Fueling the success of transplantation through nutrition: recent insights into nutritional interventions, their interplay with gut microbiota and cellular mechanisms

PURPOSE OF REVIEW

The role of nutrition in organ health including solid organ transplantation is broadly accepted, but robust data on nutritional regimens remains scarce calling for further investigation of specific dietary approaches at the different stages of organ transplantation. This review gives an update on the latest insights into nutritional interventions highlighting the potential of specific dietary regimens prior to transplantation aiming for organ protection and the interplay between dietary intake and gut microbiota.

RECENT FINDINGS

Nutrition holds the potential to optimize patients' health prior to and after surgery, it may enhance patients' ability to cope with the procedure-associated stress and it may accelerate their recovery from surgery. Nutrition helps to reduce morbidity and mortality in addition to preserve graft function. In the case of living organ donation, dietary preconditioning strategies promise novel approaches to limit ischemic organ damage during transplantation and to identify the underlying molecular mechanisms of diet-induced organ protection. Functioning gut microbiota are required to limit systemic inflammation and to generate protective metabolites such as short-chain fatty acids or hydrogen sulfide.

SUMMARY

Nutritional intervention is a promising therapeutic concept including the pre- and rehabilitation stage in order to improve the recipients' outcome after solid organ transplantation.

Immunosuppressive drug combinations after kidney transplantation and post-transplant diabetes: A systematic review and meta-analysis

Post-transplant diabetes mellitus (PTDM) is a frequent complication after kidney transplantation (KT). This systematic review investigated the effect of different immunosuppressive regimens on the risk of PTDM. We performed a systematic literature search in MEDLINE and CENTRAL for randomized controlled trials (RCTs) that included KT recipients with any immunosuppression and reported PTDM outcomes up to 1 October 2023. The analysis included 125 RCTs. We found no differences in PTDM risk within induction therapies. In de novo KT, there was an increased risk of developing PTDM with tacrolimus versus cyclosporin (RR 1.71, 95%CI [1.38-2.11]). No differences were observed between tacrolimus+mammalian target of rapamycin inhibitor (mTORi) and tacrolimus+MMF/MPA, but there was a tendency towards a higher risk of PTDM in the cyclosporin+mTORi group (RR 1.42, 95%CI [0.99-2.04]). Conversion from cyclosporin to an mTORi increased PTDM risk (RR 1.89, 95%CI [1.18-3.03]). De novo belatacept compared with a calcineurin inhibitor resulted in 50% lower risk of PTDM (RR 0.50, 95%CI [0.32-0.79]). Steroid avoidance resulted in 31% lower PTDM risk (RR 0.69, 95%CI [0.57-0.83]), whereas steroid withdrawal resulted in no differences. Immunosuppression should be decided on an individual basis, carefully weighing the risk of future PTDM and rejection.

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.

Prevalence of new-onset diabetes mellitus after kidney transplantation: a systematic review and meta-analysis

AIMS

Post-transplant diabetes is a prevalent and consequential complication following kidney transplantation, which significantly augments the risk of cardiovascular disease, graft loss, infection, and mortality, thereby profoundly impacting both graft and patient survival. However, the early stages of post-transplant diabetes often go unnoticed or receive inadequate management. Consequently, this study systematically assesses the incidence of new-onset diabetes after kidney transplantation with the aim to enhance medical staff awareness regarding post-transplantation diabetes and provide clinical management guidance.

METHODS

We conducted a comprehensive search across multiple databases including PubMed, Web of Science, Embase, The Cochrane Library, CNKI, Wanfang, VIP, and SinoMed until September 21, 2023. Data extraction was performed using standardized tables and meta-analysis was conducted using Stata 16.0 software. A random effects model was employed to estimate the combined prevalence along with its corresponding 95% confidence interval. The source of heterogeneity was explored using subgroup analysis and sensitivity analysis, while publication bias was assessed through funnel plot and Egger's test. This study has been registered with PROSPERO under the registration number CRD42023465768.

RESULTS

This meta-analysis comprised 39 studies with a total sample size of 16,584 patients. The prevalence of new-onset diabetes after transplantation was found to be 20% [95% CI (18.0, 22.0)]. Subgroup analyses were conducted based on age, gender, body mass index, family history of diabetes, type of kidney donor, immunosuppressive regimen, acute rejection episodes, hepatitis C infection status and cytomegalovirus infection.

CONCLUSIONS

The incidence of post-kidney transplantation diabetes is substantial, necessitating early implementation of preventive and control measures to mitigate its occurrence, enhance prognosis, and optimize patients' quality of life.

CLINICAL TRIAL REGISTRATION

PROSPERO: CRD42023465768.

Safety and efficacy of semaglutide in post kidney transplant patients with type 2 diabetes or Post-Transplant diabetes

Objective

Type 2 diabetes mellitus (T2DM) and post-transplant diabetes mellitus (PTDM) are common in renal transplant recipients. Semaglutide has demonstrated efficacy and safety in patients with T2DM. To date, only a limited number of studies have investigated its use in renal transplant patients. This study assessed the safety and efficacy of semaglutide in post-renal transplant patients.

Methods

A retrospective study was conducted at king Abdulaziz Medical City-Riyadh, Saudi Arabia. The subjects of the study were adults and adolescents (>14 years) who had undergone a kidney transplant and had pre-existing T2DM or PTDM. The study subjects were given semaglutide during the study period, from January 2018 to July 2022. The data were collected over a period of 18 months.

Results

A total of 39 patients were included, 29 (74 %) of whom were male. A significant decrease in hemoglobin A1c (HbA1c) was observed during the follow-up period when compared to baseline (8.4 %±1.3 % at baseline vs. 7.4 %±1.0 % at 13-18 months (p < 0.001). A significant reduction in weight was also noted at follow-up as compared to baseline (99.5 kg ± 17.7 vs 90.7 kg ± 16.8 at 13-18 months (p < 0.001). No significant changes were found in renal graft function markers.

Conclusion

Semaglutide was found to significantly reduce HbA1c levels and weight in post renal transplant patients with diabetes. No significant changes in markers of renal graft function were observed.

Induction of diabetes by Tacrolimus in a phenotypic model of obesity and metabolic syndrome

Introduction

The pathogenesis of Post-Transplant Diabetes Mellitus (PTDM) is complex and multifactorial and it resembles that of Type-2 Diabetes Mellitus (T2DM). One risk factor specific to PTDM differentiates both entities: the use of immunosuppressive therapy. Specifically, Tacrolimus interacts with obesity and insulin resistance (IR) in accelerating the onset of PTDM. In a genotypic model of IR, the obese Zucker rats, Tacrolimus is highly diabetogenic by promoting the same changes in beta-cell already modified by IR. Nevertheless, genotypic animal models have their limitations and may not resemble the real pathophysiology of diabetes. In this study, we have evaluated the interaction between beta-cell damage and Tacrolimus in a non-genotypic animal model of obesity and metabolic syndrome.

Methods

Sprague Dawley rats were fed a high-fat enriched diet during 45 days to induce obesity and metabolic dysregulation. On top of this established obesity, the administration of Tacrolimus (1mg/kg/day) during 15 days induced severe hyperglycaemia and changes in morphological and structural characteristics of the pancreas.

Results

Obese animals administered with Tacrolimus showed increased size of islets of Langerhans and reduced beta-cell proliferation without changes in apoptosis. There were also changes in beta-cell nuclear factors such as a decrease in nuclear expression of MafA and a nuclear overexpression of FoxO1A, PDX-1 and NeuroD1. These animals also showed increased levels of pancreatic insulin and glucagon.

Discussion

This model could be evidence of the relationship between the T2DM and PTDM physiopathology and, eventually, the model may be instrumental to study the pathogenesis of T2DM.

