Sitagliptin might be a favorable antiobesity drug for new onset diabetes after a renal transplant

An update review of post-transplant diabetes mellitus: Concept, risk factors, clinical implications and management

OBJECTIVE

Kidney transplantation is the gold standard therapeutic alternative for patients with end-stage renal disease; nevertheless, it is not without potential complications leading to considerable morbidity and mortality such as post-transplant diabetes mellitus (PTDM). This narrative review aims to comprehensively evaluate PTDM in terms of its diagnostic approach, underlying pathophysiological pathways, epidemiological data, and management strategies.

METHODS

Articles were retrieved from electronic databases using predefined search terms. Inclusion criteria encompassed studies investigating PTDM diagnosis, pathophysiology, epidemiology, and management strategies.

RESULTS

PTDM emerges as a significant complication following kidney transplantation, influenced by various pathophysiological factors including peripheral insulin resistance, immunosuppressive medications, infections, and proinflammatory pathways. Despite discrepancies in prevalence estimates, PTDM poses substantial challenges to transplant. Diagnostic approaches, including traditional criteria such as fasting plasma glucose (FPG) and HbA1c, are limited in their ability to capture early PTDM manifestations. Oral glucose tolerance test (OGTT) emerges as a valuable tool, particularly in the early post-transplant period. Management strategies for PTDM remain unclear, within sufficient evidence from large-scale randomized clinical trials to guide optimal interventions. Nevertheless, glucose-lowering agents and life style modifications constitute primary modalities for managing hyperglycemia in transplant recipients.

DISCUSSION

The complex interplay between PTDM and the transplant process necessitates individualized diagnostic and management approaches. While early recognition and intervention are paramount, modifications to maintenance immunosuppressive regimens based solely on PTDM risk are not warranted, given the potential adverse consequences such as increased rejection risk. Further research is essential to refine management strategies and enhance outcomes for transplant recipients.

Effect of metformin use on graft and patient survival in kidney transplant recipients with type 2 diabetes: a systematic review protocol

INTRODUCTION

Metformin is a first-line antihyperglycaemic agent for type 2 diabetes (T2DM). In addition to glycaemic control, it offers benefits related to cardiovascular health, weight neutrality and metabolic syndrome. However, its benefits in kidney transplant recipients remain unclear as metformin use is controversial in this population due to a lack of evidence and there are recommendations against its use in patients with poor kidney function. Hence, we seek to describe a protocol for a systematic review, which will assess the impact of metformin use on graft survival and mortality in kidney transplant recipients.

METHODS

This protocol was guided by the standards of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols 2015. We will search empirical databases such as MEDLINE, Embase, Cochrane Library, CINAHL and Web of Science Core Collection for relevant studies conducted in kidney transplant recipients using metformin, which report outcomes related to graft and patient survival. All studies meeting these criteria in adults and published in English from inception to 2023 will be included in our review. We will employ the Cochrane Risk of Bias Tool 2 for randomised controlled trials and the Risk of Bias in Non-randomised Studies of Intervention for non-randomised studies. We will present our data and study characteristics in a table format and determine if a meta-analysis can be performed by clinical and methodological heterogeneity, using the I2 statistics. If a meta-analysis cannot be performed, we will provide a narrative synthesis of included studies using the Synthesis Without Meta-Analysis Reporting Guideline.

ETHICS AND DISSEMINATION

Ethical approval will not be required for this review as the data used will be extracted from already published studies with publicly accessible data. As this study will assess the impact of metformin use on graft and patient survival in kidney transplant recipients, evidence gathered through it will be disseminated using traditional approaches that include open-access peer-reviewed publication, scientific presentations and a report. We will also disseminate our findings to appropriate academic bodies in charge of publishing guidelines related to T2DM and transplantation, as well as patient and research centred groups.

PROSPERO REGISTRATION NUMBER

CRD42023421799.

International consensus on post-transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM) remains a leading complication after solid organ transplantation. Previous international PTDM consensus meetings in 2003 and 2013 provided standardized frameworks to reduce heterogeneity in diagnosis, risk stratification and management. However, the last decade has seen significant advancements in our PTDM knowledge complemented by rapidly changing treatment algorithms for management of diabetes in the general population. In view of these developments, and to ensure reduced variation in clinical practice, a 3rd international PTDM Consensus Meeting was planned and held from 6-8 May 2022 in Vienna, Austria involving global delegates with PTDM expertise to update the previous reports. This update includes opinion statements concerning optimal diagnostic tools, recognition of prediabetes (impaired fasting glucose and/or impaired glucose tolerance), new mechanistic insights, immunosuppression modification, evidence-based strategies to prevent PTDM, treatment hierarchy for incorporating novel glucose-lowering agents and suggestions for the future direction of PTDM research to address unmet needs. Due to the paucity of good quality evidence, consensus meeting participants agreed that making GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) recommendations would be flawed. Although kidney-allograft centric, we suggest that these opinion statements can be appraised by the transplantation community for implementation across different solid organ transplant cohorts. Acknowledging the paucity of published literature, this report reflects consensus expert opinion. Attaining evidence is desirable to ensure establishment of optimized care for any solid organ transplant recipient at risk of, or who develops, PTDM as we strive to improve long-term outcomes.

