Effect of post-transplant glycemic control on long-term clinical outcomes in kidney transplant recipients with diabetic nephropathy: A multicenter cohort study in Korea

Metformin Use and Long-term Clinical Outcomes in Kidney Transplant Recipients

RATIONALE & OBJECTIVE

Metformin has been recommended for some patients with advanced chronic kidney disease. However, the value of metformin in kidney transplant recipients (KTRs) with pretransplant diabetes mellitus (DM) or posttransplant DM is uncertain. We investigated the clinical effects of metformin in KTRs.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A total of 1,995 KTRs with diabetes from 6 tertiary referral centers in the Republic of Korea.

EXPOSURE

Metformin usage was defined as the use of metformin for>90 days after kidney transplantation; 1,193 KTRs were metformin users, and 802 KTRs did not use metformin. Changing usage of metformin among those exposed for >90 days was also characterized.

OUTCOME

Primary outcomes were all-cause mortality and death-censored graft failure (DCGF). Secondary outcomes were biopsy-proven acute rejection (BPAR) and lactic acidosis events.

ANALYTICAL APPROACH

Survival analyses were conducted using multivariable Cox regression and competing risk analyses using Fine and Gray models. Changes in metformin use over time were modeled using a time-varying covariate. Metformin usage, mean daily dose, and hemoglobin A1c (HbA1c) changes were considered in the landmark analysis to address time-varying confounding.

RESULTS

Metformin use was associated with a lower risk of DCGF (adjusted hazard ratio [AHR], 0.47 [95% CI, 0.23-0.96], P=0.038); there was no significant association with all-cause mortality (AHR, 0.94 [95% CI, 0.32-2.76], P=0.915) or BPAR (AHR 0.98 [95% CI, 0.62-1.54], P=0.942). In the subgroup analysis, metformin usage was associated with a reduced risk of all-cause mortality and a lower risk of DCGF for both pretransplantation DM and posttransplant DM groups. Metformin usage was associated with a lower risk of BPAR in the posttransplant DM group, although it was less effective in the pretransplantation DM group. There was no confirmed case of metformin-associated lactic acidosis (MALA) in the present cohort. A higher dose of metformin was correlated with lower risks of DCGF and BPAR.

LIMITATIONS

Data on newer antidiabetic drugs such as SGLT2 inhibitors are limited, and there is potential limited generalizability to other populations.

CONCLUSIONS

Metformin usage may benefit KTRs, as evidenced by its association with a reduced risk of DCGF and the absence of MALA events. Randomized controlled trials are needed to validate these observational findings.

Continuous Glucose Monitoring in Patients Following Simultaneous Pancreas-Kidney Transplantation: Time in Range and Glucose Variability

Simultaneous pancreas-kidney transplantation (SPKT) can improve long-term patient survival and restore endogenous insulin secretion in recipients with type 1 diabetes (T1D). There are currently few data on glucose fluctuations assessed by continuous glucose monitoring (CGM) after SPKT. Aim: to evaluate CGM-derived time in range (TIR) and glucose variability (GV) in patients with T1D and functioning pancreatic grafts after SPKT. Fifty-four CGM recordings from 43 patients, 15 men and 28 women, aged 34 (31; 39) years were analyzed. Time since SKPT was up to 1 year (group 1, n = 13), from 1 to 5 years (group 2, n = 15), and from 5 to 12 years (group 3, n = 26). TIR (3.9-10 mmol/L), Time Above Range (TAR), Time Below Range (TBR), and GV parameters were estimated. There were no differences in mean glucose (5.5 [5.1; 6.2], 5.9 [5.4; 6.2], and 5.9 [5.6; 6.7] mmol/L), TIR (97.6 [92.8-99.1], 97.2 [93.2; 99.1], and 97.5 [93.4; 99]%); TAR (0, 1.8 [1.3; 3.7], and 2.5 [2; 5]%), TBR (5 [3.3; 12.7], 4.1 [2.2; 10.1], and 3.5 [1.3; 6.5]%) and GV parameters between three groups (all p > 0.05). Thus, recipients with functioning pancreatic grafts demonstrate remarkably high TIR and low GV after SPKT.

