#5237 RACIAL DISPARITY AND KIDNEY FUNCTION IN LIVING KIDNEY DONORS
Authors: Tantisattamo Ekamol , Naunsilp Piengpitch , Puchongmart Chanokporn , Wattanachayakul Phuuwadith 
Published: June 2023

Abstract

Background and Aims
Kidney disease disproportionately affects some races and ethnicities. Whether this disparity exists in living kidney donors is known. We aim to evaluate the association between races/ethnicities and kidney function after living kidney donation.

Method
A retrospective cohort study utilizing Organ Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR) database includes living kidney donors undergoing donation between June 1972 and September 2022. Time-to-event of &gt;35% rising post-donation serum creatinine from pre-donation serum creatinine among different races and ethnicities was examined by multiple Cox proportional hazard regression analyses.

Results
Of 136,814 living kidney donors, the mean±SD age was 42±12 years and 61% were female. The majority were White (70%) followed by Hispanic (14%), Black (11%), Asian (4%), multiracial (0.61%), American Indian/Alaska Native (0.47%), and native Hawaiian/other Pacific islander (0.25%). Among 103,938 living kidney donors with post-donation serum creatinine, 78,344 (75%) living kidney donors had the event over a median time to follow-up of 6.27 months (interquartile range 4.07, 8.67). The incidence rate of the event was 0.09 person-months. Mean pre-donation serum creatinine was 0.85±0.19 mg/dL and post-donation serum creatinine during routine follow-up visits at 6, 12, and 24 months were 1.22±0.30, 1.194±0.30, and 1.16±0.27 mg/dL, respectively (Figure 1A). Mean percentage of elevated serum creatinine from pre-donation serum creatinine were 46, 43, and 41%, respectively (Figure 1B). Compared to White, Blacks had a significantly higher; while Hispanics and multi-racial groups had a significantly lower risk of increased post-donation serum creatinine &gt;35% (hazard ratio (HR)Black 1.03, 95% confidence interval (CI) 1.01, 1.06, P 0.008; HRHispanic 0.95, 95%CI 0.93, 0.97, P &lt;0.001; HRMultiracial 0.92, 95%CI 0.84, 0.99, P 0.049; Figure 2). After adjusting for age, gender, U.S. citizenship, education level, pre-donation body mass index, systolic blood pressure, diastolic blood pressure, serum creatinine, post-donation proteinuria, history of pre-donation hypertension, and the interaction term between race/ethnicity and age (&lt;70 or ≥70), Black remained at greater risk for the event and Asians still had a lower the risk (HRBlack 1.22, 95%CI 1.13, 1.31, P &lt;0.001; HRAsian 0. .88, 95%CI 0.83, 0.94, P &lt;0.001. Other races/ethnic had no significant difference in the risk. Age was an effect modifier with attenuated risk for increased serum creatinine &gt;35% observed in older Hispanic, Asian, and multiracial groups (Pinteraction 0.037, 0.001, and 0.006, respectively).

Conclusion
Blacks are at risk of increased post-donation serum creatinine &gt;35%; while Asian is protective compared to White independent of pre- and post-donation factors. Elderly Hispanic, Asian, and multiracial living kidney donors do not have worsened kidney outcome compared to their younger living kidney donors with the same races/ethnicities.