Medical Research: What are the main findings of the study?
Dr. Holdaas: Most studies examining long-term risk for living kidney donors have included comparators from the background population with hypertension, diabetes mellitus, reduced renal function, cancer and other concomitant diseases; or for the few studies with more “healthy” comparators the follow-up time have been restricted. In our study we compared living donors to a healthy non-donor population which would have qualified as donors themselves, with median follow-up of 15.1 years for the donors. The relative risk for the living donors compared to a healthy control was 11.38 for endstage renal disease (ESRD), 1.4 for cardiovascular death and 1.3 for all-cause mortality (Mjoen et al., 2014).
Medical Research: Were any of the findings unexpected?
Dr. Holdaas: The findings were somewhat unexpected as this was the first paper showing an increased long-term risk for kidney donors. The paper has lead to a lot of commentaries in different journal. Drs Clancy and Geddes commented in a letter to the editor of Kidney Int, “Acceptable mortality after living kidney donation”(Clancy & Geddes, 2014). We agree with their interpretation of our findings that relative increases in the risk of death should be converted to relatively modest increased in absolute risks. Although there was a substantial increase in risk for donors themselves ending in ESRD, in term of absolute risk, only nine donors (o.47%) developed ESRD.
Medical Research: What should clinicians and patients take away from your report?
Dr. Holdaas: Clinicians should change the information to potential living donors. There has been “normal” to inform potential donors that they will live longer after nephrectomy. Donor should be informed of a small absolute risk may be a consequence of giving away a kidney. We have accordingly changed our information policy, but we need clarify we still support the policy of live kidney donation.
A key message will be that the follow-up time for the individual donor has to be thorough and extended.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Holdaas: There is a need for carefully designed prospective multicenter studies comparing living donors with a healthy background population with extended follow-up of all donors. In wait for such a study, short term studies with appropriate controls should be extended. A follow-up period of median 3-8 years is too short(Muzaale et al., 2014; Segev et al., 2010; Garg et al., 2012). The increased risk for total mortality was evident in our study 10-15 years after donation.
Clancy, M. J. & Geddes, C. C. (2014). Acceptable mortality after living kidney donation. Kidney International, 85, 1240-1241.
Garg, A. X., Meirambayeva, A., Huang, A., Kim, J., Prasad, G. V., Knoll, G. et al. (2012). Cardiovascular disease in kidney donors: matched cohort study. BMJ, 344, e1203.
Mjoen, G., Hallan, S., Hartmann, A., Foss, A., Midtvedt, K., Oyen, O. et al. (2014). Long-term risks for kidney donors. Kidney International, 86, 162-167.
Muzaale, A. D., Massie, A. B., Wang, M. C., Montgomery, R. A., McBride, M. A., Wainright, J. L. et al. (2014). Risk of end-stage renal disease following live kidney donation. JAMA, 311, 579-586.
Segev, D. L., Muzaale, A. D., Caffo, B. S., Mehta, S. H., Singer, A. L., Taranto, S. E. et al. (2010). Perioperative mortality and long-term survival following live kidney donation. JAMA, 303, 959-966.
Geir Mjøen1, Stein Hallan2,3, Anders Hartmann1, Aksel Foss1, Karsten Midtvedt1, Ole Øyen1, Anna Reisæter1, Per Pfeffer1, Trond Jenssen1, Torbjørn Leivestad4, Pål- Dag Line1, Magnus Øvrehus2, Dag Olav Dale1, Hege Pihlstrøm1, Ingar Holme5, Friedo W Dekker6 and Hallvard Holdaas1