Impact of obesity and income on the likelihood of kidney transplantation: A retrospective cohort study.

BACKGROUND: This study evaluated the joint and modifying effects of obesity and income on access to kidney transplantation, stratified by race/ethnicity. AIM: To investigate whether income modifies the association between body mass index (BMI) and the likelihood of deceased donor kidney transplantation (DDKT) and living donor kidney transplantation (LDKT). METHODS: We conducted a retrospective cohort study of 54891 adult kidney-only candidates added to the United States waiting list in 2020 and 2022, using data from the Organ Procurement and Transplantation Network and LexisNexis. RESULTS: Overall, 47% of candidates were obese (BMI ≥ 30 kg/m2). In multivariable models, BMI 30- < 35 was associated with a lower likelihood of DDKT for non-Hispanic White and non-Hispanic Black candidates [sub-distribution hazard ratio (sHR): 0.93 for both]. BMI ≥ 35 was associated with an 18% lower likelihood to DDKT for non-Hispanic White candidates only. Low income was associated with higher likelihood of DDKT among non-Hispanic White (sHR: 1.34) and Hispanic/Latino (sHR: 1.20) candidates but was not associated with DDKT among non-Hispanic Black candidates. In interaction models, income-related differences in DDKT were most consistently observed among nonobese nonHispanic White and Hispanic/Latino candidates. For LDKT, both BMI ≥ 35 and low income were associated with lower likelihood of transplantation across all racial and ethnic groups; low income was also associated with reduced likelihood of LDKT among non-obese candidates in interaction models. CONCLUSION: Obesity and income are differentially associated with access to transplantation by racial/ethnicity and transplant modality, highlighting the importance of jointly considering clinical and social risk factors in transplantation.