New-Onset Diabetes Mellitus after Kidney Transplantation

New-Onset Diabetes Mellitus after Transplantation (NODAT) emerges as a prevalent complication post-kidney transplantation, with its incidence influenced by variations in NODAT definitions and follow-up periods. The condition's pathophysiology is marked by impaired insulin sensitivity and β-cell dysfunction. Significant risk factors encompass age, gender, obesity, and genetics, among others, with the use of post-transplant immunosuppressants intensifying the condition. NODAT's significant impact on patient survival and graft durability underscores the need for its prevention, early detection, and treatment. This review addresses the complexities of managing NODAT, including the challenges posed by various immunosuppressive regimens crucial for transplant success yet harmful to glucose metabolism. It discusses management strategies involving adjustments in immunosuppressive protocols, lifestyle modifications, and pharmacological interventions to minimize diabetes risk while maintaining transplant longevity. The importance of early detection and proactive, personalized intervention strategies to modify NODAT's trajectory is also emphasized, advocating for a shift towards more anticipatory post-transplant care.

Increased Circulating Irisin Levels in Kidney Transplant Patients: Is There a Connection with Glycaemic Control?

Irisin is a myokine with potential effects on glucose metabolism and the development of diabetes in humans. We analysed irisin serum levels (ISL) in 47 patients without diabetes before and 1, 2, 3, 4 and 5 weeks after kidney transplantation (KTx). All measurements of irisin before KTx levels were lower than 25 ng/mL (median 8.4 ng/mL). We found an outstanding increase in ISL measured after KTx, reaching more than 1000 times in 44% of patients (HIL-high irisin level group). The increase appeared at the first measurement (one week after KTx). Factors connected to the large growth of ISL were, i.e., BMI > 30 (p = 0.04) and subsequent KTx-second and third (p < 0.001). The global mean blood glucose level during the first two weeks after KTx was significantly lower in the HIL group (p = 0.002), the same as the day-by-day analysed mean fasting and postprandial serum glucose in the first days after KTx. In 12 months of observation, diabetes requiring insulin therapy occurred in the HIL group at a rate of 19%, while in the rest of the patients, the rate was 27%, p = 0.526. Irisin levels increase significantly in some patients after kidney transplantation, accompanied by lower blood glucose levels in the early post-transplant period. Whether an increase in irisin levels results in better glycaemic control remains questionable and requires further research, as well as the relationship between irisin levels and the occurrence of PTDM.

Early post-transplant hyperglycemia and post-transplant diabetes mellitus following heart transplantation

INTRODUCTION

Heart transplantation is an important treatment for end-stage heart failure. Early post-transplant hyperglycemia (EPTH) and post-transplant diabetes mellitus (PTDM) are common following heart transplantation and are associated with increased morbidity and mortality.

AREAS COVERED

This review summarizes the clinical characteristics, diagnosis, and treatment of EPTH and PTDM in cardiac transplant patients, incorporating findings from non-cardiac solid organ transplant studies where relevant due to limited heart-specific research.

EXPERT OPINION

EPTH following heart transplantation is common yet understudied and is associated with the later development of PTDM. PTDM is associated with adverse outcomes including infection, renal dysfunction, microvascular disease, and an increased risk of re-transplantation and mortality. Risk factors for EPTH include the post-operative immunosuppression regimen, recipient and donor age, body mass index, infections, and chronic inflammation. Early insulin treatment is recommended for EPTH, whereas PTDM management is varied and includes lifestyle modification, anti-glycemic agents, and insulin. Given the emerging evidence on the transplant benefits associated with effective glucose control, and the cardioprotective potential of newer anti-glycemic agents, further focus on the management of EPTH and PTDM within heart transplant recipients is imperative.

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.

Diabetic Kidney Disease in Post-Kidney Transplant Patients

Post-transplant diabetes mellitus (PTDM) is a common occurrence in post-kidney transplantation and is associated with greater mortality, allograft failure, and increased risk of infections. The primary goal in the management of PTDM is to achieve glycemic control to minimize the risk of complications while balancing the need for immunosuppression to maintain the health of the transplanted kidney. This review summarizes the effects of maintenance immunosuppression and therapeutic options among kidney transplant recipients. Patients with PTDM are at increased risk of diabetic kidney disease development; therefore, in this review, we focus on evidence supporting the use of novel antidiabetic agents and discuss their benefits and potential side effects in detail.

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.

Sodium-glucose cotransporter-2 inhibitor use in kidney transplant recipients

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are novel oral hypoglycemic agents garnering much attention for their substantial benefits. These recent data have positioned SGLT2i at the forefront of diabetic chronic kidney disease (CKD) and heart failure management. SGLT2i use post-kidney transplant is an emerging area of research. Highlights from this mini review include the following: Empagliflozin is the most prescribed SGLT2i in kidney transplant recipients (KTRs), median time from transplant to initiation was 3 years (range: 0.88-9.6 years). Median baseline estimated glomerular filtration rate (eGFR) was 66.7 mL/min/1.73 m2 (range: 50.4-75.8). Median glycohemoglobin (HgbA1c) at initiation was 7.7% (range: 6.9-9.3). SGLT2i were demonstrated to be effective short-term impacting HgbA1c, eGFR, hemoglobin/hematocrit, serum uric acid, and serum magnesium levels. They are shown to be safe in KTRs with low rates of infections, hypoglycemia, euglycemic diabetic ketoacidosis, and stable tacrolimus levels. More data is needed to demonstrate long-term outcomes. SGLT2i appear to be safe, effective medications for select KTRs. Our present literature, though limited, is founded on precedent robust research in CKD patients with diabetes. Concurrent research/utilization of SGLT2i is vital to not only identify long-term patient, graft and cardiovascular outcomes of these agents, but also to augment management in KTRs.

Inflammation on the Waiting List Is a Risk Factor for New-Onset Prediabetes and Post-Transplant Diabetes Mellitus: A Prospective Study

INTRODUCTION

Inflammation is a risk factor for diabetes in the general population. The role of inflammation in prediabetes or post-transplant diabetes mellitus (PTDM) is not clear. We evaluated the association between inflammatory markers in patients on the waiting list for renal transplantation and the onset of prediabetes and PTDM 12 months after transplantation.

METHODS

This is a post hoc analysis of a prospective study that included nondiabetic patients on the waiting list for kidney transplantation who underwent an oral glucose tolerance test (OGTT) and were followed up to 12 months after transplantation. At this time, those patients without PTDM underwent another OGTT. At pre-transplantation, five cytokines: TNFα, IL6, IL1β, CRP, MCP1 were determined. The association between inflammation and prediabetes/PTDM was evaluated using multiple regression models.

RESULTS

110 patients on the waiting list were enrolled: 74 had normal glucose metabolism and 36 had prediabetes or occult diabetes. At 12 months, 53 patients had normal glucose metabolism, 25 prediabetes, and 32 PTDM. In multiple regression analysis, pre-transplant inflammation was not a risk factor for prediabetes or PTDM. This was attributed to the high interrelation between obesity, prediabetes, and inflammation: about 75% of the cases had these conditions. In a sub-analysis, we analyzed only patients without prediabetes and occult diabetes on the waiting list and found that TNFα levels and BMI at pre-transplantation were independently associated with the onset of prediabetes or PTDM 1 year after transplantation.

CONCLUSIONS

Pre-transplant inflammation and BMI are risk factors for prediabetes and PTDM in patients without glucose metabolism alterations.

Exercise and Prediabetes After Renal Transplantation (EXPRED-I): A Prospective Study

BACKGROUND

Post-transplant diabetes mellitus (PTDM) beyond 12 months (late PTDM) is a severe complication after renal transplantation. Late PTDM develops mostly in subjects with prediabetes. Although exercise may have a potential role in preventing late PTDM, there are no previous data on the effect of exercise in patients with prediabetes.

