glucagon-like-peptide-1 and Cardiotoxicity

Glucagon-like peptide (GLP)-1(7-36), a major active form of GLP-1 hormone, is rapidly cleaved by dipeptidyl peptidase-4 to generate a truncated metabolite, GLP-1(9-36) which has a low affinity for GLP-1 receptor (GLP-1R). GLP-1(7-36) has been shown to have protective effects on cardiovascular system through GLP-1R-dependent pathway. Nevertheless, the cardioprotective effects of GLP-1(9-36) have not fully understood. The present study investigated the effects of GLP-1(9-36), including its underlying mechanisms against oxidative stress and apoptosis in H9c2 cells. Here, we reported that GLP-1(9-36) protects H9c2 cardiomyoblasts from hydrogen peroxide (H2O2)-induced oxidative stress by promoting the synthesis of antioxidant enzymes, glutathione peroxidase-1, catalase, and heme oxygenase-1. In addition, treatment with GLP-1(9-36) suppressed H2O2-induced apoptosis by attenuating caspase-3 activity and upregulating antiapoptotic proteins, Bcl-2 and Bcl-xL. These protective effects of GLP-1(9-36) are attenuated by blockade of PI3K-mediated Akt phosphorylation and prevention of nitric oxide synthase-induced nitric oxide production. Thus, GLP-1(9-36) represents the potential therapeutic target for prevention of oxidative stress and apoptosis in the heart via PI3K/Akt/nitric oxide synthase signaling pathway.

Topics: Animals; Antioxidants; Apoptosis; Apoptosis Regulatory Proteins; Cardiotoxicity; Cell Line; Glucagon-Like Peptide 1; Hydrogen Peroxide; Myoblasts, Cardiac; Nitric Oxide; Nitric Oxide Synthase; Oxidative Stress; Phosphatidylinositol 3-Kinase; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction

To investigate the relative safety of various glucose-lowering agents as add-on medication to metformin in type 2 diabetes in an observational study linking five national health registers.. Patients with type 2 diabetes who had been on metformin monotherapy and started another agent in addition to metformin were eligible for inclusion. The study period was 2005-2012. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of mortality, cardiovascular disease (CVD), coronary heart disease (CHD), stroke and congestive heart failure (CHF) were estimated using Cox proportional hazards models, weighted for a propensity score.. Of the 20 422 patients included in the study, 43% started on second-line treatment with sulphonylurea (SU), 21% basal insulin, 12% thiazolidinedione (TZD), 11% meglitinide, 10% dipeptidyl peptidase-4 (DPP-4) inhibitor, 1% glucagon-like peptide-1 (GLP-1) receptor agonist and 1% acarbose. At the index date, the mean patient age was ~60 years for all groups except the GLP-1 receptor agonist (56.0 years) and SU (62.9 years) groups. Diabetes duration and glycated haemoglobin levels were similar in all groups. When compared with SU, basal insulin was associated with an 18% higher risk and TZD with a 24% lower risk of mortality [HR 1.18 (95% CI 1.03-1.36) and 0.76 (95% CI 0.62-0.94)], respectively. DPP-4 inhibitor treatment was associated with significantly lower risks of CVD, fatal CVD, CHD, fatal CHD and CHF.. This nationwide observational study showed that second-line treatment with TZD and DPP-4 inhibitor as add-on medication to metformin were associated with significantly lower risks of mortality and cardiovascular events compared with SU, whereas basal insulin was associated with a higher risk of mortality.

Topics: Aged; Blood Glucose; Cardiotoxicity; Cardiovascular Diseases; Coronary Disease; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Registries; Sulfonylurea Compounds; Sweden; Thiazolidinediones; Treatment Outcome