Hypoglycemia with insulin in post-transplant diabetes mellitus

INTRODUCTION

To prevent hypoglycemic episodes, the management of insulin therapy against post-transplant diabetes mellitus (PTDM) is important. We compared glargine (long-acting insulin) versus NPH isophane (intermediate-acting insulin) as an armamentarium against PTDM. Indeed, the study evaluated PTDM patients with hypoglycemic episodes treated with isophane or glargine.

MATERIAL AND METHODS

We evaluated a total number of 231 living-donor renal transplant recipients with PTDM of age ≥ 18 years admitted to the hospital between January 2017 and September 2021. However, patients taking hypoglycemic agents before transplantation were excluded from this study. Out of 231 patients, 52 (22.15%) suffered from PTDM out of whom 26 were treated with glargine or isophane.

RESULTS

After applying exclusion criteria, out of 52 PTDM patients 23 were included in the study: 13 PTDM patients were treated with glargine, whereas 10 PTDM patients with isophane. Our analysis revealed 12 episodes of hypoglycemia in glargine-treated PTDM patients compared to 3 in isophane-treated PTDM patients (p = 0.056). Clinically, 9 out of 15 hypoglycemic episodes were nocturnal (60%). Furthermore, no other risk factors were observed in our study population. Detailed analysis showed that both groups had equivalent doses of immunosuppressants and oral hypoglycemic agents. The odds ratio for hypoglycemia in the group treated with isophane compared to that treated with glargine was 0.224 (95% CI, 0.032-1.559). Glargine users recorded significantly lower blood sugar levels before lunch, dinner and at bedtime with p-values of 0.001, 0.009 and 0.001 respectively. A better hemoglobin A1c (HbA1c) level was seen in the glargine vs. isophane group (6.98 ± 0.52 vs. 7.45 ± 0.49, p-value 0.03).

CONCLUSION

The study shows better blood sugar control with long-acting insulin analog, glargine, than with intermediate-actin analog, isophane. Overall, a higher number of hypoglycemic episodes was nocturnal. Long term safety of long-acting insulin analogs needs to be further studied.

Clinical outcomes of posttransplantation diabetes mellitus in kidney transplantation recipients: a nationwide population-based cohort study in Korea

Posttransplantation diabetes mellitus (PTDM) is an important metabolic complication after KT that causes graft failure and cardiovascular complications in kidney transplantation (KT) recipients. Using the national claim data of South Korea, 7612 KT recipients between 2009 and 2017 were analyzed. PTDM was defined as a consecutive 30-day prescription history of antidiabetic medication after KT. Among these patients, 24.7% were diagnosed with PTDM, and 51.9% were diagnosed within 6 months after KT. Compared to patients without PTDM, those with PTDM were older, more likely to be men, more likely to be diagnosed with hypertension and cardio-cerebrovascular disease, and experienced more rejection episodes requiring high-dose steroid treatment after KT. During the follow-up, 607 DCGFs, 230 DWGFs, 244 MACEs, and 260 all-cause mortality events occurred. Patients with PTDM showed a higher risk of DCGF (adjusted hazard ratio [aHR] 1.49; 95% confidence interval [CI] 1.22-1.82; P < 0.001) and MACEs (aHR 1.76; 95% CI 1.33-2.31; P < 0.001) than patients without PTDM. The risks for all clinical outcomes were higher in the insulin group than in the non-use insulin group. PTDM in KT recipients resulted in both worse allograft and patient outcomes represented by DCGF and MACE, especially in patients needing insulin treatment.

Safety and Efficacy of Sodium-glucose Cotransporter 2 Inhibitors in Kidney Transplant Recipients With Pretransplant Type 2 Diabetes Mellitus: A Retrospective, Single-center, Inverse Probability of Treatment Weighting Analysis of 85 Transplant Patients

Supplemental Digital Content is available in the text.

