Associations Between Posttransplantation Diabetes Mellitus and Renal Graft Survival

International consensus on post-transplantation diabetes mellitus

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

Systemic inflammation early after kidney transplantation is associated with long-term graft loss: a cohort study

Background

Early graft loss following kidney transplantation is mainly a result of acute rejection or surgical complications, while long-term kidney allograft loss is more complex. We examined the association between systemic inflammation early after kidney transplantation and long-term graft loss, as well as correlations between systemic inflammation scores and inflammatory findings in biopsies 6 weeks and 1 year after kidney transplantation.

Methods

We measured 21 inflammatory biomarkers 10 weeks after transplantation in 699 patients who were transplanted between 2009 and 2012 at Oslo University Hospital, Rikshospitalet, Norway. Low-grade inflammation was assessed with predefined inflammation scores based on specific biomarkers: one overall inflammation score and five pathway-specific scores. Surveillance or indication biopsies were performed in all patients 6 weeks after transplantation. The scores were tested in Cox regression models.

Results

Median follow-up time was 9.1 years (interquartile range 7.6-10.7 years). During the study period, there were 84 (12.2%) death-censored graft losses. The overall inflammation score was associated with long-term kidney graft loss both when assessed as a continuous variable (hazard ratio 1.03, 95% CI 1.01-1.06, P = 0.005) and as a categorical variable (4th quartile: hazard ratio 3.19, 95% CI 1.43-7.10, P = 0.005). In the pathway-specific analyses, fibrogenesis activity and vascular inflammation stood out. The vascular inflammation score was associated with inflammation in biopsies 6 weeks and 1 year after transplantation, while the fibrinogenesis score was associated with interstitial fibrosis and tubular atrophy.

Conclusion

In conclusion, a systemic inflammatory environment early after kidney transplantation was associated with biopsy-confirmed kidney graft pathology and long-term kidney graft loss. The systemic vascular inflammation score correlated with inflammatory findings in biopsies 6 weeks and 1 year after transplantation.

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

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

The Efficacy and Safety of SGLT2 Inhibitor in Diabetic Kidney Transplant Recipients

BACKGROUND

The efficacy and safety of sodium-glucose cotransporter 2 inhibitors (SGLT2i) have not been investigated in kidney transplant recipients (KTRs) with diabetes. We evaluated the impact of SGLT2i in a multicenter cohort of diabetic KTRs.

METHODS

A total of 2083 KTRs with diabetes were enrolled from 6 transplant centers in Korea. Among them, 226 (10.8%) patients were prescribed SGLT2i for >90 d. The primary outcome was a composite outcome of all-cause mortality, death-censored graft failure (DCGF), and serum creatinine doubling. An acute dip in estimated glomerular filtration rate (eGFR) over 10% was surveyed after SGLT2i use.

RESULTS

During the mean follow-up of 62.9 ± 42.2 mo, the SGLT2i group had a lower risk of primary composite outcome than the control group in the multivariate and propensity score-matched models (adjusted hazard ratio, 0.43; 95% confidence interval, 0.24-0.78; P = 0.006 and adjusted hazard ratio, 0.45; 95% confidence interval, 0.24-0.85; P = 0.013, respectively). Multivariate analyses consistently showed a decreased risk of DCGF and serum creatinine doubling in the SGLT2i group. The overall eGFR remained stable without the initial dip after SGLT2i use. A minority (15.6%) of the SGLT2i users showed acute eGFR dip during the first month, but the eGFR recovered thereafter. The risk factors for the eGFR dip were time from transplantation to SGLT2i usage and mean tacrolimus trough level.

CONCLUSIONS

SGLT2i improved a composite of all-cause mortality, DCGF, or serum creatinine doubling in KTRs. SGLT2i can be used safely and have beneficial effects on preserving graft function in diabetic KTRs.

Prevention of Post-Transplant Diabetes Mellitus: Towards a Personalized Approach

Post-transplant diabetes is a frequent complication after transplantation. Moreover, patients suffering from post-transplant diabetes have increased cardiovascular morbidity and reduced survival. Pathogenesis mainly involves beta-cell dysfunction in presence of insulin resistance. Both pre- and post-transplant risk factors are well-described, and some of them may be corrected or prevented. However, the frequency of post-transplant diabetes has not decreased in recent years. We realized a critical appraisal of preventive measures to reduce post-transplant diabetes.

