Beneficial effects of glucagon-like peptide 1 receptor agonists on glucose control, cardiovascular risk profile, and non-alcoholic fatty liver disease. An expert opinion of the Italian diabetes society

Mechanisms Linking Metabolic-Associated Fatty Liver Disease (MAFLD) to Cardiovascular Disease

PURPOSE OF REVIEW

Metabolic-associated fatty liver disease (MAFLD) is a condition of fat accumulation in the liver that occurs in the majority of patients in combination with metabolic dysfunction in the form of overweight or obesity. In this review, we highlight the cardiovascular complications in MAFLD patients as well as some potential mechanisms linking MAFLD to the development of cardiovascular disease and highlight potential therapeutic approaches to treating cardiovascular diseases in patients with MAFLD.

RECENT FINDINGS

MAFLD is associated with an increased risk of cardiovascular diseases (CVD), including hypertension, atherosclerosis, cardiomyopathies, and chronic kidney disease. While clinical data have demonstrated the link between MAFLD and the increased risk of CVD development, the mechanisms responsible for this increased risk remain unknown. MAFLD can contribute to CVD through several mechanisms including its association with obesity and diabetes, increased levels of inflammation, and oxidative stress, as well as alterations in hepatic metabolites and hepatokines. Therapies to potentially treat MAFLD-induced include statins and lipid-lowering drugs, glucose-lowering agents, antihypertensive drugs, and antioxidant therapy.

Glucagon-like Peptide-1 Receptor Agonists in Patients with Type 2 Diabetes Mellitus and Nonalcoholic Fatty Liver Disease-Current Background, Hopes, and Perspectives

Nonalcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease worldwide, reaching one of the highest prevalences in patients with type 2 diabetes mellitus (T2DM). For now, no specific pharmacologic therapies are approved to prevent or treat NAFLD. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are currently evaluated as potential candidates for NAFLD treatment in patients with T2DM. Some representatives of this class of antihyperglycemic agents emerged as potentially beneficial in patients with NAFLD after several research studies suggested they reduce hepatic steatosis, ameliorate lesions of nonalcoholic steatohepatitis (NASH), or delay the progression of fibrosis in this population. The aim of this review is to summarize the body of evidence supporting the effectiveness of GLP-1RA therapy in the management of T2DM complicated with NAFLD, describing the studies that evaluated the effects of these glucose-lowering agents in fatty liver disease and fibrosis, their possible mechanistic justification, current evidence-based recommendations, and the next steps to be developed in the field of pharmacological innovation.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Nonalcoholic Steatohepatitis (NASH) and Atherosclerosis: Explaining Their Pathophysiology, Association and the Role of Incretin-Based Drugs

Nonalcoholic steatohepatitis (NASH) is the most severe manifestation of nonalcoholic fatty liver disease (NAFLD), a common complication of type 2 diabetes, and may lead to cirrhosis and hepatocellular carcinoma. Oxidative stress and liver cell damage are the major triggers of the severe hepatic inflammation that characterizes NASH, which is highly correlated with atherosclerosis and coronary artery disease. Regarding drug therapy, research on the role of GLP-1 analogues and DPP4 inhibitors, novel classes of antidiabetic drugs, is growing. In this review, we outline the association between NASH and atherosclerosis, the underlying molecular mechanisms, and the effects of incretin-based drugs, especially GLP-1 RAs, for the therapeutic management of these conditions.

Effectiveness in Real World of Once Weekly Semaglutide in People with Type 2 Diabetes: Glucagon-Like Peptide Receptor Agonist Naïve or Switchers from Other Glucagon-Like Peptide Receptor Agonists: Results from a Retrospective Observational Study in Umbria

INTRODUCTION

To complement results of the SUSTAIN program, this study assessed effectiveness and safety of once weekly subcutaneous semaglutide in people with type 2 diabetes (T2D) managed under routine care.

METHODS

This was a multicenter, observational, retrospective study including all patients treated with semaglutide. Changes in clinical outcomes from baseline to 6 and 12 months were assessed in patients who were glucagon-like peptide receptor agonist (GLP-1RA) naïve or switching from another GLP-1RA. Discontinuation rate was assessed.

