Background: Size mismatch between recipient and donor in kidney transplantation has been studied using differences in their height, weight, body mass index (BMI), and body surface area (BSA) as surrogates for kidney size. Recently a cohort study showed that height mismatch affects transplant outcome. We investigated whether height mismatch predicts graft outcome in Korean transplant patients.
Methods: We retrospectively collected records of living donor kidney transplantation between January 2008 and October 2021 in 2 transplant centers. Adult patients aged ≥18 years undergoing living donor kidney transplantation only from donors aged ≥18 years were included. The final analysis included 395 recipient and donor pairs.  
Results: The cohort was divided into 3 groups based on height discrepancy as 1) recipient ≥7 ㎝shorter than donor (R<D) 2) recipient within 7㎝ of donor’s height (R=D) 3) recipient >7 ㎝ taller than donor(R>D). There were 101 pairs in R<D, 151 pairs in R=D, and 143 pairs in R<D. The median follow-up duration was 6.2 years (IQR: 3.1, 9.3). Overall graft survival across height discrepancy between recipients and donors showed no statistical difference (Log Rank P=0.50).

R<D had lower HR than R=D (0.66, 95% CI 0.29-1.51), and R>D had a higher HR (1.07, 95% CI 0.56-2.04) in Cox regression analysis. However, there was no significant difference.
Conclusions: Height discrepancy between recipient and donor is not associated with graft outcome in living donor kidney transplantation.