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

Abstract

Background and objectivesThe 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, & measurementsWe 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.ResultsKidney 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).ConclusionsKidney 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.

Increased long‐term risk for hypertension in kidney donors – a retrospective cohort study

“…Our finding that donors have increased risk of hypertension when compared with suitable controls reaffirms what is found in two previous studies . One retrospective study on African American live donors from the United States used techniques of restriction and matching to select healthy nondonor controls.…”

“…Most recently, Holscher et al . retrospectively matched controls with donors through a propensity score model. They found a 19 % increased risk of hypertension in donors median 6 years after donation compared with a weighted cohort of healthy controls.…”

“…The long‐term risk of living donation has been accepted as sufficiently low to justify the practice, but most studies done in the past addressing blood pressure after donation have been limited by short follow‐up, small sample sizes, or inadequate control group . However, later studies with longer follow‐up and more appropriate control groups have demonstrated an increased risk of hypertension in previous kidney donors .…”

Prevalence, Mechanisms, Treatment, and Complications of Hypertension Postliving Kidney Donation

“…This study reported a hazard ratio of 1.19 ( p = 0.04), for the outcome of self-reported hypertension among donors compared to healthy controls [ 28 ]. Preexisting trial data from a population study was used as a surrogate marker for the outcome of hypertension among the general population.…”

Outcomes of Hypertensive Kidney Donors Using Current and Past Hypertension Definitions

“…1,2 Hypertension is widely cited as the second leading cause of end-stage kidney disease (ESKD) in the United States and ESKD in many former kidney donors has been attributed to hypertension. 3,4 Moreover, a recent analysis suggests that roughly a third of kidney donors developed hypertension 15 years after donation compared to <10% in non-donor healthy controls and in a separate analysis from the same investigators, pre-donation hypertension in donors over 50 years of age was associated with an overall ESKD incidence of <1% 5,6 The kidney and cardiovascular related concerns regarding hypertensive candidates are reflected by exclusions and also restrictions put on donor candidates with hypertension by many transplant centers. 7 Hypertension accelerates the progression of established kidney disease but the strength of the causal link between hypertension and incident chronic kidney disease (CKD) is not definitive.…”