There is an increase in the number of people seeking medical treatment for kidney stones as climate change worsens, says a new study published in the Environmental Health Perspectives journal of the National Institute of Environmental Health Sciences.
The researchers discovered a connection between the presence of hot days and the detection of kidney stones that affected 60,000 people in many cities in the U.S. found to have 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," Gregory E. Tasian, M.D., says in a statement.
Tasian, who is an epidemiologist and pediatric urologist at The Children’s Hospital of Philadelphia (CHOP) for the Kidney Stone Center and Center for Pediatric Clinical Effectiveness in CHOP, spearheaded the study.
Senior author Ron Keren, M.D., MPH, who is also from CPCE and CHOP, and other colleagues, assisted Tasian in the study.
Sponsor of said study is The Urologic Diseases in America Project, which also receives support from the National Institute of Diabetes and Digestive and Kidney Diseases.
The research entailed an analysis of medical records of over 60,000 adults and kids suffering from kidney stones, along with data on weather, between 2005 and 2011 in Chicago, Philadelphia, Atlanta, Dallas and Los Angeles.
Their findings suggested that the risks of kidney stones in all cities involved, save for Los Angeles, increased as the daily temperature reached over 50 F or 10 C. Discovered delay between production of kidney stones and high daily temperature was found to be short, reaching its peak in a matter of three-day exposure to hot weather.
"These findings point to potential public health effects associated with global climate change," Tasian notes. "However, although 11 percent of the U.S. population has had kidney stones, most people have not. It is likely that higher temperatures increase the risk of kidney stones in those people predisposed to stone formation."
Higher concentration of calcium and other minerals in our urine, caused by dehydration, leads to a growth of kidney stones. Dehydration, meanwhile, is partly caused by higher temperatures.
The researchers also discovered that the increased risk of kidney stones in Philadelphia, Chicago and Atlanta was also due to very low temperatures outdoors. They suggested that since cold weather pushes people to stay indoors, factors such as dietary changes, decreased physical activity and higher temperatures indoors may also increase the risk of developing kidney stones.
They likewise claimed that the number of hot days yearly than mean annual temperature may better forecast the risk of developing kidney stones.
“Kidney stone prevalence has already been on the rise over the last 30 years, and we can expect this trend to continue, both in greater numbers and over a broader geographic area, as daily temperatures increase," says Tasian. "With some experts predicting that extreme temperatures will become the norm in 30 years, children will bear the brunt of climate change."
Tasian also says there’s a need for more studies that would look further into their findings linking climate change to kidney stones.
The study entitled “Daily Mean Temperature and Clinical Kidney Stone Presentation in Five U.S. Metropolitan Areas: A Time Series Analysis,” Environmental Health Perspectives" was published on July 10, 2014.