Overweight and Obesity in Pediatric Kidney Transplant Recipients Are Not Associated With Higher Risks of Early Postoperative Complications.

Background: Childhood overweight and obesity have been hypothesized to pose challenges in pediatric kidney transplantation due to potential complications and resultant worse outcomes. Herein, we aimed to determine if pediatric patients with an elevated body mass index (BMI) (> 85th percentile) are at higher risk for short-term complications following kidney transplantation.

Methods: Following a review of our transplant database (2010-2020), patients > 2-18 years were assigned to groups based on BMI percentiles at the time of surgery: normal (5th-85th percentile; n = 120) and obese/overweight (> 85th percentile; n = 60). Patients were matched using a 1-to-2-ratio nearest-neighbor propensity score matching adjusting for underlying diagnosis, sex, and age. The primary outcome was postoperative complications classified according to Clavien-Dindo, and secondary outcomes included postoperative creatinine and kidney graft rejection.

Results: One hundred eighty patients (n = 120 in the control and n = 60 in the overweight and obese group) were included. There was no significant difference in postoperative complications (72/120 vs. 40/60, p = 0.42). We noted no difference in nadir creatinine (7 days, [interquartile range (IQR) 1, 679] and 9 days, [IQR 1, 690], p = 0.11), postoperative creatinine levels at 3-, 6-, and 12-months post-transplantation, or rejection rates (8.4% and 8.4%, p > 0.99) between normal weighed and obese/overweight patients. However, more overweight and obese patients required intraoperative blood transfusions (55% and 33.4%, p = 0.006) and longer hospital stays (18.0 [IQR 9, 133] and 15.0 [IQR 7, 49], p = 0.02).

Conclusions: It appears as though overweight and obese pediatric kidney transplant patients do not experience more postoperative complications. We propose that overweight and obesity should not be considered criteria to exclude pediatric patients from undergoing kidney transplantations.