sitagliptin-phosphate and Arrhythmias--Cardiac

In vivo studies suggest that arrhythmia risk may be greater with less selective dipeptidyl peptidase-4 inhibitors, but evidence from population-based studies is missing. We aimed to compare saxagliptin, sitagliptin, and linagliptin with regard to risk of sudden cardiac arrest (SCA)/ventricular arrhythmia (VA). We conducted high-dimensional propensity score (hdPS) matched, new-user cohort studies. We analyzed Medicaid and Optum Clinformatics separately. We identified new users of saxagliptin, sitagliptin (both databases), and linagliptin (Optum only). We defined SCA/VA outcomes using emergency department and inpatient diagnoses. We identified and then controlled for confounders via a data-adaptive, hdPS approach. We generated marginal hazard ratios (HRs) via Cox proportional hazards regression using a robust variance estimator while adjusting for calendar year. We identified the following matched comparisons: saxagliptin vs. sitagliptin (23,895 vs. 96,972) in Medicaid, saxagliptin vs. sitagliptin (48,388 vs. 117,383) in Optum, and linagliptin vs. sitagliptin (36,820 vs. 78,701) in Optum. In Medicaid, use of saxagliptin (vs. sitagliptin) was associated with an increased rate of SCA/VA (adjusted HR (aHR), 2.01, 95% confidence interval (CI) 1.24-3.25). However, in Optum data, this finding was not present (aHR, 0.79, 95% CI 0.41-1.51). Further, we found no association between linagliptin (vs. sitagliptin) and SCA/VA (aHR, 0.65, 95% CI 0.36-1.17). We found discordant results regarding the association between SCA/VA with saxagliptin compared with sitagliptin in two independent datasets. It remains unclear whether these findings are due to heterogeneity of treatment effect in the different populations, chance, or unmeasured confounding.

Topics: Adamantane; Administrative Claims, Healthcare; Aged; Arrhythmias, Cardiac; Cohort Studies; Databases, Factual; Death, Sudden, Cardiac; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Female; Humans; Kaplan-Meier Estimate; Linagliptin; Male; Middle Aged; Proportional Hazards Models; Sitagliptin Phosphate

Myocardial infarction (MI) was associated with insulin resistance, in which resistin acts as a critical mediator. We aimed to determine whether sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, can attenuate arrhythmias by regulating resistin-dependent nerve growth factor (NGF) expression in postinfarcted rats. Normoglycaemic male Wistar rats after ligating coronary artery were randomized to either vehicle or sitagliptin for 4 weeks starting 24 h after operation. Post-infarction was associated with increased myocardial noradrenaline [norepinephrine (NE)] levels and sympathetic hyperinnervation. Compared with vehicle, sympathetic innervation was blunted after administering sitagliptin, as assessed by immunofluorescent analysis of tyrosine hydroxylase, growth-associated factor 43 and neurofilament and western blotting and real-time quantitative RT-PCR of NGF. Arrhythmic scores in the sitagliptin-treated infarcted rats were significantly lower than those in vehicle. Furthermore, sitagliptin was associated with reduced resistin expression and increased Akt activity. Ex vivo studies showed that glucose-dependent insulinotropic polypeptide (GIP) infusion, but not glucagon-like peptide-1 (GLP-1), produced similar reduction in resistin levels to sitagliptin in postinfarcted rats. Furthermore, the attenuated effects of sitagliptin on NGF levels can be reversed by wortmannin (a phosphatidylinositol 3-kinase antagonist) and exogenous resistin infusion. Sitagliptin protects ventricular arrhythmias by attenuating sympathetic innervation in the non-diabetic infarcted rats. Sitagliptin attenuated resistin expression via the GIP-dependent pathway, which inhibited sympathetic innervation through a signalling pathway involving phosphatidylinositol 3-kinase (PI3K) and Akt protein.

Topics: Animals; Arrhythmias, Cardiac; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Male; Myocardial Infarction; Rats; Rats, Wistar; Resistin; Signal Transduction; Sitagliptin Phosphate

The effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on arrhythmias remains unknown. The aim of this study was to investigate whether sitagliptin attenuates arrhythmias through inhibiting nerve growth factor (NGF) expression, focusing on cyclic adenosine monophosphate (cAMP) downstream signaling such as protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac).. Male Wistar rats were randomized to either vehicle or sitagliptin for 4 weeks starting 24 h after ligating the coronary artery. Post-infarction was associated with increased oxidative stress. Measurement of myocardial norepinephrine levels revealed a significant elevation in vehicle-treated rats compared with sham. Compared with the vehicle, infarcted rats treated with sitagliptin had significantly increased cAMP levels, decreased DPP-4 activity, oxidative stress, NGF levels and immunofluorescence-stained sympathetic hyperinnervation. Arrhythmic scores were significantly lower in the sitagliptin-treated infarcted rats than in vehicle. Ex vivo studies showed that sitagliptin increased the phosphorylated cAMP response element-binding protein (CREB), which can be reversed by H-89 (a PKA inhibitor), not brefeldin A (an Epac inhibitor).Heme oxygenase-1(HO-1) expression was increased by a PKA agonist but not by an Epac agonist.HO-1expression was attenuated in KG-501 (a CREB inhibitor)-treated infarcted rats in the presence of a PKA agonist.. Sitagliptin protects ventricular arrhythmias by attenuating NGF-induced sympathetic innervation via upregulation ofHO-1expression in a cAMP/PKA/CREB-dependent antioxidant pathway in non-diabetic infarcted rats.

Topics: Animals; Arrhythmias, Cardiac; Cyclic AMP; Cyclic AMP Response Element-Binding Protein; Cyclic AMP-Dependent Protein Kinases; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Guanine Nucleotide Exchange Factors; Heme Oxygenase (Decyclizing); Male; Myocardial Infarction; Myocardium; Nerve Growth Factor; Oxidative Stress; Phosphorylation; Rats, Wistar; Signal Transduction; Sitagliptin Phosphate; Time Factors