MATERIAL AND METHODS

The design was a 12-month exploratory study to test the capacity of exercise in reverting prediabetes in order to prevent late-PTDM. The outcome was the reversibility of prediabetes, assessed every 3 months with oral glucose tolerance tests (OGTT). The protocol included an incremental plan of aerobic and/or strength training as well as an active plan for promoting adherence (telephone calls, digital technology, and visits). A priori, a sample size cannot be calculated which makes this an exploratory analysis. Based on previous studies, the spontaneous reversibility of prediabetes was 30% and the reversibility induced by exercise will account for another 30%, a total reversibility of 60% (p value < 0.05, assuming a potency of 85%). Ad interim analysis was performed during follow-up to test the certainty of this sample calculation. Patients beyond 12 months after renal transplantation with prediabetes were included.

RESULTS

The study was interrupted early due to efficacy after the evaluation of the follow-up of 27 patients. At the end of follow-up, 16 (60%) patients reverted to normal glucose levels at fasting (from 102.13 mg/dL ± 11 to 86.75 ± 6.9, p = 0.006) and at 120 min after the OGTTs (154.44 mg/dL ± 30 to 113.0 ± 13.1, p = 0.002) and 11 patients had persistent prediabetes (40%). Also, insulin sensitivity improved with the reversibility of prediabetes, compared to those with persistent prediabetes: 0.09 [0.08-0.11] versus 0.04 [0.01-0.07], p = 0.001 (Stumvoll index). Most needed at least one increment in the prescription of exercise and compliance. Finally, measures aimed at the improvement of compliance were successful in 22 (80%) patients.

CONCLUSION

Exercise training was effective to improve glucose metabolism in renal transplant patients with prediabetes. Exercise prescription must be conducted considering both the clinical characteristics of the patients and pre-defined strategy to promote adherence. The trial registration number of the study was NCT04489043.

Pretransplant evaluation and the risk of glucose metabolic alterations after renal transplantation: a prospective study

BACKGROUND

Post-transplant prediabetes (PreDM) and diabetes (PTDM) are common and have an impact on cardiovascular events. We sought to investigate the pathogenesis and best approach for prediction.

METHODS

We prospectively studied 115 waitlisted patients from a single center without manifest diabetes. An oral glucose tolerance test (OGTT) was performed yearly until transplantation and 12 months later. Insulin secretion, insulin sensitivity (IS) and disposition index (DI) were derived from the OGTT.

RESULTS

PreDM and PTDM were observed in 27% and 28.6% of patients, respectively. Pretransplant age, body mass index (BMI), 120 min glucose, IS, DI, and prediabetes or undiagnosed diabetes were significantly associated with these alterations. In multivariate analysis, pretransplant age [odds ratio (OR) 1.5; 95% confidence interval (CI) 1.04-2.1], BMI (OR 1.16; 95% CI 1.04-1.3) and cumulative steroids (OR 1.5; 95% CI 1.02-2.2) were predictors of PreDM or PTDM. Receiver operating characteristic curve analysis showed that pretransplant BMI and 120 min glucose had the highest area under the curve (0.72; 95% CI 0.62-0.8; and 0.69; 95% CI 0.59-0.79, respectively). The highest discrimination cut-off for BMI (≥28.5 kg/m2) and 120 min glucose (≥123.5 mg/dL) yielded a similar number needed to diagnose (2.5).

CONCLUSIONS

PreDM or PTDM develops in waitlisted patients with an ineffective insulin secretion and BMI shows a similar diagnostic capacity to OGTT. Pretransplant interventions may reduce post-transplant glucose alterations.

Changes over time in the causes of death with a functioning graft in kidney transplantation recipients

INTRODUCTION

Death with a functioning graft (DWFG) is the most frequent cause of loss of kidney transplantation (KT).

OBJECTIVE

To analyze the evolution of the causes of DWFG and the frequency of the types of cancer causing DWFG.

METHODS

Retrospective study of KT in Andalusia from 1984 to 2018. We analyzed the evolution according to eras (1984-1995; 1996-2007; 2008-2018) and according to post-transplant period (early death: first year post-KT; late death: after first year post-KT).

RESULTS

A total of 9905 KT were performed, registering 1861 DWFG. The most frequent causes were cardiovascular disease (25.1%), infections (21.5%) and cancer (19.9%). In early death we did not observe changes, and infections were always the main cause. In late death, cardiovascular death decreased (1984-1995: 35.2%, 1996-2007: 22.6%, 2008-2018: 23.9%), but infections (1984-1995: 12.5%, 1996-2007: 18.3%, 2008-2018: 19.9%) and, above all, cancer-related deaths increased (1984-1995: 21.8%, 1996-2007: 29%, 2008-2018: 26.8%) (P < .001). In the multivariable analysis for late death due to cardiovascular disease, recipient age, retransplantation, diabetes, and the first period were risk factors, while the risk of late death due to cancer and infections was associated with recent eras. In the first year after transplantation, the most frequent neoplasia causing DWFG was post-transplant lymphoproliferative disease, and after the first year, it was lung cancer, without differences when it was analyzed by eras.

CONCLUSIONS

Despite the greater comorbidity of the recipients, cardiovascular deaths have decreased. Cancer has been the main cause of late death in recent years. Lung cancer is the most frequent malignancy that causes DWFG in our transplant patients.

Characterization, evolution and risk factors of diabetes and prediabetes in a pediatric cohort of renal and liver transplant recipients

BACKGROUND

Hyperglycemia (HG) and prediabetes are rarely sought in pediatric liver (LT) and renal (RT) transplantation, yet their presence indicates a high risk of diabetes and cardiovascular disease. The objectives of our DIABGRAFT study were to retrospectively (rDIABGRAFT) and longitudinally (pDIABGRAFT) characterize HG and (pre)diabetes in a cohort of children with LT or/and RT.

METHODS

We retrospectively analyzed risk factors of HG from 195 children with LT from 2012 to 2019 and twenty children with RT from 2005 to 2019 at Cliniques universitaires Saint-Luc. In addition, we prospectively followed four LT and four RT children to evaluate the evolution of their glucose metabolism.

RESULTS

Our rDIABGRAFT study showed that 25% and 35% of LT and RT children respectively presented transient HG and 20% of RT developed diabetes. The occurrence of HG was associated with the use of glucocorticoids and with acute events as graft rejection and infection. In our pDIABGRAFT cohort, biological markers of diabetes were in the normal range for HbA_1C, fasting glucose and insulin levels. However, oral glucose tolerance test and glucose sensors showed insulin resistance, impaired glucose tolerance and HG in the post-prandial afternoon period.

CONCLUSION

Our study shows that children with LT and RT were more at risk of developing HG when glucocorticoids were required and that HbA_1C and fasting glucose lack sensitivity for early detection of glucose intolerance. Also, measurement of glycemia immediately after the transplantation and in postprandial period is key to detect dysglycemia since insulin resistance prevailed in our cohort.

CLINICALTRIALSGOV ID

NCT05464043.

Monitoring of blood glucose after pediatric kidney transplantation: a longitudinal cohort study

BACKGROUND

Glucose metabolism after kidney transplantation (KT) is highly dynamic with the first post-transplantation year being the most critical period for new-onset diabetes after transplantation (NODAT) occurrence. The present study aimed to analyze dynamics of glucose metabolism and report incidence/risk factors of abnormal glycemic state during the first year after KT in children.

METHODS

Twenty-one consecutive freshly transplanted pediatric kidney transplant recipients (KTRs) were assessed for fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) weekly for 4 weeks, then every 3 months for 1 year.

