A kidney donor may have only one kidney after a transplant but it continues to function well, with four in 10 regaining 75 per cent of their pre-donation kidney function after five years.
In fact, donors lead healthy lives and are not at a higher risk of kidney failure or dying compared to the general population, according to a new study conducted by researchers from Singapore General Hospital (SGH) and Duke-NUS Medical School - believed to be the largest of its kind in South-east Asia.
The study looked at about 180 living kidney donors at SGH from 1976 to 2012. These patients had an average follow-up period of 11 years during which doctors looked at their blood pressure, urine test and kidney function during medical check-ups. It was also noted that kidney function in donors also stabilised after about a decade.
Which is why authors of the study are hoping that their findings will persuade more to consider being a living donor.
"The kidney function is actually not declining. We've removed your kidney but the kidney function tends to gradually increase... It's a very gradual, slow process and then it tends to stabilise. After stabilising, there will not be a dip," said Duke-NUS Programme in Health Services' Professor Tazeen H. Jafar, who was involved in the study.
Singapore is among the top five countries in the world with the highest incidence rates of kidney failure. In the last reported figures from the Renal Registry, 1,730 people suffered from kidney failure in 2014.
Kidney transplant from a live donor remains the best option for patients with end-stage kidney failure. Patients who undergo a transplant tend to have higher survival rates than those who undergo dialysis.
However, the latest figures from the National Organ Transplant Unit, Ministry of Health, show that while the waiting list for kidney transplants was 310 for the first half of this year, the number of kidney transplants from living donors stood at 16 as of the same period.
As for deceased donor kidney transplants, there were only 19. (See table at right.)
Researchers cited a 2012 study which found the fear of surgical risks and poorer health after donation as the main reasons for respondents not considering being a living kidney donor. The risks for surgery, however, are minimal.
Dr Terence Kee, director of the renal transplant programme at SGH, said the risk of complications arising from surgical procedures for kidney transplants ranges from 1 per cent to 5 per cent.
Internationally, the statistic for the risk of death from a donor surgery is one in 3,000 which is considered to be very low, as low as going for an appendix operation, he added.
Researchers say one in 2,000 people is born with one kidney - a condition known as renal agenesis, and yet they lead a normal life and have a normal lifespan.
Dr Tan Ru Yu, associate consultant from SGH's department of renal medicine and lead author of the study, said 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," she added.