Consequences of Low eGFR either before or early after Kidney Donation

In the general population, decreases in glomerular filtration rate (GFR) are associated with subsequent development of chronic kidney disease (CKD), cardiovascular disease (CVD), and death. It is unknown if low estimated GFR (eGFR) before or early after kidney donation was also associated with these risks. 1699 living donors (LDs) had both pre- and early (4-10 weeks) postdonation eGFR. We studied the relationships between eGFR, age at donation, and the time to sustained eGFR<45 (CKD Stage 3b) and <30 mL/min/1.73m2 (CKD Stage 4), hypertension, diabetes mellitus (DM), CVD, and death. Median follow-up was 12 (IQR, 6–21) years. Twenty-year event rates were 5.8% eGFR<45 mL/min/1.73m2; 1.2% eGFR<30 mL/min/1.73m2; 29.0% hypertension; 7.8% DM; 8.0% CVD; and 5.2% death. Median time to eGFR<45 (N=79) was 17 years; eGFR<30 (N=22), 25 years. Both low pre- and early postdonation eGFR were associated with eGFR<45 (p<0.0001) and eGFR<30 (p<0.006); however, the primary driver of risk for all ages was low postdonation (rather than predonation) eGFR. Pre- and postdonation eGFR were not associated with hypertension, DM, CVD, or death. Low pre- and early postdonation eGFR are risk factors for developing eGFR<45 mL/min/1.73m2 (CKD Stage 3b) and <30 mL/min/1.73m2 (CKD Stage 4), but not CVD, hypertension, DM, or death. Significance Statement Although the vast majority of living kidney donors do well, some develop low GFR and kidney failure. Understanding risk factors for these events impacts donor acceptance and long-term donor care. We show that low predonation eGFR and low eGFR at approximately 6 weeks postdonation are risk factors for development of CKD Stages 3b and 4, with increased risk concentrated in those with early postdonation eGFR <50 ml/min/m2. Low pre- or postdonation eGFR were not associated with increased risk for mortality, cardiovascular disease, diabetes, or hypertension. Early postdonation eGFR <50 ml/min/m2 should lead to increased long-term follow-up of living donor kidney function.