). The percentage of participants who had an improvement of at least one fibrosis stage without worsening of MASH was 30% in the placebo group, 55% in the 5-mg tirzepatide group (difference vs. placebo, 25 percentage points; 95% CI, 5 to 46), 51% in the 10-mg tirzepatide group (difference, 22 percentage points; 95% CI, 1 to 42), and 51% in the 15-mg tirzepatide group (difference, 21 percentage points; 95% CI, 1 to 42). The most common adverse events in the tirzepatide groups were gastrointestinal events, and most were mild or moderate in severity.

CONCLUSIONS

In this phase 2 trial involving participants with MASH and moderate or severe fibrosis, treatment with tirzepatide for 52 weeks was more effective than placebo with respect to resolution of MASH without worsening of fibrosis. Larger and longer trials are needed to further assess the efficacy and safety of tirzepatide for the treatment of MASH. (Funded by Eli Lilly; SYNERGY-NASH ClinicalTrials.gov number, NCT04166773.).

Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial

Retatrutide is a novel triple agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1 and glucagon receptors. A 48-week phase 2 obesity study demonstrated weight reductions of 22.8% and 24.2% with retatrutide 8 and 12 mg, respectively. The primary objective of this substudy was to assess mean relative change from baseline in liver fat (LF) at 24 weeks in participants from that study with metabolic dysfunction-associated steatotic liver disease and ≥10% of LF. Here, in this randomized, double-blind, placebo-controlled trial, participants (n = 98) were randomly assigned to 48 weeks of once-weekly subcutaneous retatrutide (1, 4, 8 or 12 mg dose) or placebo. The mean relative change from baseline in LF at 24 weeks was -42.9% (1 mg), -57.0% (4 mg), -81.4% (8 mg), -82.4% (12 mg) and +0.3% (placebo) (all P < 0.001 versus placebo). At 24 weeks, normal LF (<5%) was achieved by 27% (1 mg), 52% (4 mg), 79% (8 mg), 86% (12 mg) and 0% (placebo) of participants. LF reductions were significantly related to changes in body weight, abdominal fat and metabolic measures associated with improved insulin sensitivity and lipid metabolism. The ClinicalTrials.gov registration is NCT04881760 .

Randomised clinical trial: Design of the SYNERGY-NASH phase 2b trial to evaluate tirzepatide as a treatment for metabolic dysfunction-associated steatohepatitis and modification of screening strategy to reduce screen failures

BACKGROUND

The use of histological inclusion criteria for clinical trials of at-risk metabolic dysfunction-associated steatohepatitis (MASH) is often associated with high screen failure rates.

AIMS

To describe the design of a trial investigating tirzepatide treatment of MASH and to examine the effect of new inclusion criteria incorporating the use of the FibroScan-AST (FAST) score on the proportion of patients meeting histological criteria.

METHODS

SYNERGY-NASH is a Phase 2b, multicentre, randomised, double-blinded, placebo-controlled trial in patients with biopsy-confirmed MASH, F2-F3 fibrosis and NAFLD Activity Score ≥4. New inclusion criteria (FAST score >0.35 and an increase in AST inclusion criterion from >20 to >23 U/L) were adopted during the trial, allowing us to examine its impact on the qualification rate.

RESULTS

1583 participants were screened, 651 participants proceeded to liver biopsy and 190 participants were randomised with an overall screen fail rate of 87%. Following the protocol amendment, the overall qualification rate for per-protocol biopsies was minimally changed from 27.5% to 28.9% with considerable variation among different investigator medical speciality types: endocrinology: from 37.5% to 39.3%; gastroenterology/hepatology: from 26.0% to 23.3%; other specialities: from 21.3% to 29.7%. At 29 sites that performed per-protocol biopsies before and after the amendment, qualification rates changed as follows: all: 26.1% to 29.1%; endocrinology: from 35.0% to 40.9%; gastroenterology/hepatology: 25.6% to 20.0%; other specialities: from 16.1% to 27.8%.

CONCLUSIONS

For at-risk MASH trials based on liver histology, the implementation of inclusion criteria with the proposed FAST score and AST cut-offs in this trial was most effective at non-specialist sites.

The sclerotic component of metabolic syndrome: Fibroblast activities may be the central common denominator driving organ function loss and death

Fibrosis is a common feature of more than 50 different diseases and the cause of more than 35% of deaths worldwide, of which liver, kidney, skin, heart and, recently, lungs are receiving the most attention. Tissue changes, resulting in loss of organ function, are both a cause and consequence of disease and outcome. Fibrosis is caused by an excess deposition of extracellular matrix proteins, which over time results in impaired organ function and organ failure, and the pathways leading to increased fibroblast activation are many. This narrative review investigated the common denominator of fibrosis, fibroblasts, and the activation of fibroblasts, in response to excess energy consumption in liver, kidney, heart, skin and lung fibrosis. Fibroblasts are the main drivers of organ function loss in lung, liver, skin, heart and kidney disease. Fibroblast activation in response to excess energy consumption results in the overproduction of a range of collagens, of which types I, III and VI seem to be the essential drivers of disease progression. Fibroblast activation may be quantified in serum, enabling profiling and selection of patients. Activation of fibroblasts results in the overproduction of collagens, which deteriorates organ function. Patient profiling of fibroblast activities in serum, quantified as collagen production, may identify an organ death trajectory, better enabling identification of the right treatment for use in different metabolic interventions. As metabolically activated patients have highly elevated risk of kidney, liver and heart failure, it is essential to identify which organ to treat first and monitor organ status to correct treatment regimes. In direct alignment with this, it is essential to identify the right patients with the right organ deterioration trajectory for enrolment in clinical studies.

