Climate Change May Bring More Kidney Stones

As daily temperatures rise because of climate change, so does the number of patients with kidney stones. New research has found a link between warm days and kidney stones in 60,000 patients in several US cities with varying climates.

"We found that as daily temperatures rise, there is a rapid increase in the probability of patients presenting over the next 20 days with kidney stones," study leader Gregory E. Tasian, a pediatric urologist and epidemiologist at The Children's Hospital of Philadelphia, said in a statement.

Kidney stones are a painful condition that brings half a million people to US emergency rooms each year. While stones remain more common in adults, the numbers of children developing kidney stones have climbed at a dramatically high rate over the last 25 years. The factors that cause kidney stones are currently unknown, but researchers behind this study suspect that climate change and the warming temperatures it brings with it could be responsible.

The study team analyzed the records of more than 60,000 adults and children with kidney stones between 2005 and 2011 in the US cities Atlanta, Chicago, Dallas, Los Angeles and Philadelphia, in connection with weather data.

As mean daily temperatures rose above 50 degrees Fahrenheit (10 degrees Celsius), the risk of kidney stone presentation increased in all the cities except Los Angeles. They also found that lower outdoor temperatures (and therefore warmer indoor temperatures used to keep warm) increased the risk of kidney stones in Atlanta, Chicago and Philadelphia.

"These findings point to potential public health effects associated with global climate change," Tasian said.

Although, he notes that only 11 percent of the US population has ever had kidney stones.

"It is likely that higher temperatures increase the risk of kidney stones in those people predisposed to stone formation," Tasian explained.

Other studies, the researchers say, project that the Earth's average temperature will rise by 2 to 8 degrees F (1 to 4.5 degrees C) by 2100 due to greenhouse gas emissions.

"Kidney stone prevalence has already been on the rise over the last 30 years, and we can expect this trend to continue," concluded Tasian.

The study's findings were published in the journal Environmental Health Perspectives.