Diabetes Mellitus and Renal Transplantation in Adults: Is There Enough Evidence for Diagnosis, Treatment, and Prevention of New-Onset Diabetes After Renal Transplantation?

Kidney Transplant: More than Immunological Problems

Kidney transplantation (KT) represents a pivotal intervention for patients with chronic kidney disease (CKD), significantly improving survival and quality of life. However, KT recipients face an array of non-immunological complications, collectively amplifying cardiovascular (CV) and metabolic risks. This review explores the intersection of cardio-metabolic syndrome and KT, emphasizing the recently introduced cardiovascular-kidney-metabolic (CKM) syndrome. CKM syndrome integrates metabolic risk factors, CKD, and CV disease, with KT recipients uniquely predisposed due to immunosuppressive therapies and pre-existing CKD-related risks. Key issues include post-transplant hypertension, obesity, dyslipidemia, post-transplant diabetes mellitus (PTDM), and anemia. Immunosuppressive agents such as corticosteroids, calcineurin inhibitors, and mTOR inhibitors contribute significantly to these complications, exacerbating metabolic dysfunction, insulin resistance, and lipid abnormalities. For instance, corticosteroids and calcineurin inhibitors heighten the risk of PTDM, while mTOR inhibitors are strongly associated with dyslipidemia. These pharmacologic effects underscore the need for tailored immunosuppressive strategies. The management of these conditions requires a multifaceted approach, including lifestyle interventions, pharmacological therapies like SGLT2 inhibitors and GLP-1 receptor agonists, and close monitoring. Additionally, emerging therapies hold promise in addressing metabolic complications in KT recipients. Proactive risk stratification and early intervention are essential to mitigating CKM syndrome and improving outcomes. This comprehensive review highlights the importance of integrating cardio-metabolic considerations into KT management, offering insights into optimizing long-term recipient health and graft survival.

Exploring the Impact of Diabetes on Kidney Transplant: Patient Outcomes and Management Strategies

Diabetic kidney disease (DKD) is a serious consequence of diabetes mellitus (DM). If not managed effectively, DKD often develops into end-stage renal disease (ESRD). The most successful treatment for ESRD is kidney transplantation, offering improved quality of life and survival rates. For insulin-dependent diabetic patients with ESRD, simultaneous pancreas-kidney transplantation (SPKT) offers a treatment alternative that treats both kidney failure and the underlying diabetes. However, SPKT involves more complicated surgery, prolonged operative time, and a higher risk of complications. This review aims to highlight the impact of DM on kidney transplant recipients (KTRs) regarding post-transplant complications, graft survival, mortality rates, and the role of glucose-lowering medications and immunosuppressants. The incidence of urinary tract infections, cardiovascular complications, and diabetic foot disease was higher among KTRs. A decrease in graft survival rate at five years was observed among diabetics compared to non-diabetics, with similar graft survival rates among type 1 and type 2 DM. The mortality rate was notably higher among diabetic patients, with cardiovascular complications being the leading cause. The emergence of new-onset diabetes mellitus post-transplantation (NODAT) is a significant cause of concern. Certain risk factors, including a family history of DM, age >45 years, obesity, male gender, and immunosuppressive medications, have been linked to this phenomenon. Immunosuppression is a substantial challenge among diabetics as certain medications such as tacrolimus have shown to be considerably diabetogenic compared to cyclosporine and belatacept, and it is also postulated that corticosteroids can lead to hyperglycemia. Some studies proved that glucose-lowering medications, including insulin degludec, glucagon-like peptide-1 receptor agonists, thiazolidinediones, and sodium-glucose cotransporter 2 inhibitors, are safe and effective among KTRs. However, these studies are debatable and of low confidence. Hence, it is imperative to conduct large clinical trials and establish definitive guidelines to manage pre-existing diabetes and NODAT among KTRs with multidisciplinary care to help clinicians improve patient outcomes.