Metabolic Disorders in Liver Transplant Recipients: The State of the Art

Liver transplantation represents a chief therapeutic approach for acute liver failure, end-stage liver disease and hepatocellular carcinoma. Despite witnessing advancements in short- and medium-term survival over recent decades, attributed to refinements in surgical techniques and immunosuppressive protocols, long-term mortality remains impervious to modification. Notably, cardiovascular disease emerges as a predominant cause of mortality among liver transplant recipients. This trend is accentuated by the increasing prominence of non-alcoholic steatohepatitis-related cirrhosis as an indication for liver transplantation. Moreover, the administration of immunosuppressive agents is intricately linked to the degradation of the metabolic profile in liver transplant recipients, thereby contributing to the initiation or exacerbation of cardiovascular risk factors, such as hypertension, diabetes, and dyslipidaemia. In addition, the post-liver transplantation period is marked by a decline in lifestyle quality and a failure to acknowledge the psychological distress experienced by patients throughout the transplant process. These factors can precipitate a deterioration in the patient's metabolic profile, exacerbated by suboptimal therapeutic compliance. This narrative review aims to comprehensively address the principal metabolic disorders intricately associated with liver transplantation.

Sweet and simple as syrup: A review and guidance for use of novel antihyperglycemic agents for post-transplant diabetes mellitus and type 2 diabetes mellitus after kidney transplantation

Uncontrolled type 2 diabetes mellitus (T2DM) and post-transplant diabetes mellitus (PTDM) increase morbidity and mortality after kidney transplantation. Conventional strategies for diabetes management in this population include metformin, sulfonylureas, meglitinides and insulin. Limitations with these agents, as well as promising new antihyperglycemic agents, create a need and opportunity to explore additional options for transplant diabetes pharmacotherapy. Novel agents including sodium glucose co-transporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP1RA), and dipeptidyl peptidase IV inhibitors (DPP4i) demonstrate great promise for T2DM management in the non-transplant population. Moreover, many of these agents possess renoprotective, cardiovascular, and/or weight loss benefits in addition to improved glucose control while having reduced risk of hypoglycemia compared with certain other conventional agents. This comprehensive review examines available literature evaluating the use of novel antihyperglycemic agents in kidney transplant recipients (KTR) with T2DM or PTDM. Formal grading of recommendations assessment, development, and evaluation (GRADE) system recommendations are provided to guide incorporation of these agents into post-transplant care. Available literature was evaluated to address the clinical questions of which agents provide greatest short- and long-term benefits, timing of novel antihyperglycemic therapy initiation after transplant, monitoring parameters for these antihyperglycemic agents, and concomitant antihyperglycemic agent and immunosuppression regimen management. Current experience with novel antihyperglycemic agents is primarily limited to single-center retrospective studies and case series. With ongoing use and increasing comfort, further and more robust research promises greater understanding of the role of these agents and place in therapy for kidney transplant recipients.

Interventions Against Posttransplantation Diabetes: A Scientific Rationale for Treatment Hierarchy Based on Literature Review

Posttransplant diabetes (PTD) is a common medical complication after solid organ transplantation. Because of adverse outcomes associated with its development and detrimental impact on long-term survival, strategies to prevent or manage PTD are critically important but remain underresearched. Treatment hierarchies of antidiabetic therapies in the general population are currently being revolutionized based on cardiovascular outcome trials, providing evidence-based rationale for optimization of medical management. However, opportunities for improving medical management of PTD are challenged by 2 important considerations: (1) translating clinical evidence data from the general population to underresearched solid organ transplant cohorts and (2) targeting treatment based on primary underlying PTD pathophysiology. In this article, the aim is to provide an overview of PTD treatment options from a new angle. Rationalized by a consideration of underlying PTD pathophysiological defects, which are heterogeneous among diverse transplant patient cohorts, a critical appraisal of the published literature and summary of current research in progress will be reviewed. The aim is to update transplant professionals regarding medical management of PTD from a new perspective tailored therapeutic intervention based on individualized characteristics. As the gap in clinical evidence between management of PTD versus type 2 diabetes widens, it is imperative for the transplant community to bridge this gap with targeted clinical trials to ensure we optimize outcomes for solid organ transplant recipients who are at risk or develop PTD. This necessary clinical research should help efforts to improve long-term outcomes for solid transplant patients from both a patient and graft survival perspective.

