beta-Cell dysfunction rather than insulin resistance is the main contributing factor for the development of postrenal transplantation diabetes mellitus

Risk of Incident Post-Transplantation Diabetes Mellitus After Solid Organ Transplantation in Taiwan: A Population-Based Cohort Study

Background: Solid organ transplant (SOT) recipients have an elevated risk of diabetes mellitus (DM). This study investigated the risk of posttransplant DM (PTDM) in a retrospective cohort study. Methods: We analyzed patients aged over 18 years who received an SOT between 2002 and 2013. Each patient was matched with four control individuals by age, sex, insured salary, urbanization level, Charlson's comorbidity index (CCI), and year of inclusion in the study. After matching, the study comprised 6874 patients who underwent an SOT and 27,496 matched general patients as the comparison. The risk of DM among the SOT recipients was assessed using a Cox proportional hazards model after adjustment for all relevant variables. Results: The SOT cohort had a significantly higher risk of DM than general patients (adjusted hazard ratio [aHR], 1.61; 95% confidence interval [CI], 1.51-1.72). Kidney and liver recipients, respectively, had DM incidence rates 1.57 (95% CI, 1.46-1.70) and 1.73 (95% CI, 1.53-1.94) times that of the general patients. Conclusions: SOT recipients had an elevated risk of DM. Among various organ recipients, liver recipients had the highest PTDM risk. Kidney and liver recipients demonstrated the highest DM risk at 6 months after their SOT. The risk of PTDM following an SOT may result in long-term consequences. Hence, we advise the critical need for proper management to mitigate related complications after transplantation.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Continuous Insulin Therapy to Prevent Post-Transplant Diabetes Mellitus: A Randomized Controlled Trial

Rationale & Objectives

Hyperglycemia is frequently observed early after transplantation and associated with development of post-transplant diabetes mellitus (PTDM). Here, we assessed continuous subcutaneous insulin infusion (CSII) targeting afternoon hyperglycemia.

Study Design

Open-label randomized parallel 3-arm design.

Settings & Participants

In total, 85 kidney transplant recipients without previous diabetes diagnosis were randomized to postoperative CSII therapy, basal insulin, or control.

Interventions

Insulin was to be initiated at afternoon capillary blood glucose level of ≥140 mg/dL (7.8 mmol/L; CSII and basal insulin) or fasting plasma glucose level of ≥200 mg/dL (11.1 mmol/L; control).

Outcomes

Hemoglobin A1c (HbA1c) levels at 3 months post-transplant (primary endpoint). PTDM assessed using oral glucose tolerance test at 12 and 24 months.

Results

CSII therapy lasted until median day 18 and maximum day 88. The median HbA1c value at month 3 was 5.6% (38 mmol/mol) in the CSII group versus 5.7% (39 mmol/mol) in the control group (P = 0.70) and 5.4% (36 mmol/mol) in the basal insulin group (P = 0.02). At months 12 and 24, the odds for PTDM were similar compared with the control group (odds ratios [95% confidence intervals], 0.80 [0.18-3.49] and 0.71 [0.15-3.16], respectively) and the basal insulin group (0.96 [0.18-5.68] and 1.51 [0.24-12.84], respectively). Mild hypoglycemia events occurred in the CSII and the basal insulin groups.

Limitations

This study is limited by outdated insulin pump technology, frequent discontinuations of CSII, a complex protocol, and concerns regarding reliability of HbA1c measurements.

Conclusions

CSII therapy was not superior at reducing HbA1c levels at month 3 or PTDM prevalence at months 12 and 24 compared with the control or basal insulin group.

Posttransplantation diabetes mellitus after liver transplant and the impact of family history of diabetes in a Mexican cohort

INTRODUCTION AND AIMS

Posttransplantation diabetes mellitus (PTDM) is a serious long-term complication that has a negative impact on graft and patient survival. The purpose of the present study was to describe the incidence of PTDM in a Mexican cohort and evaluate its association with a previous family history of diabetes (FHD).

METHODS

A retrospective single-center cohort study was conducted on patients undergoing liver transplantation (LT). The primary outcome was time from LT to PTDM. The diagnosis of PTDM was established using the ADA criteria. A mediation analysis that used adjusted Cox regression models and considered pretransplant prediabetes a mediator was performed, to determine the total effect and direct effect of FHD on PTDM.

RESULTS

A total of 152 patients were included, with a median follow-up time of 41 months; 19.2% (n = 29) had pretransplant diabetes. During the follow-up time, 15% of patients developed PTDM (n = 23), with an incidence rate of 4.71 cases/100 person-years. PTDM was significantly higher in patients with FHD, compared with those with no FHD (8.72 cases/100 person-years vs 2.04 cases/100 person-years, respectively; p = 0.001). The adjusted hazard ratio of PTDM for FHD was 4.14 (95% CI 1.60-10.7), p = 0.005) and 3.48 (95% CI 1.35-9.01, p = 0.010), when further controlled for pretransplant prediabetes.

CONCLUSION

The occurrence of PTDM was similar to that reported in most international studies. As with type 2 diabetes, family history plays an important role in the development of PTDM, even after accounting for pretransplant prediabetes. Patients with FHD should undergo a stricter metabolic program.

Cyclosporine-induced kidney damage was halted by sitagliptin and hesperidin via increasing Nrf2 and suppressing TNF-α, NF-κB, and Bax

Cyclosporine A (CsA) is employed for organ transplantation and autoimmune disorders. Nephrotoxicity is a serious side effect that hampers the therapeutic use of CsA. Hesperidin and sitagliptin were investigated for their antioxidant, anti-inflammatory, and tissue-protective properties. We aimed to investigate and compare the possible nephroprotective effects of hesperidin and sitagliptin. Male Wistar rats were utilized for induction of CsA nephrotoxicity (20 mg/kg/day, intraperitoneally for 7 days). Animals were treated with sitagliptin (10 mg/kg/day, orally for 14 days) or hesperidin (200 mg/kg/day, orally for 14 days). Blood urea, serum creatinine, albumin, cystatin-C (CYS-C), myeloperoxidase (MPO), and glucose were measured. The renal malondialdehyde (MDA), glutathione (GSH), catalase, and SOD were estimated. Renal TNF-α protein expression was evaluated. Histopathological examination and immunostaining study of Bax, Nrf-2, and NF-κB were performed. Sitagliptin or hesperidin attenuated CsA-mediated elevations of blood urea, serum creatinine, CYS-C, glucose, renal MDA, and MPO, and preserved the serum albumin, renal catalase, SOD, and GSH. They reduced the expressions of TNF-α, Bax, NF-κB, and pathological kidney damage. Nrf2 expression in the kidney was raised. Hesperidin or sitagliptin could protect the kidney against CsA through the mitigation of oxidative stress, apoptosis, and inflammation. Sitagliptin proved to be more beneficial than hesperidin.

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.

