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

SGLT2 inhibitors in diabetic and non-diabetic kidney transplant recipients: current knowledge and expectations

The beneficial effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown recently in numerous randomized controlled trials (RCT) and systematic reviews. According to KDIGO guidelines, SGLT2i currently represent a first choice for diabetic patients with chronic kidney disease (CKD). In addition, a recent meta-analysis of 13 large led by the 'SGLT2 inhibitor Meta-Analysis Cardio-Renal Trialists' Consortium' (SMART-C) provided solid evidence of SGLT2i beneficial effects in CKD or in patients with heart failure, with and without diabetes. Collectively, the patients treated with SGLT2i had a decreased risk of CKD progression, acute kidney injury (AKI), end-stage kidney disease (ESKD) or death from heart failure. Whether these cardio-renal benefits should be extrapolated to kidney transplant recipients (KTR) needs to be assessed in further studies. In this article, we report recent data accumulated so far in the literature, looking at the efficacy and safety of SGLT2i in diabetic and non-diabetic KTR. We found encouraging data regarding the use of SGLT2i in KTR with diabetes. These agents appeared to be safe, and they reduced body weight and blood pressure in this group of patients. Potential effects on kidney graft function and survival are yet to be investigated.

Posttransplant Diabetes Mellitus: Recent Developments in Pharmacological Management of Hyperglycemia

CONTEXT

The management of solid-organ transplantation is rapidly evolving, and posttransplant diabetes mellitus (PTDM), which is increasingly common, is a barrier to transplant success, adversely impacting infection rates, allograft survival, cardiovascular disease, quality of life, and overall mortality. Currently, the management of PTDM relies primarily on intensified insulin therapy. However, emerging studies report that several noninsulin glucose-lowering agents are safe and effective in improving metabolic control and enhancing treatment adherence. More importantly, their use in PTDM can potentially transform the long-term management of these complex patients, as some glucose-lowering agents may provide benefits beyond glycemic control. For instance, glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter 2 (SGLT-2) inhibitors may offer cardiorenal protection, and pioglitazone may treat nonalcoholic fatty liver disease (NAFLD). This review will focus on the pharmacological management of PTDM and the emerging evidence for noninsulin glucose-lowering agents in this population.

EVIDENCE ACQUISITION

Evidence from observational studies, randomized controlled trials, and meta-analyses.

EVIDENCE SYNTHESIS

PTDM adversely affects the outcomes of infection, organ survival, cardiovascular events, and mortality. Insulin therapy has been the drug of choice but is associated with weight gain and hypoglycemia. In contrast, noninsulin agents appear safe and may provide additional benefits, such as cardiorenal protection with SGLT-2 inhibitors and GLP-1 RA, and cardiometabolic benefits with pioglitazone, in patients undergoing solid-organ transplantation.

CONCLUSIONS

Optimal care of patients with PTDM requires close monitoring and the early involvement of the endocrinologist as part of a multidisciplinary team. Noninsulin glucose-lowering agents will likely play an increasing role as more long-term, controlled studies become available in this setting.

Use of Sodium-Glucose Cotransporter-2 Inhibitor for Diabetes Management in Patients Following Kidney Transplantation

Objective: To evaluate data sources pertaining to the safety and efficacy of sodium-glucose cotransporter-2 (SGLT2) inhibitor use for diabetes management in patients following kidney transplantation. Data Sources: A literature search was conducted through PubMed (1966-January 2023), EMBASE (1973-January 2023), and clinicaltrials.gov databases using the search terms kidney transplantation, diabetes mellitus, and SGLT2 inhibitor or empagliflozin, dapagliflozin, and canagliflozin. Study Selection and Data Extraction: Studies evaluating human kidney transplant recipients (KTR) receiving SGLT2 inhibitors treatment and published in the English language were included. Eight case series or retrospective analyses, 4 prospective observational studies, and 1 randomized controlled trial were identified. Data Synthesis: Available literature provides evidence that the addition of SGLT2 inhibitors may provide modest benefits on glycemic control, body weight, and serum uric acid levels in certain KTR. Various studies and case reports found that incidence of urinary tract infections was low, but still present. Overall, there are limited data on mortality and graft survival; however, one study reported a benefit of SGLT2 inhibitor use in KTR relative to these outcomes. Conclusions: The current literature evaluated demonstrates that there may be benefit to the addition of SGLT2 inhibitors for diabetes management in select KTR. However, the limited evidence within a large diverse population and extended duration of treatment makes it difficult to definitively identify the true efficacy and safety of SGLT2 inhibitor use in this population.