Donor obesity and weight gain after transplantation: two still overlooked threats to long-term graft survival

The effect of donor obesity on kidney transplantation success has long been an overlooked clinical research area. Even though there is no strict guideline in most countries prohibiting donation from obese individuals, most candidates with a body mass index >35-40 kg/m² are rejected due to concerns regarding long-term renal functional deterioration in the donor. The effects of excessive fat mass on renal function and allograft survival have been analysed by several longitudinal and follow-up studies. These studies have documented the deleterious effect on long-term graft outcomes of excessive body mass in living kidney donors and de novo obesity or pre-existing obesity worsening after transplantation on kidney outcomes. However, there is a paucity of clinical trials aimed at countering overweight and obesity in living and deceased kidney donors and in transplant patients. In this review we will briefly discuss the mechanism whereby fat excess induces adverse kidney outcomes and describe the effects on graft function and survival in living obese donors.

Management of post-transplant diabetes mellitus: an opportunity for novel therapeutics

Post-transplant diabetes mellitus (PTDM) is a common problem after kidney transplantation (KT), occurring in 50% of high-risk recipients. The clinical importance of PTDM lies in its impact as a significant risk factor for cardiovascular and chronic kidney disease (CKD) after solid organ transplantation. Kidney Disease: Improving Global Outcomes (KDIGO) has recently updated the treatment guidelines for diabetes management in CKD with emphasis on the newer antidiabetic agents such as dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter 2 inhibitors as add-on therapy to metformin. Given all these new diabetes treatments and the updated KDIGO guidelines, it is necessary to evaluate and give guidance on their use for DM management in KT recipients. This review summarizes the scarce published literature about the use of these new agents in the KT field. In summary, it is absolutely necessary to generate evidence in order to be able to safely use these new treatments in the KT population to improve blood glucose control, but specially to evaluate their potential cardiovascular and renal benefits that would seem to be independent of blood glucose control in PTDM patients.

Global Epidemiology, Health Outcomes, and Treatment Options for Patients With Type 2 Diabetes and Kidney Failure

The burden of type 2 diabetes and related complications has steadily increased over the last few decades and is one of the foremost global public health threats in the 21st century. Diabetes is one of the leading causes of chronic kidney disease and kidney failure and is an important contributor to the cardiovascular morbidity and mortality in this population. In addition, up to one in three patients who have received kidney transplants develop post-transplant diabetes, but the management of this common complication continues to pose a significant challenge for clinicians. In this review, we will describe the global prevalence and temporal trend of kidney failure attributed to diabetes mellitus in both developing and developed countries. We will examine the survival differences between treated kidney failure patients with and without type 2 diabetes, focusing on the survival differences in those on maintenance dialysis or have received kidney transplants. With the increased availability of novel hypoglycemic agents, we will address the potential impacts of these novel agents in patients with diabetes and kidney failure and in those who have developed post-transplant diabetes.

Obesity and Post-Transplant Diabetes Mellitus in Kidney Transplantation

Worldwide, the prevalence obesity, diabetes, and chronic kidney disease is increasing apace. The relationship between obesity and chronic kidney disease is multidimensional, especially when diabetes is also considered. The optimal treatment of patients with chronic kidney disease includes the need to consider weight loss as part of the treatment. The exact relationship between obesity and kidney function before and after transplantation is not as clear as previously imagined. Historically, patients with obesity had worse outcomes following kidney transplantation and weight loss before surgery was encouraged. However, recent studies have found less of a correlation between obesity and transplant outcomes. Transplantation itself is also a risk factor for developing diabetes, a condition known as post-transplant diabetes mellitus, and is related to the use of immunosuppressive medications and weight gain following transplantation. Newer classes of anti-diabetic medications, namely SGLT-2 inhibitors and GLP-1 agonists, are increasingly being recognized, not only for their ability to control diabetes, but also for their cardio and renoprotective effects. This article reviews the current state of knowledge on the management of obesity and post-transplant diabetes mellitus for kidney transplant patients.

Current Pharmacological Intervention and Medical Management for Diabetic Kidney Transplant Recipients

Hyperglycemia after kidney transplantation is common in both diabetic and non-diabetic patients. Both pretransplant and post-transplant diabetes mellitus are associated with increased kidney allograft failure and mortality. Glucose management may be challenging for kidney transplant recipients. The pathophysiology and pattern of hyperglycemia in patients following kidney transplantation is different from those with type 2 diabetes mellitus. In patients with pre-existing and post-transplant diabetes mellitus, there is limited data on the management of hyperglycemia after kidney transplantation. The following article discusses the nomenclature and diagnosis of pre- and post-transplant diabetes mellitus, the impact of transplant-related hyperglycemia on patient and kidney allograft outcomes, risk factors and potential pathogenic mechanisms of hyperglycemia after kidney transplantation, glucose management before and after transplantation, and modalities for prevention of post-transplant diabetes mellitus.