Managing Post-Transplant Diabetes Mellitus after Kidney Transplantation: Challenges and Advances in Treatment

Kidney transplantation is the most effective treatment for end-stage renal failure but is associated with complications, including post-transplant diabetes mellitus (PTDM). It affects the quality of life and survival of patients and the transplanted organ. It can cause complications, including infections and episodes of acute rejection, further threatening graft survival. The prevalence of PTDM, depending on the source, can range from 4 to 30% in transplant patients. This article aims to discuss issues related to diabetes in kidney transplant patients and the latest treatments. Knowledge of the mechanisms of action of immunosuppressive drugs used after transplantation and their effect on carbohydrate metabolism is key to the rapid and effective detection of PTDM. Patient therapy should not only include standard management such as lifestyle modification, insulin therapy or pharmacotherapy based on well-known oral and injection drugs. New opportunities are offered by hypoglycemic drugs still in clinical trials, including glucokinase activators, such as dorzagliatin, ADV-1002401, LY2608204, TMG-123, imeglimine, amycretin and pramlintide. Although many therapeutic options are currently available, PTDM often creates uncertainty about the most appropriate treatment strategy. Therefore, more research is needed to individualize therapeutic plans and monitor these patients.

Micro-vascular complications of post-transplant diabetes mellitus in renal transplant recipients- an observational study

INTRODUCTION

The incidence of post-transplant diabetes mellitus (PTDM) ranges from 2.5% to 20% in kidney transplant recipients. Diabetic retinopathy (DR), diabetic kidney disease (DKD), and distal symmetric polyneuropathy (DSPN) are the microvascular complications frequently seen in both type 1 and 2 diabetes mellitus (DM). However, the data regarding these complications in patients with PTDM is lacking.

METHOD

A retrospective and prospective observational study of PTDM conducted at a tertiary care hospital from November 2018 to December 2020. 115 kidney transplant recipients who had PTDM of ≥5 years duration were included and analysed.

RESULTS

The mean duration of PTDM was 8.8 ± 3.0 years, and the mean of all available HbA1c values was 7.0 ± 0.9%. while none of the patients had evidence of diabetic retinopathy on direct ophthalmoscopy, 37.4% of patients (n = 43) had DSPN and this was associated with the duration of PTDM and age. The mean estimated glomerular filtration rate (eGFR) was 59.24 ± 21.82 ml/min/1.73m2, and patients had a median proteinuria of 620 mg/day (IQR 1290). Out of 115 patients, 20% of them (n = 23) underwent graft kidney biopsy, and 10 biopsies were diagnosed as de-novo DKD. Patients with biopsy proven DKD had a mean PTDM duration of 143.3 ± 52.4 months; a mean HbA1c level of 7.9 ± 1.3%; a mean eGFR of 44.8 ± 21.8 ml/min; and a median proteinuria of 2653 mg (IQR 2758). An additional analysis of all 23 biopsied patients showed that HbA1c level and degree of proteinuria were significantly associated with de-novo DKD.

CONCLUSION

PTDM in transplant patients had milder microvascular complications than usually expected in Type 1/2 diabetes in non-transplant patients. DR was not strongly associated with DKD in PTDM patients. Furthermore, de-novo DKD development was associated with poor glycaemic control and increased proteinuria.

Study of weight and body mass index on graft loss after transplant over 5 years of evolution

Patients frequently experience a weight gain after organ transplantation. This increase in weight is the result of multiple factors, and is usually intensified by glucocorticoids and immunosuppressive drugs. It can also delay graft function and cause serious health problems. The objective of this study was to study the obesity as well as its causes and consequences in kidney transplant patients. The sample population consisted of 282 renal transplant patients, 170 men and 112 women, 18-74 years of age, who were monitored over a period of five years. For the purposes of our research, the patients were divided into two groups: (1) normal weight 18.5 ≤ BMI <25; (2) overweight 25 ≤ BMI ≤30. The association between BMI as an independent variable and graft survival was determined by means of a Cox regression analysis. Overweight patients were characterized by a higher comorbidity prevalence. In the Cox multivariate analysis, the initial BMI, evaluated as a continuous variable continued to be an independent predictor of delayed graft function and chronic nephropathy. This study evaluated the BMI as a continuous value instead of a categorical value. In conclusion, our results suggest that an increase in BMI without categorical variation can be an independent risk factor for graft loss. Consequently, obesity prevention for renal transplant patients should include dietary counseling and management, moderate physical activity, and steroid minimization.