Glucometabolism in Kidney Transplant Recipients with and without Posttransplant Diabetes: Focus on Beta-Cell Function

Posttransplant diabetes mellitus (PTDM) is a common complication after kidney transplantation. Pathophysiologically, whether beta-cell dysfunction rather than insulin resistance may be the predominant defect in PTDM has been a matter of debate. The aim of the present analysis was to compare glucometabolism in kidney transplant recipients with and without PTDM. To this aim, we included 191 patients from a randomized controlled trial who underwent oral glucose tolerance tests (OGTTs) 6 months after transplantation. We derived several basic indices of beta-cell function and insulin resistance as well as variables from mathematical modeling for a more robust beta-cell function assessment. Mean ± standard deviation of the insulin sensitivity parameter PREDIM was 3.65 ± 1.68 in PTDM versus 5.46 ± 2.57 in NON-PTDM. Model-based glucose sensitivity (indicator of beta-cell function) was 68.44 ± 57.82 pmol∙min-1∙m-2∙mM-1 in PTDM versus 143.73 ± 112.91 pmol∙min-1∙m-2∙mM-1 in NON-PTDM, respectively. Both basic indices and model-based parameters of beta-cell function were more than 50% lower in patients with PTDM, indicating severe beta-cell impairment. Nonetheless, some defects in insulin sensitivity were also present, although less marked. We conclude that in PTDM, the prominent defect appears to be beta-cell dysfunction. From a pathophysiological point of view, patients at high risk for developing PTDM may benefit from intensive treatment of hyperglycemia over the insulin secretion axis.

Tacrolimus and Diabetes in Kidney Transplantation: The Impact of Cyp3a5 Gene Polymorphism

BACKGROUND

To explore the correlation between single nucleotide polymorphisms (SNPs) of CYP3A4 rs2740574 and CYP3A5 rs776746 and post-transplant diabetes mellitus (PTDM) in Chinese renal allograft recipients treated with tacrolimus.

METHODS

A total of 244 patients treated with tacrolimus were included in this study, wherein DNA sequencing was detected through fluorescence in situ hybridization, and SNP genotyping was performed.

RESULTS

Among the 244 patients, 44 (18%) developed PTDM. The PTDM group exhibited higher preoperative body mass index and fasting plasma glucose levels, with higher creatinine values one year after surgery. The CYP3A4 rs2740574 genotype was found to be unique in its homozygous AA form. For CYP3A5 rs776746, the genotypes were distributed as follows: 28 (11.5%) cases with AA, 101 (41.4%) cases with AG, and 115 (47.1%) cases with GG, respectively (P = .042). The AA genotype showed a statistically significant difference from both AG and GG genotypes. Furthermore, the A allele of CYP3A5 rs776746 was found to be associated with an increased risk for PTDM development.

CONCLUSIONS

The occurrence of tacrolimus-related PTDM is associated with body mass index, fasting plasma glucose levels, and CYP3A5 genotype before renal transplantation. Post-transplant diabetes mellitus is correlated with unfavorable long-term renal graft function, whereas the expression of the CYP3A5 rs776746 gene is linked to an elevated risk of PTDM.

Microbial and metabolic features in renal transplant recipients with post-transplantation diabetes mellitus

OBJECTIVE

Post-transplantation diabetes mellitus (PTDM) is a common complication in renal transplant recipients (RTRs). Gut microbiome plays important roles in a variety of chronic metabolic diseases, but its association with the occurrence and development of PTDM is still unknown. The present study integrates the analysis of gut microbiome and metabolites to further identify the characteristics of PTDM.

METHODS

A total of 100 RTRs fecal samples were collected in our study. Among them, 55 samples were submitted to Hiseq sequencing, and 100 samples were used for non-targeted metabolomics analysis. The gut microbiome and metabolomics of RTRs were comprehensively characterized.

RESULTS

The species Dialister invisus was significantly associated with fasting plasma glucose (FPG). The functions of tryptophan and phenylalanine biosynthesis were enhanced in RTRs with PTDM, while the functions of fructose and butyric acid metabolism were reduced. Fecal metabolome analysis indicated that RTRs with PTDM had unique metabolite distribution characteristics, and two differentially expressed specific metabolites were significantly correlated with FPG. The correlation analysis of gut microbiome and metabolites showed that gut microbiome had an obvious effect on the metabolic characteristics of RTRs with PTDM. Moreover, the relative abundance of microbial function is associated with the expression of several specific gut microbiome and metabolites.

CONCLUSIONS

Our study identified the characteristics of gut microbiome and fecal metabolites in RTRs with PTDM, and we also found two important metabolites and a bacterium were significantly associated with PTDM, which might be used as novel targets in the research field of PTDM.

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.

The Association of Pre-Transplant C-Peptide Level with the Development of Post-Transplant Diabetes: A Cohort Study

Background

Post-transplant diabetes mellitus (PTDM) is an important complication after kidney transplantation that results in reduced patient and allograft survival. Although there are established risk factors for PTDM, whether pretransplant C-peptide levels associate with PTDM is unknown. Therefore, in this study, we aimed to examine the association of pretransplant C-peptide levels with PTDM.

Methods

This was a cohort study of nondiabetic adult patients who underwent kidney transplant in Nova Scotia, Canada, between January 1, 2016, and March 31, 2021, with fasting C-peptide levels measured before transplant. Multivariable logistic regression was used to determine the association of pretransplant C-peptide (dichotomized around the median) with PTDM at 1 year post transplant. Given the known association between pretransplant obesity and PTDM, we repeated our primary analysis in a cohort restricted to a BMI of 20-35 kg/m².

Results

The median C-peptide value was 3251 (Q1 2480, Q3 4724); pretransplant C-peptide level was dichotomized at 3000 pmol/L. PTDM occurred in 25 (19%) individuals. Thirty percent of patients in the high and only 2% of patients in the low C-peptide groups developed PTDM (P<0.001). A C-peptide level ≥3000 pmol/L was strongly associated with PTDM in multivariable analysis (OR=18.9, 95% CI, 2.06 to 174.2). In a restricted cohort with a BMI of 20-35 kg/m², an elevated pretransplant C-peptide remained independently associated with the risk of PTDM (OR=15.7, 95% CI, 1.64 to 150.3). C-peptide was the only factor independently associated with PTDM in this restricted BMI cohort.

Conclusions

A pretransplant C-peptide level ≥3000 pmol/L was associated with a nearly 20-fold increased odds of PTDM at 1 year post kidney transplantation. Identifying patients with high pretransplant C-peptide levels may therefore help identify those at risk for PTDM who may benefit from focused preventative and therapeutic interventions and support.

New-Onset Diabetes Mellitus (NODM) After Liver Transplantation (LT): The Ultimate Non-diabetogenic Immunosuppressive Therapy

New-onset diabetes mellitus (NODM) is a common long-term complication after liver transplantation (LT). It is thought to be drug-induced in most cases, no matter the underlying disease that cause liver failure and indicated transplantation. Standard post-transplantation (PT) immunosuppressive regimens include prolonged use of calcineurin inhibitors (CNIs), namely tacrolimus (TAC), alongside corticosteroids to avoid acute and chronic graft rejection. This combination is well known for its diabetogenicity. Significant differences between the applied regimens stand out concerning the duration and dosages to prevent the metabolic side effects of these drugs in the long run without compromising the graft's survival. Studies were collected after an extensive research of PubMed database for this very specific topic using the following MeSH keywords in multiple combinations: "Liver Transplantation," "Diabetes Mellitus," "NODM," "Tacrolimus," "Cyclosporine A," and "Steroids." In addition, we used the same keywords for regular searches in Google Scholar. Only the relevant English human studies between 2010 and 2020 were collected except for review articles. Duplicates were eliminated using Mendeley software. Twelve relevant studies directly related to the targeted topic were collected and discussed, including five retrospective cohorts, four prospective cohorts, one clinical trial, one prospective pilot, and one case report. Their topics included primarily the factors increasing the risk of new-onset diabetes mellitus after liver transplantation (NODALT), TAC-based immunosuppression and its relative blood levels affecting the possible development of NODALT, the role of cyclosporine in substituting TAC regimen, and the effect of different steroids-avoiding protocols on the prevention of NODALT. The reviewed studies suggested that lowering the serum concentration of tacrolimus (cTAC) throughout the PT period and eliminating the corticosteroids regimen as early as possible, among other measures, can significantly impact the rate of emergence of NODM. This traditional review tackles the most recent studies about NODALT to establish a comprehensive view on this issue and guide clinicians and researchers for the safest immunosuppressive regimen to date, while maintaining a balanced metabolic profile.