RESULTS

Interpretation of OGTT test showed normal glucose tolerance (NGT) in 6 patients (28.6%) while 15 (71.4%) experienced impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) at any time point of monitoring. Seven patients had NODAT, for which three needed insulin therapy. Hyperglycemia onset was 7.8 ± 13.12 weeks (median (range) = 1 (0-24) week) after KT. Percent of patients with abnormal OGTT was significantly more than that of IFG (38.1% vs. 71.4%, p = 0.029). Patients with abnormal glycemic state had significantly elevated trough tacrolimus levels at 6 months (p = 0.03). Glucose readings did not correlate with steroid doses nor rejection episodes while positively correlating with tacrolimus doses at 3 months (p = 0.02, CC = 0.73) and 6 months (p = 0.01, CC = 0.63), and negatively correlating with simultaneous GFR at 9 months (p = 0.04, CC =  - 0.57).

CONCLUSIONS

Up to two thirds of pediatric KTRs (71.4%) experienced abnormal glycemic state at some point with peak incidence within the first week up to 6 months after KT. OGTT was a better tool for monitoring of glucose metabolism than FPG. Abnormal glycemic state was induced by tacrolimus and adversely affected graft function. A higher resolution version of the Graphical abstract is available as Supplementary information.

Diabetic Ketoacidosis Management: Updates and Challenges for Specific Patient Population

Diabetic ketoacidosis (DKA) is the most common hyperglycemic emergency and causes the greatest risk for death that could be prevented in patients with diabetes mellitus. DKA occurs more commonly among patients with type-1 diabetes with a thirty percent of the cases take place in patients with type 2 diabetes. DKA is characterized by sever hyperglycemia, metabolic acidosis and ketosis. Proper management of DKA requires hospitalization for aggressive replacement and monitoring of fluids, electrolytes and insulin therapy. Management of DKA has been updated with guidelines, to help standardize care, and reduce mortality and morbidity. The major precipitating factors for DKA include new diagnosis of diabetes, non-adherence to insulin therapy as well as infection in patients with diabetes. Discharge plans should include appropriate selection of insulin dosing and regimens as well as patient education to prevent recurrence of DKA. Further, definition and management of euglycemic DKA in patients prescribed sodium-glucose co-transporter 2 inhibitors are discussed. Special consideration is reviewed for specific patient population including pregnancy, renal replacement, acute pancreatitis, and insulin pump users as well as patients with COVID-19.

Criteria for prediabetes and posttransplant diabetes mellitus after kidney transplantation: A 2-year diagnostic accuracy study of participants from a randomized controlled trial

Posttransplant diabetes mellitus (PTDM) and prediabetes (impaired glucose tolerance [IGT] and impaired fasting glucose [IFG]) are associated with cardiovascular events. We assessed the diagnostic performance of fasting plasma glucose (FPG) and HbA_1c as alternatives to oral glucose tolerance test (OGTT)-derived 2-hour plasma glucose (2hPG) using sensitivity and specificity in 263 kidney transplant recipients (KTRs) from a clinical trial. Between visits at 6, 12, and 24 months after transplantation, 28%-31% of patients switched glycemic category (normal glucose tolerance [NGT], IGT/IFG, PTDM). Correlations of FPG and HbA_1c against 2hPG were lower at 6 months (r = 0.59 [FPG against 2hPG]; r = 0.45 [HbA_1c against 2hPG]) vs. 24 months (r = 0.73 [FPG against 2hPG]; r = 0.74 [HbA_1c against 2hPG]). Up to 69% of 2hPG-defined PTDM cases were missed by conventional HbA_1c and FPG thresholds. For prediabetes, concordance of FPG and HbA_1c with 2hPG ranged from 6%-9%. In conclusion, in our well-defined randomized trial cohort, one-third of KTRs switched glycemic category over 2 years and although the correlations of FPG and HbA_1c with 2hPG improved with time, their diagnostic concordance was poor for PTDM and, especially, prediabetes. Considering posttransplant metabolic instability, FPG's and HbA_1c 's diagnostic performance, the OGTT remains indispensable to diagnose PTDM and prediabetes after kidney transplantation.

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.

Nutrition Disturbances and Metabolic Complications in Kidney Transplant Recipients: Etiology, Methods of Assessment and Prevention-A Review

Nutrition disturbances occur at all stages of chronic kidney disease and progress with the decrease of the kidney filtration rate. Kidney transplantation (KTx) as the best form of kidney replacement therapy poses various nutritional challenges. Prior to transplantation, recipients often present with mild to advanced nutrition disturbances. A functioning allograft not only relieves uremia, acidosis, and electrolyte disturbances, but also resumes other kidney functions such as erythropoietin production and vitamin D3 metabolism. KTx recipients represent a whole spectrum of undernutrition and obesity. Since following transplantation, patients are relieved of most dietary restrictions and appetite disturbances; they resume old nutrition habits that result in weight gain. The immunosuppressive regimen often predisposes them to dyslipidemia, glucose intolerance, and hypertension. Moreover, most recipients present with chronic kidney graft disease at long-term follow-ups, usually in stages G2-G3T. Therefore, the nutritional status of KTx patients requires careful monitoring. Appropriate dietary and lifestyle habits prevent nutrition disturbances and may improve kidney graft function. Despite many nutritional guidelines and recommendations targeted at chronic kidney disease, there are few targeted at KTx recipients. We aimed to provide a brief review of nutrition disturbances and known nutritional recommendations for kidney transplant recipients based on the current literature and dietary trends.

Post-transplant diabetes mellitus and renal cell cancer after renal transplantation

Background

Diabetes is a risk factor for cancer in the general population. However, few data are available on the association between post-transplant diabetes mellitus (PTDM) and cancer after transplantation.

Methods

We analyzed this issue in a Spanish cohort of patients without diabetes before transplantation. PTDM was diagnosed with consensus criteria at 12 months after transplantation and 12 months before the diagnosis of cancer. The association between PTDM and cancer (overall and specific types) was evaluated with regression analysis.

Results

During a follow-up of 12 years (interquartile range 8–14), 85 cases of 603 developed cancer (829/100 000/year) and 164 (27%) PTDM. The most frequent cancers were renal cell cancer (RCC) n = 15, 146/cases/100 000/year), lung (n = 12, 117/cases/100 000/year), colon (n = 9, 88/cases/100 000/year) and prostate (n = 9, 88/cases/100 000/year). In logistic regression, PTDM was not associated with cancer. Eight of the 164 patients with PTDM (4.9%) vs 7 of the 439 without PTDM developed RCC (1.6%) (P = .027). In multivariate analysis, PTDM was independently associated with RCC [odds ratio (OR) 2.92, confidence interval (CI) 1.03–8.27], adjusting for smoking (OR 4.020, 95% CI 1.34–12.02) and other covariates. PTDM was not associated with other types of cancer.

Conclusions

Patients with PTDM must be considered a population at risk for RCC and accordingly, the subject of active surveillance.

A Lipotoxic Medium Decreases the Number of Lipid Droplets in β Cells: One Possible Explanation of the β-Cell Failure in Patients With Hyperlipidemia Receiving Tacrolimus

OBJECTIVES

Dyslipidemia is a risk factor for post- transplant diabetes mellitus, especially in patients who are taking tacrolimus. Although lipotoxicity of dyslipidemia leads to β-cell failure, the handling of lipids by β cells is a mystery in molecular endocrinology. Likewise, lipid droplet homeostasis is appreciated as a key component of lipid metabolism in cells like hepatocytes, but its role in β cells remains to be elucidated.

MATERIALS AND METHODS

To evaluate the morphologic changes in β cells with special focus on lipid droplets, we evaluated electron micrographs under metabolic stress conditions of glucotoxicity, lipotoxicity, and glucolipotoxicity in isolated rat insulinoma INS-1E β cells. Cells were treated with palmitic acid (0.5 mM), glucose (33 mM), or both for 16 hours, after which morphologic changes were observed with an electron microscope.

