Original Investigation 

May 23, 2024

Hypertension and Kidney Function After Living Kidney Donation

Amit X. Garg, Jennifer B. Arnold, Meaghan S. Cuerden, et al

JAMA. Published online May 23, 2024. doi:10.1001/jama.2024.8523

Key Points

Question  Do normotensive living kidney donors, compared with nondonors, have a higher risk of hypertension in the first 7 years following donation?

Findings  In this 17-center prospective cohort study that included 924 living kidney donors and 396 nondonors, there were no significant between-group differences in the risk of hypertension and no significant between-group differences in mean blood pressure or the change in blood pressure during a median follow-up of 7.3 years.

Meaning  After accounting for differences in baseline risk, living donors had a similar risk of hypertension as nondonors in the 7 years following donation and no significant difference in mean blood pressure.

Abstract

Importance  Recent guidelines call for better evidence on health outcomes after living kidney donation.

Objective  To determine the risk of hypertension in normotensive adults who donated a kidney compared with nondonors of similar baseline health. Their rates of estimated glomerular filtration rate (eGFR) decline and risk of albuminuria were also compared.

Design, Setting, and Participants  Prospective cohort study of 924 standard-criteria living kidney donors enrolled before surgery and a concurrent sample of 396 nondonors. Recruitment occurred from 2004 to 2014 from 17 transplant centers (12 in Canada and 5 in Australia); follow-up occurred until November 2021. Donors and nondonors had the same annual schedule of follow-up assessments. Inverse probability of treatment weighting on a propensity score was used to balance donors and nondonors on baseline characteristics.

Exposure  Living kidney donation.

Main Outcomes and Measures  Hypertension (systolic blood pressure [SBP] ≥140 mm Hg, diastolic blood pressure [DBP] ≥90 mm Hg, or antihypertensive medication), annualized change in eGFR (starting 12 months after donation/simulated donation date in nondonors), and albuminuria (albumin to creatinine ratio ≥3 mg/mmol [≥30 mg/g]).

Results  Among the 924 donors, 66% were female; they had a mean age of 47 years and a mean eGFR of 100 mL/min/1.73 m². Donors were more likely than nondonors to have a family history of kidney failure (464/922 [50%] vs 89/394 [23%], respectively). After statistical weighting, the sample of nondonors increased to 928 and baseline characteristics were similar between the 2 groups. During a median follow-up of 7.3 years (IQR, 6.0-9.0), in weighted analysis, hypertension occurred in 161 of 924 donors (17%) and 158 of 928 nondonors (17%) (weighted hazard ratio, 1.11 [95% CI, 0.75-1.66]). The longitudinal change in mean blood pressure was similar in donors and nondonors. After the initial drop in donors’ eGFR after nephrectomy (mean, 32 mL/min/1.73 m²), donors had a 1.4-mL/min/1.73 m² (95% CI, 1.2-1.5) per year lesser decline in eGFR than nondonors. However, more donors than nondonors had an eGFR between 30 and 60 mL/min/1.73 m² at least once in follow-up (438/924 [47%] vs 49/928 [5%]). Albuminuria occurred in 132 of 905 donors (15%) and 95 of 904 nondonors (11%) (weighted hazard ratio, 1.46 [95% CI, 0.97-2.21]); the weighted between-group difference in the albumin to creatinine ratio was 1.02 (95% CI, 0.88-1.19).

Conclusions and Relevance  In this cohort study of living kidney donors and nondonors with the same follow-up schedule, the risks of hypertension and albuminuria were not significantly different. After the initial drop in eGFR from nephrectomy, donors had a slower mean rate of eGFR decline than nondonors but were more likely to have an eGFR between 30 and 60 mL/min/1.73 m² at least once in follow-up.

Trial Registration  ClinicalTrials.gov Identifier: NCT00936078