SGH and Duke-NUS study confirms remaining kidney of Southeast Asian donors functioning well

In one of Asia’s largest studies on living kidney donors, researchers from the Singapore General Hospital (SGH) and Duke-NUS Medical School (Duke-NUS) have confirmed that the remaining kidney of Southeast Asian donors continues to function well, long after donation. Previous studies in this aspect of donors’ health have largely been based on the Western population.

Every healthy individual has two kidneys. It plays an important role in filtering the blood in our body, getting rid of waste products, and stimulating the production of red blood cells, etc. Each kidney performs about 50 percent of these functions. Some people are naturally concerned about the detrimental effects to their health with one kidney less after donation. In a related SGH study, poor health was cited as one of the reasons influencing Singaporean’s decision not to donate.

This does not bode well for Singapore, which is among the top five countries with the highest incident rates of end stage kidney disease requiring dialysis or kidney transplantation to sustain life. Patients who receive kidney transplants have longer life expectancy and better quality of life compared with those on dialysis. However, there is a shortage of donor kidneys worldwide, especially in Singapore.

“End-stage kidney failure patients wait close to 10 years for a cadaveric kidney donor transplant. But the best option for them is a transplant from a living donor as outcomes are better. We hope the findings of our study will encourage more people to consider being a living donor, more so if the patient is their loved one,” Dr Tan Ru Yu, Associate Consultant, Department of Renal Medicine, SGH, and lead author of the paper.

In examining kidney function changes of 180 living kidney donors at SGH from 1976 to 2012, the researchers found that function of the remaining kidney started increasing to compensate for the loss of the other kidney within six months after donation. This will take more than 10 years before kidney function stabilises. In fact, four in 10 living donors gradually regained 75 percent or more of their pre-donation kidney function after five years. Some donors recovered so well that the remaining kidney could provide the function of two.

The study also indicated that donors were not at higher risk of kidney failure or dying as compared to the general population. In fact, donors tend to be healthier because of their regular follow-ups at the hospital.

“Our findings from analysis of available information on living kidney donors at Singapore General Hospital during the last 40 years indicates that kidney function is well preserved after kidney donation, especially in donors with very good kidney function before donation. We hope these findings will reassure individuals in Singapore and Asia that kidney donation is safe for their health in the long term”, said Professor Tazeen H Jafar, Programme in Health Services and Systems Research, Duke-NUS.

The study was funded by Venerable Yen Pei – NKF Research Fund and the findings were published recently in Nephrology.