Whether sodium-glucose cotransporter 2 (SGLT2) inhibitors can be used effectively and safely in kidney transplant (KT) recipients with pretransplant type 2 diabetes as the primary cause of end-stage renal disease (ESRD) remains unclear. In this study, we retrospectively analyzed the efficacy and safety of SGLT2 inhibitors compared with other oral hypoglycemic agents (OHAs) in KT recipients with pretransplant type 2 diabetes as the primary cause of ESRD.

Trends in the effects of pre-transplant diabetes on mortality and cardiovascular events after kidney transplantation

AIMS/INTRODUCTION

It is not clear whether survival in kidney transplant recipients with pre-transplant diabetes has improved over the past decades. We compared the rates of mortality and major adverse cardiovascular events (MACE) after renal transplantation in patients with and without pre-transplant diabetes. Furthermore, we investigated whether transplant era and recipient age affected the association between diabetes status and adverse events.

MATERIALS AND METHODS

This retrospective cohort study included 691 patients who underwent renal transplantation between 1994 and 2016 at a single tertiary center. We compared the incidences of post-transplant mortality and four-point MACE in patients with and without pre-transplant diabetes using Kaplan-Meier analysis and the Cox proportional hazard model, and assessed the interactions between diabetes status and transplant era and recipient age.

RESULTS

Of 691 kidney recipients, 143 (20.7%) had pre-transplant diabetes. The mean follow-up duration was 94.5 months. Kaplan-Meier analysis showed that patients with pre-transplant diabetes had higher incidences of post-transplant mortality and four-point MACE compared with those without pre-transplant diabetes (log-rank test, P < 0.001 for both). After adjusting for potential confounding factors, pre-transplant diabetes was associated with an increased risk of post-transplant mortality and four-point MACE (hazard ratio 1.90, 95% confidence interval 1.05-3.44, P = 0.034; and hazard ratio 1.75; 95% confidence interval 1.02-3.00, P = 0.043, respectively). The associations between pre-transplant diabetes status and all-cause mortality and four-point MACE were not affected by transplant era or recipient age.

CONCLUSIONS

Pre-transplant diabetes remains a significant risk factor for mortality and four-point MACE in kidney transplant recipients.

Current Pharmacological Intervention and Medical Management for Diabetic Kidney Transplant Recipients

Hyperglycemia after kidney transplantation is common in both diabetic and non-diabetic patients. Both pretransplant and post-transplant diabetes mellitus are associated with increased kidney allograft failure and mortality. Glucose management may be challenging for kidney transplant recipients. The pathophysiology and pattern of hyperglycemia in patients following kidney transplantation is different from those with type 2 diabetes mellitus. In patients with pre-existing and post-transplant diabetes mellitus, there is limited data on the management of hyperglycemia after kidney transplantation. The following article discusses the nomenclature and diagnosis of pre- and post-transplant diabetes mellitus, the impact of transplant-related hyperglycemia on patient and kidney allograft outcomes, risk factors and potential pathogenic mechanisms of hyperglycemia after kidney transplantation, glucose management before and after transplantation, and modalities for prevention of post-transplant diabetes mellitus.

[Preparation of the dialysis patient with type 1 diabetes mellitus for kidney transplantation]

Kidney transplantation is unique method of renal replacement therapy, allowing to improve quality and duration of life for patients with diabetes mellitus type 1 (DM1) and end-stage renal disease (ESRD) on dialysis therapy. Recently using of innovation technologies for diabetes management and modern immunosuppression enable achieving better results of posttransplant rehabilitation for patients with DM1, especially if kidney transplantation is performed early after initiation of dialysis. Detailed examination of patient with DM1 before potential kidney transplantation is very important to reduce of early and late postoperative complications. Kidney transplantation preparation includes effective glycemic control, adequate dialysis therapy, treatment of diabetes and ESRD complications and concomitant conditions, especially cardiovascular diseases, accounting for kidney transplantation perspective. Furthermore, diagnostics and treatment of any infectious process, timely vaccination, cancer screening are basic approaches of kidney transplantation preparation program, providing the best survival rate of kidney graft and patient.

