Impact of Incretin-Based Therapies on Adipokines and Adiponectin

Effects of Glucagon-Like Peptide-1 Receptor Agonists and Sodium-Glucose Cotransporter 2 Inhibitors on Intima-Media Thickness: Systematic Review and Meta-Analysis

Background

Beyond glycemic control, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been proposed to reduce the risk of cardiovascular events. The aim of the present systematic review and meta-analysis is to demonstrate the effects of GLP-1 RA and SGLT2is on intima-media thickness (IMT).

Methods

PubMed, EMBASE, Web of Science, SCOPUS, and Google Scholar databases were searched from inception to September 9, 2023. All interventional and observational studies that provided data on the effects of GLP-1 RAs or SGLT2is on IMT were included. Critical appraisal was performed using the Joanna Briggs Institute checklists. IMT changes (preintervention and postintervention) were pooled and meta-analyzed using a random-effects model. Subgroup analyses were based on type of medication (GLP-1 RA: liraglutide and exenatide; SGLT2i: empagliflozin, ipragliflozin, tofogliflozin, and dapagliflozin), randomized clinical trials (RCTs), and diabetic patients.

Results

The literature search yielded 708 related articles after duplicates were removed. Eighteen studies examined the effects of GLP-1 RA, and eleven examined the effects of SGLT2i. GLP-1 RA and SGLT2i significantly decreased IMT (MD = -0.123, 95% CI (-0.170, -0.076), P < 0.0001, I2 = 98% and MD = -0.048, 95% CI (-0.092, -0.004), P = 0.031, I2 = 95%, respectively). Metaregression showed that IMT change correlated with baseline IMT, whereas it did not correlate with gender, duration of diabetes, and duration of treatment.

Conclusions

Treatment with GLP-1 RA and SGLT2i can lower IMT in diabetic patients, and GLP-1 RA may be more effective than SGLT2i.

Tumor Necrosis Factor-Alpha and Adiponectin in Nonalcoholic Fatty Liver Disease-Associated Hepatocellular Carcinoma

Nonalcoholic fatty liver disease (NAFLD) is emerging as an important risk factor for hepatocellular carcinoma (HCC), whose prevalence is rising. Although the mechanisms of progression from NAFLD to HCC are not fully elucidated, tumor necrosis factor-α (TNF-α) and adiponectin, as well as their interplay, which seems to be antagonistic, may contribute to the pathophysiology of NAFLD-associated HCC. TNF-α initially aims to protect against hepatocarcinogenesis, but during the progression of NAFLD, TNF-α is increased, thus probably inducing hepatocarcinogenesis in the long-term, when NAFLD is not resolved. On the other hand, adiponectin, which is expected to exert anti-tumorigenic effects, is decreased during the progression of the disease, a trend that may favor hepatocarcinogenesis, but is paradoxically increased at end stage disease, i.e., cirrhosis and HCC. These observations render TNF-α and adiponectin as potentially diagnostic biomarkers and appealing therapeutic targets in the setting of NAFLD-associated HCC, possibly in combination with systematic therapy. In this regard, combination strategy, including immune checkpoint inhibitors (ICIs) with anti-TNF biologics and/or adiponectin analogs or medications that increase endogenous adiponectin, may warrant investigation against NAFLD-associated HCC. This review aims to summarize evidence on the association between TNF-α and adiponectin with NAFLD-associated HCC, based on experimental and clinical studies, and to discuss relevant potential therapeutic considerations.

Benefits of GLP-1 Mimetics on Epicardial Adiposity

The epicardial adipose tissue, which is referred to as fats surrounding the myocardium, is an active organ able to induce cardiovascular problems in pathophysiologic conditions through several pathways, such as inflammation, fibrosis, fat infiltration, and electrophysiologic problems. So, control of its volume and thickness, especially in patients with diabetes, is highly important. Incretin-based pharmacologic agents are newly developed antidiabetics that could provide further cardiovascular benefits through control and modulating epicardial adiposity. They can reduce cardiovascular risks by rapidly reducing epicardial adipose tissues, improving cardiac efficiency. We are at the first steps of a long way, but current evidence demonstrates the sum of possible mechanisms. In this study, we evaluate epicardial adiposity in physiologic and pathologic states and the impact of incretin-based drugs.

