Self-Reported Incident Hypertension and Long-Term Kidney Function in Living Kidney Donors Compared with Healthy Nondonors

Abstract

Background and objectives: The risk of hypertension attributable to living kidney donation remains unknown as does the effect of developing postdonation hypertension on subsequent eGFR. We sought to understand the association between living kidney donation, hypertension, and long-term eGFR by comparing donors with a cohort of healthy nondonors.

Design, setting, participants, & measurements: We compared 1295 living kidney donors with median 6 years of follow-up with a weighted cohort of 8233 healthy nondonors. We quantified the risk of self-reported hypertension using a parametric survival model. We examined the association of hypertension with yearly change in eGFR using multilevel linear regression and clustering by participant, with an interaction term for race.

Results: Kidney donation was independently associated with a 19% higher risk of hypertension (adjusted hazard ratio, 1.19; 95% confidence interval, 1.01 to 1.41; P=0.04); this association did not vary by race (interaction P=0.60). For white and black nondonors, there was a mean decline in eGFR (-0.4 and -0.3 ml/min per year, respectively) that steepened after incident hypertension (-0.8 and -0.9 ml/min per year, respectively; both P<0.001). For white and black kidney donors, there was a mean increase in eGFR after donation (+0.4 and +0.6 ml/min per year, respectively) that plateaued after incident hypertension (0 and -0.2 ml/min per year, respectively; P=0.07 and P=0.01, respectively, after hypertension).

Conclusions: Kidney donors are at higher risk of hypertension than similar healthy nondonors, regardless of race. Donors who developed hypertension had a plateau in the usual postdonation increase of eGFR.

Keywords: United States; confidence intervals; follow-up studies; glomerular filtration rate; hypertension; kidney; kidney donation; linear models; living donors; self report; tissue and organ harvesting.

Copyright © 2019 by the American Society of Nephrology.

Figures

Graphical abstract

Figure 1.

Donors have a higher incidence of hypertension compared to nondonors. Cumulative incidence of self-reported hypertension in black and white kidney donors and weighted nondonors over 15 years.

Figure 2.

Donors have an increase in eGFR while nondonors have a decrease in eGFR over time. eGFR trajectory in black and white kidney donors and weighted nondonors. Trajectories are shown with 95% confidence intervals (gray).

Figure 3.

Donors have a plateau in eGFR associated with hypertension while nondonors have a steepened decline in eGFR associated with hypertenion. eGFR trajectory in black and white kidney donors and nondonors after incident hypertension. Trajectories are shown with 95% confidence intervals (gray).