Small donor size does not negatively impact outcomes after deceased-donor renal transplantation

Higher body mass index (BMI) of deceased-donors is associated with poorer outcomes in transplant recipients. The effect of low donor BMI on recipient graft function is not clear. Scientific Registry of Transplant Recipients data on recipients of deceased-donor kidneys from 2000 to 2019 were categorized by donor BMI (donor BMI < 18, 18-27, and >27). Primary outcome was death-censored graft survival. The impact of multiple recipient and donor variables, including low donor BMI and the difference between donor and recipient BMI, was evaluated using a multivariate Cox proportional-hazards model. Low BMI donors (LBD) were more likely to be younger, female, and white (all P < .05). LBD were less likely to be Hispanic, diabetic, or have hypertension (all P < .001). LBD recipients were more likely to be younger and female (both P < .001). Low donor BMI was not significantly associated with recipient graft survival. Donor-recipient BMI difference did not correlate with an increased risk of graft failure. Similar results were obtained when donors were classified using body surface area (BSA). Small donor size in terms of BMI or BSA or a large discrepancy between donor and recipient size should not necessarily preclude transplantation of an otherwise acceptable kidney.