The risk factors for treatment-related mortality within first three months after kidney transplantation

Mortality at an early stage after kidney transplantation is a disastrous event. Treatment-related mortality (TRM) within 1 or 3 months after kidney transplantation has been rarely reported. We designed a cohort study using the national Korean Network for Organ Sharing database that includes information about kidney recipients between 2002 and 2016. Their demographic, and laboratory data were collected to analyze risk factors of TRM. A total of 19,815 patients who underwent kidney transplantation in any of 40 medical centers were included. The mortality rates 1 month (early TRM) and 3 months (TRM) after transplantation were 1.7% (n = 330) and 4.1% (n = 803), respectively. Based on a multivariate analysis, older age (hazard ratio [HR] = 1.044), deceased donor (HR = 2.210), re-transplantation (HR = 1.675), ABO incompatibility (HR = 1.811), higher glucose (HR = 1.002), and lower albumin (HR = 0.678) were the risk factors for early TRM. Older age (HR = 1.014), deceased donor (HR = 1.642), and hyperglycemia (HR = 1.003) were the common independent risk factors for TRM. In contrast, higher serum glutamic oxaloacetic transaminase (HR = 1.010) was associated with TRM only. The identified risk factors should be considered in patient counselling, and management to prevent TRM. The recipients assigned as the high-risk group require intensive management including glycemic control at the initial stage after transplant.

Management of metabolic alterations in adult kidney transplant recipients: A joint position statement of the Italian Society of Nephrology (SIN), the Italian Society for Organ Transplantation (SITO) and the Italian Diabetes Society (SID)

Chronic metabolic alterations such as post-transplant diabetes mellitus (PTDM), dyslipidaemias and overweight/obesity significantly impact on kidney transplant (KT) outcomes. This joint position statement is based on the evidence on the management of metabolic alterations in KT recipients (KTRs) published after the release of the 2009 KDIGO clinical practice guideline for the care of KTRs. Members of the Italian Society of Nephrology (SIN), the Italian Society for Organ Transplantation (SITO) and the Italian Diabetes Society (SID) selected to represent professionals involved in the management of KTRs undertook a systematic review of the published evidence for the management of PTDM, dyslipidaemias and obesity in this setting. The aim of this work is to provide an updated review of the evidence on the prevention, diagnosis and treatment of metabolic alterations in KTRs, in order to support physicians, patients and the Healthcare System in the decision-making process when choosing among the various available options.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Should Pre-Transplant Hemoglobin A1c Be Used to Predict Post-Transplant Compliance in End-Stage Renal Disease Patients Undergoing Kidney Transplantation?

Background

Patient compliance with immunosuppressive therapy after transplant has impacts on both graft and patient outcomes. For diabetic end-stage renal disease (ESRD) patients who are undergoing evaluation for kidney transplantation in our program, hemoglobin A_1c (HbA_1c) level of >10% is used as a flag that the patient may be at risk for noncompliance and that more comprehensive psychosocial screening is needed prior to transplant. We evaluated the association between pre-transplant HbA_1c level and post-transplant compliance, as no study to date has looked at this in the transplant population.

Material/Methods

The charts of 392 patients who received a kidney transplant at a single institution between July 2008 and June 2012 were retrospectively reviewed. One hundred and sixty-five diabetic patients who received a kidney transplant alone were included in the final analysis. Our predictive variable was HbA_1c level greater than 7.7% based on previous reports in the diabetic population. Outcome measures were graft survival, rejection episodes, unexplained low immunosuppressant levels, and documented noncompliance.