Incretin based therapies and SGLT-2 inhibitors in kidney transplant recipients with diabetes: A systematic review and meta-analysis

AIMS

We aimed to conduct a systematic review and meta-analysis regarding the use of incretin-based therapies including dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists as well as sodium-glucose co-transporter-2 (SGLT2) inhibitorsin persons with posttransplantation diabetes mellitus (PTDM) so as to assess both their efficacy and safety.

METHODS

We searched for publications on Kidney/Renal Transplantation and DPP-4 inhibitors, GLP-1-receptor agonists and SGLT-2 inhibitors and included every study using these antidiabetics. A p-value < 0.05 was considered statistical significant.

RESULTS

Sixteen studies and 310 individuals with a mean age of 55.98 ± 8.81 years were included in the analysis. Participants received DPP-4 inhibitors in 8 studies, SGLT-2 inhibitors in 6 studies and GLP-1 receptor agonists in 2 studies, with a mean follow-up of 22.03 ± 14.95 weeks. Hemoglobin A1c (HbA1c) reduction was demonstrated in 10 studies (mean +/- standard deviation (MD) = - 0.38%, I² = 45%). MD of HbA1c was -0.3741 and -0.4596 mg/dl for DPP-4 inhibitors and SGLT-2 inhibitors respectively. Nine studies demonstrated differences in fasting plasma glucose (FPG) (MD = - 25,76) and 5 studies in post-prandial glucose (PPG) (MD = - 6.61) before and following treatment. Most studies did not show adverse effects on the glomerular filtration rate (GFR) and hepatic function.

CONCLUSIONS

DPP-4 inhibitors and SGLT2 inhibitors appear both efficacious and safe in renal transplant recipients. More high-quality studies are required to guide therapeutic choices for PTDM.

Review of Newer Antidiabetic Agents for Diabetes Management in Kidney Transplant Recipients

OBJECTIVE

This systematic review describes the efficacy, safety, and drug interactions of dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), and sodium-glucose transport protein 2 (SGLT2) inhibitors in kidney transplant recipients (KTRs).

DATA SOURCES

Articles were identified by English-language MEDLINE search, published prior to May 2020, using the terms kidney transplant, OR PTDM, OR NODAT, AND metformin, OR DPP4, OR GLP1, OR SGLT2.

STUDY SELECTION AND DATA EXTRACTION

All selected studies were included if the study population was composed of adult KTRs who were diagnosed with either impaired glucose tolerance, diabetes mellitus (DM), new-onset diabetes after transplant (NODAT), or posttransplantation diabetes mellitus (PTDM).

DATA SYNTHESIS

In KTRs, there is evidence for safety with DPP-4 inhibitors, GLP-1 RAs, and SGLT2 inhibitors. However, urinary tract infections and a slight initial decrease in renal function may limit use of SGLT2 inhibitors. As compared with the nontransplant type 2 DM population, SGLT2 inhibitors are not as efficacious in KTRs.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review provides an overview of the current literature on newer antidiabetic agents, addressing efficacy, safety, and drug interactions to help guide clinical decision-making for their use in KTRs.

CONCLUSION

Newer antidiabetic agents have been recommended by the American Diabetes Association for potential cardiovascular, renal, and hypoglycemic benefits. Particular agents, such as DPP-4 inhibitors and GLP-1 RAs may play a role in correcting PTDM-related defects. Clinicians need to take into account both patient-specific and drug-specific characteristics when initiating these agents in KTRs.

Post-transplant diabetes mellitus: incidence, predicting factors and outcomes

PURPOSE

To identify predictors and evaluate outcomes of posttransplant diabetes mellitus (PTDM) and to investigate the effect of treatment modalities on outcomes.

METHODS

The database of a tertiary medical center was searched for all adult patients without prior diabetes who underwent lung, liver, or heart transplantation between January 1, 2012 and June 30, 2018. Patients in whom PTDM (defined as HbA1C ≥ 6.5% at least 3 months post transplantation) developed during follow-up (mean 3.32 years) were identified. Risk factors for PTDM, determined by regression analysis and clinical outcomes [all-cause mortality, severe infections, graft loss, and major adverse cardiovascular events (MACE)], were compared between those who developed PTDM and those who did not; in the former, insulin-based therapy was compared with non-insulin regimen.

