According to a recent study donating a kidney does not appear to have any long term consequence with donors being able to lead a normal long, healthy life.  The study was undertaken by researchers at the University of Minnesota and researchers found that these people despite having donated one kidney do not increase the risk of kidney failure and were as healthy as the general population.

"Their lifespan is comparable to others of the same age, gender and ethnic background," said study author Dr. Hassan N. Ibrahim, an associate professor of medicine at the University of Minnesota. "Indeed, it appears that kidney donors might actually have better survival."

Dr. Ibrahim and colleagues followed 3,698 people who had donated a kidney at the university since 1963 to study the outcomes. 268 of the donors had died which the researchers said were figures that were comparable to the general population. Out of the donors decades later eleven of them developed kidney failure and needed dialysis or a transplant and these rates the researchers said were lower than those in the general public.

Out of these a group of 255 donors was randomly selected to undergo kidney and other tests and the results were compared with health outcomes of the general population. The researchers found that most of the donors who were tested had good kidney function and found that "their quality of life was better than 60 percent of the people in the general population of the same age and gender," Ibrahim said.

The study also looked at measures of kidney function such as the glomerular filtration rate (the flow of filtered fluid through the kidney) as well as the presence of conditions such as high blood pressure.

"Kidney donors have excellent glomerular filtration rates 85 percent of the time," Ibrahim said. "Kidney donors are not likely to develop high blood pressure or have protein in their urine."

One of the reasons for the results Dr. Ibrahim feels could be the strict selection process for a donor who ideally is a healthy young person with normal blood pressure. "It is clear that the excellent results seen here reflect very strict criteria," Ibrahim said. "Transplant centers now are willing to consider older donors and people with mild hypertension." That could mean that in decades to come the outcomes for these less-healthy donors "might look different," he said.

As kidney donation from a living donor is becoming more popular the age and other restrictions are becoming less strict, Dr. Jane Tan, an assistant professor of medicine at Stanford University and co-author of an accompanying editorial felt it could be likely as "the average age of living donors continues to increase."

"Many of the patients I see have been waiting for seven years," Tan said. "Spouses want to donate, people in their 60s. We don't know what the consequences will be."

 A balance of possible benefits and dangers must be made when considering less-than-ideal donors, Ibrahim said. "Take a 65-year-old donor with mild hypertension," he said. "There might be less severe consequences than for a 20-year-old with hypertension."

"The standards by which we screen kidney donors are quite rigorous right now," Tan said. "We believe it is safe, but we want to ensure that we have donor safety in mind."

The findings are reported in Thursday's New England Journal of Medicine. (Harkiran Contributed to this report)