Role of dipeptidyl peptidase-4 inhibitors in new-onset diabetes after transplantation

Glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors for the treatment of diabetes mellitus in liver transplant recipients

AIM

To investigate the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 (SGLT2) inhibitors in liver transplant (LT) recipients with diabetes.

METHODS

A single-centre, retrospective analysis of prospectively collected data from an LT recipient database (1990-2023) was conducted. We included adults with pre-existing diabetes and post-transplant diabetes, newly started on GLP-1RAs and/or SGLT2 inhibitors after LT. Metabolic and biochemical parameters and outcomes were collected for up to 12 months after starting medications and were compared to those in patients receiving dipeptidyl peptidase-4 (DPP-4) inhibitors. Statistical analysis included descriptive statistics and linear mixed models.

RESULTS

We included participants on GLP-1RAs (n = 46), SGLT2 inhibitors (n = 87), combination therapy (n = 12), and a DPP-4 inhibitor comparator (n = 217). Both GLP-1RAs and combination therapy decreased mean glycated haemoglobin (HbA1c) levels, and combination therapy remained significant when adjusted for DPP-4 inhibitor treatment (-3.5%, 95% CI [-6.1, -0.95]; p = 0.0089) at 12 months. All three groups had significant decreases in mean weight and body mass index, but these remained significant in the GLP-1RA (-5.2 kg, 95% CI [-8.7, -1.7], p = 0.0039 and 1.99 kg/m2, 95% CI [-3.4, -0.6], p = 0.0048) and combination therapy groups (-5.4 kg, 95% CI [-10.5, -0.36], p = 0.04 and -3.4 kg/m2, 95% CI [-5.5, -1.3], p = 0.0015) when adjusted for DPP-4 inhibitor treatment at 12 months. Alanine aminotransferase levels decreased with GLP-1RA and combination therapy. There were two (1.4%) cases of graft rejection.

CONCLUSION

We found that GLP-1RAs, SGLT2 inhibitors, and their combination, led to significant weight loss in LT recipients with diabetes. Combination therapy, in particular, lowered HbA1c and alanine aminotransferase levels compared to DPP-4 inhibitors. Further studies are needed to assess long-term safety and efficacy.

Oral Glucose Tolerance Test as a Risk Marker for Developing Post-Transplant Diabetes Mellitus

INTRODUCTION

The incidence of post-transplant diabetes mellitus (PTDM) can reach 30% during the first 6 months after kidney transplantation (KT), increasing the risk of graft failure and mortality. There is no well-established biomarker for predicting PTDM occurrence. This study evaluated the association between the abnormal 2-hour oral glucose tolerance test (OGTT) and the PTDM incidence.

METHODS

A retrospective single-center study, including adult kidney transplant recipients from deceased donors, was performed between March 2021 and June 2022.

EXCLUSION CRITERIA

age <18 years; pretransplant diabetes mellitus (DM); death with a functioning graft; loss of follow-up and/or graft failure before 6 months post-transplant. The results of pretransplant OGTT, fasting (FPG), and afternoon plasma glucose levels at hospitalization and FPG in the first, second, and third months post-transplant were evaluated. For analysis, patients were grouped according to the PTDM diagnosis: PTDM and non-PTDM.

RESULTS

From 164 KT performed in the period, 50 (30%) were included, most male (n = 34, 68%), with a mean age of 48.3 ± 12.5 years. Nine patients (18%) developed PTDM, 44% between 3 and 6 months. General characteristics and immunosuppressive therapy were similar between the groups. The mean FPG in the pretransplant OGTT was significantly higher in the PTDM group compared with the non-PTDM group (85.7 ± 7.9 vs 79.1 ± 8.2, P = .03). The number of patients classified as impaired glucose tolerance (IGT) on the pre-transplant OGTT was significantly higher in the PTDM group.

CONCLUSION

IGT in the pretransplant OGTT was associated with PTDM cases in kidney transplant recipients without a previous diagnosis of DM.

Post-transplant diabetes mellitus: risk factors and outcomes in a 5-year follow-up

Introduction

Kidney transplantation is associated with an increased risk of posttransplant diabetes mellitus (PTDM), impacting recipient and graft survivals. The incidence of PTDM ranges from 15% to 30%, with most cases occurring in the first year post-transplant. Some clinical and laboratory characteristics pre- and post-transplant may be associated with a higher PTDM incidence in a more extended follow-up period. This study aimed to analyze the prevalence of PTDM among renal transplant recipients without previous DM diagnosis during a five-year post-transplant follow-up, as well as clinical and laboratory characteristics associated with a higher incidence of PTDM during this period.