RESULTS

The cohort included 281 transplant recipients: 158 lung, 109 liver, and 14 heart. PTDM was diagnosed in 60 (21.35%) patients at a mean of 11.3 ± 12.89 months post transplantation. The only significant independent risk factor for PTDM was age (HR 1.028, 95% CI = 1.002-1.054, P = 0.0314). PTDM was associated with higher rates of severe infections (HR 2.565, 95% CI = 1.626-4.050, P < 0.0001), MACE (HR 1.856, 95% CI = 1.013-3.401, P = 0.0454) and death (HR 1.840, 95% CI = 1.024-3.304, P = 0.0413). Recipients treated with insulin-based regimens had a higher risk of severe infections (HR 2.579, 95% CI = 1.640-4.055, P < 0.0001), MACE (1.925, 95% CI = 1.074-3.451, P = 0.0278) and death (HR 1.960, 95% CI = 1.071-3.586, P = 0.0291).

CONCLUSIONS

PTDM is associated with increased mortality and poor outcomes in lung, liver, and heart transplant recipients. Early identification and aggressive treatment of PTDM and its associated cardiometabolic risk factors may improve outcomes.

Glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients

BACKGROUND

Kidney transplantation is the preferred management for patients with end-stage kidney disease (ESKD). However, it is often complicated by worsening or new-onset diabetes. The safety and efficacy of glucose-lowering agents after kidney transplantation is largely unknown. This is an update of a review first published in 2017.

OBJECTIVES

To evaluate the efficacy and safety of glucose-lowering agents for treating pre-existing and new onset diabetes in people who have undergone kidney transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 16 January 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs), quasi-RCTs and cross-over studies examining head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in patients who have received a kidney transplant and have diabetes were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study eligibility and quality and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD) or standardised mean difference (SMD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Ten studies (21 records, 603 randomised participants) were included - three additional studies (five records) since our last review. Four studies compared more intensive versus less intensive insulin therapy; two studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; one study compared DPP-4 inhibitors to insulin glargine; one study compared sodium glucose co-transporter 2 (SGLT2) inhibitors to placebo; and two studies compared glitazones and insulin to insulin therapy alone. The majority of studies had an unclear to a high risk of bias. There were no studies examining the effects of biguanides, glinides, GLP-1 agonists, or sulphonylureas. Compared to less intensive insulin therapy, it is unclear if more intensive insulin therapy has an effect on transplant or graft survival (4 studies, 301 participants: RR 1.12, 95% CI 0.32 to 3.94; I² = 49%; very low certainty evidence), delayed graft function (2 studies, 153 participants: RR 0.63, 0.42 to 0.93; I² = 0%; very low certainty evidence), HbA1c (1 study, 16 participants; very low certainty evidence), fasting blood glucose (1 study, 24 participants; very low certainty evidence), kidney function markers (1 study, 26 participants; very low certainty evidence), death (any cause) (3 studies, 208 participants" RR 0.68, 0.29 to 1.58; I² = 0%; very low certainty evidence), hypoglycaemia (4 studies, 301 participants; very low certainty evidence) and medication discontinuation due to adverse effects (1 study, 60 participants; very low certainty evidence). Compared to placebo, it is unclear whether DPP-4 inhibitors have an effect on hypoglycaemia and medication discontinuation (2 studies, 51 participants; very low certainty evidence). However, DPP-4 inhibitors may reduce HbA1c and fasting blood glucose but not kidney function markers (1 study, 32 participants; low certainty evidence). Compared to insulin glargine, it is unclear if DPP-4 inhibitors have an effect on HbA1c, fasting blood glucose, hypoglycaemia or discontinuation due to adverse events (1 study, 45 participants; very low certainty evidence). Compared to placebo, SGLT2 inhibitors probably do not affect kidney graft survival (1 study, 44 participants; moderate certainty evidence), but may reduce HbA1c without affecting fasting blood glucose and eGFR long-term (1 study, 44 participants, low certainty evidence). SGLT2 inhibitors probably do not increase hypoglycaemia, and probably have little or no effect on medication discontinuation due to adverse events. However, all participants discontinuing SGLT2 inhibitors had urinary tract infections (1 study, 44 participants, moderate certainty evidence). Compared to insulin therapy alone, it is unclear if glitazones added to insulin have an effect on HbA1c or kidney function markers (1 study, 62 participants; very low certainty evidence). However, glitazones may make little or no difference to fasting blood glucose (2 studies, 120 participants; low certainty evidence), and medication discontinuation due to adverse events (1 study, 62 participants; low certainty evidence). No studies of DPP-4 inhibitors, or glitazones reported effects on transplant or graft survival, delayed graft function or death (any cause).