Therapeutic implications for sphingolipid metabolism in metabolic dysfunction-associated steatohepatitis

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), a leading cause of chronic liver disease, has increased worldwide along with the epidemics of obesity and related dysmetabolic conditions characterized by impaired glucose metabolism and insulin signaling, such as type 2 diabetes mellitus (T2D). MASLD can be defined as an excessive accumulation of lipid droplets in hepatocytes that occurs when the hepatic lipid metabolism is totally surpassed. This metabolic lipid inflexibility constitutes a central node in the pathogenesis of MASLD and is frequently linked to the overproduction of lipotoxic species, increased cellular stress, and mitochondrial dysfunction. A compelling body of evidence suggests that the accumulation of lipid species derived from sphingolipid metabolism, such as ceramides, contributes significantly to the structural and functional tissue damage observed in more severe grades of MASLD by triggering inflammatory and fibrogenic mechanisms. In this context, MASLD can further progress to metabolic dysfunction-associated steatohepatitis (MASH), which represents the advanced form of MASLD, and hepatic fibrosis. In this review, we discuss the role of sphingolipid species as drivers of MASH and the mechanisms involved in the disease. In addition, given the absence of approved therapies and the limited options for treating MASH, we discuss the feasibility of therapeutic strategies to protect against MASH and other severe manifestations by modulating sphingolipid metabolism.

Emerging drugs for the treatment of hepatic fibrosis on nonalcoholic steatohepatitis

INTRODUCTION

Approved drug therapies for nonalcoholic steatohepatitis (NASH) are lacking, for which various agents are currently being tested in clinical trials. Effective drugs for liver fibrosis, the factor most associated with prognosis in NASH, are important.

AREAS COVERED

This study reviewed the treatment of NASH with a focus on the effects of existing drugs and new drugs on liver fibrosis.

EXPERT OPINION

Considering the complex pathophysiology of fibrosis in NASH, drug therapy may target multiple pathways. The method of assessing fibrosis is important when considering treatment for liver fibrosis in NASH. The Food and Drug Administration considers an important fibrosis endpoint to be histological improvement in at least one fibrosis stage while preventing worsening of fatty hepatitis. To obtain approval as a drug for NASH, efficacy needs to be demonstrated on endpoints such as liver-related events and myocardial infarction. Among the current therapeutic agents for NASH, thiazolidinedione, sodium-glucose co-transporter 2, and selective peroxisome proliferator-activated receptors α modulator have been reported to be effective against fibrosis, although further evidence is required. The effects of pan-peroxisome proliferator-activated receptors, obeticholic acid, and fibroblast growth factor-21 analogs on liver fibrosis in the development stage therapeutics for NASH are of particular interest.

Incretin-based investigational therapies for the treatment of MASLD/MASH

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most common form of chronic liver disease. It exists as either simple steatosis or its more progressive form, metabolic dysfunction-associated steatohepatitis (MASH), formerly, non-alcoholic steatohepatitis (NASH). The global prevalence of MASLD is estimated to be 32% among adults and is projected to continue to rise with increasing rates of obesity, type 2 diabetes, and metabolic syndrome. While simple steatosis is often considered benign and reversible, MASH is progressive, potentially leading to the development of cirrhosis, liver failure, and hepatocellular carcinoma. Treatment of MASH is therefore directed at slowing, stopping, or reversing the progression of disease. Evidence points to improved liver histology with therapies that result in sustained body weight reduction. Incretin-based molecules, such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs), alone or in combination with glucose-dependent insulinotropic polypeptide (GIP) and/or glucagon receptor agonists, have shown benefit here, and several are under investigation for MASLD/MASH treatment. In this review, we discuss current published data on GLP-1, GIP/GLP-1, GLP-1/glucagon, and GLP-1/GIP/glucagon RAs in MASLD/MASH, focusing on their efficacy on liver histology, liver fat, and MASH biomarkers.

Glucagon-like peptide-1 analogs: Miracle drugs are blooming?

Glucagon-like peptide-1 (GLP-1), secreted by L cells in the small intestine, assumes a central role in managing type 2 diabetes mellitus (T2DM) and obesity. Its influence on insulin secretion and gastric emptying positions it as a therapeutic linchpin. However, the limited applicability of native GLP-1 stems from its short half-life, primarily due to glomerular filtration and the inactivating effect of dipeptidyl peptidase-IV (DPP-IV). To address this, various structural modification strategies have been developed to extend GLP-1's half-life. Despite the commendable efficacy displayed by current GLP-1 receptor agonists, inherent limitations persist. A paradigm shift emerges with the advent of unimolecular multi-agonists, such as the recently introduced tirzepatide, wherein GLP-1 is ingeniously combined with other gastrointestinal hormones. This novel approach has captured the spotlight within the diabetes and obesity research community. This review summarizes the physiological functions of GLP-1, systematically explores diverse structural modifications, delves into the realm of unimolecular multi-agonists, and provides a nuanced portrayal of the developmental prospects that lie ahead for GLP-1 analogs.