Beneficial Effects of Dipeptidyl Peptidase-4 Inhibitors on Heart Failure With Preserved Ejection Fraction and Diabetes

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to exert pleiotropic effects on heart failure (HF) in animal experiments.

OBJECTIVES

This study sought to investigate the impact of DPP-4 inhibitors on HF patients with diabetes mellitus (DM).

METHODS

We analyzed hospitalized patients with HF and DM enrolled in the JROADHF (Japanese Registry Of Acute Decompensated Heart Failure) registry, a nationwide registry of acute decompensated HF. Primary exposure was the use of a DPP-4 inhibitor. The primary outcome was a composite of cardiovascular death or HF hospitalization during the median follow-up of 3.6 years according to left ventricular ejection fraction.

RESULTS

Out of 2,999 eligible patients, 1,130 had heart failure with preserved ejection fraction (HFpEF), 572 had heart failure with midrange ejection fraction (HFmrEF), and 1,297 had heart failure with reduced ejection fraction (HFrEF). In each cohort, 444, 232, and 574 patients received a DPP-4 inhibitor, respectively. A multivariable Cox regression model showed that DPP-4 inhibitor use was associated with a lower composite of cardiovascular death or HF hospitalization in HFpEF (HR: 0.69; 95% CI: 0.55-0.87; P = 0.002) but not in HFmrEF and HFrEF. Restricted cubic spline analysis demonstrated that DPP-4 inhibitors were beneficial in patients with higher left ventricular ejection fraction. In HFpEF cohort, propensity score matching yielded 263 pairs. DPP-4 inhibitor use was associated with a lower incidence rate of the composite of cardiovascular death or HF hospitalization (19.2 vs 25.9 events per 100 patient-years; rate ratio: 0.74; 95% CI: 0.57-0.97; P = 0.027) in matched patients.

CONCLUSIONS

DPP-4 inhibitor use was associated with better long-term outcomes in HFpEF patients with DM.

Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan (Trp)−kynurenine (KYN)−kynurenic acid (KA) axis metabolism. Mechanistically, chemotherapy-induced intestinal damage triggered the formation of an interleukin-6 (IL-6)−indoleamine 2,3-dioxygenase 1 (IDO1)−aryl hydrocarbon receptor (AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35 (GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity in vivo suggests that chemotherapeutics combined with the two could be a promising therapeutic strategy for cancer patients in clinic. This work highlights GPR35 and AHR as the guardian of kynurenine pathway metabolism and core component of defense responses against intestinal damage.

NAFLD and liver transplantation: Disease burden, current management and future challenges

Non-alcoholic fatty liver disease (NAFLD), specifically its progressive form non-alcoholic steatohepatitis (NASH), represents the fastest growing indication for liver transplantation in Western countries. Diabetes mellitus, morbid obesity and cardiovascular disease are frequently present in patients with NAFLD who are candidates for liver transplantation. These factors require specific evaluation, including a detailed pre-surgical risk stratification, in order to improve outcomes after liver transplantation. Moreover, in the post-transplantation setting, the incidence of cardiovascular events and metabolic complications can be amplified by immunosuppressive therapy, which is a well-known driver of metabolic alterations. Indeed, patients with NASH are more prone to developing early post-transplant complications and, in the long-term, de novo malignancy and cardiovascular events, corresponding to higher mortality rates. Therefore, a tailored multidisciplinary approach is required for these patients, both before and after liver transplantation. Appropriate candidate selection, lifestyle modifications and specific assessment in the pre-transplant setting, as well as pharmacological strategies, adjustment of immunosuppression and a healthy lifestyle in the post-transplant setting, play a key role in correct management.

The effect of DPP-4-protected GLP-1 (7-36) on coronary microvascular function in obese adults

Objective

Glucagon-like-peptide-1 (GLP-1) receptor analogues have been shown to reduce cardiovascular events in patients with type 2 diabetes. However, the mechanism behind is still unknown. The aim of the study was to investigate the effect of intact GLP-1 (7-36) on coronary microcirculation in overweight adults.

Design and methods

A double-blinded randomized cross-over study was performed, with 12 overweight participants. Effects of intact GLP-1 (7-36) infusion were compared with a saline infusion on separate days. A DPP-4 inhibitor was administered to block degradation of intact GLP-1 (7-36) to the GLP-1 metabolite (9-36). Coronary microcirculation was assessed by Doppler coronary flow velocity reserve (CFVR) before and after 2 h of infusion. Peripheral endothelial function was assessed by flow mediated dilation (FMD) before and after one hour of infusion.