AUTHORS' CONCLUSIONS

The efficacy and safety of glucose-lowering agents in the treatment of pre-existing and new-onset diabetes in kidney transplant recipients is questionable. Evidence from existing studies examining the effect of intensive insulin therapy, DPP-4 inhibitors, SGLT inhibitors and glitazones is mostly of low to very low certainty. Appropriately blinded, larger, and higher quality RCTs are needed to evaluate and compare the safety and efficacy of contemporary glucose-lowering agents in the kidney transplant population.

Efficacy and Safety of Dipeptidyl Peptidase-4 Inhibitors in Kidney Transplant Recipients with Post-transplant Diabetes Mellitus (PTDM)- a Systematic Review and Meta-Analysis

BACKGROUND

Kidney transplant recipients may develop post-transplant diabetes mellitus (PTDM). Dipeptidyl peptidase 4(DPP-4) inhibitors are evolving agents in the management of patients with diabetes mellitus.

AIM

To evaluate the efficacy and safety of DPP-4 inhibitors in the management of post-transplant diabetes mellitus (PTDM) in renal transplant recipients.

METHODS

We performed a systematic search of the electronic databases using keys words and Mesh terms. Data were extracted and reviewed using structured proforma. A comprehensive review of the eligible studies was performed independently by each of two reviewers; conflicts were resolved by the third reviewer. The primary efficacy endpoint was the difference in glycosylated hemoglobin (HbA1c) comparing any of the DPP-4 inhibitors to either placebo or other hypoglycaemic agent. The primary safety endpoints were the worsening of graft functions and change in Tacrolimus trough level. We performed the Random effect model using standardised mean difference.

RESULTS

We identified seven studies that were eligible for the systematic review; only one study compared Sitagliptin to insulin Glargine. One study involved head to head comparison of three DPP-4 inhibitors. The other five studies were pooled in the meta-analysis. DPP-4 inhibitors had a favourable glycemic effect as measured by HbA1c when compared to either placebo or oral anti-hyperglycemic medications (standardised mean difference in HbA1c = -0.993, 95% CI= -1.303 to -0.683, P=0.001). DPP-4 inhibitors use did not result in significant change in eGFR ((standardised mean difference = 0.147, 95% CI= -0.139 - 0.433, p=0.312).) nor Tacrolimus level (standardised Mean Difference= 0.152, 95% CI= -0.172 to 0.477, P=0.354).

CONCLUSION

Current evidence supports the short term efficacy and safety of DDP-4 inhibitor agents in the management of post transplantation diabetes mellitus (PTDM) in kidney transplant recipients. However, more RCTs are required to investigate the long-term safety and efficacy of these agents in kidney transplant recipients.

Post-Liver Transplantation Diabetes Mellitus: A Review of Relevance and Approach to Treatment

Post-liver transplantation diabetes mellitus (PLTDM) develops in up to 30% of liver transplant recipients and is associated with increased risk of mortality and multiple morbid outcomes. PLTDM is a multicausal disorder, but the main risk factor is the use of immunosuppressive agents of the calcineurin inhibitor (CNI) family (tacrolimus and cyclosporine). Additional factors, such as pre-transplant overweight, nonalcoholic steatohepatitis and hepatitis C virus infection, may further increase risk of developing PLTDM. A diagnosis of PLTDM should be established only after doses of CNI and steroids are stable and the post-operative stress has been overcome. The predominant defect induced by CNI is insulin secretory dysfunction. Plasma glucose control must start immediately after the transplant procedure in order to improve long-term results for both patient and transplant. Among the better known antidiabetics, metformin and DPP-4 inhibitors have a particularly benign profile in the PLTDM context and are the preferred oral agents for long-term management. Insulin therapy is also an effective approach that addresses the prevailing pathophysiological defect of the disorder. There is still insufficient evidence about the impact of newer families of antidiabetics (GLP-1 agonists, SGLT-2 inhibitors) on PLTDM. In this review, we summarize current knowledge on the epidemiology, pathogenesis, course of disease and medical management of PLTDM.

New onset diabetes after kidney transplantation is associated with increased mortality-A retrospective cohort study

OBJECTIVE

Clinical outcomes in individuals with new onset diabetes after transplantation (NODAT) and the optimal treatment for this complication are poorly characterized. This study was intended to better define these issues.

METHODS

Patients who underwent kidney transplantation and did not have diabetes prior to transplantation were included in the study. Clinical outcomes were compared between those who developed NODAT and those who did not. In those who developed NODAT, oral therapy was compared with insulin based therapy.

RESULTS

A total of 266 kidney transplant recipients were included, of which 71 (27%) developed NODAT during the time of the follow-up. Using Cox multivariate analysis adjusted for age and gender, hazard ratio for overall mortality among patients with NODAT versus those without NODAT was 2.69 (95% CI 1.04-7.01). Among patients who developed NODAT, 29 patients (40%) were treated with an insulin-based regimen. At the end of follow-up, no difference was found in mean HbA1c, and therapy regimen was not associated with greater mortality.

