Changes in Blood Pressure and Arterial Hemodynamics following Living Kidney Donation

Abstract

Background and objectivesThe Effect of a Reduction in GFR after Nephrectomy on Arterial Stiffness and Central Hemodynamics (EARNEST) study was a multicenter, prospective, controlled study designed to investigate the associations of an isolated reduction in kidney function on BP and arterial hemodynamics.Design, setting, participants, & measurementsProspective living kidney donors and healthy controls who fulfilled criteria for donation were recruited from centers with expertise in vascular research. Participants underwent office and ambulatory BP measurement, assessment of arterial stiffness, and biochemical tests at baseline and 12 months.ResultsA total of 469 participants were recruited, and 306 (168 donors and 138 controls) were followed up at 12 months. In the donor group, mean eGFR was 27 ml/min per 1.73 m2 lower than baseline at 12 months. Compared with baseline, at 12 months the mean within-group difference in ambulatory day systolic BP in donors was 0.1 mm Hg (95% confidence interval, −1.7 to 1.9) and 0.6 mm Hg (95% confidence interval, −0.7 to 2.0) in controls. The between-group difference was −0.5 mm Hg (95% confidence interval, −2.8 to 1.7; P=0.62). The mean within-group difference in pulse wave velocity in donors was 0.3 m/s (95% confidence interval, 0.1 to 0.4) and 0.2 m/s (95% confidence interval, −0.0 to 0.4) in controls. The between-group difference was 0.1 m/s (95% confidence interval, −0.2 to 0.3; P=0.49).ConclusionsChanges in ambulatory peripheral BP and pulse wave velocity in kidney donors at 12 months after nephrectomy were small and not different from controls.Clinical Trial registry name and registration numberNCT01769924 (https://clinicaltrials.gov/ct2/show/NCT01769924).

Risk for subsequent hypertension and cardiovascular disease after living kidney donation: is it clinically relevant?

“…[ 15 ] in a study from the Netherlands on 761 donors and 1522 propensity score-matched controls from general population cohort studies and a median follow-up period of 8 years found a lower incidence of hypertension in donors. Three studies are perhaps worthy of special mention [ 37 , 38 , 40 ]. All three of these studies recruited controls that had passed the selection criteria for donation except for those that required exposure to radiation.…”

“…They also performed 24-h ambulatory blood pressure measurements providing a gold standard for the measurement of blood pressure and the diagnosis of hypertension. After 1 [ 38 ], 5 [ 37 ] and 9 [ 40 ] years of follow-up, none of these studies found any difference in 24-h systolic or diastolic blood pressure, nor in the incidence of hypertension.…”

“…However, recent work has provided some information. The EARNEST (Effect of A Reduction in glomerular filtration rate after NEphrectomy on arterial STiffness and central hemodynamics) study had a prospective, UK, multicentre, controlled, longitudinal design [ 38 , 104 ]. It had the ambitious aim of recruiting 400 donors and controls, but was eventually terminated with 469 subject recruited and 306 (168 donors and 138 controls) followed up at 12 months.…”

Arterial Mechanics following Living Kidney Donation

“…Because living kidney donation is associated with GFR decline, and kidney donors are actively selected for the absence of comorbid conditions affecting arterial stiffening, the possibility that lower GFR leads to changes in arterial mechanics can be tested independently of these comorbid conditions. In CJASN, Price et al (3) report the results of one such study, the Effect of a Reduction in GFR after Nephrectomy on Arterial Stiffness and Central Hemodynamics (EARNEST) study. EARNEST was primarily designed as a mechanistic 12-month longitudinal study of 168 kidney donors and 138 matched healthy controls to evaluate changes in 24-hour ambulatory BP and carotid-femoral (aortic) pulse wave velocity as the coprimary outcomes, neither of which was different between donors and controls despite a 27-ml/min per 1.73 m 2 decline in GFR.…”

“…Arterial stiffness progresses according to CKD stages, being most prominent in patients with GFR below 30-45 ml/min. In EARNEST, only 4% of the 168 donors reached CKD stage 3b, and a single patient reached CKD stage 4 (3). By methodically phenotyping donor hemodynamics, EAR-NEST set off to better understand cardiovascular risk in donors and to advance the understanding of mechanisms of arterial dysfunction related to loss of GFR.…”