Androgens and Development of Posttransplantation Diabetes Mellitus in Male Kidney Transplant Recipients: A Post Hoc Analysis of a Prospective Study

OBJECTIVE

Posttransplantation diabetes mellitus (PTDM) effects up to 30% of all kidney transplant recipients (KTR). Recent studies in mice found that sufficient androgen levels are necessary for β-cell health and adequate insulin secretion. This raises the question whether a similar relationship might be present in KTR. Hence, we hypothesized that dihydrotestosterone and testosterone are associated with the development of PTDM in male KTR.

RESEARCH DESIGN AND METHODS

We conducted a post hoc analyses of a prospective single-center cohort study including adult male KTR with a functioning graft ≥1 year posttransplantation. Androgen levels were assessed by liquid chromatography-tandem mass spectrometry. Development of PTDM was defined according to the American Diabetes Association's criteria.

RESULTS

We included 243 male KTR (aged 51 ± 14 years), with a median dihydrotestosterone 0.9 (0.7-1.3) nmol/L and testosterone of 12.1 (9.4-15.8) nmol/L. During 5.3 (3.7-5.8) years of follow-up, 28 KTR (11.5%) developed PTDM. A clear association was observed, as 15 (19%), 10 (12%), and 3 (4%) male KTR developed PTDM in the respective tertiles of dihydrotestosterone (P = 0.008). In Cox regression analyses, both dihydrotestosterone and testosterone as continuous variables were inversely associated with the risk to development PTDM, independent of glucose and HbA_1c (hazard ratio [HR] 0.31 [95% CI 0.16-0.59], P < 0.001; and HR 0.32 [95% CI 0.15-0.68], P = 0.003, respectively).

CONCLUSIONS

Our results suggest that low androgen levels are a novel potential modifiable risk factor for the development of PTDM in male KTR.

Diabetes in Kidney Transplantation

Diabetes mellitus (DM) is one of the most common complications after kidney transplantation and is associated with unfavorable outcomes including death. DM can be present before transplant but post-transplant DM (PTDM) refers to diabetes that is diagnosed after solid organ transplantation. Despite its high prevalence, optimal treatment to prevent complications of PTDM is unknown. Medical therapy of pre-existent DM or PTDM after transplant is challenging because of frequent interactions between antidiabetic and immunosuppressive agents. There is also frequent need for medication dose adjustments due to residual kidney disease and a higher risk of medication side effects in patients treated with immunosuppressive agents. Sodium-glucose cotransporter 2 inhibitors have demonstrated a favorable cardio-renal profile in patients with DM without a transplant and hence hold great promise in this patient population although there is concern about the higher risk of urinary tract infections. The significant gaps in our understanding of the pathophysiology, diagnosis, and management of DM after kidney transplantation need to be urgently addressed.

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.

Effects of Late Conversion from Twice-Daily to Once-Daily Slow Release Tacrolimus on the Insulin Resistance Indexes in Kidney Transplant Patients

The use of tacrolimus (Tac) may be involved in the development of new-onset diabetes after transplantation (NODAT) in a dose-related manner. This study aimed to evaluate the effects of a standard twice-daily formulation of Tac (TacBID) vs. the once-daily slow-release formulation (TacOD) on the basal insulin resistance indexes (Homa and McAuley), and related metabolic parameters, in a cohort of kidney transplant patients. We retrospectively evaluated 20 stable renal transplant recipients who were switched from TacBID to TacOD. Blood levels of Tac were analyzed at one-month intervals from 6 months before to 8 months after conversion. Moreover, Homa and McAuley indexes, C-peptide, insulin, HbA1c, uric acid, triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)-cholesterol serum levels and their associations with Tac levels were evaluated. We observed a significant decrease in Tac exposure (8.5 ± 2 ng/mL, CV 0.23 vs. 6.1 ± 1.9 ng/mL, CV 0.31, TacBID vs. TacOD periods, p < 0.001) and no significant changes in Homa (1.42 ± 0.4 vs. 1.8 ± 0.7, p > 0.05) and McAuley indexes (7.12 ± 1 vs. 7.58 ± 1.4, p > 0.05). Similarly, blood levels of glucose, insulin, HbA1c, lipids, and uric acid were unchanged between the two periods, while C-peptide resulted significantly lower after conversion to TacOD. These data suggest that in kidney transplant recipients, reduced Tac exposure has no significant effects on basal insulin sensitivity indexes and metabolic parameters.

Long-term efficacy and safety of anti-hyperglycaemic agents in new-onset diabetes after transplant: Results from outpatient-based 1-year follow-up and a brief review of treatment options

BACKGROUND AND AIMS

Evaluation of long-term efficacy and safety of various anti-hyperglycaemic agents (AHA) for glycaemic control in NODAT, in stable kidney transplant recipients (KTRs) during 1-year outpatient follow-up.

METHODS

We collected FPG, PPG, HbA1c, serum creatinine, eGFR, blood tacrolimus level, hypoglycaemia and body weight values from an existing database of KTRs diagnosed to have NODAT. Those newly initiated on AHA over 3 months post-transplant; received standard triple immunosuppressive therapy; and followed up for 1-year after referral, were included.

RESULTS

In ninety-five patients' (Male = 65), mean decrease at 1-year from baseline in FPG (185.01 ± 62.11 mg/dL), PPG (293.21 ± 85.23 mg/dL) and HbA1c (8.48 ± 1.08%) was 67.09, 126.11 and 1.4 respectively (p < 0.0001). At 1-year, mean HbA1c was 7.08 ± 0.38%, ninety-one patients achieving HbA1c ≤ 7.5%. Fifty-two patients received oral combination therapy based on linagliptin/metformin/repaglinide/gliclazide, 19 received insulin-based regimen, and 24 received linagliptin monotharapey. Thirty patients reported hypoglycaemia (10 with gliclazide and 15 with insulin) and fifty patients gained body-weight at 1-year. Mean serum creatinine and eGFR significantly improved by 0.29 and 15.77 from baseline of 1.56 ± 0.62 mg/dL and 53.95 ± 16.10 mL/min/1.73 m² respectively.

CONCLUSIONS

Significant proportion of NODAT patients achieved long-term glycemic control with improved renal function. Combination therapy was needed in most within 1-year. Linagliptin monotherapy was effective, without producing hypoglycaemia or weight gain.

Insulin Secretion and Insulin Resistance Trajectories over 1 Year after Kidney Transplantation: A Multicenter Prospective Cohort Study

BACKGROUND

We investigated the changing patterns of insulin secretion and resistance and risk factors contributing to the development of post-transplant diabetes mellitus (PTDM) in kidney recipients under tacrolimus-based immunosuppression regimen during 1 year after transplantation.