RESULTS

Overall, 216 patients (mean age 64 years, 65.7% men) were evaluated: 135 (61.5%) naïve and 81 (38.5%) switchers from another GLP-1RA. In the naïve cohort, after 6 months from semaglutide initiation, levels of HbA1c significantly decreased by - 1.31% (p < 0.0001). All obesity indices improved, with mean reductions in body weight of - 3.92 kg, in BMI of - 1.43 kg/m², and in waist circumference of - 5.03 cm. In the switcher cohort, statistically significant improvements in HbA1c (- 0.78%), body weight (- 2.64 kg), and waist circumference (- 3.03 cm) were obtained after 6 months. Reductions were sustained after 12 months in both cohorts (mean semaglutide dose: 0.86 mg in naïve and 0.96 mg in switcher cohort). Blood pressure and lipid profile mean levels decreased after 12 months from semaglutide initiation in both cohorts. No severe hypoglycemia occurred; 6.5% of patients discontinued semaglutide (2.8% due to gastrointestinal side effects).

CONCLUSION

Effectiveness and tolerability of semaglutide have been confirmed in the real world irrespective of diabetes duration and severity. As expected, more marked reductions in HbA1c and obesity indices were obtained in naïve patients, but it is noteworthy that relevant improvements were also obtained in patients already treated with GLP-1RAs.

Effectiveness and Tolerability of Once-Weekly GLP-1 Receptor Agonists in Clinical Practice: A Focus on Switching Between Once-Weekly Molecules in Type 2 Diabetes

AIMS

This study aims to evaluate the effectiveness and tolerability of once-weekly glucagon-like peptide receptor agonists (OW GLP-1RAs) and to assess the clinical benefits of switching from one GLP-1RA to another (switchers) in a routine clinical setting.

MATERIALS AND METHODS

This is a retrospective, real-world cohort study, based on electronic medical records utilized in one Italian diabetes clinic. Estimated mean changes in HbA1c and body weight after 6 and 12 months from the first prescription of a long-acting GLP1-RA were evaluated using longitudinal linear mixed models for repeated measures. The effectiveness of the three long-acting GLP1-RAs was compared separately in the GLP1-RA naive and switchers cohorts, after propensity score adjustment.

RESULTS

Initiating a long-acting GLP1-RA was associated with statistically significant improvements in HbA1c (-1%) and body weight (-2.6 kg) after 6 months, and benefits were maintained after 12 months. In GLP1-RA naive cohort, semaglutide showed the largest effect on HbA1c (-1.55%; 95%CI, -1.77;-1.34) and body weight (-3.76 kg; 95%CI, -5.05;-2.47) at 6 months, maintained at 12 months (-1.55%; 95%CI, -1.82;-1.28 and -6.29 kg; 95%CI, -7.94;-4.63). In the switchers' cohort, statistically significant reductions at 6 months in HbA1c and body weight were documented with semaglutide and dulaglutide only, with semaglutide associated with the most marked reduction (-0.84%; 95%CI, -1.03;-0.65 and -3.43 kg; 95%, -4.67;-2.19). Dropout rates were 9.2%, 28.5%, and 41.7% in semaglutide, dulaglutide, and exenatide groups, respectively.

CONCLUSIONS

The effectiveness and tolerability of the OW GLP-1RAs in the real world were documented. Semaglutide was associated with the highest response without impact on safety. Clinical improvements were obtained even in switchers, especially in those switching to semaglutide.

TNFSF14-Derived Molecules as a Novel Treatment for Obesity and Type 2 Diabetes

Obesity is one of the most prevalent metabolic diseases in the Western world and correlates directly with glucose intolerance and insulin resistance, often culminating in Type 2 Diabetes (T2D). Importantly, our team has recently shown that the TNF superfamily (TNFSF) member protein, TNFSF14, has been reported to protect against high fat diet induced obesity and pre-diabetes. We hypothesized that mimics of TNFSF14 may therefore be valuable as anti-diabetic agents. In this study, we use in silico approaches to identify key regions of TNFSF14 responsible for binding to the Herpes virus entry mediator and Lymphotoxin β receptor. In vitro evaluation of a selection of optimised peptides identified six potentially therapeutic TNFSF14 peptides. We report that these peptides increased insulin and fatty acid oxidation signalling in skeletal muscle cells. We then selected one of these promising peptides to determine the efficacy to promote metabolic benefits in vivo. Importantly, the TNFSF14 peptide 7 reduced high fat diet-induced glucose intolerance, insulin resistance and hyperinsulinemia in a mouse model of obesity. In addition, we highlight that the TNFSF14 peptide 7 resulted in a marked reduction in liver steatosis and a concomitant increase in phospho-AMPK signalling. We conclude that TNFSF14-derived molecules positively regulate glucose homeostasis and lipid metabolism and may therefore open a completely novel therapeutic pathway for treating obesity and T2D.