Impact of antibody induction on the outcomes of new onset diabetes after kidney transplantation: a registry analysis

PURPOSE

We conducted this observational study to examine the impact of antibody inductions administered at kidney transplant (KT) on outcomes of 5 year exposure to post-transplant diabetes (PTDM) in adult deceased-donor kidney transplant recipients (DDKTRs). We also studied the risk of PTDM associated with antibody inductions.

METHODS

Using 2000-2016 Organ Procurement Transplantation Network data, we employed multivariable Cox models to determine the adjusted hazard ratios (HR) of death, and overall and death-censored graft loss (OAGL, DCGL; respectively) at the 5 year landmark period in antibody induction cohorts with and without PTDM at the 1 year post-transplant index time point. We used multivariable logistic regression in determining the risk factors for PTDM. All multivariable analyses were adjusted for the potential confounding effects of maintenance immunosuppression, steroid regimens, and other relevant covariates.

RESULTS

48,031 adult DDKTRs were classified into cohorts based on antibody induction at transplant: (anti-thymocyte globulin) ATG (n = 26, 788); (alemtuzumab) ALM (n = 5916); and interleukin-2 receptor antagonist (IL-2RA) (n = 15,327). PTDM was a risk factor for 5 year OAGL and death, not DCGL [(HR = 1.25, CI = 1.16-1.36), (HR = 1.13, CI = 1.06-1.21), and (HR = 1.05, CI = 0.96-1.16); respectively]. Induction regimens were not risk factors for 5 year outcomes in DDKTRs with and without PTDM. Risk factors for PTDM included DDKTR obesity, age > / = 50 years, acute rejection, and ATG induction, among others.

CONCLUSIONS

In adult DDKTRs, after controlling the confounding effects of clinically relevant variables including maintenance and steroid regimens, PTDM at 1 year post-transplant is associated with death and OAGL, not DCGL in the following 5 years: induction received at KT did not modify these associations.

Association of British Clinical Diabetologists and Renal Association guidelines on the detection and management of diabetes post solid organ transplantation

Post-transplant diabetes mellitus (PTDM) is common after solid organ transplantation (SOT) and associated with increased morbidity and mortality for allograft recipients. Despite the significant burden of disease, there is a paucity of literature with regards to detection, prevention and management. Evidence from the general population with diabetes may not be translatable to the unique context of SOT. In light of emerging clinical evidence and novel anti-diabetic agents, there is an urgent need for updated guidance and recommendations in this high-risk cohort. The Association of British Clinical Diabetologists (ABCD) and Renal Association (RA) Diabetic Kidney Disease Clinical Speciality Group has undertaken a systematic review and critical appraisal of the available evidence. Areas of focus are; (1) epidemiology, (2) pathogenesis, (3) detection, (4) management, (5) modification of immunosuppression, (6) prevention, and (7) PTDM in the non-renal setting. Evidence-graded recommendations are provided for the detection, management and prevention of PTDM, with suggested areas for future research and potential audit standards. The guidelines are endorsed by Diabetes UK, the British Transplantation Society and the Royal College of Physicians of London. The full guidelines are available freely online for the diabetes, renal and transplantation community using the link below. The aim of this review article is to introduce an abridged version of this new clinical guideline ( https://abcd.care/sites/abcd.care/files/site_uploads/Resources/Position-Papers/ABCD-RA%20PTDM%20v14.pdf).

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Serum uric acid is associated with increased risk of posttransplantation diabetes in kidney transplant recipients: a prospective cohort study

BACKGROUND

Serum uric acid (SUA) is associated with fasting glucose in healthy subjects, and prospective epidemological studies have shown that elevated SUA is associated with increased risk of type 2 diabetes. Whether SUA is independently associated with higher risk of posttransplantation diabetes mellitus (PTDM) in kidney transplant recipients (KTR) remains unknown.

METHODS

We performed a longitudinal cohort study of 524 adult KTR with a functioning graft ≥1-year, recruited at a university setting (2008-2011). Multivariable-adjusted Cox proportional-hazards regression analyses were performed to assess the association between time-updated SUA and risk of PTDM (defined according the American Diabetes Association's diagnostic criteria).

