Obesity as an isolated contraindication to kidney transplantation in the end-stage renal disease population: A cohort study

Engineering Equity Into the Promise of Xenotransplantation

Two of the greatest challenges facing kidney transplantation are the lack of donated organs and inequities in who receives a transplant. Xenotransplantation holds promise as a treatment approach that could solve the supply problem. Major advances in gene-editing procedures have enabled several companies to raise genetically engineered pigs for organ donation. These porcine organs lack antigens and have other modifications that should reduce the probability of immunological rejection when transplanted into humans. The US Food and Drug Administration and transplantation leaders are starting to chart a path to test xenotransplants in clinical trials and later integrate them into routine clinical care. Here we provide a framework that industry, regulatory authorities, payers, transplantation professionals, and patient groups can implement to promote equity during every stage in this process. We also call for immediate action. Companies developing xenotransplant technology should assemble patient advocacy boards to bring the concerns of individuals with end-stage kidney disease to the forefront. For trials, xenotransplantation companies should partner with transplant programs with substantial patient populations of racial and ethnic minority groups and that have reciprocal relationships with those communities. Those companies and transplant programs should reach out now to those communities to inform them about xenotransplantation and try to address their concerns. These actions have the potential to make these communities full partners in the promise of xenotransplantation.

Comparable kidney transplant outcomes in selected patients with a body mass index ≥ 40: A personalized medicine approach to recipient selection

INTRODUCTION

Many kidney transplant (KT) centers decline patients with a body mass index (BMI) ≥40 kg/m2 . This study's aim was to evaluate KT outcomes according to recipient BMI.

METHODS

We performed a single-center, retrospective review of adult KTs comparing BMI ≥40 patients (n = 84, BMI = 42 ± 2 kg/m2 ) to a matched BMI < 40 cohort (n = 84, BMI = 28 ± 5 kg/m2 ). Patients were matched for age, gender, race, diabetes, and donor type.

RESULTS

BMI ≥40 patients were on dialysis longer (5.2 ± 3.2 years vs. 4.1 ± 3.5 years, p = .03) and received lower kidney donor profile index (KDPI) kidneys (40 ± 25% vs. 53 ± 26%, p = .003). There were no significant differences in prevalence of delayed graft function, reoperations, readmissions, wound complications, patient survival, or renal function at 1 year. Long-term graft survival was higher for BMI ≥40 patients, including after adjusting for KDPI (BMI ≥40: aHR = 1.79, 95% CI = 1.09-2.9). BMI ≥40 patients had similar BMI change in the first year post-transplant (delta BMI: BMI ≥ 40 +.9 ± 3.3 vs. BMI < 40 +1.1 ± 3.2, p = .59).

CONCLUSIONS

Overall outcomes after KT were comparable in BMI ≥40 patients compared to a matched cohort with lower BMI with improved long-term graft survival in obese patients. BMI-based exclusion criteria for KT should be reexamined in favor of a more individualized approach.

An ethical analysis of obesity as a contraindication of pediatric kidney transplant candidacy

The inclusion of body mass index (BMI) as a criterion for determining kidney transplant candidacy in children raises clinical and ethical challenges. Childhood obesity is on the rise and common among children with kidney failure. In addition, obesity is reported as an independent risk factor for the development of CKD and kidney failure. Resultantly, more children with obesity are anticipated to need kidney transplants. Most transplant centers around the world use high BMI as a relative or absolute contraindication for kidney transplant. However, use of obesity as a relative or absolute contraindication for pediatric kidney transplant is controversial. Empirical data demonstrating poorer outcomes following kidney transplant in obese pediatric patients are limited. In addition, pediatric obesity is distributed inequitably among groups. Unlike adults, most children lack independent agency to choose their food sources and exercise opportunities; they are dependent on their families for these choices. In this paper, we define childhood obesity and review (1) the association and impact of obesity on kidney disease and kidney transplant, (2) existing adult guidelines and rationale for using high BMI as a criterion for kidney transplant, (3) the prevalence of childhood obesity among children with kidney failure, and (4) the existing literature on obesity and pediatric kidney transplant outcomes. We then discuss ethical considerations related to the use of obesity as a criterion for kidney transplant.

Outcomes of kidney transplant recipients who underwent pre-transplant bariatric surgery for severe obesity: a long-term follow-up study

BACKGROUND

Kidney transplantation (KT) is the preferred therapy for end-stage renal disease (ESRD). While a major cause for ESRD, obesity is also a key obstacle to candidacy for KT. Bariatric surgery, particularly sleeve gastrectomy (SG), is increasingly used to improve access to KT in patients with obesity, but the literature especially on outcomes post-KT remains lacking. We aimed to provide a long-term follow-up analysis of efficacy and outcomes of a previously described cohort of patients with obesity, who had SG as a means for access to KT.

