Living kidney donors are at greater risk for developing hypertension than nondonors, without modification by race, according to a new online report published in the Clinical Journal of the American Society of Nephrology.
Dorry Segev, MD, PhD, of Johns Hopkins Medical Institutions in Baltimore, and colleagues compared 1295 living kidney donors from WHOLE-Donor (Wellness and Health Outcomes in the LivE Donor) cohort to 8233 healthy nondonors. At 15 years, 8% of white nondonors, 9% of black non-donors, 23% of white donors, and 42% of black donors developed hypertension. Kidney donation was independently associated with a 19% higher risk for hypertension, regardless of race (although baseline hypertension risk was 27% higher for blacks generally).
In healthy nondonors, estimated glomerular filtration rate (eGFR) declined more rapidly after hypertension. For kidney donors, however, eGFR increased after donation as expected, but then plateaued in those developing hypertension. “This identifies incident hypertension as a risk factor in eGFR following kidney donation,” Dr Segev’s team explained. It “merits aggressive preventive measures and careful management, as it is associated with cessation of the increase in eGFR following donation.”
The study has several notable limitations. First, hypertension status was determined by patient report rather than direct measurement. Second, the investigators did not study the association between use of antihypertensive drugs and eGFR. Third, although patients were propensity-score matched by age, race, sex, predonation eGFR, education level, and tobacco use, they were not matched by baseline body mass index or pre-donation blood pressure, both of which affect future hypertension risk. Finally, WHOLE Donor is a contemporary cohort, whereas healthy nondonors originated from the Atherosclerosis Risk in Communities (ARIC) and the Coronary Artery Risk Development in Young Adults (CARDIA) cohorts started in the 1980s.
William S. Asch, MD, PhD, of the Yale University School of Medicine in New Haven, Connecticut, discussed the study’s limitations in an accompanying editorial but also acknowledged its importance.
If corroborated, he wrote, the new findings “are anticipated to have a meaningful impact on the transplant community across multiple dimensions, including the informed consent process, and policy decisions regarding obligations for the parent center to provide truly long-term (decades) follow up for their living donors. These findings also have the potential to further shift the public and media’s perception of the safety of living kidney donation, especially when coupled with the earlier reports already indicating an increased risk of ESKD in living donors.”
Holscher CM, Haugen CE, Jackson KR, et al. Self-reported incident hypertension and long-term kidney function in living kidney donors compared to healthy non-donors [published online September 19, 2019]. Clin J Am Soc Nephrol.
Asch WS. Is hypertension following donor nephrectomy cause for elevated living donor kidney function concern? [Published online September 19, 2019]. Clin J Am Soc Nephrol.