Results

CFVR was 3.77 ± 1.25 during GLP-1 infusion and 3.85 ± 1.32 during saline infusion, endothelial function was 16.3 ± 15.5 % during GLP-1 infusion and 7.85 ± 7.76 % during saline infusion. When adjusting for baseline values no significant differences in CFVR (ΔCFVR 0.38 ± 0.92 vs. ΔCFVR 0.71 ± 1.03, p = 0.43) and no difference in peripheral endothelial function (ΔFMD 7.34 ± 11.5 % vs. ΔFMD -1.25 ± 9.23%, p = 0.14) was found.

Conclusions

We found no effect of intact GLP-1 (7-36), protected from DPP4 mediated degradation on coronary microcirculation in overweight adults.

Development and analytical performance of a new ARCHITECT automated dipeptidyl peptidase-4 immunoassay

Background

Dipeptidyl peptidase-4 (DPP-4) may be a suitable biomarker to identify people with severe asthma who have greater activation of the interleukin-13 (IL-13) pathway and may therefore benefit from IL-13-targeted treatments. We report the analytical performance of an Investigational Use Only immunoassay and provide data on the biological range of DPP-4 concentrations.

Methods

We assessed assay performance, utilising analyses of precision, linearity and sensitivity; interference from common endogenous assay interferents, and from asthma and anti-diabetic medications, were also assessed. The assay was used to measure the range of serum DPP-4 concentrations in healthy volunteers and subjects with diabetes and severe, uncontrolled asthma.

Results

The total precision of DPP-4 concentration measurement (determined using percentage coefficient of variation) was ≤5% over 20 days. Dilution analysis yielded linear results from 30 to 1305 ng/mL; the limit of quantitation was 19.2 ng/mL. No notable endogenous or drug interferences were observed at the expected therapeutic concentration. Median DPP-4 concentrations in healthy volunteers and subjects with asthma or Type 1 diabetes were assessed, with concentrations remaining similar in subjects with diabetes and asthma across different demographics.

Conclusion

These analyses indicate that the ARCHITECT DPP-4 Immunoassay is a reliable and robust method for measuring serum DPP-4 concentration.

Efficacy and safety of the glucagon-like peptide-1 receptor agonist lixisenatide versus the dipeptidyl peptidase-4 inhibitor sitagliptin in young (<50 years) obese patients with type 2 diabetes mellitus

Objective

To compare the efficacy and safety of the once-daily prandial glucagon-like peptide-1 receptor agonist lixisenatide with the dipeptidyl peptidase-4 inhibitor sitagliptin in patients aged <50 years affected by obesity and type 2 diabetes mellitus (T2DM).

Materials and methods

This was a 24-week, double-blind, randomized, parallel-group study. Obese patients with T2DM inadequately controlled on metformin were randomized to lixisenatide 20 μg once-daily injection (n = 158) or once-daily oral sitagliptin 100 mg (n = 161). The primary endpoint was the proportion of patients with a glycated hemoglobin (HbA_1c) <7% and ≥5% weight loss at 24 weeks.

Results

The proportion of patients that achieved the primary endpoint was 12.0% for lixisenatide versus 7.5% for sitagliptin; weighted average of proportion difference: 4.6%, p = 0.1696). A total of 40.7% of patients achieved HbA_1c <7% with lixisenatide versus 40.0% with sitagliptin. Lixisenatide produced greater reductions in body weight (LS mean difference: −1.3 kg, p = 0.0006) and postprandial plasma glucose after a standardized meal test (LS mean difference: −34.4 mg/dL [−1.9 mmol/L], p = 0.0001) versus sitagliptin. There was a similar incidence of treatment-emergent adverse events (63.9% vs. 60.9%) and serious treatment-emergent adverse events (1.9% vs. 1.9%), with low rates of symptomatic hypoglycemia (0.6% vs. 1.9%) for lixisenatide and sitagliptin, respectively, and no cases of severe hypoglycemia.

Conclusion

In obese patients aged <50 years with T2DM, the proportion of patients with an HbA_1c <7% with weight loss ≥5% was similar between groups. Lixisenatide, however, resulted in significantly greater reductions in body weight and postprandial plasma glucose excursions than sitagliptin. Tolerability was similar between groups.