METHODS

This is a single-center retrospective follow-up study of 32 patients with advanced chronic kidney disease or ESRD, who were referred and underwent SG between 2013 and 2018 as an access strategy to KT. The primary outcome was successful KT. Ninety-day outcomes, long-term graft function, and changes in weight and obesity-related comorbidities after KT were assessed. Descriptive statistics are presented as count (percentage) or median (interquartile range).

RESULTS

At baseline, 18 (56%) were male with a median age and BMI of 51 (11) years and 42.3 (5.2) kg/m², respectively. Median follow-up time post-SG was 53 (58) months. At last follow-up, 23 (72%) patients received KT. Median time to KT was 16 (20) months and BMI was 34.0 (5.1) kg/m² at time of transplant. At KT, 13 (57%) and 20 (87%) had diabetes and hypertension, respectively. Median follow-up post-KT was 16 (47) months. There was one graft loss requiring return to dialysis. At 5-year post-KT, median serum creatinine was 136 (66) µmol/l. At last follow-up post-KT, median BMI remained at 33.7 (7.6) kg/m². Among patients with diabetes and hypertension, 7/13 (54%) and 5/20 (25%) had either improvement or remission of their comorbidities, respectively.

CONCLUSION

SG is an effective strategy to improve access to KT in patients with severe obesity. Transplant recipients also continue to benefit from sustained weight loss and improved related comorbidities that may positively impact their graft function after KT.

Impact of refitted race-free eGFR formula on obesity pharmacotherapy options

OBJECTIVE

Recent changes to the Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration rate (eGFR) formula (2021 CKD-EPI) removed race from the 2009 formula, increasing the number of Black people classified as having CKD, but these changes may impact eligibility and/or dosing for antiobesity medications. This study estimated the number of people with obesity nationwide who might have pharmacotherapy options impacted by the new formula.

METHODS

Using National Health and Nutrition Examination Survey (NHANES) cohort study data, the number of people eligible for antiobesity medication was estimated, and the number who would require a dosage reduction or would no longer be eligible for specific medications based on the new eGFR formula was also estimated.

RESULTS

Among 16,412,571 Black and 109,654,751 non-Black people eligible for antiobesity medication, 911,336 (6.1%) Black and 6,925,492 (6.6%) non-Black people had ≥CKD stage 3 by the 2009 CKD-EPI formula. Applying the 2021 CKD-EPI formula, 1,260,969 (8.5%) Black people and 4,989,919 (4.7%) non-Black people had ≥CKD stage 3. For medications requiring renal adjustment, the number of Black people who would require a lower dose or be precluded from using a medication increased by 24.7% to 50.2%.

CONCLUSIONS

These findings highlight the importance of measuring-rather than estimating-GFR in Black people with CKD when considering many antiobesity pharmacotherapy options.

Gender Disparities in Kidney Transplantation Referral Vary by Age and Race – A Multi-Regional Cohort Study in the Southeast US

Introduction

Methods

Results

Conclusion

Weight Loss Challenges in Achieving Transplant Eligibility in Patients With Kidney Failure: A Qualitative Study

Rationale & Objective

Patients with kidney failure need kidney replacement therapy to maximize survival. Kidney transplant is a superior mode of kidney replacement therapy for most individuals with kidney failure. Patients with obesity often are not approved for kidney transplant until they lose sufficient weight, as obesity may complicate the surgical procedure, and the risk of graft loss increases with a higher body mass index. To help potential kidney transplant recipient candidates lose weight, further knowledge of their thoughts, feelings, and attitudes is needed.

Study Design

Qualitative study with semistructured interviews and an exploratory research design, guided by qualitative content analysis.

Setting & Participants

Patients at a hospital in Denmark required to lose weight to achieve kidney transplant eligibility.

Analytical Approach

From patients’ responses, we identified descriptive themes using a phenomenological approach. The factors affecting outcomes were derived reflexively from these themes.

Results

Ten interviews were analyzed. Experiences of obesity and weight-loss attempts were described across 4 themes; (1) restrictions and exhaustion, (2) hope and hopelessness, (3) support and self-discipline, and (4) motivation based on severity. A major motivating factor to achieving weight loss in the studied group of patients was their declining kidney function and the fact that kidney transplant cannot be considered until sufficient weight loss is achieved.

Limitations

Thematic saturation was reached after an unexpectedly low number of participants. The patients were only interviewed once and over the phone.

Conclusions

Patients with obesity who are seeking kidney transplant need additional help with the dietary restrictions brought on by kidney disease. They need assistance bridging between a kidney-friendly diet and a sustainable diet that will ensure weight loss. These patients also express not wanting to feel alone in their weight-loss battle. They are looking for help and support to achieve weight loss.