Is big bad or bearable? Long-term renal transplant outcomes in obese recipients

Case report of the successful use of semaglutide to achieve target BMI prior to renal transplant in two patients with end-stage-kidney-disease

The following cases demonstrate a proof of concept for the safe and effective use of the glucagon-like-peptide-1 receptor agonist (GLP-1 RA) semaglutide for weight loss in obese, non-diabetic, end stage kidney disease (ESKD) patients on haemodialysis (HD), who are unable to undergo renal transplantation due to obesity. Obesity is a common barrier to wait-listing for renal transplantation with effective, broadly applicable weight loss strategies lacking. GLP-1 RAs have been shown to be effective adjuncts to achieve weight loss in non-diabetic obese people. However, the major clinical trials excluded patients with ESKD on dialysis. This paper outlines the successful use of semaglutide to achieve a target body mass index (BMI) prior to renal transplant wait-listing in two obese, non-diabetic, HD patients. These patients achieved a 16% and 12.6% weight loss in under 9 months with one now waitlisted and the other transplanted. This strategy has the potential for broader use in this patient cohort to improve wait-list times by overcoming this common barrier to renal transplantation.

Effect of weight change after renal transplantation on outcomes of graft survival

BACKGROUND AND OBJECTIVE

After kidney transplantation, there is an overall increase in weight, which may increase the risk of chronic kidney disease (CKD) and graft loss. But, not all patients gain weight, and the impact on the graft of this different evolution has not been well studied. The objective was to determine the causes of this different evolution and its effect on the graft.

PATIENTS AND METHODS

Retrospective single-center cohort study of 201 patients followed up after transplantation, analyzing the determinants of the variation in weight at one year using logistic regression, and its effect on graft survival at the end of follow-up using Cox regression.

RESULTS

Globally, there was an average weight gain of 4.5 kg in the first year, but 26.6% lost weight. 37.2% increased their BMI, while 9.5% decreased it. The determinants of the different evolution of weight were age (OR for every 10 years: 0.6, p = 0.002), previous dialysis modality (ref. hemodialysis) (OR 0.3, p = 0.003), and BMI before transplantation (OR 0.9, p = 0.017). The different evolution of weight did not influence the final situation of the graft. The BMI at one year did influence as a continuous variable (HR 1.3, p = 0.003), and obesity, with a worse evolution (HR 7.0, p = 0.025).

CONCLUSIONS

Although not all patients gain weight after kidney transplantation, the different evolution of weight does not influence graft survival.

The application of body mass index-based eligibility criteria may represent an unjustified barrier to renal transplantation in people with obesity

The prevalence of both obesity and end-stage kidney disease is increasing. In many centres, obesity is considered a relative contraindication to kidney transplantation due to an association with short- and longer-term adverse outcomes. This leads to delayed transplant waitlisting and longer organ waiting times for people with obesity. This review evaluates whether intentional pre-transplant weight loss in people with obesity improves kidney transplant outcomes. There are currently no data showing that non-surgical weight loss of 10% or more improves graft or patient survival over 4-5 years. Outcomes from bariatric surgery cohorts have been generally neutral or favourable after pre-transplant weight loss of ~25%. Given the survival benefit of kidney transplantation compared to maintenance dialysis, and the difficulty of achieving and maintaining weight loss, the common practice of recommending weight loss to achieve arbitrary targets prior to waiting list activation needs to be carefully considered.

Nonlinear relationship between body mass index and clinical outcomes after kidney transplantation: A dose-response meta-analysis of 50 observational studies

BACKGROUND

Exact dose-response relationship between body mass index at transplantation and clinical outcomes after kidney transplantation remained unclear, and no specific body mass index threshold and pretransplant weight loss aim were recommended for kidney transplantation candidates among transplant centers.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched for literature published up to December 31, 2019. The two-stage, random effect meta-analysis was performed to estimate the dose-response relationship between body mass index and clinical outcomes after kidney transplantation.

RESULTS

Ninety-four studies were included for qualitative assessment and 50 for dose-response meta-analyses. There was a U-shaped relationship between graft loss, patient death, and body mass index. Body mass index with the lowest risk of graft loss was 25.2 kg/m², and preferred body mass index range was 22-28 kg/m². Referring to a body mass index of 22 kg/m², the risk of graft loss was 1.088, 0.981, 1.003, and 1.685 for a body mass index of 18, 24, 28, and 40 kg/m², respectively. Body mass index with the lowest risk of patient death was 24.7 kg/m², and preferred body mass index range was 22-27 kg/m². Referring to a body mass index of 22 kg/m², the patient death risk was 1.115, 0.981, 1.032, and 2.634 for a body mass index of 18, 24, 28, and 40 kg/m², respectively. J-shaped relationships were observed between body mass index and acute rejection, delayed graft function, primary graft nonfunction, and de novo diabetes. Pair-wise comparisons showed that higher body mass index was also a risk factor for cardiovascular diseases, hypertension, infection, longer length of hospital stay, and lower estimated glomerular filtration rate level.

CONCLUSION

Underweight and severe obesity at transplantation are associated with a significantly increased risk of graft loss and patient death. A target body mass index at kidney transplantation is 22-27 kg/m².

Effect of weight change after renal transplantation on outcomes of graft survival

BACKGROUND AND OBJECTIVE

After kidney transplantation, there is an overall increase in weight, which may increase the risk of chronic kidney disease (CKD) and graft loss. But, not all patients gain weight, and the impact on the graft of this different evolution has not been well studied. The objective was to determine the causes of this different evolution and its effect on the graft.

PATIENTS AND METHODS

Retrospective single-center cohort study of 201 patients followed up after transplantation, analyzing the determinants of the variation in weight at one year using logistic regression, and its effect on graft survival at the end of follow-up using Cox regression.

RESULTS

Globally, there was an average weight gain of 4.5kg in the first year, but 26.6% lost weight. 37.2% increased their BMI, while 9.5% decreased it. The determinants of the different evolution of weight were age (OR for every 10 years: 0.6, P=.002), previous dialysis modality (ref. hemodialysis) (OR 0.3, P=.003), and BMI before transplantation (OR 0.9, P=.017). The different evolution of weight did not influence the final situation of the graft. The BMI at one year did influence as a continuous variable (HR 1.3, P=.003), and obesity, with a worse evolution (HR 7.0, P=.025).

CONCLUSIONS

Although not all patients gain weight after kidney transplantation, the different evolution of weight does not influence graft survival.