RESULTS

Many lipid droplets were observed in the cytoplasm of healthy β cells in the control group (no treatment). Lipid droplets were also visible in the cytosol, and the cytoplasm was rich in organelles and insulin vesicles under high glucose stimulation. However, after treatment with palmitic acid, almost no lipid droplets were observed. Endocrine vesicles were also depleted, with severe morphologic disruption of other organelles. Under glucolipotoxic conditions, β cells showed a decreased number of lipid droplets and insulin vesicles compared with controls.

CONCLUSIONS

Lipid droplet dynamics seemed important in the homeostasis of β-cell metabolism. In this preliminary study, healthy β cells appeared rich in lipid droplets under normal conditions. However, lipotoxicity depleted and glucolipotoxicity decreased the number of lipid droplets in β cells. Because dyslipidemia causing lipotoxicity is one of the most frequent metabolic problems in transplant patients and increases risk of posttransplant diabetes mellitus, understanding the mystery of lipid droplets in β cells and the pathophysiology of diabetes in transplant patients is important, especially for those taking tacrolimus.

Recoverability of Diabetic Nephropathy of Donor Kidney After Kidney Transplantation

Some kidney donors have diabetes, and little of their natural course of diabetic nephropathy (DN) is known. The aim of this study was to analyze the changes in pathologic lesions in the diabetic donor kidney after KT by performing protocol biopsy two weeks and one year after KT. This retrospective study included 103 patients who underwent KT, with kidneys from donors with a history of diabetes mellitus (DM). Among them, data of 34 patients who underwent biopsy two weeks and one year after KT were reviewed. Biopsy specimens were reviewed using light microscopy and electron microscopy. Glomerular basement membrane (GBM) thickness at 2 weeks and 1 year was compared. Biopsy showed that DN occurred in 29 of the 34 patients. Only trivial histological changes were observed in 22 patients (64.7%), including 5 patients who did not show DN. At one year after transplantation, there was no change in the DN histologic class in 26 patients (76.5%), and there was no statistically significant difference in the change in GBM thickness. This pattern was observed regardless of the recipient’s DM or glycemic control. With this understanding, clinicians can use kidneys from DM donors with more comfort, thereby reducing the kidney discard rate.

Analysis of risk factors and establishment of a risk prediction model for post-transplant diabetes mellitus after kidney transplantation

Introduction

Post-transplant diabetes mellitus (PTDM) is a known side effect in transplant recipients administered immunosuppressant drugs, such as tacrolimus. This study aimed to investigate the risk factors related to PTDM, and establish a risk prediction model for PTDM. In addition, we explored the effect of PTDM on the graft survival rate of kidney transplantation recipients.

Methods

Patients with pre-diabetes mellitus before kidney transplant were excluded, and 495 kidney transplant recipients were included in our study, who were assigned to the non-PTDM and PTDM groups. The cumulative incidence was calculated at 3 months, 6 months, 1 year, 2 years, and 3 years post-transplantation. Laboratory tests were performed and the tacrolimus concentration, clinical prognosis, and adverse reactions were analyzed. Furthermore, binary logistic regression analysis was used to identify the independent risk factors of PTDM.

Results

Age ≥ 45 years (adjusted odds ratio [aOR] 2.25, 95% confidence interval [CI] 1.14–3.92; P = 0.015), body mass index (BMI) > 25 kg/m² (aOR 3.12, 95% CI 2.29–5.43, P < 0.001), tacrolimus concentration > 10 ng/mL during the first 3 months post-transplantation (aOR 2.46, 95%CI 1.41–7.38; P < 0.001), transient hyperglycemia (aOR 4.53, 95% CI 1.86–8.03; P < 0.001), delayed graft function (DGF) (aOR 1.31, 95% CI 1.05–2.39; P = 0.019) and acute rejection (aOR 2.16, 95% CI 1.79–4.69; P = 0.005) were identified as independent risk factors of PTDM. The PTDM risk prediction model was developed by including the above six risk factors, and the area under the receiver operating characteristic curve was 0.916 (95% CI 0.862–0.954, P < 0.001). Furthermore, the cumulative graft survival rate was significantly higher in the non- PTDM group than in the PTDM group.

Conclusions

Risk factors related to PTDM were age ≥ 45 years, BMI > 25 kg/m², tacrolimus concentration > 10 ng/mL during the first 3 months post-transplantation, transient hyperglycemia, DGF and acute rejection.

Donor and recipient polygenic risk scores influence the risk of post-transplant diabetes

Post-transplant diabetes mellitus (PTDM) reduces allograft and recipient life span. Polygenic risk scores (PRSs) show robust association with greater risk of developing type 2 diabetes (T2D). We examined the association of PTDM with T2D PRS in liver recipients (n = 1,581) and their donors (n = 1,555), and kidney recipients (n = 2,062) and their donors (n = 533). Recipient T2D PRS was associated with pre-transplant T2D and the development of PTDM. T2D PRS in liver donors, but not in kidney donors, was an independent risk factor for PTDM development. The inclusion of a combined liver donor and recipient T2D PRS significantly improved PTDM prediction compared with a model that included only clinical characteristics: the area under the curve (AUC) was 67.6% (95% confidence interval (CI) 64.1-71.1%) for the combined T2D PRS versus 62.3% (95% CI 58.8-65.8%) for the clinical characteristics model (P = 0.0001). Liver recipients in the highest quintile of combined donor and recipient T2D PRS had the greatest risk of PTDM, with an odds ratio of 3.22 (95% CI 2.07-5.00) (P = 1.92 × 10^-7) compared with those in the lowest quintile. In conclusion, T2D PRS identifies transplant candidates with high risk of PTDM for which pre-emptive diabetes management and donor selection may be warranted.

The Utility of Pre- and Post-Transplant Oral Glucose Tolerance Tests: Identifying Kidney Transplant Recipients With or at Risk of New Onset Diabetes After Transplant

Background: New onset diabetes after transplant (NODAT) is common in kidney transplant recipients (KTRs). Identifying patients at risk prior to transplant may enable strategies to mitigate NODAT, with a pre-transplant oral glucose tolerance test (OGTT) suggested by the KDIGO 2020 Guidelines for this purpose.

Methods: We investigated the utility of pre- and post-transplant OGTTs to stratify risk and diagnose NODAT in a retrospective, single-centre cohort study of all non-diabetic KTRs transplanted between 2003 and 2018.

Results: We identified 597 KTRs who performed a pre-transplant OGTT, of which 441 had their post-transplant glycaemic status determined by a clinical diagnosis of NODAT or OGTT. Pre-transplant dysglycaemia was identified in 28% of KTRs and was associated with increasing age (p < 0.001), BMI (p = 0.03), and peritoneal dialysis (p < 0.001). Post-transplant dysglycaemia was common with NODAT and impaired glucose tolerance (IGT) occurring in 143 (32%) and 121 (27%) patients, respectively. Pre-transplant IGT was strongly associated with NODAT development (OR 3.8, p < 0.001).

Conclusion: A pre-transplant OGTT identified candidates at increased risk of post-transplant dysglycaemia and NODAT, as diagnosed by an OGTT. Robust prospective trials are needed to determine whether various interventions can reduce post-transplant risk for candidates with an abnormal pre-transplant OGTT.

Early Post-Renal Transplant Hyperglycemia

CONTEXT

Though posttransplant diabetes mellitus (PTDM, occurring > 45 days after transplantation) and its complications are well described, early post-renal transplant hyperglycemia (EPTH) (< 45 days) similarly puts kidney transplant recipients at risk of infections, rehospitalizations, and graft failure and is not emphasized much in the literature. Proactive screening and management of EPTH is required given these consequences.

OBJECTIVE

The aim of this article is to promote recognition of early post-renal transplant hyperglycemia, and to summarize available information on its pathophysiology, adverse effects, and management.