RESULTS

Mean (SD) SUA was 0.43 (0.11) mmol/L at baseline. During 5.3 (IQR, 4.1-6.0) years of follow-up, 52 (10%) KTR developed PTDM. In univariate prospective analyses, SUA was associated with increased risk of PTDM (HR 1.75, 95% CI 1.36-2.26 per 1-SD increment; P < 0.001). This finding remained materially unchanged after adjustment for components of the metabolic syndrome, lifestyle, estimated glomerular filtration rate, immunosuppressive therapy, cytomegalovirus and hepatitis C virus infection (HR 1.89, 95% CI 1.32-2.70; P = 0.001). These findings were consistent in categorical analyses, and robust in sensitivity analyses without outliers.

CONCLUSIONS

In KTR, higher SUA levels are strongly and independently associated with increased risk of PTDM. Our findings are in agreement with accumulating evidence supporting SUA as novel independent risk marker for type 2 diabetes, and extend the evidence, for the first time, to the clinical setting of outpatient KTR.

Efficacy and Safety of SGLT-2 Inhibitors for Treatment of Diabetes Mellitus among Kidney Transplant Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The objective of this systematic review was to evaluate the efficacy and safety profiles of sodium-glucose co-transporter 2 (SGLT-2) inhibitors for treatment of diabetes mellitus (DM) among kidney transplant patients.

METHODS

We conducted electronic searches in Medline, Embase, Scopus, and Cochrane databases from inception through April 2020 to identify studies that investigated the efficacy and safety of SGLT-2 inhibitors in kidney transplant patients with DM. Study results were pooled and analyzed utilizing random-effects model.

RESULTS

Eight studies with 132 patients (baseline estimated glomerular filtration rate (eGFR) of 64.5 ± 19.9 mL/min/1.73m2) treated with SGLT-2 inhibitors were included in our meta-analysis. SGLT-2 inhibitors demonstrated significantly lower hemoglobin A1c (HbA1c) (WMD = -0.56% [95%CI: -0.97, -0.16]; p = 0.007) and body weight (WMD = -2.16 kg [95%CI: -3.08, -1.24]; p < 0.001) at end of study compared to baseline level. There were no significant changes in eGFR, serum creatinine, urine protein creatinine ratio, and blood pressure. By subgroup analysis, empagliflozin demonstrated a significant reduction in body mass index (BMI) and body weight. Canagliflozin revealed a significant decrease in HbA1C and systolic blood pressure. In terms of safety profiles, fourteen patients had urinary tract infection. Only one had genital mycosis, one had acute kidney injury, and one had cellulitis. There were no reported cases of euglycemic ketoacidosis or acute rejection during the treatment.

CONCLUSION

Among kidney transplant patients with excellent kidney function, SGLT-2 inhibitors for treatment of DM are effective in lowering HbA1C, reducing body weight, and preserving kidney function without reporting of serious adverse events, including euglycemic ketoacidosis and acute rejection.

The usefulness of glycated albumin for post-transplantation diabetes mellitus after kidney transplantation: A diagnostic accuracy study

BACKGROUND

There is no study evaluating the use of glycated albumin (GA) for the detection of post-transplantation diabetes mellitus (PTDM) in kidney transplant recipients. We evaluated the overall accuracy of GA at four months after kidney transplantation.

METHODS

Diagnostic test accuracy study including 134 kidney transplant recipients without pre-existing diabetes. Receiver operator characteristic (ROC) curve was used to estimate sensitivity, specificity, likelihood ratios and area under the curve (AUC) for GA, considering oral glucose tolerance test (OGTT) and/or glycated hemoglobin (HbA1c) as reference criteria.

RESULTS

Thirty-three patients were diagnosed with PTDM by OGTT and/or HbA1c ≥ 6.5%. GA showed moderate accuracy to detect PTDM [AUC 0.673 (95% CI 0.557-0.789, p < 0.01)]. The use of OGTT and/or HbA1c ≥ 6.2% increased the number of PTDM cases from 33 to 38, and AUC was 0.713 (95% CI 0.608-0.819, p < 0.01). GA ≥ 17% showed specificity close to 90% when OGTT and/or HbA1c ≥ 6.5% were used as reference tests.

CONCLUSIONS

GA showed low diagnostic accuracy for the detection of PTDM at the fourth month after transplantation. The use of a single GA point is not enough for the screening and diagnosis of PTDM; however, GA ≥ 17% presented high specificity to rule in the disease after kidney transplantation.

