Global warming associated with higher incidence of kidney stones

With the planet getting warmer, the number of hot days are expected to increase, there will be more sweaty people and more dehydration, a key risk factor for higher incidence of kidney stones, according to researchers, AP reports.

The study in the journal Environmental Health Perspectives had found a link between hot days and kidney stones in 60,000 patients whose medical records were studied in Atlanta, Chicago, Dallas, Los Angeles and Philadelphia.

According to lead author Gregory Tasian, a paediatric urologist and epidemiologist at The Children's Hospital of Philadelphia, they found that with the increase in daily temperature, there was a rapid increase in the probability of patients developing kidney stones over the next 20 days.

As average daily temperatures increased above 10 degrees Celsius, the risk of kidney stone presentation rose in all the cities except Los Angeles.

While comparing daily average temperatures of 10 to 30 degrees Celsius, researchers found a 38 per cent higher risk of kidney stone in Atlanta and a 37 per cent higher risk in Chicago.

In the same way the risk in Dallas was 37 per cent higher while it was 47 per cent higher in Philadelphia. In Los Angeles the increased risk was smaller at 11 per cent on hotter days.

Tasian was assisted in the study, by senior author Ron Keren, MD, MPH, who is also from CPCE and CHOP and other colleagues.

The study was sponsored by the Urologic Diseases in America Project, which also received support from the National Institute of Diabetes and Digestive and Kidney Diseases.

The research studied the 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.

The findings suggested that kidney stones risk in all cities involved, excepting Los Angeles, increased as the daily temperature reached over 50 F or 10 C.

According to Tasian, the findings pointed to potential public health effects associated with global climate change. He notes that although 11 per cent of the US population had had kidney stones, most people had not.

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