METHODS

A PubMed search was conducted for "early post-renal transplant hyperglycemia," "immediate posttransplant hyperglycemia," "post-renal transplant diabetes," "renal transplant," "diabetes," and combinations of these terms. EPTH is associated with significant complications including acute graft failure, rehospitalizations, cardiovascular events, PTDM, and infections.

CONCLUSION

Patients with diabetes experience better glycemic control in end-stage renal disease (ESRD), with resurgence of hyperglycemia after kidney transplant. Patients with and without known diabetes are at risk of EPTH. Risk factors include elevated pretransplant fasting glucose, diabetes, glucocorticoids, chronic infections, and posttransplant infections. We find that EPTH increases risk of re-hospitalizations from infections (cytomegalovirus, possibly COVID-19), acute graft rejections, cardiovascular events, and PTDM. It is essential, therefore, to provide diabetes education to patients before discharge. Insulin remains the standard of care while inpatient. Close follow-up after discharge is recommended for insulin adjustment. Some agents like dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists have shown promise. The tenuous kidney function in the early posttransplant period and lack of data limit the use of sodium-glucose cotransporter 2 inhibitors. There is a need for studies assessing noninsulin agents for EPTH to decrease risk of hypoglycemia associated with insulin and long-term complications of EPTH.

Posttransplant Diabetes Mellitus and Immunosuppression Selection in Older and Obese Kidney Recipients

Rationale & Objective

Posttransplant diabetes mellitus (DM) after kidney transplantation increases morbidity and mortality, particularly in older and obese recipients. We aimed to examine the impact of immunosuppression selection on the risk of posttransplant DM among both older and obese kidney transplant recipients.

Study Design

Retrospective database study.

Setting & Participants

Kidney-only transplant recipients aged ≥18 years from 2005 to 2016 in the United States from US Renal Data System records, which integrate Organ Procurement and Transplantation Network/United Network for Organ Sharing records with Medicare billing claims.

Exposures

Various immunosuppression regimens in the first 3 months after transplant.

Outcomes

Development of DM >3 months-to-1 year posttransplant.

Analytical Approach

We used multivariable Cox regression to compare the incidence of posttransplant DM by immunosuppression regimen with the reference regimen of thymoglobulin (TMG) or alemtuzumab (ALEM) with tacrolimus + mycophenolic acid + prednisone using inverse propensity weighting.

Results

12.7% of kidney transplant recipients developed posttransplant DM with higher incidences in older (≥55 years vs <55 years: 16.7% vs 10.1%) and obese (body mass index [BMI] ≥ 30 kg/m² vs BMI < 30 kg/m²: 17.1% vs 10.9%) patients. The incidence of posttransplant DM was lower with steroid avoidance [TMG/ALEM + no prednisone (8.4%) and IL2rAb + no prednisone (9.7%)] than TMG/ALEM with triple therapy (13.1%). After adjustment for donor and recipient characteristics, TMG/ALEM with steroid avoidance was beneficial for all groups [age < 55 years: adjusted HR (aHR), 0.63 (95% confidence interval [CI], 0.54-0.72); age ≥ 55 years: aHR, 0.69 (95% CI, 0.60-0.79); BMI < 30 kg/m²: aHR, 0.69 (95% CI, 0.60-0.78); BMI ≥ 30 kg/m²: aHR, 0.67 (95% CI, 0.57-0.79)]. However, IL2rAb with steroid avoidance was beneficial only for older patients (aHR, 0.76; 95% CI, 0.58-0.99) and for those with BMI < 30 kg/m² (aHR, 0.63; 95% CI, 0.46-0.87).

Limitations

Retrospective study and lacked data on immunosuppression levels.

Conclusions

The beneficial impact of steroid avoidance using tacrolimus on posttransplant DM appears to differ by patient age and induction regimen.

Beta-Cell Dysfunction Induced by Tacrolimus: A Way to Explain Type 2 Diabetes?

The combination of insulin resistance and β-cells dysfunction leads to the onset of type-2 diabetes mellitus (T2DM). This process can last for decades, as β-cells are able to compensate the demand for insulin and maintain normoglycemia. Understanding the adaptive capacity of β-cells during this process and the causes of its failure is essential to the limit onset of diabetes. Post-transplant diabetes mellitus (PTDM) is a common and serious disease that affects 30% of renal transplant recipients. With the exception of immunosuppressive therapy, the risk factors for T2D are the same as for PTDM: obesity, dyslipidaemia, insulin resistance and metabolic syndrome. Tacrolimus (TAC) is the immunosuppressant of choice after renal transplantation but it has the highest rates of PTDM. Our group has shown that insulin resistance and glucolipotoxicity, without favouring the appearance of apoptosis, modify key nuclear factors for the maintenance of identity and functionality of β-cells. In this context, TAC accelerates or enhances these changes. Our hypothesis is that the pathways that are affected in the progression from pre-diabetes to diabetes in the general population are the same pathways that are affected by TAC. So, TAC can be considered a tool to study the pathogenesis of T2DM. Here, we review the common pathways of β-cells dysfunction on T2DM and TAC-induced diabetes.

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.

Early Postoperative Basal Insulin Therapy versus Standard of Care for the Prevention of Diabetes Mellitus after Kidney Transplantation: A Multicenter Randomized Trial

BACKGROUND

Post-transplantation diabetes mellitus (PTDM) might be preventable.

METHODS

This open-label, multicenter randomized trial compared 133 kidney transplant recipients given intermediate-acting insulin isophane for postoperative afternoon glucose ≥140 mg/dl with 130 patients given short-acting insulin for fasting glucose ≥200 mg/dl (control). The primary end point was PTDM (antidiabetic treatment or oral glucose tolerance test-derived 2 hour glucose ≥200 mg/dl) at month 12 post-transplant.

RESULTS

In the intention-to-treat population, PTDM rates at 12 months were 12.2% and 14.7% in treatment versus control groups, respectively (odds ratio [OR], 0.82; 95% confidence interval [95% CI], 0.39 to 1.76) and 13.4% versus 17.4%, respectively, at 24 months (OR, 0.71; 95% CI, 0.34 to 1.49). In the per-protocol population, treatment resulted in reduced odds for PTDM at 12 months (OR, 0.40; 95% CI, 0.16 to 1.01) and 24 months (OR, 0.54; 95% CI, 0.24 to 1.20). After adjustment for polycystic kidney disease, per-protocol ORs for PTDM (treatment versus controls) were 0.21 (95% CI, 0.07 to 0.62) at 12 months and 0.35 (95% CI, 0.14 to 0.87) at 24 months. Significantly more hypoglycemic events (mostly asymptomatic or mildly symptomatic) occurred in the treatment group versus the control group. Within the treatment group, nonadherence to the insulin initiation protocol was associated with significantly higher odds for PTDM at months 12 and 24.

CONCLUSIONS

At low overt PTDM incidence, the primary end point in the intention-to-treat population did not differ significantly between treatment and control groups. In the per-protocol analysis, early basal insulin therapy resulted in significantly higher hypoglycemia rates but reduced odds for overt PTDM-a significant reduction after adjustment for baseline differences-suggesting the intervention merits further study.Clinical Trial registration number: NCT03507829.

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.

Post-Transplant Diabetes Mellitus and Prediabetes in Renal Transplant Recipients: An Update

Post-transplant diabetes mellitus (PTDM) is a frequent and relevant complication after renal transplantation: it affects 20-30% of renal transplant recipients and increases the risk for cardiovascular and infectious events. Thus, understanding pathogenesis of PTDM would help limiting its consequences. In this review, we analyse novel aspects of PTDM, based on studies of the last decade, such as the clinical evolution of PTDM, early and late, the reversibility rate, diagnostic criteria, risk factors, including pre-transplant metabolic syndrome and insulin resistance (IR) and the interaction between these factors and immunosuppressive medications. Also, we discuss novel pathogenic factors, in particular the role of β-cell function in an environment of IR and common pathways between pre-existing cell damage and tacrolimus-induced toxicity. The relevant role of prediabetes in the pathogenesis of PTDM and cardiovascular disease is also addressed. Finally, current evidence on PTDM treatment is discussed.