A Triple-Blind Randomized Controlled Trial on Impacts of Pioglitazone on Oxidative Stress Markers in Diabetic Kidney Transplant Recipients

Background: Oxidative stress as a major mediator of adverse outcomes in kidney transplant recipients who are prone to oxidative stress-mediated injury by pre-transplant and post-transplant conditions. Objectives: The purpose of this study was to assess the effects of Pioglitazone on oxidative stress biomarkers and blood glucose control in diabetic patients receiving insulin after kidney transplantation. Methods: In a triple-blind randomized placebo-controlled trial, sixty-two kidney transplanted diabetic patients (40 men and 24 women) were followed for 4 months after randomly assigned to the placebo group and Pioglitazone group (30 mg/d). All of the patients continued their insulin therapy irrespective of the group that they were assigned to evaluate the effects of the addition of pioglitazone on blood glucose and oxidative stress biomarkers, Malondialdehyde (MDA) and total protein carbonyls (TPC) serum levels. Results: At baseline, there were no statistically significant differences in glycemic control levels and oxidative markers between the two groups. After 4 months of intervention, a significant improvement occurred in Hemoglobin A1c (HBA1c) in the Pioglitazone group. The changes of HBA1c during 4 months of follow up in the Pioglitazone group show improvement in glucose control were as HBA1c in the placebo group increased by 0.3% (P = 0.0001). Moreover, at the end of the study, the MDA level was significantly lower in the Pioglitazone group (P < 0.0001, 1.22 - 3.90). Regarding the serum level of TPC, the changes were not statistically different at baseline and also at the end of the study between two groups. Conclusions: Administration of Pioglitazone in addition to insulin in diabetic kidney transplant patients not only improved glycemic control (evidenced by HBA1c) but also significantly decreased oxidative stress markers such as MDA.

Incidence of Post-transplantation Diabetes Mellitus Within 1 Year After Kidney Transplantation and Related Factors in Korean Cohort Study

BACKGROUND

Post-transplantation diabetes mellitus (PTDM) is associated with a higher risk of mortality and graft loss. The reported incidence of PTDM after kidney transplantation (KT) varies from 10% to 74% and varies by country and ethnicity. There are few reports of nationwide cohort studies on PTDM incidence and related factors in Korea. The purpose of this study was to evaluate incidence of PTDM and related factors within 1 year after KT in Korea.

METHODS

The KoreaN cohort study for Outcome in patients With Kidney Transplantation (KNOW-KT) enrolled 1080 recipients from July 2012 to August 2016. This study included 723 recipients, excluding 273 patients with pretransplant DM and 84 patients who were lost from follow-up within 1 year after KT.

RESULTS

Among 723 recipients, 85 (11.8%) recipients were diagnosed and treated with PTDM. Recipient age, HLA mismatches, hemoglobin A1c (HbA1c), waist-hip ratio (WHR), and use of prednisolone were significantly higher in PTDM group than the nondiabetic group. In the multivariable logistic regression analysis, independent risk factors for PTDM were older recipient age, higher WHR, and HbA1c before KT.

CONCLUSION

The incidence of PTDM was 11.8% in a nationwide Korean cohort study. The factors related to the development of PTDM within 1 year after KT were older recipient age and higher WHR, and HbA1c levels before KT. In recipients with high WHR, it is important to control pretransplant abdominal obesity to prevent PTDM after KT.

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.

Prospective randomized study of conversion from tacrolimus to cyclosporine A to improve glucose metabolism in patients with posttransplant diabetes mellitus after renal transplantation

Tacrolimus (TAC) increases the risk of posttransplant diabetes (PTDM) compared with cyclosporine A (CYC). The present 12-month, multicenter, investigator-driven, prospective, randomized study was designed to assess whether conversion from tacrolimus to CYC can reverse PTDM after renal transplantation. Predominantly white patients with PTDM according to the 2005 American Diabetes Association criteria were randomized to either replacement of TAC with CYC or continuation of their TAC-based regimen after stratification for type of glucose-lowering therapy, steroid therapy, and hepatitis C status. At 12 months, 14 of 41 patients with complete data in the CYC arm (34%; 95%CI 19%-49%) were free of diabetes, whereas this was the case in only 4 of 39 patients (10%; 95%CI 3%-20%) in the TAC arm (P = .01). At 12 months, 39% of patients in the CYC arm were off glucose-lowering medication vs 13% of patients in the TAC arm (P = .01). The CYC group decreased glycated hemoglobin level during the 12-month follow-up, resulting in significantly lower levels compared with the TAC group (6.0 ± 0.9% vs 7.1 ± 1.7% at 12 months; P = .002). In conclusion, replacement of TAC with CYC significantly improves glucose metabolism and has the potential to reverse diabetes during the first year after conversion. (EU Clinical Trials Register No. 2006-001765-42).