METHODS

This was a multicenter prospective cohort study. Of the 168 subjects enrolled in this study, we analyzed a total 87 kidney transplant recipients without diabetes which was assessed by oral glucose tolerance test before transplantation. We evaluated the incidence of PTDM and followed up the index of insulin secretion (insulinogenic index [IGI]) and resistance (homeostatic model assessment for insulin resistance [HOMA-IR]) at 3, 6, 9 months, and 1 year after transplantation by oral glucose tolerance test and diabetes treatment. We also assessed the risk factors for incident PTDM.

RESULTS

PTDM developed in 23 of 87 subjects (26.4%) during 1 year after transplantation. More than half of total PTDM (56.5%) occurred in the first 3 months after transplantation. During 1 year after transplantation, insulin resistance (HOMA-IR) was increased in both PTDM and no PTDM group. In no PTDM group, the increase in insulin secretory function to overcome insulin resistance was also observed. However, PTDM group showed no increase in insulin secretion function (IGI). Old age, status of prediabetes and episode of acute rejection were significantly associated with the development of PTDM.

CONCLUSION

In tacrolimus-based immunosuppressive drugs regimen, impaired insulin secretory function for reduced insulin sensitivity contributed to the development of PTDM than insulin resistance during 1 year after transplantation.

Analysis of Risk Factors for Posttransplant Diabetes Mellitus After Kidney Transplantation: Single-Center Experience

OBJECTIVES

Posttransplant diabetes mellitus may severely affect the short-term and long-term outcomes of grafts and patient survival in kidney transplant recipients. The annual incidence rate of posttransplant diabetes mellitus ranges from 4% to 25%. In this study, our aim was to determine the possible risk factors in patients diagnosed with this disease.

MATERIALS AND METHODS

From November 1975 to May 2019, our transplant team performed 3012 kidney transplant procedures at different units within Baskent University Transplantation Centers. We retrospectively analyzed data of patients who were diagnosed with posttransplant diabetes mellitus between 2010 and 2019. The diagnosis was made according to the 2001 American Diabetes Association criteria (fasting plasma glucose level ≥ 126 mg/dL [7 mmol/L] in 2 measurements or random blood glucose level ≥ 200 mg/dL [11.1 mmol/L] within 12 months posttransplant).

RESULTS

For this study, 400 patients (292 male, 108 female) with end-stage renal disease and without diabetes met the initial inclusion criteria; 270 received hemodialysis, 26 received peritoneal dialysis, and 104 underwent preemptive kidney transplant. In this patient group, 62 patients (15.5%) developed post-transplant diabetes mellitus. When we compared patients who developed and did not develop posttransplant diabetes mellitus, cause of end-stage renal disease, dialysis type and duration, type of donor (living or deceased), and graft survival posttransplant were similar between groups. Baseline fasting plasma glucose level was significantly higher in patients who developed posttransplant diabetes mellitus (90 vs 85 mg/dL; P = .034). Patients who developed the disease were significantly older.

CONCLUSIONS

In our study, recipient age was the only risk factor for posttransplant diabetes mellitus. Older recipients should be examined more carefully for posttransplant diabetes mellitus, and less diabetogenic immunosuppressive drugs may be preferred.

Validation of Identified Susceptible Gene Variants for New-Onset Diabetes in Renal Transplant Recipients

Genome-wide association studies (GWAS) and candidate gene approaches have identified single nucleotide polymorphisms (SNPs) associated with new-onset diabetes after renal transplantation (NODAT). We evaluated associations between NODAT and SNPs identified in previous studies. We genotyped 1102 renal transplant recipients from the Korean Organ Transplantation Registry (KOTRY) database; 13 SNPs were assessed for associations with NODAT (occurring in 254 patients; 23.0%), within one year after transplantation. The frequency of the T allele at KCNQ1 rs2237892 was significantly lower in patients with NODAT compared to control patients (0.30 vs. 0.39; p = 8.5 × 10^-5). The T allele at rs2237892 was significantly associated with decreased risk of NODAT after adjusting for multiple variables, compared to the C allele (OR 0.63, 95% CI 0.51-0.79; p = 5.5 × 10^-5). Dominant inheritance modeling showed that CT/TT genotypes were associated with a lower risk for development of NODAT (OR 0.56, 95% CI 0.42-0.76; p = 2.0 × 10^-4) compared to the CC genotype. No other SNPs were associated with NODAT. Our study validated the protective effect of T allele at KCNQ1 rs2237892 on the development of NODAT in a large cohort of renal transplant recipients. Our findings on susceptibility variants might be a useful tool to predict NODAT development after renal transplantation.

Comparison of Glucose Tolerance between Kidney Transplant Recipients and Healthy Controls

Post-transplant hyperglycemia and new-onset diabetes mellitus after transplantation (NODAT) are common and important metabolic complications. Decreased insulin secretion and increased insulin resistance are important to the pathophysiologic mechanism behind NODAT. However, the progression of glucose intolerance diagnosed late after kidney transplantation remains clearly unknown. Enrolled in this study were 94 kidney transplant recipients and 134 kidney transplant donors, as the healthy controls, who were treated at our institution. The 75 g-oral glucose tolerance test (OGTT) was performed in the recipients, and the healthy controls received an OGTT before donor nephrectomy. We assessed the prevalence of glucose intolerance including impaired fasting glucose and/or impaired glucose tolerance, as well as insulin secretion and insulin resistance using the homeostasis model assessment, and compared the results between the two groups. Multivariate analysis after adjustment for age, gender, body mass index, estimated glomerular filtration rate, and systolic blood pressure showed that the prevalence of glucose intolerance, insulin resistance, insulin secretion, and 2 h plasma glucose levels were significantly higher in the kidney transplant recipients compared to the healthy controls. Elevation of insulin secretion in kidney transplant recipients may be compensatory for increase of insulin resistance. Impaired compensatory pancreas β cell function may lead to glucose intolerance and NODAT in the future.

Transplantation and diabetes (Transdiab): a pilot randomised controlled trial of metformin in impaired glucose tolerance after kidney transplantation

BACKGROUND

Post transplantation diabetes mellitus (PTDM) is a common and serious complication after renal transplantation with significant morbidity and mortality. Metformin has proven benefits in the general population and might be advantageous in the prevention and management of PTDM.

METHODS

Transplantation and Diabetes (Transdiab) is a single-centre, unblinded, pilot randomised controlled trial assessing the feasibility, tolerability and efficacy of metformin after renal transplantation in patients with impaired glucose tolerance (IGT). Participants had an oral glucose tolerance test (OGTT) in the 4-12 weeks post-transplantation; those with IGT were randomised to standard care or standard care and metformin 500 mg twice daily and followed up for 12 months.

RESULTS

Seventy eight patients had an OGTT over 24 months, 25 of them had IGT, of those, 19 patients were randomised, giving a feasibility of recruitment of 24.4%. Ten patients were randomised to metformin and 9 patients to standard care. Tolerability and efficacy was similar between the 2 groups with no serious adverse events. There was no difference in secondary outcomes relating to the metabolic profile.

CONCLUSIONS

The use of metformin post renal transplantation appeared feasible and safe. Larger randomised controlled trials (RCTs) are needed to establish and confirm the efficacy and safety of metformin post renal transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12614001171606 . Date of registration 7/11/2014.

Pretransplant Homeostasis Model Assessment of Insulin Resistance and Fasting Plasma Glucose Predict New-Onset Diabetes After Renal Transplant in Chinese Patients

BACKGROUND AND AIM

The present study aims to determine if homeostasis model assessment of insulin resistance (HOMA-IR) index, fasting plasma glucose (FPG), and plasma insulin (Ins) are able to predict development of new onset diabetes after transplant (NODAT) for kidney recipients.