Material and methods

Single-center retrospective cohort including kidney transplant recipients older than 18 years with a functioning graft over six months of follow-up between January and December 2018. Exclusion criteria were recipients younger than 18 years at kidney transplantation, previous diabetes mellitus diagnosis, and death with a functioning graft or graft failure within six months post-transplant.

Results

From 117 kidney transplants performed during the period, 71 (60.7%) fulfilled the inclusion criteria, 18 (25.3%) had PTDM diagnosis, and most (n=16, 88.9%) during the 1st year post-transplant. The need for insulin therapy during the hospital stay was significantly higher in the PTDM group (n=11, 61.1% vs. n=14, 26.4%, PTDM vs. non-PTDM). Other PTDM risk factors, such as older age, high body mass index, HLA mismatches, and cytomegalovirus or hepatitis C virus infections, were not associated with PTDM occurrence in this series. During 5-year post-transplant follow-up, the graft function remained stable in both groups.

Conclusion

The accumulated incidence of PTDM in this series was similar to the reported in other studies. The perioperative hyperglycemia with the need for treatment with insulin before hospital discharge was associated with PTDM.

A Comprehensive Review on Weight Loss Associated with Anti-Diabetic Medications

Obesity is a complex metabolic condition that can have a negative impact on one's health and even result in mortality. The management of obesity has been addressed in a number of ways, including lifestyle changes, medication using appetite suppressants and thermogenics, and bariatric surgery for individuals who are severely obese. Liraglutide and semaglutide are two of the five Food and Drug Administration (FDA)-approved anti-obesity drugs that are FDA-approved agents for the treatment of type 2 diabetes mellitus (T2DM) patients. In order to highlight the positive effects of these drugs as anti-obesity treatments, we analyzed the weight loss effects of T2DM agents that have demonstrated weight loss effects in this study by evaluating clinical studies that were published for each agent. Many clinical studies have revealed that some antihyperglycemic medications can help people lose weight, while others either cause weight gain or neutral results. Acarbose has mild weight loss effects and metformin and sodium-dependent glucose cotransporter proteins-2 (SGLT-2) inhibitors have modest weight loss effects; however, some glucagon-like peptide-1 (GLP-1) receptor agonists had the greatest impact on weight loss. Dipeptidyl peptidase 4 (DPP-4) inhibitors showed a neutral or mild weight loss effect. To sum up, some of the GLP-1 agonist drugs show promise as weight-loss treatments.

Effects of canary seed on two patients with disseminated granuloma annulare

Treatment of disseminated granuloma annulare (GA) can be challenging and there is no gold standard for treatment.  We observed two cases of generalized GA that had been resistant to other treaments successfully treated with canary seed milk. Canary seed milk has antioxidant (contains vitamin E), anti-diabetic (DPP-4 inhibition), and anti-hypertensive (ACE inhibition) properties. Therefore, dermatologists can consider alpiste milk as a sole or supplemental treatment for patients with GA with or without comorbidities such as diabetes and hypertension, in GA patients who prefer alternative therapy or failed other treatments. 

Novel hit of DPP-4Is as promising antihyperglycemic agents with dual antioxidant/anti-inflammatory effects for type 2 diabetes with/without COVID-19

DPP-4Is are well recognized therapy for type 2 diabetes. In spite of sharing a common mode of action, the chemical diversity among members of DPP-4Is raised the question whether structural differences may result in distinguished activities. DPP-4Is were recently explored as drug repurposing means for treatment of SARS-CoV-2 due to the urgent need for small molecule drugs for controlling infections. The use of DPP-4Is was not correlated with adverse COVID-19-related consequences among patients with type 2 diabetes. Inspired by these reasons and the importance of pyrimidinone ring as DPP-4I with both antioxidant and anti-inflammatory activities, we succeeded to prepare some novel pyrimidinone and thio-pyrimidinone derivatives, which were then screened for their antidiabetic activity and DPP-4 inhibition. In addition, their anti-inflammatory effect on LPS-stimulated RAW 264.7 cells were evaluated. Furthermore, their antioxidant activities were also tested.

Shen-Kang protects against tacrolimus-induced renal injury

BACKGROUND/AIMS

Evidence suggests that Shen-Kang (SK), a traditional Chinese herbal medicine, protects against various types of renal injury. In this study, we evaluated whether SK treatment confers renoprotection in a rat model of chronic tacrolimus (TAC) nephropathy.