CONCLUSIONS

New onset diabetes in kidney transplanted patients is associated with increased mortality compared with kidney transplanted patients without NODAT.

Glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients

BACKGROUND

Kidney transplantation is the preferred form of kidney replacement therapy for patients with end-stage kidney disease (ESKD) and is often complicated by worsening or new-onset diabetes. Management of hyperglycaemia is important to reduce post-transplant and diabetes-related complications. The safety and efficacy of glucose-lowering agents after kidney transplantation is largely unknown.

OBJECTIVES

To evaluate the efficacy and safety of pharmacological interventions for lowering glucose levels in patients who have undergone kidney transplantation and have diabetes.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 15 April 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs), quasi-RCTs and cross-over studies examining head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in patients who have received a kidney transplant and have diabetes were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and quality and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD) or standardised mean difference (SMD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven studies that involved a total of 399 kidney transplant recipients. All included studies had observed heterogeneity in the patient population, interventions and measured outcomes or missing data (which was unavailable despite correspondence with authors). Many studies had incompletely reported methodology preventing meta-analysis and leading to low confidence in treatment estimates.Three studies with 241 kidney transplant recipients examined the use of more intensive compared to less intensive insulin therapy in kidney transplant recipients with pre-existing type 1 or 2 diabetes. Evidence for the effects of more intensive compared to less intensive insulin therapy on transplant graft survival, HbA1c, fasting blood glucose, all cause mortality and adverse effects including hypoglycaemia was of very low quality. More intensive versus less intensive insulin therapy resulted in no difference in transplant or graft survival over three to five years in one study while another study showed that more intensive versus less intensive insulin therapy resulted in more rejection events over the three year follow-up (11 events in total; 9 in the more intensive group, P = 0.01). One study showed that more intensive insulin therapy resulted in a lower mean HbA1c (10 ± 0.8% versus 13 ± 0.9%) and lower fasting blood glucose (7.22 ± 0.5 mmol/L versus 13.44 ± 1.22 mmol/L) at 13 months compared with standard insulin therapy. Another study showed no difference between more intensive compared to less intensive insulin therapy on all-cause mortality over a five year follow-up period. All studies showed either an increased frequency of hypoglycaemia or severe hypoglycaemia episodes.Three studies with a total of 115 transplant recipients examined the use of DPP4 inhibitors for new-onset diabetes after transplantation. Evidence for the treatment effect of DPP4 inhibitors on transplant or graft survival, HbA1c and fasting blood glucose levels, all cause mortality, and adverse events including hypoglycaemia was of low quality. One study comparing vildagliptin to placebo and another comparing sitagliptin to placebo showed no difference in transplant or graft survival over two to four months of follow-up. One study comparing vildagliptin to placebo showed no significant change in estimated glomerular filtration rate from baseline (1.9 ± 10.3 mL/min/1.73 m2, P = 0.48 and 2.1 ± 6.1 mL/min/1.73 m2, P = 0.22) and no deaths, in either treatment group over three months of follow-up. One study comparing vildagliptin to placebo showed a lower HbA1c level (mean ± SD) (6.3 ± 0.5% versus versus 6.7 ± 0.6%, P = 0.03) and trend towards a greater lowering of fasting blood glucose (-0.91 ± -0.92 mmol/L versus vs -0.19 ± 1.16 mmol/L, P = 0.08) with vildagliptin. One study comparing sitagliptin to insulin glargine showed an equivalent lowering of HbA1c (-0.6 ± 0.5% versus -0.6 ± 0.6%, P = NS) and fasting blood glucose (4.92 ± 1.42 versus 4.76 ± 1.09 mmol/L, P = NS) with sitagliptin. For the outcome of hypoglycaemia, one study comparing vildagliptin to placebo reported no episodes of hypoglycaemia, one study comparing sitagliptin to insulin glargine reported fewer episodes of hypoglycaemia with sitagliptin (3/28 patients; 10.7% versus 5/28; 17.9%) and one cross-over study of sitagliptin and placebo reported two episodes of asymptomatic moderate hypoglycaemia (2 to 3.9 mmol/L) when sitagliptin was administered with glipizide. All three studies reported no drug interactions between DPP4 inhibitors and the immunosuppressive agents taken.Evidence for the treatment effect of pioglitazone for treating pre-existing diabetes was of low quality. One study with 62 transplant recipients compared the use of pioglitazone with insulin to insulin alone for treating pre-existing diabetes. Pioglitazone resulted in a lower HbA1c level (mean ± SD) (-1.21 ± 1.2 versus 0.39 ± 1%, P < 0.001) but had no effects on fasting blood glucose (6.58 ± 2.71 versus 7.28 ± 2.78 mmol/L, P = 0.14 ), and change in creatinine (3.54 ± 15.03 versus 10.61 ± 18.56 mmol/L, P = 0.53) and minimal adverse effects (no episodes of hypoglycaemia, three dropped out due to mild to moderate lower extremity oedema, cyclosporin levels were not affected).