METHODS

We performed a single-center retrospective study of 123 nondiabetic patients receiving a first renal transplant. The NODAT was diagnosed between 1 month and 1 year post transplant. Both univariate and multivariable analyses, including logistic regression analysis and Cox proportional hazards model, were applied to dissect potential pretransplant risk factors of NODAT.

RESULTS

A total of 26.8% (33/123) of recipients developed NODAT in the first year post transplant. The NODAT patients showed higher HOMA-IR index and increased levels of FPG and Ins than non-NODAT. Interestingly, we consistently revealed that both FPG (logistic: odds ratio [OR], 3.17 [1.41-6.45]; P = .01; Cox: OR, 2.75 [1.26-4.56]; P = .02) and HOMA-IR index (logistic: OR, 1.73 [1.21-2.87]; P = .02; Cox: OR, 1.72 [1.21-2.46]; P = .002) robustly predicted the development of NODAT. However, these analyses showed that neither plasma Ins nor hemoglobin A_1c was associated with NODAT.

CONCLUSION

Our findings suggest that pretransplant HOMA-IR and FPG are independent predictors for the development of NODAT in Chinese nondiabetic patients receiving a first renal transplant.

Pre, peri and posttransplant diabetes mellitus

PURPOSE OF REVIEW

The leading cause of death in both chronic kidney disease (CKD) and renal transplant patients is cardiovascular events. Post-transplant diabetes mellitus (PTx-DM), which is a major cardiovascular risk factor, is a metabolic disorder that affects 5.5-60.2% of renal allograft recipients by 1-year posttransplant (PTx). PTx-DM has been associated with a negative impact on patient and graft outcomes and survival.

RECENT FINDINGS

Individuals who develop PTx-DM are usually prone to this condition prior to and/or after developing CKD. Genetic factors, obesity, inflammation, medications and CKD all are risk factors for PTx-diabetes mellitus. The path to development of disease continues PTx frequently augmented by the use of diabetogenic maintenance immunosuppressive and some nonimmunosuppressive medications. These risk factors are usually associated with an increase in insulin resistance, a decrease in insulin gene expression and/or β-cell dysfunction and apoptosis.

SUMMARY

Some new anti-diabetes mellitus medications may help to improve the overall outcome; however, there is a real need for developing a preventive strategy. Identifying and targeting PTx-DM risk factors may help to guide the development of an effective programme. This could include the adoption of nondiabetogenic immunosuppressive protocols for high-risk patients.

Post-transplantation diabetes in kidney transplant recipients: an update on management and prevention

Post-transplantation diabetes mellitus (PTDM) may severely impact both short- and long-term outcomes of kidney transplant recipients in terms of graft and patient survival. However, PTDM often goes undiagnosed is underestimated or poorly managed. A diagnosis of PTDM should be delayed until the patient is on stable maintenance doses of immunosuppressive drugs, with stable kidney graft function and in the absence of acute infections. Risk factors for PTDM should be assessed during the pre-transplant evaluation period, in order to reduce the likelihood of developing diabetes. The oral glucose tolerance test is considered as the gold standard for diagnosing PTDM, whereas HbA1c is not reliable during the first months after transplantation. Glycaemic targets should be individualised, and comorbidities such as dyslipidaemia and hypertension should be treated with drugs that have the least possible impact on glucose metabolism, at doses that do not interact with immunosuppressants. While insulin is the preferred agent for treating inpatient hyperglycaemia in the immediate post-transplantation period, little evidence is available to guide therapeutic choices in the management of PTDM. Metformin and incretins may offer some advantage over other glucose-lowering agents, particularly with respect to risk of hypoglycaemia and weight gain. Tailoring immunosuppressive regimens may be of help, although maintenance of good kidney function should be prioritised over prevention/treatment of PTDM. The aim of this narrative review is to provide an overview of the available evidence on management and prevention of PTDM, with a focus on the available therapeutic options.

Pretransplant HbA1c and Glucose Metabolism Parameters in Predicting Posttransplant Diabetes Mellitus and Their Course in the First 6 Months After Living-Donor Renal Transplant

OBJECTIVES

Posttransplant diabetes mellitus is a common and serious metabolic complication after renal transplant. Patients with uremia are known to have abnormal glucose metabolism characterized by insulin resistance and defects in insulin secretion, which are ameliorated to some extent with renal replacement therapy and more so with renal transplant. However, the diabetogenicity of calcineurin inhibitors compounds this state of dysglycemia and promotes the development of diabetes in some patients. It is not clear whether pretransplant dysglycemia is a risk factor for posttransplant diabetes mellitus and, if so, which between insulin resistance and pancreatic β-cell dysfunction is a major determinant in predicting posttransplant diabetes mellitus. Here, we examined the roles of the pretransplant oral glucose tolerance test, glycated hemoglobin (HbA1c) levels, and homeostatic model assessment-derived insulin resistance and beta-cell function in the prediction of posttransplant diabetes mellitus and the course of these indexes posttransplant. Our aim was to examine the correlations between these factors and their changes posttransplant with the development of posttransplant diabetes mellitus.

MATERIALS AND METHODS

Pretransplant fasting blood was drawn from patients for plasma glucose, insulin, C-peptide, and HbA1c levels, which was followed by a 2-hour oral glucose tolerance test. After transplant, patients were followed for 6 months to detect posttransplant diabetes mellitus. Serum insulin, C-peptide, and glycated hemoglobin levels were reexamined in patients with posttransplant diabetes mellitus at 1 and 6 months.

RESULTS

Twenty-one patients (29%) developed posttransplant diabetes mellitus. Pretransplant HbA1c was associated with development of posttransplant diabetes mellitus (odds ratio 27.04) on logistic regression. Homeostatic model assessment-derived insulin resistance improved significantly at 6 months posttransplant, whereas beta-cell function remained lower than pretransplant levels in patients with posttransplant diabetes mellitus.

CONCLUSIONS

Pretransplant HbA1c may be used as a predictive marker for posttransplant diabetes mellitus. Insulin resistance but not beta-cell function improves in patients with posttransplant diabetes mellitus at 6 months posttransplant.

Dynamics of Glucose Metabolism After Kidney Transplantation

BACKGROUND/AIMS

Posttransplantation diabetes mellitus (PTDM) impacts patient and allograft survival after kidney transplantation. Prediabetes, which is an independent risk factor for PTDM, is modifiable also in a post-transplant setting. Understanding the risks and dynamics of impaired glucose metabolism after transplantation is a key component for targeted intervention.

METHODS

A retrospective chart analysis of all adult non-diabetic renal allograft recipients (n=251, 2007-2014) was performed. Longitudinal follow-up included fasting plasma glucose and HbA1c, as well as data on allograft function and immunosuppression at consecutive time points (months 3-6 to >5 years post transplantation).

RESULTS

Throughout follow-up, median prevalence of prediabetes and PTDM was 53.3 [52.4-55.7]% and 15.4 [15.0-16.5]%, respectively. Continuously high fluxes between states of glucose metabolism, with individual patients' state deteriorating or improving over time, resulted in a high number of incident patients even long after transplantation. The greatest number of patients shifted between normal glucose tolerance and prediabetes, followed by those between prediabetes and PTDM.

CONCLUSION

Prediabetes and PTDM are highly prevalent after kidney transplantation and incidences remain relevant throughout follow-up. Patient fluxes into and out of the prediabetic state show that glucose metabolism is highly dynamic after transplantation. This provides a continuous opportunity for intervention in an aim to reduce diabetes-associated complications.