Results

There were no statistically significant differences between the HbA_1c groups of ≤7.7% and >7.7% in outcomes of failed grafts (22.0% and 17.8%, p=0.2), rejection episodes (15.0% and 6.7%, p=0.3), unexplained low immunosuppressant level (46.6% and 37.9%, p=0.3), and documented noncompliance (25.0% and 16.7%, p=0.4).

Conclusions

In diabetic ESRD patients selected for renal transplantation, elevated pre-transplant HbA_1c levels, defined as HbA_1c >7.7%, are not predictive of post-transplant medication compliance. We advocate that this group of patients should not be denied transplant solely on their elevated pre-transplant HbA_1c.

Ten-Year Outcome of Islet Alone or Islet After Kidney Transplantation in Type 1 Diabetes: A Prospective Parallel-Arm Cohort Study

OBJECTIVE

The long-term outcome of allogenic islet transplantation is unknown. The aim of this study was to evaluate the 10-year outcome of islet transplantation in patients with type 1 diabetes and hypoglycemia unawareness and/or a functioning kidney graft.

RESEARCH DESIGN AND METHODS

We enrolled in this prospective parallel-arm cohort study 28 subjects with type 1 diabetes who received islet transplantation either alone (ITA) or after a kidney graft (IAK). Islet transplantation consisted of two or three intraportal infusions of allogenic islets administered within (median [interquartile range]) 68 days (43-92). Immunosuppression was induced with interleukin-2 receptor antibodies and maintained with sirolimus and tacrolimus. The primary outcome was insulin independence with A1C ≤6.5% (48 mmol/mol). Secondary outcomes were patient and graft survival, severe hypoglycemic events (SHEs), metabolic control, and renal function.

RESULTS

The primary outcome was met by (Kaplan-Meier estimates [95% CI]) 39% (22-57) and 28% (13-45) of patients 5 and 10 years after islet transplantation, respectively. Graft function persisted in 82% (62-92) and 78% (57-89) of case subjects after 5 and 10 years, respectively, and was associated with improved glucose control, reduced need for exogenous insulin, and a marked decrease of SHEs. ITA and IAK had similar outcomes. Primary graft function, evaluated 1 month after the last islet infusion, was significantly associated with the duration of graft function and insulin independence.

CONCLUSIONS

Islet transplantation with the Edmonton protocol can provide 10-year markedly improved metabolic control without SHEs in three-quarters of patients with type 1 diabetes, kidney transplanted or not.

XBP1 inhibits mesangial cell apoptosis in response to oxidative stress via the PTEN/AKT pathway in diabetic nephropathy

Diabetic nephropathy (DN) is a complication of diabetes mellitus (DM) that frequently results in renal disease, and is characterized by a variety of symptoms, including albuminuria. It has been shown that apoptosis of glomerular mesangial cells (MCs) can aggravate albuminuria and contribute to the development of diabetic glomerulosclerosis. Hence, determination of the mechanisms leading to MC apoptosis may help us gain insights into the pathogenesis of DN. As our understanding of the role of high glucose (HG) in MC apoptosis remains elusive, we explored the interplay between X‐box binding protein 1 (XBP1) and MC apoptosis in this study. XBP1 was observed to be downregulated both in vivo and in vitro. Treatment of XBP1‐overexpressing cells with HG resulted in a decrease of reactive oxygen species (ROS) and a suppression of cell apoptosis, concomitant with decreases in cleaved caspase‐3 and Bax. Subsequent analyses demonstrated that XBP1 overexpression inhibited the expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and enhanced the activation of AKT in MCs exposed to HG. In addition, XBP1‐induced injuries in MC were reversed by overexpression of PTEN, and XBP1 inhibited apoptosis, which was mediated by the activated PTEN/AKT signaling pathway. Thus, our data indicate that XBP1 can activate the PTEN/AKT signaling pathway, thereby alleviating oxidative stress caused by HG or MC apoptosis. These findings suggest that XBP1 may have potential in the development of treatment methods for DN.