Defining kidney allograft benefit from successful pancreas transplant: separating fact from fiction

PURPOSE OF REVIEW

To define the natural history of kidney allograft loss related to recurrent diabetes following transplant, and to understand the potential benefit of pancreas transplantation upon kidney allograft survival.

RECENT FINDINGS

A postulated benefit of simultaneous pancreas kidney transplant is that, unlike kidney transplant alone, euglycemia from the added pancreas allograft may confer a nephroprotective benefit and prevent recurrent diabetic nephropathy in the renal allograft. Recent large database analyses and long-term histological assessments have been published that assist in quantifying the problem of recurrent diabetic nephropathy and answering the question of the potential benefits of euglycemia. Further data may be extrapolated from larger single-center series that follow the prognosis of early posttransplant diabetes mellitus as another barometer of risk from diabetic nephropathy and graft loss.

SUMMARY

Recurrent diabetic nephropathy following kidney transplant is a relatively rare, late occurrence and its clinical significance is significantly diminished by the competing risks of death and chronic alloimmune injury. Although there are hints of a protective effect upon kidney graft survival with pancreas transplant, these improvements are small and may take decades to appreciate. Clinical decision-making regarding pancreas transplant solely based upon nephroprotective effects of the kidney allograft should be avoided.

Inflammatory and related biomarkers are associated with post-transplant diabetes mellitus in kidney recipients: a retrospective study

In this study, we investigate the association between selected inflammatory-related biomarkers and post-transplant hyperglycemia in kidney transplant recipients. This retrospective analysis comprises 852 patients receiving a kidney transplant at the Norwegian national transplant center between 2007 and 2012, all having a normal oral glucose tolerance test (OGTT) before transplantation. A diagnostic OGTT was performed 10 weeks post-transplant to examine the association between inflammation-related biomarkers and two-hour plasma glucose (2HPG) by multivariable linear regression models adjusting for BMI, age, graft function, fasting insulin levels, dosage of prednisolone, and concentration of calcineurin inhibitors. Six of 20 biomarkers were significantly associated with 2HPG in multivariate analyses showing strong associations with soluble tumor necrosis factor type 1 (P = 0.027), Pentraxin 3 (P = 0.019), macrophage migration inhibitory factor (P = 0.024), and endothelial protein C receptor (P = 0.001). These associated markers reflect several distinct but also overlapping pathways including activation of tumor necrosis factor, macrophages, and endothelial cells. The multinomial logistic regression model showed a clear association between the inflammatory biomarkers and post-transplant diabetes mellitus (PTDM). The association between a range of inflammation markers and PTDM suggests that these markers may be target for future studies on pathogenesis and perhaps also treatment of PTDM.

Haptoglobin 2-2 Genotype, Patient, and Graft Survival in Renal Transplant Recipients

BACKGROUND

Cardiovascular disease is the leading cause of death in renal transplant recipients. An association between haptoglobin genotype 2-2 and cardiovascular disease has been found in patients with diabetes mellitus and liver transplant recipients. To date, the role of haptoglobin genotype after renal transplantation has not been studied.

METHODS

In this single-center retrospective cohort study of 1975 adult Norwegian transplant recipients, who underwent transplantation between 1999 and 2011, we estimated the risk of all-cause and cardiovascular mortality and overall and death-censored graft loss for patients with haptoglobin genotype 2-2 compared to genotype 2-1 or 1-1, after adjustment for confounders and competing risks.

RESULTS

We found no associations between haptoglobin genotype 2-2 and cardiovascular mortality (subdistributional hazard ratio 1.08, 95% confidence interval 0.78-1.49; P = .63). We also failed to detect any association between haptoglobin 2-2 genotype and all-cause mortality, overall graft loss, and death-censored graft loss. Similar results were found in the subpopulation of transplant recipients with diabetes.

CONCLUSION

In this large cohort of kidney transplant recipients, we could not demonstrate any association between haptoglobin 2-2 genotype and patient or graft survival after renal transplantation.

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.