Factors Associated With Residual Kidney Function and Proteinuria After Living Kidney Donation in the United States

Background. Living kidney donors are carefully screened, but despite overall good health, long-term donor outcomes have been shown to vary by predonation demographics. Since 2013, the United Network for Organ Sharing has mandated 2-year postdonation follow-up with measurements of kidney function and proteinuria. Methods. Using data from the Scientific Registry of Transplant Recipients, we sought to analyze donor factors associated with the percent change of kidney function from baseline (predonation) to 2-year postdonation, along with incidence of proteinuria reported within the same follow-up period. Results. Older donor age, male gender, black race, and body mass index >25 kg/m(2) were independently associated with a greater percent decline in estimated glomerular filtration rate (eGFR). Male gender, black race, and higher body mass index were also independently associated with incident proteinuria. In contrast, younger donor age was associated with proteinuria, but proteinuria did not correlate with greater decline in eGFR in the overall cohort. Conclusions. Donor factors associated with lower eGFR at 2-year postdonation were similar to those previously found to be associated with long-term risk for end-stage renal disease. Early postdonation assessment of kidney function and proteinuria may help to identify donors who are at greater risk of end-stage renal disease and who may benefit from more intense long-term monitoring.