Genetic Variants Associated With Immunosuppressant Pharmacokinetics and Adverse Effects in the DeKAF Genomics Genome-wide Association Studies

BACKGROUND

The immunosuppressants tacrolimus and mycophenolate are important components to the success of organ transplantation, but are also associated with adverse effects, such as nephrotoxicity, anemia, leukopenia, and new-onset diabetes after transplantation. In this report, we attempted to identify genetic variants which are associated with these adverse outcomes.

METHODS

We performed a genome-wide association study, using a genotyping array tailored specifically for transplantation outcomes containing 722 147 single nucleotide polymorphisms, and 2 cohorts of kidney allograft recipients-a discovery cohort and a confirmation cohort-to identify and then confirm genetic variants associated with immunosuppressant pharmacokinetics and adverse outcomes.

RESULTS

Several genetic variants were found to be associated with tacrolimus trough concentrations. We did not confirm variants associated with the other phenotypes tested although several suggestive variants were identified.

CONCLUSIONS

These results show that adverse effects associated with tacrolimus and mycophenolate are complex, and recipient risk is not determined by a few genetic variants with large effects with but most likely are due to many variants, each with small effect sizes, and clinical factors.

Microvascular Complications of Posttransplant Diabetes Mellitus in Kidney Transplant Recipients: A Longitudinal Study

OBJECTIVE

To assesses microvascular complications in renal transplant recipients with posttransplant diabetes mellitus (PTDM).

RESEARCH DESIGN AND METHODS

In this observational study, patients with ≥5 years of PTDM were included from a cohort of 895 kidney recipients transplanted from 2000 through 2011. Diabetic retinopathy was evaluated by fundus photographs and optical coherence tomography (OCT). Diabetes kidney disease was evaluated by protein to creatinine ratio (PCR) and estimated glomerular filtration rate (eGFR). Distal polyneuropathy was assessed by Michigan Protocol and 10 g-monofilament feet examinations. The Ewing protocol identified cardiovascular autonomic neuropathy. Renal transplant recipients without PTDM diagnosis (NPTDM) were considered controls.

RESULTS

After 144.5 months of follow-up, 135 (15%) patients developed PTDM, and 64 had a PTDM duration ≥5 years. None of the patients with PTDM presented diabetic retinopathy at fundus photographs, but thinning of inner retinal layers was observed with OCT. More than 60% of patients with PTDM had distal polyneuropathy (OR, 1.55; 95% CI, 1.26 to 1.91; P < 0.001). Cardiovascular reflex tests abnormalities were similar between patients with PTDM and NPTDM (P = 0.26). During the first year and 8.5 ± 3.0 years after renal transplantation, eGFR and PCR did not differ significantly between patients with PTDM or NPTDM.

CONCLUSIONS

This longitudinal study assesses microvascular complications in renal transplant patients with PTDM. A lower than expected prevalence as well as a different clinical course of the complications was observed. PTDM seems to be a unique type of diabetes, and its consequences may be milder than expected in type 1 and type 2 diabetes.

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.

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.

Diabetes and disordered bone metabolism (diabetic osteodystrophy): time for recognition

Diabetes and osteoporosis are rapidly growing diseases. The link between the high fracture incidence in diabetes as compared with the non-diabetic state has recently been recognized. While this review cannot cover every aspect of diabetic osteodystrophy, it attempts to incorporate current information from the First International Symposium on Diabetes and Bone presentations in Rome in 2014. Diabetes and osteoporosis are fast-growing diseases in the western world and are becoming a major problem in the emerging economic nations. Aging of populations worldwide will be responsible for an increased risk in the incidence of osteoporosis and diabetes. Furthermore, the economic burden due to complications of these diseases is enormous and will continue to increase unless public awareness of these diseases, the curbing of obesity, and cost-effective measures are instituted. The link between diabetes and fractures being more common in diabetics than non-diabetics has been widely recognized. At the same time, many questions remain regarding the underlying mechanisms for greater bone fragility in diabetic patients and the best approach to risk assessment and treatment to prevent fractures. Although it cannot cover every aspect of diabetic osteodystrophy, this review will attempt to incorporate current information particularly from the First International Symposium on Diabetes and Bone presentations in Rome in November 2014.