Novel Drugs for the Management of Diabetes Kidney Transplant Patients: A Literature Review

The management of diabetes and renal failure is changing thanks to the appearance of new drugs such as glucagon-like peptide 1 receptor agonists (GLP1-RA) and sodium-glucose cotransporter type 2 inhibitors (SGLT2i) that have benefits in terms of survival and cardiorenal protection. Based on the potential mechanisms of GLP1-RA, kidney transplant recipients (KTRs) could benefit from their effects. However, high-quality studies are needed to demonstrate these benefits, in the transplant population, especially those related to cardiovascular benefits and renal protection. Studies with SGLT2i performed in KTRs are much less potent than in the general population and therefore no benefits in terms of patient or graft survival have been clearly demonstrated in this population to date. Additionally, the most frequently observed side effects could be potentially harmful to this population profile, including severe or recurrent urinary tract infections and impaired kidney function. However, benefits demonstrated in KTRs are in line with a known potential effects in cardiovascular and renal protection, which may be essential for the outcome of transplant recipients. Better studies are still needed to confirm the benefits of these new oral antidiabetics in the renal transplant population. Understanding the characteristics of these drugs may be critical for KTRs to be able to benefit from their effects without being damaged. This review discusses the results of the most important published studies on KTRs with GLP1-RA and SGLT2i as well as the potential beneficial effects of these drugs. Based on these results, approximate suggestions for the management of diabetes in KTRs were developed.

Use of sodium-glucose co-transporter 2 inhibitors in solid organ transplant recipients with pre-existing type 2 or post-transplantation diabetes mellitus: A systematic review

INTRODUCTION

Sodium-Glucose Co-Transporter 2 (SGLT2) inhibitors have demonstrated kidney, cardiovascular and mortality benefits in the general population; however, the evidence is limited in solid organ transplant recipients. The aim of this systematic review was to evaluate the current efficacy and safety data of SGLT2 inhibitors in adult kidney, heart, lung, and liver transplant recipients with pre-existing type 2 or post-transplantation diabetes mellitus.

METHOD

We searched MEDLINE, MEDLINE Epub, CENTRAL, CDSR, EMBASE, CINAHL, and sources of unpublished literature. All primary interventional and observational studies on SGLT2 inhibitors in transplant recipients were included. Clinical outcomes included mortality, cardiovascular and kidney events, and adverse events such as graft rejection. Surrogate markers including hemoglobin A1c (HbA1c) and weight reduction were also evaluated.

RESULTS

Of the 17 studies that were included in this systematic review, there were 15 studies on kidney transplant recipients (n = 2417 patients) and two studies on heart transplant recipients (n = 122 patients). There was only one randomized controlled trial which evaluated 49 kidney transplant patients over 24 weeks. Overall, studies were heterogeneous in study design, sample size, duration of diabetes, time to SGLT2 inhibitor initiation post-transplantation (ranging from 0.88 to 11 years post kidney transplant; five to 5.7 years post heart transplant) and follow-up (ranging from 0.4 to 5.25 years in kidney transplant patients; 0.75 to one year in heart transplant patients). Only one retrospective study evaluated mortality as a part of a composite outcome in kidney transplant patients; however, study limitations restrict generalizability of results. Overall, studies could not confirm clinical cardiovascular and kidney benefits in the transplant population. Findings suggested that SGLT2 inhibitors may improve glycemic control; however, they are associated with urinary tract infection. Diabetic ketoacidosis and acute kidney injury also occurred in these studies, with precipitating factors such as infection and acute heart failure exacerbation.

CONCLUSIONS

While SGLT2 inhibitors are promising agents with expanding indications in the non-transplant population, these agents may not be suitable for all solid organ transplant recipients, and close monitoring (e.g. for urinary tract infections) and patient education (e.g. sick day management) are essential if these agents are initiated. Evidence is based on short-term findings and suggests an association with hemoglobin A1c reduction and increased adverse events. Further long-term randomized controlled trials are needed to evaluate the effect of SGLT2 inhibitors on clinically important outcomes, including mortality reduction, in solid organ 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.