AUTHORS' CONCLUSIONS

Evidence concerning the efficacy and safety of glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients is limited. Existing studies examine more intensive versus less intensive insulin therapy, and the use of DPP4 inhibitors and pioglitazone. The safety and efficacy of more intensive compared to less intensive insulin therapy is very uncertain and the safety and efficacy of DPP4 inhibitors and pioglitazone is uncertain, due to data being limited and of poor quality. Additional RCTs are required to clarify the safety and efficacy of current glucose-lowering agents for kidney transplant recipients with diabetes.

Drug-drug interactions between immunosuppressants and antidiabetic drugs in the treatment of post-transplant diabetes mellitus

Post-transplant diabetes mellitus is a frequent complication of solid organ transplantation that generally requires treatment with lifestyle interventions and antidiabetic medication. A number of demonstrated and potential pharmacokinetic drug-drug interactions (DDIs) exist between commonly used immunosuppressants and antidiabetic drugs, which are comprehensively summarized in this review. Cyclosporine (CsA) itself inhibits the cytochrome P450 (CYP) 3A4 enzyme and a variety of drug transporters. As a result, it increases exposure to repaglinide and sitagliptin, will likely increase the exposure to nateglinide, glyburide, saxagliptin, vildagliptin and alogliptin, and could theoretically increase the exposure to gliquidone and several sodium-glucose transporter (SGLT)-2 inhibitors. Currently available data, although limited, suggest that these increases are modest and, particularly with regard to gliptins and SGLT-2 inhibitors, unlikely to result in hypoglycemia. The interaction with repaglinide is more pronounced but does not preclude concomitant use if repaglinide dose is gradually titrated. Mycophenolate mofetil and azathioprine do not engage in DDIs with any antidiabetic drug. Although calcineurin inhibitors (CNIs) and mammalian target of rapamycin inhibitors (mTORi) are intrinsically prone to DDIs, their disposition is not influenced by metformin, pioglitazone, sulfonylureas (except possibly glyburide) or insulin. An effect of gliptins on the disposition of CNIs and mTORi is unlikely, but has not been definitively ruled out. Based on their disposition profiles, glyburide and canagliflozin could affect CNI and mTORi disposition although this requires further study. Finally, delayed gastric emptying as a result of glucagon-like peptide-1 agonists seems to have a limited, but not necessarily negligible effect on CNI disposition.

Diabetes Care After Transplant: Definitions, Risk Factors, and Clinical Management

Patients who undergo solid organ transplantation may have preexisting diabetes mellitus (DM), develop new-onset DM after transplantation (NODAT), or have postoperative hyperglycemia that resolves shortly after surgery. Although insulin is usually used to control hyperglycemia in the hospital, following discharge most of the usual diabetes oral and parenteral medications can be used in treatment. However, when there are comorbidities such as impaired kidney or hepatic function, or heart disease, special precautions may be necessary. In addition, drug-drug interactions, such as drugs interacting with CYP3A4 enzyme pathway, require additional consideration because of possible interaction with immunosuppressive drug metabolism.

HYPERGLYCEMIA MANAGEMENT IN PATIENTS WITH POSTTRANSPLANTATION DIABETES

OBJECTIVE

Posttransplantation diabetes (PTDM) is a common occurrence after solid-organ transplantation and is associated with increased morbidity, mortality, and health care costs. There is a limited number of studies addressing strategies for hyperglycemia management in this population, with a few articles emerging recently.

METHODS

We performed a PubMed search of studies published in English addressing hyperglycemia management of PTDM/new-onset diabetes after transplant (NODAT). Relevant cited articles were also retrieved.

RESULTS

Most of the 25 publications eligible for review were retrospective studies. Insulin therapy during the early posttransplantation period showed promise in preventing PTDM development. Thiazolidinediones have been mostly shown to exert glycemic control in retrospective studies, at the expense of weight gain and fluid retention. Evidence with metformin, sulfonylureas, and meglitinides is very limited. Incretins have shown promising results in small prospective studies using sitagliptin, linaglitpin, and vildagliptin and a case series using liraglutide.

CONCLUSION

Prospective randomized studies assessing the management of hyperglycemia in PTDM are urgently needed. In the meantime, clinicians need to be aware of the high risk of PTDM and associated complications and current concepts in management.