METHODS

Rats were treated daily with TAC (1.5mg/kg, subcutaneously) and SK (450 mg/kg, intravenously) for 4 weeks. The effects of SK on TAC-induced renal injury were assessed by measuring renal function, urine albumin excretion, histopathology, inflammatory cell infiltration, expression of profibrotic (transforming growth factor β1 [TGF-β1] and TGF-β inducible gene-h3 [βig-h3]) and proinflammatory cytokines, oxidative stress, and apoptotic cell death.

RESULTS

Administration of SK preserved glomerular integrity (fractional mesangial area and Wilms tumor 1-positive glomeruli), attenuated tubulointerstitial fibrosis, and reduced the number of ectodermal dysplasia 1-positive cells, and this was paralleled by improved urine albumin excretion and renal dysfunction. At the molecular level, SK treatment suppressed expression of TGF-β1/Smad2/3, βig-h3, and proinflammatory cytokines. Oxidative stress and apoptotic cell death were significantly decreased with SK treatment, and apoptosis-related genes were regulated toward cell survival (active caspase-3 and the B-cell lymphoma-2/Bcl2-associated X [Bcl-2/Bax] ratio).

CONCLUSION

SK protects against TAC-induced renal injury.

Effects of metformin on hyperglycemia in an experimental model of tacrolimus- and sirolimus-induced diabetic rats

BACKGROUND/AIMS

Metformin (MET) is a first-line drug for type 2 diabetes mellitus (DM); its effect on new-onset diabetes after transplantation caused by immunosuppressant therapy is unclear. We compared the effects of MET on DM caused by tacrolimus (TAC) or sirolimus (SRL).

METHODS

DM was induced by injection of TAC (1.5 mg/kg) or SRL (0.3 mg/kg) for 2 weeks in rats, and MET (200 mg/kg) was injected for 2 more weeks. The effects of MET on DM caused by TAC or SRL were evaluated using an intraperitoneal glucose tolerance test (IPGTT) and by measuring plasma insulin concentration, islet size, and glucose-stimulated insulin secretion (GSIS). The effects of MET on the expression of adenosine monophosphate-activated protein kinase (AMPK), a pharmacological target of MET, were compared between TAC- and SRL-treated islets.

RESULTS

IPGTT showed that both TAC and SRL induced hyperglycemia and reduced plasma insulin concentration compared with vehicle. These changes were reversed by addition of MET to SRL but not to TAC. Pancreatic islet cell size was decreased by TAC but not by SRL, but addition of MET did not affect pancreatic islet cell size in either group. MET significantly increased GSIS in SRL- but not in TAC-treated rats. AMPK expression was not affected by TAC but was significantly decreased in SRL-treated islets. Addition of MET restored AMPK expression in SRL-treated islets but not in TAC-treated islets.

CONCLUSIONS

MET has different effects on hyperglycemia caused by TAC and SRL. The discrepancy between these drugs is related to their different mechanisms causing DM.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Effects of addition of a dipeptidyl peptidase IV inhibitor to metformin on sirolimus-induced diabetes mellitus

The guideline for the management of new-onset diabetes after transplantation recommends metformin (MET) as a first-line drug, and addition of a second-line drug is needed to better control of hyperglycemia. We tested the effect of addition of a dipeptidyl peptidase IV (DPP IV) inhibitor to MET on sirolimus (SRL)-induced diabetes mellitus (DM). In animal model of SRL-induced DM, MET treatment improved pancreatic islet function (blood glucose level and insulin secretion) and attenuated oxidative stress and apoptotic cell death. Addition of a DPP IV inhibitor to MET improved these parameters more than MET alone. An in vitro study showed that SRL treatment increased pancreas beta cell death and production of reactive oxygen species (ROS), and pretreatment of ROS inhibitor, or p38MAPK inhibitor effectively decreased SRL-induced islet cell death. Exendin-4 (EXD), a substrate of DPP IV or MET significantly improved cell viability and decreased ROS production compared with SRL treatment, and combined treatment with the 2 drugs improved both parameters. At the subcellular level, impaired mitochondrial respiration by SRL were partially improved by MET or EXD and much improved further after addition of EXD to MET. Our data suggest that addition of a DPP IV inhibitor to MET decreases SRL-induced oxidative stress and improves mitochondrial respiration. This finding provides a rationale for the combined use of a DPP IV inhibitor and MET in treating SRL-induced DM.