Access to renal transplantation in the diabetic population-effect of comorbidities and body mass index

Diabetic kidney disease versus non‐diabetic kidney disease in type 2 diabetic patients on dialysis: An observational cohort

Background

All chronic kidney diseases in diabetic patients are not diabetic kidney diseases. The objective was to compare the clinical characteristics, survival and access to transplantation in diabetic patients starting dialysis and classified either as diabetic kidney disease (DKD) or non‐diabetic kidney disease in diabetic patients (NDKD).

Methods

We used the nationwide French REIN registry to analyse baseline clinical characteristics at dialysis inception and outcomes defined as kidney transplantation, deaths and their causes. The probability of death or transplantation was analysed using a multivariate Cox model and the Fine and Gray competing for risk model (sdHT).

Results

We included 65,136 patients from January 2009 to December 2015 with a median follow‐up of 31 months. The cumulative incidence of kidney transplantation over eight years was 46.9% (44.8–48.9) in non‐diabetic patients (ND), higher than the 19.3% (17.5–21.2) in the DKD group and 22.2% (18.4–26.7) in the NDKD group. The risk of death was significantly higher in the NDKD group than in the DKD group, even after accounting for the competing risk of transplantation (NDKD/sdHR 1.22; 95%CI 1.18–1.27; p < 0.005 vs. DKD/sdHR 1.12; 95%CI 1.08–1.16; p < 0.005 with adjustment for age, sex, major adverse cardiovascular events, cancer and chronic respiratory failure, compared to ND).

Conclusions

In diabetic patients starting dialysis, patients in the DKD group had reduced access to kidney transplantation. NDKD patients had a higher risk of mortality than DKD. The distinction between DKD and NDKD should be accounted for in the plan of care of diabetic patients starting dialysis.

Outcomes of end-stage renal disease patients on the waiting list for deceased donor kidney transplantation: A single-center study

Background

Kidney transplantation is an effective renal replacement therapy for patients with end-stage renal disease (ESRD). In this study, we assessed the impact of the baseline characteristics and comorbidities of ESRD patients on the probability of deceased donor kidney transplantation (DDKT) and evaluated the morbidity and mortality during the time spent waiting.

Methods

The study population consisted of 544 ESRD patients on the waiting list for DDKT at Chungnam National University Hospital in South Korea between February 2000 and October 2015. The patients were observed from the date of transplantation list registration to the date of transplantation. Baseline characteristics and comorbidities were investigated together with new-onset comorbidities that occurred during the waiting time.

Results

Diabetes mellitus (39.0%), hypertension (25.2%), and glomerulonephritis (21.3%) were the three most common causes of ESRD in this study, and coronary artery disease (9.4%) was the most common comorbidity. The 115 patients (19.3%) who underwent DDKT had a mean waiting time of 1,711 days (768–2,654 days or 4.68 years [2.10–7.27]). Blood groups other than type O, peritoneal dialysis, and nondiabetic ESRD were significantly associated with a higher likelihood of DDKT. Infection was the leading cause of death and the most common comorbidity that arose during the waiting time. Patients who experienced cardiovascular events during the waiting time showed a lower transplant rate compared with those who did not.

Conclusion

The prevalence of comorbidities was high in renal transplantation candidates. During the often-long waiting time, new comorbidities may occur, with long-term sequelae limiting access to kidney transplantation or resulting in death.

Obesity and access to kidney transplantation in patients starting dialysis: A prospective cohort study

Background

Obesity has been linked to poor access to medical care. Although scientific evidence suggest that kidney transplantation improves survival and quality of life in obese patients with end-stage renal disease (ESRD), few data exist on the impact of obesity on access to kidney transplantation in this population.

Objectives

We aimed to characterize the relationships between body mass index (BMI) at the start of dialysis, changes in BMI after the start of dialysis, and either access to kidney transplantation or overall mortality in dialysis or transplantation among ESRD patients.

Methods

Between 2002 and 2011, 19524 dialysis patients with ESRD were included in the study via the French nationwide Renal Epidemiology and Information Network. Data on sociodemographic factors, comorbidities and laboratory test results were recorded upon entry into the registry. BMI were obtained at the start of dialysis and then yearly. Cubic spline regression analyses provided a graphic evaluation of the relationships between BMI at the start of dialysis and outcomes. Joint models were used to evaluate the association between the change over time in BMI and outcomes.