Implications of cancer stem cells in diabetes and pancreatic cancer

This review provides a detailed study of pancreatic cancer (PC) and the implication of different types of cancers concerning diabetes. The combination of anti-diabetic drugs with other anti-cancer drugs and phytochemicals can help prevent and treat this disease. PC cancer stem cells (CSCs) and how they migrate and develop into malignant tumors are discussed. A detailed explanation of the different mechanisms of diabetes development, which can enhance the pancreatic CSCs' proliferation by increasing the IGF factor levels, epigenetic modifications, DNA damage, and the influence of lifestyle factors like obesity, and inflammation, has been discussed. It also explains how cancer due to diabetes is associated with high mortality rates. One of the well-known diabetic drugs, metformin, can be combined with other anti-cancer drugs and prevent the development of PC and has been taken as one of the prime focus in this review. Overall, this paper provides insight into the relationship between diabetes and PC and the methods that can be employed to diagnose this disease at an earlier stage successfully.

The effect of Glucagon-like peptide-1 receptor agonists on serum uric acid concentration: A systematic review and meta-analysis

AIMS

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a class of medications mainly used for the treatment of type 2 diabetes. They improve glucose tolerance, increase insulin secretion, and induce weight loss. There is controversy about the effect of GLP-1RAs on serum uric acid (SUA) concentration. Our systematic review aims to objectively answer whether GLP-1RAs affect SUA levels.

METHODS

We performed a systematic search on PubMed, Web of Science, Embase, Scopus, and Google Scholar datasets up to 27August,2021 with a language restriction of English only. Randomized controlled trials, observational studies, uncontrolled trials, and conference abstracts were included. Studies with insufficient data, irrelevant types of study, and follow-up duration of less than a month were excluded from the review. After critical appraisal by the Joanna Briggs Institute checklists, articles underwent data extraction using a pre-specified Microsoft Excel sheet.

RESULTS

Of 1004 identified studies, 17 were eligible for inclusion in this systematic review. Pre- to post-administration analysis of GLP-1RA effects on SUA demonstrated that GLP-1RAs could significantly reduce SUA concentration (difference in means=-0.341;SE=0.063;P-value<0.001). However, when compared to placebo, GLP-1 RAs did not perform any better in lowering SUA concentration (difference in means=-0.455;SE=0.259;P-value=0.079). Surprisingly, the active controls, that included insulin, metformin, sodium-glucose co-transporter 2 (SGLT-2) inhibitors, and dipeptidyl-peptidase 4 (DPP-4) inhibitors, did outperform GLP-1RAs in reducing SUA concentration (difference in means=0.250;SE=0.038;P-value<0.001).

CONCLUSIONS

Administration of GLP-1RAs can result in a significant reduction in SUA concentration. However, this reduction is less than that seen with the use of insulin, metformin, and SGLT-2 inhibitors.

The Impact of Incretin-Based Medications on Lipid Metabolism

Pathophysiological pathways that are induced by chronic hyperglycemia negatively impact lipid metabolism. Thus, diabetes is commonly accompanied by varying degrees of dyslipidemia which is itself a major risk factor for further macro- and microvascular diabetes complications such as atherosclerosis and nephropathy. Therefore, normalizing lipid metabolism is an attractive goal for therapy in patients with diabetes. Incretin-based medications are a novel group of antidiabetic agents with potent hypoglycemic effects. While the impact of incretins on glucose metabolism is clear, recent evidence indicates their positive modulatory roles on various aspects of lipid metabolism. Therefore, incretins may offer additional beneficial effects beyond that of glucose normalization. In the current review, how these antidiabetic medications can regulate lipid homeostasis and the possible cellular pathways involved are discussed, incorporating related clinical evidence about incretin effects on lipid homeostasis.