A Prospective Controlled Study of Kidney Donors: Baseline and 6-Month Follow-up

Abstract

Background Most previous studies of living kidney donors have been retrospective and have lacked suitable healthy controls. Needed are prospective controlled studies to better understand the effects of a mild reduction in kidney function from kidney donation in otherwise normal individuals. Study Design Prospective, controlled, observational cohort study. Setting & Participants Consecutive patients approved for donation at 8 transplant centers in the US were asked to participate. For every donor enrolled, an equally healthy control with 2 kidneys who theoretically would have been suitable to donate a kidney was also enrolled. Predictor Kidney donation. Measurements At baseline pre-donation and at 6 months after donation, a medical history, vital signs, measured (iohexol) glomerular filtration rate and other measurements were collected. There were 201 donors and 198 controls that completed both baseline and 6 month visits and form the basis of this report. Results Compared to controls, donors had 28% lower glomerular filtration rate at 6 months (94.6±15.1 [SD] v. 67.6±10.1 mL/min/1.73m2; P<0.001), associated with a 23% greater parathyroid hormone (42.8±15.6 v. 52.7±20.9 pg/mL; P<0.001), 5.4% lower serum phosphate (3.5±0.5 v. 3.3±0.5 mg/dL; P<0.001), 3.7% lower hemoglobin (13.6±1.4 v. 13.1±1.2 g/dL; P<0.001), 8.2% greater uric acid (4.9±1.2 v. 5.3±1.1 mg/dL; P<0.001), 24% greater homocysteine (1.20±0.34 v. 1.49±0.43 mg/L; P<0.001), and 1.5% lower high density lipoprotein cholesterol (54.9±16.4 v. 54.1±13.9 mg/dL; P=0.03) level. There were no differences in albumin-creatinine ratios (5.0 [IQR, 4.0-6.6] v. 5.0 [IQR, 3.3-5.4] mg/g; P=0.5), office blood pressure, or glucose homeostasis. Limitations Short duration of follow-up and possible bias resulting from an inability to screen controls with kidney and vascular imaging performed in donors. Conclusions Kidney donors have some, but not all, abnormalities typically associated with mild chronic kidney disease 6 months after donation. Additional follow up is warranted.

Long-term health-related quality of life of living kidney donors: a single-center experience

“…LKDT is considered a safe procedure for donors, and there seems to be no increased risk of deteriorated renal function or other relevant disabilities like hypertension or proteinuria [7][8][9]. Nevertheless, mild changes after kidney donation similar to chronic kidney disease have been reported [10][11][12]. There appears to be some risk of the development of end-stage renal disease (ESRD) in the long term [13].…”

Impact of Living Kidney Donation on Long-Term Renal and Patient Survival: An Evolving Paradigm

“…On the other hand, controls were assembled from the general population, and obviously did not undergo the same rigorous testing that donors face before surgery. A group from the U.S. and Canada recently published 6-month data on 201 donors and matched controls followed since nephrectomy [32]. Though there were no differences in blood pressure, a longer follow-up time may be needed.…”

Reassessing Medical Risk in Living Kidney Donors

“…11 Several important new reports, all using controls with health status comparable to donors at the onset of observation, have now further expanded our understanding of donor risk. In a prospective evaluation of living donors (n=201) and matched healthy concurrent controls (n=198) at eight centers, Kasiske et al 12 reported mean GFR 6 months postdonation as 68610 ml/min per 1.73 m 2 that was accompanied by significant alteration in the calcium/phosphorus/parathyroid axis. Donor Nephrectomy Outcomes Research (DONOR) Network investigators, in a cross-sectional study of 198 previous donors, documented similar changes plus increased fibroblast growth factor 23 levels.…”

“…The works by Kasiske et al 12 and the DONOR Network investigators 13 document preservation of renal function without significant proteinuria in the overwhelming majority of previous donors. Additionally, regardless of hazard ratios or cohort characteristics, the incidence of ESRD and mortality among previous donors is very low over very lengthy periods of time.…”

“…7 Second, these reports clearly advance and refine our understanding of medical risk in living donors. Certainly, maturing of the databases examined by Kasiske et al 12 and the DONOR Network 13 should result in additional insight into physiologic and potentially pathophysiologic consequences of donor nephrectomy. Third, payers and regulators alike must understand these data as a work in progress, requiring the same perspicuity in interpretation as we practitioners ought to practice; rash decisions on the basis of superficial reading of evolving data are never justified.…”