Most kidney transplants involve organs from cadaveric donors; however, the demand for these organs far exceeds their supply. Therefore, some people opt to donate one of their two healthy kidneys, often to a sibling or other relative whose kidneys have failed. A recent study of nearly 3,700 people who donated kidneys between 1963 and 2007 found that people who choose to donate a kidney appear to have a normal life span, and that their risk of developing kidney failure is similar to that of the general population. Within a subset of donors who were studied more intensively, kidney function and high blood pressure were similar to the general population, and their quality-of-life was found to be excellent. Importantly, the researchers found no evidence of excess loss of kidney function over time in donors, some of whom donated kidneys twenty or more years ago.
Although the results of this study are good news for the participants, there are some important caveats. Potential kidney donors must meet strict selection criteria before they are allowed to donate. The relatively good health of the donors may explain at least part of the reason why their health and quality-of-life was found to be at least equal to, or better than, that of the general population. Additionally, in the past many volunteers donated a kidney at a relatively young age. In more recent times, however, the average age of donors has risen, and researchers and physicians will need to carefully monitor the health of these older volunteers. Additionally, participants in the current study were overwhelmingly Caucasian, and researchers do not know to what extent these findings can be extrapolated to kidney donors of other races and ethnicities. For example, African Americans have a much higher rate of diabetes, high blood pressure, and kidney failure than Caucasians, and it is possible they might be more likely to develop those conditions after donating a kidney. Further research will be necessary to better understand the long-term implications of kidney donation across a broad spectrum of the American population.
Nevertheless, the results of the current study indicate that there are few or no long-term detrimental health consequences for individuals who choose to donate a kidney. This finding may make potential donors more likely to donate a kidney, and have the consequence of increasing the supply of organs available for transplant.
Ibrahim HN, Foley R, Tan L, Rogers T, Bailey RF, Guo H, Gross CR, and Matas AJ. Long-Term Consequences of Kidney Donation. New Engl J Med 360: 459-469, 2009.