Diabetic Ketoacidosis in Patients with End-stage Kidney Disease: A Review

Diabetes mellitus is a highly prevalent disease. Chronic kidney disease is one of its chronic complications, and diabetic ketoacidosis is one of the most dreaded acute complications. The increasing prevalence of diabetes mellitus and renal failure has resulted in physicians increasingly encountering diabetic ketoacidosis in this complicated subgroup of patients. This review discusses the pathophysiologic understanding of diabetic ketoacidosis in patients with renal failure, its varying clinical presentation, and management and prevention. We have also highlighted the role of patient weight and proximity to dialysis as tools to assess and manage fluid status in this challenging group of patients.

Diabetes and Cardiovascular Risk in Renal Transplant Patients

End-stage kidney disease (ESKD) is a main public health problem, the prevalence of which is continuously increasing worldwide. Due to adverse effects of renal replacement therapies, kidney transplantation seems to be the optimal form of therapy with significantly improved survival, quality of life and diminished overall costs compared with dialysis. However, post-transplant patients frequently suffer from post-transplant diabetes mellitus (PTDM) which an important risk factor for cardiovascular and cardiovascular-related deaths after transplantation. The management of post-transplant diabetes resembles that of diabetes in the general population as it is based on strict glycemic control as well as screening and treatment of common complications. Lifestyle interventions accompanied by the tailoring of immunosuppressive regimen may be of key importance to mitigate PTDM-associated complications in kidney transplant patients. More transplant-specific approach can include the exchange of tacrolimus with an alternative immunosuppressant (cyclosporine or mammalian target of rapamycin (mTOR) inhibitor), the decrease or cessation of corticosteroid therapy and caution in the prescribing of diuretics since they are independently connected with post-transplant diabetes. Early identification of high-risk patients for cardiovascular diseases enables timely introduction of appropriate therapeutic strategy and results in higher survival rates for patients with a transplanted kidney.

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.

Management of post-transplant diabetes: immunosuppression, early prevention, and novel antidiabetics

Post-transplant diabetes mellitus (PTDM) shows a relationship with risk factors including obesity and tacrolimus-based immunosuppression, which decreases pancreatic insulin secretion. Several of the sodium-glucose-linked transporter 2 inhibitors (SGLT2is) and glucagon-like peptide 1 receptor agonists (GLP1-RAs) dramatically improve outcomes of individuals with type 2 diabetes with and without chronic kidney disease, which is, as heart failure and atherosclerotic cardiovascular disease, differentially affected by both drug classes (presumably). Here, we discuss SGLT2is and GLP1-RAs in context with other PTDM management strategies, including modification of immunosuppression, active lifestyle intervention, and early postoperative insulin administration. We also review recent studies with SGLT2is in PTDM, reporting their safety and antihyperglycemic efficacy, which is moderate to low, depending on kidney function. Finally, we reference retrospective case reports with GLP1-RAs that have not brought forth major concerns, likely indicating that GLP1-RAs are ideal for PTDM patients suffering from obesity. Although our article encompasses PTDM after solid organ transplantation in general, data from kidney transplant recipients constitute the largest proportion. The PTDM research community still requires data that treating and preventing PTDM will improve clinical conditions beyond hyperglycemia. We therefore suggest that it is time to collaborate, in testing novel antidiabetics among patients of all transplant disciplines.

Incidence and relative risk factors in posttransplant diabetes mellitus patients: a retrospective cohort study

Background

Posttransplant diabetes mellitus (PTDM) has a long-term impact on kidney transplantation outcomes, such as graft and patient survival. The incidence and risk factors of PTDM are well studied, but long-term follow-up results remain unavailable. We examined the long-term incidence and relative risk factors of PTDM.

Methods

A hospital information system database for kidney transplant recipients (KTRs) for a transplantation center between 1983 and 2018 was used to perform this retrospective cohort study. KTRs with DM diagnosis and continuous use of hypoglycemic agents for more than 3 months were defined as having PTDM. Demographics and comorbidities before transplantation were also collected. Kaplan-Meier analyses were used to determine the cumulative incidence and relative risk factors.

Results

A total of 296 PTDM cases were confirmed (28.46%) in this study. An increased cumulative incidence associated with age was noted, which was significantly increased in those aged ≥40 years. Male sex, hypertension, hyperlipidemia before transplantation, cytomegalovirus (CMV) infection, and tacrolimus-based regimens were also risk factors. No significant correlation was found between the development of PTDM and the increase of human leukocyte antigen mismatches, the primary causes of end-stage renal disease, and acute rejection.

Conclusions

PTDM incidence was high in this cohort study. Characteristics such as age ≥40 years, tacrolimus use, comorbidity of hypertension and hyperlipidemia before transplantation, and CMV infection were associated with a high risk of PTDM. Monitoring and adjusting preventable risk factors such as CMV infection might be useful to prevent PTDM.

Exercise and Prediabetes after Renal Transplantation (EXPRED): Protocol Description

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a frequent and severe complication after renal transplantation. In fact, PTDM is a risk factor for both infection and cardiovascular diseases. The prevalence and incidence of PTDM have a bimodal evolution: early (up to 3 months) and late PTDM (beyond 12 months). The majority of late PTDM occurs in subjects with prediabetes after transplantation. So, treating patients with prediabetes, a potentially reversible condition, might help preventing PTDM. In the general population, exercise prevents the evolution from prediabetes to diabetes. However, in renal transplantation, not enough evidence is available in this field.

OBJECTIVES

We designed an exploratory analysis to evaluate the feasibility of exercise to reverse prediabetes as a first step in the design of a trial to prevent PTDM.

METHODS

Only patients with prediabetes beyond 12 months after transplantation with capacity to perform exercise will be included. Prediabetes will be diagnosed based on fasting glucose levels and oral glucose tolerance tests (OGTTs). Patients will be treated with a stepped training intervention, starting with aerobic exercise training (brisk walking, swimming, and cycling) 5 times per week and 30 min/day. Aerobic exercise training will be gradually increased to 60 min/day or eventually combined with anaerobic exercise training in case of persistent prediabetes. The reversibility/persistence of prediabetes will be measured with fasting glucose and OGTTs every 3 months. This study will last for 12 months.

Comparing Glycaemic Benefits of Active Versus Passive Lifestyle Intervention in Kidney Allograft Recipients: A Randomized Controlled Trial

BACKGROUND

New-onset diabetes is common after kidney transplantation, but the benefit of lifestyle intervention to improve glucose metabolism posttransplantation is unproven.

METHODS

We conducted a single-center, randomized controlled trial involving 130 nondiabetic kidney transplant recipients with stable function between 3 and 24 months post-transplantation. Participants were randomly assigned in a 1:1 ratio to receive active intervention (lifestyle advice delivered by renal dietitians using behavior change techniques) versus passive intervention (leaflet advice alone). Primary outcome was 6-month change in insulin secretion, insulin sensitivity, and disposition index. Secondary outcomes included patient-reported outcomes, cardiometabolic parameters, clinical outcomes, and safety endpoints.

RESULTS

Between August 17, 2015 and December 18, 2017, 130 individuals were recruited, of whom 103 completed the study (drop-out rate 20.8%). Active versus passive intervention was not associated with any change in glucose metabolism: insulin secretion (mean difference, -446; 95% confidence interval [CI], -3184 to 2292; P = 0.748), insulin sensitivity (mean difference, -0.45; 95% CI, -1.34 to 0.44; P = 0.319), or disposition index (mean difference, -940; 95% CI, -5655 to 3775; P = 0.693). Clinically, active versus passive lifestyle intervention resulted in reduced incidence of posttransplantation diabetes (7.6% versus 15.6%, respectively, P = 0.123), reduction in fat mass (mean difference, -1.537 kg; 95% CI, -2.947 to -0.127; P = 0.033), and improvement in weight (mean difference, -2.47 kg; 95% CI, -4.01 to -0.92; P = 0.002). No serious adverse events were noted.