BK Virus Nephropathy in Kidney Transplantation: An Approach Proposal and Update on Risk Factors, Diagnosis, and Treatment

BK virus belongs to Polyomaviridae family; it causes 95% of nephropathy cases related to polyomavirus, with the other 5% caused by JC virus. Nephropathy jeopardizes graft function, causing a premature failure of the graft in 1%-10% of patients with kidney transplants. Nowadays, antiviral effective treatment is unknown, which is why blood and urine screening of renal transplantation patients has become the most important recommendation to guide the decrease of immunosuppression, and the only proven method to decrease poor outcomes. Different interventions, such as cidofovir, leflunomide, fluoroquinolones, and intravenous immunoglobulin, have been attempted with no improvement at all. This review aims to summarize the most relevant features of BK virus, historical issues, transmission mechanisms, risk factors, and therapeutic interventions.

Glycaemic changes in patients with chronic kidney disease

In Argentina, there have been no studies aimed at establishing the prevalence of dysglycaemia (impaired fasting glucose [IFG], impaired glucose tolerance [IGT] and diabetes mellitus [DM]) in patients with chronic kidney disease (CKD). Our group decided to conduct an observational study to evaluate the frequency with oral glucose tolerance test (OGTT) in CKD patients with no previous data for dysglycaemia in their medical records. OGTT was performed in 254 patients (60.62% male) with stage 3, 4 and 5 CKD under conservative treatment, haemodialysis or transplantation. Results for DM were found in 10 patients according to fasting glucose alone (3.94%; 95% CI: 1.35-6.53%), 11 patients with exclusively the second hour criterion (4.33%; 95% CI: 1.63-7.03%), 15 with both criteria (5.91%; 95% CI: 2.81-9.00%) and 36 patients with at least one criteria (14.17%; 95% CI: 9.69-18.66%). In a multivariate analysis, DM was associated with waist circumference (OR=1.033 per cm; 95% CI, 1.005 to 1.062; P=.019) and with conservative treatment vs. replacement therapy (OR=0.41; 95% CI: 0.19-0.92; P=.028). IGT was evident in 24.6% and 20.3 on conservative vs. replacement therapy, with no statistically significant difference. IFG (ADA criteria) was 19.75 vs. 9.24% in conservative vs. replacement therapy, with a statistically significant difference. OGTT is suggested for all CKD patients since it is able to detect the full range of unknown dysglycaemias, which avoids underdiagnoses and favours performing treatments to prevent progression in DM risk groups (IFG and/or IGT). It also aids in the selection of the most appropriate medication for transplantation or treatment initiation in new cases of undiagnosed DM to decrease morbidity and mortality.

Validation of the association of TCF7L2 and SLC30A8 gene polymorphisms with post-transplant diabetes mellitus in Asian Indian population

The rs7903146 and rs13266634 polymorphisms in the TCF7L2 and SLC30A8 genes, respectively, have been reported to be associated with type 2 diabetes. However, little is known about the association of these polymorphisms with post-transplant diabetes mellitus (PTDM). To study this linkage, we determined a distribution of allele and genotype frequencies in Asian Indians. 42 PTDM and 98 non-PTDM subjects were recruited. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect for rs7903146 and rs13266634 polymorphisms. The clinical details and statistical analysis for PTDM and non-PTDM subjects were recorded. Our results observed higher frequencies of the minor alleles in rs7903146 and rs13266634 polymorphisms in the PTDM group compared to the non-PTDM subjects. The allele frequencies also found to be significantly associated with PTDM (rs7903146: T vs C: OR-2.6; (95%CI: 1.2-5.6); p = 0.01; rs13266634: T vs C: OR-2.0; (95%CI: 1.1-3.4); p = 0.01). These findings suggest that rs7903146 and rs13266634 polymorphisms are associated with PTDM in the Asian Indian population despite a relatively small study group.