Trajectory of GFR in Live Kidney Donors.

Abstract

Although live kidney donation is generally regarded as safe, much is unknown about long-term risks to donors. Glomerular Filtration Rate (GFR) is known to decrease in live kidney donors following donation, but the long-term trajectory of GFR has not been described. In a retrospective cohort study, we obtained serum creatinine values from medical records of 642 live kidney donors (2800 total measurements) to calculate estimated GFR (eGFR). We calculated the proportion of eGFR measurements that were <60 mL/min/1.73 m2 over time, and modeled the trajectory of eGFR over time as a function of age at donation (<40 years vs ≥40 years), race, and gender, using multilevel mixed-effects linear regression. Shortly after donation, 60% of patients had eGFR < 60; this proportion declined steadily over time, reaching 20% of donors at 15 years after donation (Figure 1). Mean initial eGFR (immediately following donation) was 57.0 in nonblack female donors age≥40; initial eGFR was higher in donors age<40 and black donors, and lower in male donors (Table 1). Differences in initial eGFR were p<0.01 for age and gender and p=0.1 for race. eGFR increased by 1.2 each year for the first 5 years, and 0.8 each year thereafter (nonblack donors age≥40, Table 1). eGFR climbed faster for black donors, and more slowly for donors age <40 (Figure 2, interactions p<0.05). In this longitudinal study, average eGFR in live donors increased over time following donation, particularly for black donors and donors age≥40.Table: No Caption available.Figure: No Caption available.Figure: No Caption available.