Diabetes Mellitus Following Renal Transplantation: Clinical and Pharmacological Considerations for the Elderly Patient

Post-transplant diabetes mellitus occurs in 30-50% of cases during the first year post-renal transplantation. It is associated with increased morbidity, mortality and healthcare costs. Risk factors include age and specific immunosuppression regimens. At the same time, renal transplantation is increasingly indicated in elderly (aged >65 years) patients as this proportion of older patients in the prevalent dialysis population has increased. The immune system and β cells undergo senescence and this impacts on the risk for developing post-transplant diabetes and our ability to prevent such development. It may, however, be possible to identify patients at risk of developing post-transplant diabetes, enabling treatment protocols that prevent or reduce the impact of post-transplant diabetes. Much work remains to be completed in this area and is facilitated by the growing base of knowledge regarding the pathophysiology of post-transplant diabetes. Should post-transplant diabetes develop, there are a range of treatment options available. There is increasing interest in using newer agents, although their safety and efficacy in transplant recipients remains to be conclusively established.

[Post-transplantation diabetes mellitus in kidney recipients]

Post-transplantation diabetes mellitus is defined as diabetes that is diagnosed in grafted patients. It affects 20 to 30 % of kidney transplant recipients, with a high incidence in the first year. The increasing age at transplantation and the rising incidence of obesity may increase its prevalence in the next years. Post-transplantation diabetes mellitus is associated with poor outcomes, such as mortality, cardiovascular events or graft dysfunction. Its occurrence is mainly related to immunosuppressive agents, affecting both insulin secretion and sensibility. Immunosuppressants may be iatrogenic, and as such, induce an early and transient diabetes. They may also precociously determine a permanent diabetes, acting here as a promoting factor in patients proned to the development of type 2 diabetes. Lastly, they may behave, far from transplantation, as an additional risk factor for type 2 diabetes. The screening, management and prognosis of these different subtypes of post-transplantation diabetes mellitus will be different.

Genetic factors in pathogenesis of diabetes mellitus after kidney transplantation

Posttransplant diabetes mellitus (PTDM) is one of the major metabolic complications after transplantation of solid organs including the kidney. This type of diabetes mellitus affects allograft survival, cardiovascular complications and overall patient survival. The modifiable risk factors that contribute to PTDM include obesity, some viral infections (eg, hepatitis C virus, cytomegalovirus) and especially immunosuppressive drugs including corticosteroids, tacrolimus, cyclosporine and sirolimus. Currently, predisposing genetic factors have been considered important in PTDM development. The commonly evaluated genetic determinants include genes encoding transcription factors, cytokines, chemokines, adipokines, ionic channels, glucose transporters, cytochrome P450 enzymes and other enzymes metabolizing drugs, drug transporters. Unfortunately, the results of studies are inconclusive and differ between populations. There is a need for large genome-wide association study to identify the genetic risk factors associated with PTDM development.

Impact of renal transplantation on glucose tolerance in Japanese recipients with impaired glucose tolerance

AIMS

To investigate changes in glucose tolerance, insulin secretion and insulin sensitivity in Japanese recipients before and 1 year after renal transplantation.

METHODS

We conducted a study of Japanese recipients without diabetes who underwent renal transplantation at Hokkaido University Hospital. A 75-g oral glucose tolerance test was performed before and 1 year after renal transplantation in these recipients. Insulin sensitivity was estimated using the Matsuda index and homeostasis model assessment of insulin resistance (HOMA-IR). Insulin secretion was evaluated based on the insulin secretion sensitivity index-2 (ISSI-2).

RESULTS

Of the 62 renal transplant recipients, 31 were diagnosed as having impaired glucose tolerance before transplantation. Among these 31 recipients, after 1 year, four had developed new-onset diabetes after transplantation, and nine had impaired glucose tolerance. Unexpectedly, 18 changed from impaired to normal glucose tolerance. When these recipients with impaired glucose tolerance were classified into a non-amelioration group and an amelioration group, the ISSI-2 was significantly reduced, with no significant changes in the Matsuda index or HOMA-IR, in the non-amelioration group 1 year after renal transplantation. By contrast, ISSI-2 and Matsuda index values were significantly increased, with no significant changes in HOMA-IR values in the amelioration group.

CONCLUSIONS

More than half of Japanese renal transplant recipients with impaired glucose tolerance had normal glucose tolerance 1 year after renal transplantation. These results suggest that an increase in insulin secretion and whole insulin sensitivity was associated with improvement in glucose tolerance in these recipients.

A Prospective Study of Renal Transplant Recipients: A Fall in Insulin Secretion Underpins Dysglycemia After Renal Transplantation

Background

Dysglycemia (encompassing impaired glucose tolerance and diabetes mellitus) arising after renal transplantation is common and confers a significant cardiovascular mortality risk. Nonetheless, the pathophysiology of posttransplant dysglycemia is not well described. The aim of this study was to prospectively and comprehensively assess glucose handling in renal transplant recipients from before to 12 months after transplantation to determine the underpinning pathophysiology.

Materials and Methods

Intravenous and oral glucose tolerance testing was conducted before and at 3 and 12 months posttransplantation. An intravenous glucose tolerance test was also performed on day 7 posttransplantation. We followed up 16 transplant recipients for 3 months and 14 recipients for 12 months. Insulin secretion, resistance and a disposition index (DI (IV)), a measure of β cell responsiveness in the context of prevailing insulin resistance, were also determined.

Results

At 12 months, 50% of renal transplant recipients had dysglycemia. Dysglycemia was associated with a dramatic fall in DI (IV) and this loss in β cell function was evident as early as 3 months posttransplantation (23.5 pretransplant; 6.4 at 3 months and 12.2 at 12 months posttransplant). Differences in the β cell response to oral glucose challenge were evident pretransplant in those destined to develop dysglycemia posttransplant (2-hour blood glucose level 5.6 mmol/L versus 6.8 mmol/L; P < 0.01).

Conclusions

Dysglycemia after renal transplantation is common, and the loss of insulin secretion is a major contributor. Subclinical differences in glucose handling are evident pretransplant in those destined to develop dysglycemia potentially heralding a susceptible β cell which under the stressors associated with transplantation fails.

Association of Inflammation prior to Kidney Transplantation with Post-Transplant Diabetes Mellitus

BACKGROUND/OBJECTIVE

Post-transplant diabetes mellitus (PTDM) is both common and associated with poor outcomes after kidney transplantation. Our objective was to examine relationships of uremia-associated inflammation and adiponectin with PTDM.

METHODS

Nondiabetic kidney transplant patients were enrolled with donor controls. Inflammatory cytokines and adiponectin were measured before and after transplantation. Adipose tissue was obtained for gene expression analysis. Glucose transport was quantified in vitro in C2C12 cells following cytokine exposure. The patients were monitored up to 12 months for PTDM.

RESULTS

We studied 36 controls and 32 transplant patients, of whom 11 (35%) developed PTDM. Compared to controls, plasma TNFα, IL-6, MCP-1, and CRP levels were higher in transplant patients (p < 0.01). In multivariable analysis, TNFα plasma levels before transplantation were associated with development of PTDM (OR = 2.03, p = 0.04). Visceral adipose tissue TNFα mRNA expression was higher in transplant patients than controls (fold change 1.33; p < 0.05). TNFα mRNA expression was also higher in patients who developed PTDM than in those who did not (fold change 1.42; p = 0.05), and adiponectin mRNA expression was lower (fold change 0.48; p < 0.05). The studies on the C2C12 cells demonstrated an increase in glucose uptake following exposure to adiponectin and no significant change after exposure to TNFα alone. Concomitant TNFα and adiponectin exposure blunted adiponectin-induced glucose uptake (11% reduction; p < 0.001).

