Got Stones, Need Kidneys

Getting rid of kidney stones can be quite painful, but most people are able to pass them without medical intervention. However, having kidney stones in the first place can lead to other predicaments down the road.

A new study found that people who have kidney stones are twice as likely to need a kidney transplant or dialysis to remove them later in life.

This means, if you have kidney stones removed, watch for them to come back.

Ask your doctor how to avoid kidney stones.

The study, led by Todd Alexander and Marcello Tonelli from the University of Alberta, included more than 3 million Canadian adults who were registered with the health ministry Alberta Health and Wellness from 1997 to 2009.

Researchers gathered information from physician claims, hospitalizations, and ambulance usage to show whether patients had kidney stones, or crystal masses in the kidneys and ureter.

People with inflamed kidneys because of a bacterial infection were excluded from the study since they are already likely to develop kidney stones.

They found that between 5 and 7 percent of Albertans will develop a kidney stone in their lifetime.

In the United States, they said, 10 to 11 percent of the population will develop a kidney stone at some point in their life. And half of those who get kidney stones will develop one or more in the future.

The researchers found that those who had a history of kidney stones were twice as likely to have serious kidney problems later in life compared to people who never had them.

During the middle follow-up period, 5,333 or 0.2 percent of patients received a kidney transplant or began dialysis to remove the stones, 7 percent died, and another 7 percent moved outside Alberta.

Patients with kidney stones needed a new kidney 2.16 times more often than people who did not have the stones.

People with stones developed long-term kidney disease 1.74 times more often than those without.

Further, women under 50 who have a history of kidney stones are four times as likely to develop kidney failure later in life.

The number who had developed kidney failure in the study was small, but the link to having a history of kidney stones was noteworthy, the authors said.

“It’s important to note that the vast majority of people with kidney stones won’t develop permanent kidney damage,” Tonelli said.

“But a few will, and that’s why it’s important for people with stones to get proper follow-up care – to reduce their risk of another stone, and to detect kidney damage if it has occurred.”

The authors note a couple of limitations with their study. First, they only identified people with kidney stones through their doctors and medical services.

They also may have misclassified participants in order to take unknown cases of kidney stones into account. Researchers also did not measure the size and type of kidney stones, nor did they consider the patients' family history.

Grants from the Alberta Heritage Foundation for Medical Research, the Kidney Foundation of Canada, and the University Hospital Foundation funded the study.

The authors declare no financial or other relationships with organizations that might have an interest in their study.

The article was published online Aug. 30 in the British Medical Journal.