Investigating kidney donation as a risk factor for hypertension and microalbuminuria: findings from the Swiss prospective follow-up of living kidney donors

Abstract

ObjectivesTo assess the role of nephrectomy as a risk factor for the development of hypertension and microalbuminuria.DesignProspective, long-term follow-up study.SettingSwiss Organ Living-Donor Health Registry.ParticipantsAll living kidney donors in Switzerland between 1993 and 2009.InterventionsData on health status and renal function before 1 year and biennially after donation were collected.Primary and secondary outcome measuresComparison of 1-year and 5-year occurrences of hypertension among normotensive donors with 1-year and 5-year estimates from the Framingham hypertension risk score. Multivariate random intercept models were used to investigate changes of albumin excretion after donation, correcting for repeated measurements and cofactors such as age, male gender and body mass index.ResultsA total of 1214 donors contributed 3918 data entries with a completed biennial follow-up rate of 74% during a 10-year period. Mean (SD) follow-up of donors was 31.6 months (34.4). Median age at donation was 50.5 years (IQR 42.2–58.8); 806 donors (66.4%) were women. Donation increased the risk of hypertension after 1 year by 3.64 (95% CI 3.52 to 3.76; p<0.001). Those participants remaining normotensive 1 year after donation return to a risk similar to that of the healthy Framingham population. Microalbuminuria before donation was dependent on donor age but not on the presence of hypertension. After nephrectomy, hypertension became the main driver for changes in albumin excretion (OR 1.19; 95% CI 0.13 to 2.25; p=0.03) and donor age had no effect.ConclusionsNephrectomy propagates hypertension and increases susceptibility for the development of hypertension-induced microalbuminuria.

Neonatal nephron loss during active nephrogenesis – detrimental impact with long-term renal consequences

“…There are conflicting data concerning the development of hypertension in humans with reduced renal mass: Our observations of arterial normotension after early uninephrectomy are in line with several clinical studies showing no significantly increased incidence of arterial hypertension in individuals born with a solitary kidney or in kidney donors 20 , 21 . On the other hand, there are also several clinical studies, which describe an increased risk for the development of hypertension in children with a solitary kidney 5 , 22 or in kidney donors 23 . The reasons for the discrepancies in study outcomes regarding blood pressure are still unclear, but might reflect different study designs or differences in the selection of the study collective.…”

Evaluation of renal function in a specific population of living kidney donors

“…The present study showed the presence of microalbuminuria in 12.12% of the sample. It has recently been demonstrated that nephrectomy in kidney donors increases the occurrence of microalbuminuria and susceptibility to hypertension‐induced microalbuminuria in this group of patients (Thiel et al ). Microalbuminuria is an early marker of glomerular injury (National Kidney Foundation Kidney Disease Outcomes Quality Initiative ), and most studies with long‐term follow‐up of living kidney donors have reported the presence of microalbuminuria in these patients (Gossmann et al ; Von Zur‐Muhlen et al .…”

The Long-Term Follow-up and Support for Living Organ Donors: A Center-Based Initiative Founded on Developing a Community of Living Donors

“…However, most have limitations in long‐term compliance. One successful program is the Swiss Organ Living Donor Health Registry, which has provided data on postdonation incidence of hypertension and microalbuminuria . Despite the government‐mandated coverage of biennial medical follow‐up testing and a funded central donor registry, 10‐year follow‐up data were reported for only 65% of living donors .…”

“…One successful program is the Swiss Organ Living Donor Health Registry, which has provided data on postdonation incidence of hypertension and microalbuminuria . Despite the government‐mandated coverage of biennial medical follow‐up testing and a funded central donor registry, 10‐year follow‐up data were reported for only 65% of living donors . The Australia/New Zealand Dialysis and Transplant Living Kidney Donor Registry is another program that has collected long‐term data on living kidney donors since 2004.…”