CONCLUSION

Our in vitro and clinical observations suggest that TNFα could contribute to PTDM through an effect on adiponectin. Our study proposes that inflammation is involved in glucose regulation after kidney transplantation.

mTOR Inhibition: Reduced Insulin Secretion and Sensitivity in a Rat Model of Metabolic Syndrome

BACKGROUND

Sirolimus (SRL) has been associated with new-onset diabetes mellitus after transplantation. The aim was to determine the effect of SRL on development of insulin resistance and β -cell toxicity.

METHODS

Lean Zucker rat (LZR) and obese Zucker rat (OZR) were distributed into groups: vehicle and SRL (0.25, 0.5, or 1.0 mg/kg) during 12 or 28 days. Intraperitoneal glucose tolerance test (IPGTT) was evaluated at days 0, 12, 28, and 45. Islet morphometry, β-cell proliferation, and apoptosis were analyzed at 12 days. Islets were isolated to analyze insulin content, insulin secretion, and gene expression.

RESULTS

After 12 days, SRL treatment only impaired IPGTT in a dose-dependent manner in OZR. Treatment prolongation induced increase of area under the curve of IPGTT in LZR and OZR; however, in contrast to OZR, LZR normalized glucose levels after 2 hours. The SRL reduced pancreas weight and islet proliferation in LZR and OZR as well as insulin content. Insulin secretion was only affected in OZR. Islets from OZR + SRL rats presented a downregulation of Neurod1, Pax4, and Ins2 gene. Genes related with insulin secretion remained unchanged or upregulated.

CONCLUSIONS

In conditions that require adaptive β -cell proliferation, SRL might reveal harmful effects by blocking β -cell proliferation, insulin production and secretion. These effects disappeared when removing the therapy.

Assessment of beta-cell function and insulin secretion in subjects that underwent renal transplantation

In this study we aimed to assess the performance of various indices of beta-cell function derived from oral glucose tolerance test (OGTT) in subjects that underwent renal transplantation. Impaired insulin secretion seems in fact central for development of new onset diabetes after transplantation, but its assessment has not been systematically evaluated. Twenty subjects underwent a 75 g 2h-OGTT for measurement of glucose, insulin, C-peptide. OGTT indices of beta-cell function were either derived by mathematical modeling (yielding the reference index: glucose sensitivity) or were empirical: insulinogenic index (IGI), IGI derived indices, whole shape C-peptide (WHOSH_CP). Indices of beta cell function, showed significant correlation with glucose sensitivity (R(2)=0.40-0.86, all P<;0.003). The majority of beta-cell function indices provided comparable results also when subjects were divided into subgroups according to sex, age, body mass index, mean glycemia. In conclusion, in transplanted subjects OGTT empirical indices are typically acceptable for the estimation of beta-cell function.

Diabetes Mellitus and Prediabetes on Kidney Transplant Waiting List- Prevalence, Metabolic Phenotyping and Risk Stratification Approach

BACKGROUND

Despite a significant prognostic impact, little is known about disturbances in glucose metabolism among kidney transplant candidates. We assess the prevalence of diabetes mellitus (DM) and prediabetes on kidney transplant waiting list, its underlying pathophysiology and propose an approach for individual risk stratification.

METHODS

All patients on active kidney transplant waiting list of a large European university hospital transplant center were metabolically phenotyped.

RESULTS

Of 138 patients, 76 (55%) had disturbances in glucose metabolism. 22% of patients had known DM, 3% were newly diagnosed. 30% were detected to have prediabetes. Insulin sensitivity and-secretion indices allowed for identification of underlying pathophysiology and risk factors. Age independently affected insulin secretion, resulting in a relative risk for prediabetes of 2.95 (95%CI 1.38-4.83) with a cut-off at 48 years. Body mass index independently affected insulin sensitivity as a continuous variable.

CONCLUSIONS

The prevalence of DM or prediabetes on kidney transplant waiting list is as high as 55%, with more than one third of patients previously undiagnosed. Oral glucose tolerance test is mandatory to detect all patients at risk. Metabolic phenotyping allows for differentiation of underlying pathophysiology and provides a basis for early individual risk stratification and specific intervention to improve patient and allograft outcome.

Historical cohort with diabetes mellitus after kidney transplantation and associated factors of its development in adult patients of a transplantation reference center in the State of Ceará, Brazil

Post-transplantation diabetes mellitus (PTDM) is an important complication related to kidney transplantation (KT), and its occurrence is associated with increased morbidity and mortality. Nevertheless, KT is considered to be the most effective treatment option that offers better quality of life for patients with end-stage kidney disease. This study aimed to describe the occurrence of PTDM and the risk factors associated with its development in kidney transplant patients of a transplantation reference center in the State of Ceará (Brazil). This historical cohort study, based on medical records data, included adult patients undergoing KT from January 2006 to December 2010 in a public tertiary hospital. Multivariate analysis was performed with the use of a logistic regression model, with PTDM presence as dependent variable and the possible risk factors under study as independent variables. Throughout the evaluated period, 430 KTs were performed; 92 patients were excluded. Diabetes mellitus was already present in 9.2% of patients before KT. Hyperglycemia during the 1st month after transplantation occurred in 34.5% of recipients, and the occurrence of PTDM to the end of study was 19.9%. Factors associated with PTDM development were: fasting plasma glucose 1 month after KT (P < .001; odds ratio [OR] 1.05), deceased-donor KT (P = .015; OR 3.53), impaired fasting glucose before transplantation (P = .014; OR 4.10), and acute rejection occurrence (P = .003; OR 6.43). High PTDM occurrence was found, in accordance with the literature. Identification of factors associated with PTDM development, as well as its early diagnosis, could result in long-term improvement in patient and graft survivals.

New-onset diabetes after kidney transplant in children

The development of new-onset diabetes after kidney transplantation (NODAT) is associated with reduced graft function, increased cardiovascular morbidity and lower patient survival among adult recipients. In the pediatric population, however, the few studies examining NODAT have yielded inconsistent results. Therefore, the true incidence of NODAT in the pediatric population has been difficult to establish. The identification of children and adolescents at risk for NODAT requires appropriate screening questions and tests pre- and post-kidney transplant. Several risk factors have been implicated in the pathogenesis of NODAT and post-transplant glucose intolerance, including African American race, obesity, family history of diabetes and the type of immunosuppressant regimen. Moreover, uremia per se results in a state of insulin resistance that increases the risk of developing diabetes post-transplant. When an individual becomes glucose intolerant, early lifestyle modification and antihyperglycemic measures with tailoring of the immunosuppressant regimen should be implemented to prevent the development of NODAT. For the child or adolescent with NODAT, antihyperglycemic therapy should be prescribed in order to achieve optimal glycemic control, ultimately reducing complications and improving overall allograft and patient survival. In this article, we review the risk factors, screening methods, diagnosis, management and outcome of children and adolescents with NODAT and post-kidney transplant glucose intolerance.