CONCLUSIONS

Active lifestyle intervention led by renal dietitians did not improve surrogate markers of glucose metabolism. Further investigation is warranted to determine if clinical outcomes can be improved using this methodology.

Butyric acid normalizes hyperglycemia caused by the tacrolimus-induced gut microbiota

Approximately 33.6% of nondiabetic solid organ transplant recipients who received tacrolimus developed hyperglycemia. Whether the tacrolimus-induced gut microbiota is involved in the regulation of hyperglycemia has not been reported. Hyperglycemia was observed in a tacrolimus-treated mouse model, with reduction in taxonomic abundance of butyrate-producing bacteria and decreased butyric acid concentration in the cecum. This tacrolimus-induced glucose metabolic disorder was caused by the gut microbiota, as confirmed by a broad-spectrum antibiotic model. Furthermore, oral supplementation with butyrate, whether for remedy or prevention, significantly increased the butyric acid content in the cecum and arrested hyperglycemia through the regulation of glucose-regulating hormones, including glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and insulin, in serum. The butyrate-G-protein-coupled receptor 43-GLP-1 pathway in the intestinal crypts may be involved in the pathogenesis of normalization of hyperglycemia caused by the tacrolimus. Therefore, tacrolimus affects glucose metabolism through the butyrate-associated GLP-1 pathway in the gut, and oral supplementation with butyrate provides new insights for the prevention and treatment of tacrolimus-induced hyperglycemia in transplant recipients.

Glycemic management and clinical outcomes in underserved minority kidney transplant recipients with type 2 and posttransplantation diabetes: A single-center retrospective study

AIMS

Little is known about glycemic management, particularly with novel cardio-nephroprotecive agents, in underserved minority kidney transplant recipients with pre-transplant type 2 (T2DM) and posttransplantation diabetes mellitus (PTDM). We assessed glycemic management and outcomes in this high-risk population.

METHODS

We reviewed records of patients who received kidney transplants between June 2012 and December 2014 at a single center. Hemoglobin A1c (HbA1c) and prescribed glucose-lowering medications were examined, and mortality was compared between T2DM, PTDM, and no diabetes (NoDM) patients.

RESULTS

We followed 302 patient records (41.1% Hispanic, 41.1% non-Hispanic black) for a median (IQR) of 45.5 (37.0, 53.0) months post-transplant. Pre-transplant T2DM was present in 152 (50.3%), while 58 (19.2%) developed PTDM and 92 (30.4%) remained NoDM. At 1-year post-transplant, the average HbA1c was 8.1 ± 1.8% in T2DM and 6.6 ± 1.3% in PTDM. No glucose-lowering agents were prescribed in 3.4% of T2DM and 44.8% of PTDM. When treated, both received mostly insulin and metformin. Diabetes, HbA1c and insulin therapy were not independently associated with risk of mortality.

CONCLUSIONS

Glycemic management was suboptimal and relied on older medications. Further studies are needed to assess longer-term outcomes of more rigorous glycemic management, and the value of novel cardio-nephroprotective agents in kidney transplant recipients.

Risk of Graft Failure in Kidney Recipients with Cured Post-Transplant Cancer

BACKGROUND

Post-transplant cancer (PTC) is a critical complication after kidney transplantation. However, whether successfully cured PTC affects the long-term graft outcome remains unclear.

METHODS

We retrospectively reviewed 1,629 kidney transplant recipients from 1995 to 2017 after excluding patients with post-transplant hematologic or advanced non-curable cancers and who underwent allograft nephrectomy because of cancer. Cured PTCs were defined as cancers treated with curative methods and/or adjuvant therapy without recurrence during ≥ 2 years. Propensity score matching was performed to match cured PTC patients with cancer-naïve patients (i.e., non-PTC group).

RESULTS

During the median period of 7 years (maximum, 23 years), 70 patients (4.3%) had cured PTCs. The PTC group showed significantly higher risks of death-censored graft failure (adjusted hazard ratio [HR], 2.56 [1.05-6.23]), class II donor-specific antibodies (adjusted HRs, 3.37 [1.30-8.71]), estimated glomerular filtration rate < 30 mL/min/1.73 m² (adjusted HR, 2.68 [1.43-5.02]) and random urine protein/creatinine ratio > 1 g (adjusted HR, 3.61 [1.92-6.79]) compared to non-PTC group. However, the risk of mortality was not different between the PTC and non-PTC groups. According to the cancer type, only urogenital cancer had a significant association with graft failure (adjusted HR, 4.26 [1.19-15.22]) and the gastrointestinal cancer showed elevated risk of T cell mediated rejection compared to non-PTC (adjusted HR, 20.44 [6.02-69.39]).

CONCLUSION

Appropriate monitoring of graft function is necessary in patients with cured PTCs.

Determinants of Poor Glycemic Control in Patients with Kidney Transplants: A Single-Center Retrospective Cohort Study in Canada

Background:

Kidney transplant immunosuppressive medications are known to impair glucose metabolism, causing worsened glycemic control in patients with pre-transplant diabetes mellitus (PrTDM) and new onset of diabetes after transplant (NODAT).

Objectives:

To determine the incidence, risk factors, and outcomes of both PrTDM and NODAT patients.

Design:

This is a single-center retrospective observational cohort study.

Setting:

The Ottawa Hospital, Ontario, Canada.

Participant:

A total of 132 adult (>18 years) kidney transplant patients from 2013 to 2015 were retrospectively followed 3 years post-transplant.

Measurements:

Patient characteristics, transplant information, pre- and post-transplant HbA1C and random glucose, follow-up appointments, complications, and readmissions.

Methods:

We looked at the prevalence of poor glycemic control (HbA1c >8.5%) in the PrTDM group before and after transplant and compared the prevalence, follow-up appointments, and rate of complications and readmission rates in both the PrTDM and NODAT groups. We determined the risk factors of developing poor glycemic control in PrTDM patients and NODAT. Student t-test was used to compare means, chi-squared test was used to compare percentages, and univariate analysis to determine risk factors was performed by logistical regression.

Results:

A total of 42 patients (31.8%) had PrTDM and 12 patients (13.3%) developed NODAT. Poor glycemic control (HbA1c >8.5%) was more prevalent in the PrTDM (76.4%) patients compared to those with NODAT (16.7%; P < .01). PrTDM patients were more likely to receive follow-up with an endocrinologist (P < .01) and diabetes nurse (P < .01) compared to those with NODAT. There were no differences in the complication and readmission rates for PrTDM and NODAT patients. Receiving a transplant from a deceased donor was associated with having poor glycemic control, odds ratio (OR) = 3.34, confidence interval (CI = 1.08, 10.4), P = .04. Both patient age, OR = 1.07, CI (1.02, 1.3), P < .01, and peritoneal dialysis prior to transplant, OR = 4.57, CI (1.28, 16.3), P = .02, were associated with NODAT.

Limitations:

Our study was limited by our small sample size. We also could not account for any diabetes screening performed outside of our center or follow-up appointments with family physicians or community endocrinologists.

Conclusion:

Poor glycemic control is common in the kidney transplant population. Glycemic targets for patients with PrTDM are not being met in our center and our study highlights the gap in the literature focusing on the prevalence and outcomes of poor glycemic control in these patients. Closer follow-up and attention may be needed for those who are at risk for worse glycemic control, which include older patients, those who received a deceased donor kidney, and/or prior peritoneal dialysis.