Results

During a median follow-up of 20.3 months, 6634 patients underwent kidney transplantation. A BMI >31 kg/m² at the start of the dialysis was associated with a lower likelihood of receiving a kidney transplant, and the likelihood decreased even further with higher BMI values. For patients with BMI ≥30kg/m² at the start of the dialysis, a 1 kg/m² decrease in BMI during follow-up was associated with a 9% to 11% increase in the likelihood of receiving a transplant. There was an L-shaped relationship between BMI at the start of dialysis and overall mortality. We showed that obese patients with ESRD face barriers to the receipt of a kidney transplant without valid reasons.

Conclusion

Greater attention to this issue would improve the fairness of the organ allocation process and might improve outcomes for obese patients with ESRD.

Survey of Canadian Kidney Transplant Specialists on the Management of Morbid Obesity and the Transplant Waiting List

Background:

Obesity is associated with increased surgical complications and long-term cardiovascular mortality. Studies of access in kidney transplantation have found a bias against obese patients on the wait-listing.

Objective:

To determine the current state of clinical practice for the management of obesity in kidney transplantation.

Design:

A survey in two versions, PDF and traditional paper, composed of categorical questions.

Setting:

A pan-Canadian survey of transplant nephrologists and surgeons.

Methods:

The survey PDF was distributed electronically to the Kidney Group of the Canadian Society of Transplantation. A shorter, hardcopy version was distributed subsequently at a national transplant meeting.

Results:

There were 47 responses, including almost every Canadian adult transplant program. Most (81%) reported the use of a body mass index limit for access to the waiting list. However, only 40% reported a strict enforcement. There were several instances of intra-hospital disagreements regarding the use of a policy, among the centers with multiple responses. The body mass index limit was most commonly 40 kg/m² (62%), followed by 35 kg/m² (36%). Despite the body mass index limit, few centers (30%) reported having a weight management program. The reported experience with bariatric surgery was small, though nearly all replied that they would refer to a bariatric specialist in the future.

Limitations:

This national survey provides a broad assessment of clinical practice. The distinction between an official policy and informal clinical tendencies is difficult. The results cannot be used to support any specific limit or policy.

Conclusions:

This survey found that the body mass index limit for access to the kidney transplant waiting list was common in Canada. Several inconsistencies suggest a lack of official policy. To achieve equity in access, clear guidelines for obesity should be established and enforced. Bariatric surgery has the promise of rapid weight loss. Resource allocation to study obesity in transplant patients will be essential.

Absence of the Effect of Pretransplant Body Mass Index on Post Kidney Transplant Outcomes

CONTEXT

Obesity has been reported as risk factor for reduced posttransplant graft and patient survival and increased delayed graft function (DGF).

OBJECTIVE

The purpose of this work is to analyze the effect of body mass index (BMI) on defined transplant outcomes in patients transplanted under defined guidelines in a kidney transplant program.

DESIGN

Review of a prospectively collected database in renal transplant recipients receiving rabbit antithymocyte globulin induction, mycophenolate mofetil, tacrolimus, and early corticosteroid withdrawal between 2001 and 2011.

SETTING

This review was conducted in a single abdominal transplant program in the United States.

MAIN OUTCOME MEASURES

Primary outcome was death-censored graft survival categorized by posttransplant body mass groups. Secondary outcomes included DGF as well as patient survival.

RESULTS

Four hundred sixty seven patients were identified. No difference was observed in graft survival or DGF between BMI groups. One-year, death-censored graft survival and patient survival rates ranged from 97.5% to 100% and 96.6% to 100%, respectively. Delayed graft function was uncommon across all BMI groups, ranging from 5.3% to 9.1%, with the lowest incidence in patients with a BMI ≥ 35 kg/m(2). Biopsy-proven acute rejection rates at 1 year were similar across all groups (10.1%-14%) as were estimated glomerular filtration rates were at 1, 3, and 5 years.

CONCLUSION

Our results do not show an effect of BMI on posttransplant outcomes, suggesting that relaxation of BMI criteria may be warranted for recipient selection.

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.

Obesity and organ transplantation: successes, failures, and opportunities

The increasing rate of societal obesity is also affecting the transplant world through obesity in candidates and donors as well as its posttransplant repercussions. Being overweight and obese has been shown to have significant effects on both short- and long-term complications as well as patient and graft survival. However, much of the comorbidity can be controlled or prevented with careful patient selection and aggressive management. A team approach to managing obesity and its comorbidities both pre- and posttransplant is essential for successful transplant outcomes. Complicating understanding the results of obesity research is the inclusion different weight categories, use of listing vs transplant weights, patient populations large enough for statistical power, and changes in transplant management, especially immunosuppression protocols, anti-infection protocols, and operative techniques. Much more research is needed regarding many elements, including safe weight loss before transplantation, prevention of weight gain after transplant, genomic influences, and the role of bariatric surgery in the transplant process.