Antidiabetic therapy in post kidney transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM) is a common complication after kidney transplantation that affects up to 40% of kidney transplant recipients. By pathogenesis, PTDM is a diabetes form of its own, and may be characterised by a sudden, drug-induced deficiency in insulin secretion rather than worsening of insulin resistance over time. In the context of deteriorating allograft function leading to a re-occurrence of chronic kidney disease after transplantation, pharmacological interventions in PTDM patients deserve special attention. In the present review, we aim at presenting the current evidence regarding efficacy and safety of the modern antidiabetic armamentarium. Specifically, we focus on incretin-based therapies and insulin treatment, besides metformin and glitazones, and discuss their respective advantages and pitfalls. Although recent pilot trials are available in both prediabetes and PTDM, further studies are warranted to elucidate the ideal timing of various antidiabetics as well as its long-term impact on safety, glucose metabolism and cardiovascular outcomes in kidney transplant recipients.

Insulin resistance as a risk factor for new-onset diabetes after kidney transplantation

INTRODUCTION

New-onset diabetes after transplantation (NODAT) is a serious and common complication after kidney transplantation. Insulin resistance, together with β-cell dysfunction, plays an essential role in the development of diabetes. Homeostasis model assessment of insulin resistance (HOMA-IR), which is calculated as [fasting plasma glucose (mmol/L) × fasting insulin (mU/L)]/22.5, is widely used as an index of insulin resistance. However, the correlation between pretransplant HOMA-IR and the development of NODAT has not been fully established.

METHODS

We performed a retrospective study of 44 nondiabetic patients who underwent living donor kidney transplantation in our hospital from July 2006 to October 2009. We compared the HOMA-IR and demographic variables of patients who developed NODAT with those who did not.

RESULTS

Five patients (11.4%) developed NODAT within 3 years after transplantation. There were no differences in demographic variables between patients who developed NODAT and those who did not. Logistic regression analysis revealed that HOMA-IR was a predictive factor of NODAT (odds ratio, 2.88; 95% CI, 1.11-9.59; P < .05).

CONCLUSIONS

Our results indicate that high HOMA-IR might be an important predictive factor for NODAT. These findings underline the importance of routine pretransplant measurements of fasting plasma glucose and serum insulin for evaluating HOMA-IR.

L-carnitine protects against cyclosporine-induced pancreatic and renal injury in rats

BACKGROUND

L-carnitine has protective effects against various types of injury. This study was designed to evaluate the beneficial effects of L-carnitine on pancreatic and renal injuries caused by cyclosporine (CsA).

METHODS

Rats maintained on a low sodium diet were given vehicle (olive oil, 1 mL/kg/d), CsA (15 mg/kg/d), L-carnitine (50 or 200 mg/kg/d), or a combination of CsA and L-carnitine for 4 weeks. The impact of L-carnitine on pancreatic injury was assessed by blood glucose levels, plasma insulin concentrations, and hemoglobulin A1c (HbA1c). In addition, the protective effects of L-carnitine against CsA-induced kidney injury were evaluated in terms of renal function, histopathology (inflammatory cell influx and tubulointerstitial fibrosis), oxidative stress (8-hydroxy 2'-deoxyguanosine, 8-OHdG), transforming growth factor-betal (TGF-β1), apoptosis (caspase-3), and autophagy (LC3-II).

RESULTS

CsA treatment caused diabetes, renal dysfunction, tubulointerstitial inflammation (ED-1-positive cells), and fibrosis, which were accompanied by an increase in 8-OHdG production and upregulation of TGF-β1, caspase-3, and LC3-II. Concomitant administration of L-carnitine increased plasma insulin concentrations, decreasing plasma glucose and HbA1c levels. In the kidney, L-carnitine induced dose-dependent improvement of renal function, inflammation, and fibrosis in parallel with suppression of the expression of TGF-β1 and 8-OHdG. Furthermore, the administration of L-carnitine at a high dose inhibited the expression of caspase-3 and LC3-II.

CONCLUSION

These findings suggest that L-carnitine has a protective effect against CsA-induced pancreatic and renal injuries.

Long-term progression of abnormal glucose tolerance and its relationship with the metabolic syndrome after kidney transplantation

BACKGROUND

Metabolic syndrome (MS) diagnosed early after kidney transplantation is a risk factor for developing new-onset diabetes. The aim of this study was to examine whether glucose intolerance and MS identified late after transplantation influence the progression of glycemic abnormalities in kidney transplant recipients.

METHODS

This is a retrospective study in which 76 non-diabetic renal transplant recipients underwent oral glucose tolerance tests (OGTT) in 2005 to 2006 (baseline) and then in 2011 to 2012 (follow-up). MS was identified using the International Diabetes Federation criteria and OGTT was interpreted according to the WHO classification.

RESULTS

At follow-up, median time from transplantation was 11.1 years (range 6.2-23.8). Mean 0-hour and 2-hour plasma glucose levels were significantly higher at follow-up compared to baseline (5.7 ± 0.7 vs. 5.9 ± 0.9 mmol/L, P=0.03 and 6.7 ± 1.9 vs. 7.5 ± 2.8 mmol/L, P=0.03, respectively). The proportion of patients with an abnormal OGTT increased from 42% at baseline to 61% at follow-up (P=0.007). Patients with MS were more likely to progress to a higher degree of glucose intolerance compared to those without MS (58% vs. 27%, P=0.01). On multivariable logistic regression adjusted for age and gender, MS was significantly associated with the progression of glucose intolerance (OR 3.5, CI 1.2-9.9, P=0.01), as was a fasting glucose greater than 5.6 mmol/L (OR 4.8, CI 1.6-14.8, P=0.006).

CONCLUSION

MS is a risk factor for the progression of glucose intolerance in renal transplant recipients in the late posttransplant period. Therefore, MS has to be considered in tandem with OGTT results to assess cardiovascular risk.

Steroid-induced diabetes: a clinical and molecular approach to understanding and treatment

Since the advent of glucocorticoid therapy for autoimmune disease in the 1940s, their widespread application has led to the concurrent therapy-limiting discovery of many adverse metabolic side effects. Unanticipated hyperglycemia associated with the initiation of glucocorticoids often leads to preventable hospital admissions, prolonged hospital stays, increased risks for infection and reduced graft function in solid organ transplant recipients. Challenges in managing steroid-induced diabetes stem from wide fluctuations in post-prandial hyperglycemia and the lack of clearly defined treatment protocols. The mainstay of treatment is insulin therapy coincident with meals. This article aims to review the pathogenesis, risk factors, diagnosis and treatment principles unique to steroid-induced diabetes.

Obesity and metabolic syndrome in kidney transplantation

The epidemic of obesity and metabolic syndrome (MS) contributes to the rapid growth of chronic kidney disease (CKD) and end-stage renal disease (ESRD). There is a reverse epidemiology, known as the "obesity paradox," in ESRD patients receiving maintenance dialysis. Obese patients are routinely referred for kidney transplant, and they have more surgical and medical complications than non-obese patients. However, compared to dialysis, kidney transplant provides a survival benefit for obese patients. After kidney transplant, obese patients tend to gain more body weight, and non-obese patients can develop new-onset obesity/MS. Obesity/MS is not only associated with serious morbidities, but also compromises the long-term graft and patient survival. The immunosuppressive drugs commonly used as maintenance therapy, including corticosteroids, calcineurin inhibitors and mammalian target-of-rapamycin inhibitors, contribute to obesity/MS. Development of novel immunosuppressive drugs free of metabolic adverse effects is needed, so that the full potential and benefits of kidney transplantation can be realized.