Kidney and heart failure outcomes associated with SGLT2 inhibitor use

Chronic kidney disease (CKD) and heart failure affect many people worldwide. Despite the availability of pharmacological treatments, both diseases remain associated with considerable morbidity and mortality. After observations that sodium-glucose co-transporter 2 (SGLT2) inhibitors - originally developed as glucose-lowering agents - improved cardiovascular and renal outcomes in patients with type 2 diabetes, dedicated trials were initiated to evaluate the cardiovascular and kidney protective effects in patients with CKD or heart failure. The results of these clinical trials and subsequent detailed analyses have shown that the benefits of SGLT2 inhibitors are consistent across many patient subgroups, including those with and without type 2 diabetes, at different stages of CKD, and in patients with heart failure with preserved or reduced ejection fraction. In addition, post-hoc analyses revealed that SGLT2 inhibitors reduce the risk of anaemia and hyperkalaemia in patients with CKD. With respect to their safety, SGLT2 inhibitors are generally well tolerated. More specifically, no increased risk of hypoglycaemia has been observed in patients with CKD or heart failure without diabetes and they do not increase the risk of acute kidney injury. SGLT2 inhibitors therefore provide clinicians with an exciting new treatment option for patients with CKD and heart failure.

Recent advances in new-onset diabetes mellitus after kidney transplantation

A common challenge in managing kidney transplant recipients (KTR) is post-transplant diabetes mellitus (PTDM) or diabetes mellitus (DM) newly diagnosed after transplantation, in addition to known pre-existing DM. PTDM is an important risk factor for post-transplant cardiovascular (CV) disease, which adversely affects patient survival and quality of life. CV disease in KTR may manifest as ischemic heart disease, heart failure, and/or left ventricular hypertrophy. Available therapies for PTDM include most agents currently used to treat type 2 diabetes. More recently, the use of sodium glucose co-transporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and dipeptidyl peptidase 4 inhibitors (DPP4i) has cautiously extended to KTR with PTDM, even though KTR are typically excluded from large general population clinical trials. Initial evidence from observational studies seems to indicate that SGLT2i, GLP-1 RA, and DPP4i may be safe and effective for glycemic control in KTR, but their benefit in reducing CV events in this otherwise high-risk population remains unproven. These newer drugs must still be used with care due to the increased propensity of KTR for intravascular volume depletion and acute kidney injury due to diarrhea and their single-kidney status, pre-existing burden of peripheral vascular disease, urinary tract infections due to immunosuppression and a surgically altered urinary tract, erythrocytosis from calcineurin inhibitors, and reduced kidney function from acute or chronic rejection.

CD161a-positive natural killer (NK) cells and α-smooth muscle actin-positive myofibroblasts were upregulated by extrarenal DPP4 in a rat model of acute renal rejection

AIMS

Systemic inhibition of dipeptidyl peptidase 4 (DPP4) showed a protective effect in several transplant models. Here we assessed the specific role of extrarenal DPP4 in renal transplant rejection.

METHODS

Kidneys from wildtype (wt) F344 rats were either transplanted in wt Dark Agouti or congenic rats not expressing DPP4. The remaining, not transplanted donor kidney served as healthy controls. To investigate early inflammatory events rats were sacrificed 3 days after transplantation and kidneys were evaluated for inflammatory cells, capillary rarefaction, proliferation, apoptosis and myofibroblasts by immunohistochemistry.

RESULTS

Capillary ERG-1-positive endothelial cells were significantly more abundant in renal cortex when transplanted into DPP4 deficient compared to wt recipients. In contrast, TGF-ß and myofibroblasts were reduced by more than 25% in kidneys transplanted into DPP4 deficient compared to wt recipients. Numbers of CD161a-positive NK-cells were significantly lower in allografts in DPP4 deficient compared to wt recipients. Numbers of all other investigated immune cells were not affected by the lack of extrarenal DPP4.

CONCLUSION

In early transplant rejection extrarenal DPP4 is involved in the recruitment of NK-cells and early fibrosis. Beneficial effects were less pronounced than reported for systemic DPP4 inhibition, indicating that renal DPP4 is an important player in transplantation-mediated injury.