Introduction:
Obesity is an increasingly prevalent condition worldwide, and its impact on kidney transplantation has attracted significant attention. While large registry data have shown that obese patients, particularly those with a body mass index (BMI) ≥ 35, exhibit poorer graft survival compared to individuals with normal BMI, they still demonstrate a survival advantage when compared to remaining on dialysis. However, these conclusions predominantly derive from large transplant centers, leaving a gap in understanding how obesity affects outcomes in smaller, single-center settings. We therefore conducted a single-center audit evaluating transplant outcomes in patients with BMI ≥ 35 at the time of transplant at the Sheffield Kidney Institute, UK from 2010-2023.
Methods:
This retrospective, single-center study focused on a cohort of 53 patients who underwent kidney transplantation between 2010 and 2023, all of whom had a BMI ≥ 35 kg/m² at the time of their transplant. Detailed patient data were collected, including demographic information, primary renal disease, post-transplant complications, and graft function over time. The primary outcomes assessed included death-censored graft survival, along with the incidence of medical and surgical complications. Statistical analyses were performed to compare outcomes within this cohort, aiming to provide an understanding of the impact of obesity on transplantation success in a smaller center context.
Results:
Over the 13-year study period, a total of 53 transplants were performed on patients with a BMI ≥ 35. The mean age of recipients was 58 years (SD 10.7), with an average BMI of 36.8 kg/m² (Range: 35-40.9) at the time of transplantation. The most common primary renal disease leading to transplantation was IgA Nephropathy (n=11), followed by Diabetic Nephropathy (n=8). Graft failure occurred in 10 patients (18.8%), while 13 patients (24.6%) died with a functioning graft. Among the 38 patients with at least five years of follow-up, 23 (60.6%) had a functioning graft, with 6 graft failures (15.8%) observed over a median follow-up of 6.29 years. The average estimated glomerular filtration rate (eGFR) among those with functioning grafts was 53.9 ml/min/1.73m², with a mean graft survival of 6.8 years. Medical complications included biopsy-proven rejection in 6 patients (11.3%), delayed graft function in 28 patients (52.8%), and post-transplant cytomegalovirus (CMV) infection in 3 patients. New-onset diabetes after transplantation (NODAT) was documented in 11 patients (28.9%). Notably, 6% of grafts failed within the first three months. The most common surgical complication was wound infection, occurring in 8 patients (15.1%). The average length of hospital stay was 7.8 days, and 11 patients (20.7%) required readmission within 30 days.
Conclusions:
Patients with BMI ≥ 35 do have increased medical and surgical complications including NODAT, delayed graft function and wound infection but can be successfully transplanted. These findings highlight the importance of individualized patient selection and careful preoperative preparation to optimize transplant success. The results also suggest that patients in smaller centers should not be excluded from kidney transplantation based solely on BMI and emphasize the need for thorough preoperative evaluations by the surgical team. This abstract was previously accepted as a poster presentation at the American Society of Nephrology meeting. The re-submission of this abstract is permitted by the organizers of the original meeting.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.