Rising temperatures linked to increased stone risk

Author(s):

Increasing daily temperature appears to be associated with an increased risk of kidney stones, results of a recently published multicenter study suggest.

“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,” said first author Gregory E. Tasian, MD, MSc, MSCE, of the Children’s Hospital of Philadelphia, in a press release from the hospital.

For the study, which was published online in Environmental Health Perspectives (July 10, 2014), Dr. Tasian and co-authors analyzed medical records of more than 60,000 children and adults who presented for evaluation or treatment of kidney stones between 2005 and 2011 in Atlanta, Chicago, Dallas, Los Angeles, and Philadelphia, in connection with weather data. They described the risk of stone presentation for the full range of temperatures in each city.

As mean daily temperatures rose above 50°F (10°C), the risk of kidney stone presentation increased in all the cities included in the analysis except Los Angeles. The delay between high daily temperatures and kidney stone presentation was short, peaking within 3 days of exposure to hot days.

Researchers also found that very low outdoor temperatures increased the risk of kidney stones in three cities: Atlanta, Chicago and Philadelphia. The authors suggest that as very cold weather keeps people indoors more, higher indoor temperatures, changes in diet, and decreased physical activity may increase their stone risk.

“These findings point to potential public health effects associated with global climate change. However, although 11% 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,” said Dr. Tasian.

The study was sponsored by the Urologic Diseases in America Project, which is supported by the National Institute of Diabetes and Digestive and Kidney Diseases.

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Publication of the current results come not long after research presented at the AUA annual meeting in Orlando, FL, found that pediatric patients with a positive family history appear to be at risk for recurrent stones.

In that study, researchers at the University of Wisconsin, Madison, evaluated the characteristics of patients seen in their pediatric stone clinic between 2007 and 2013. Review of the clinical features of the patients in the study and findings from 24-hour urine evaluation (27 patients) revealed a non-genetic etiology for stone disease in three patients (renal tubular acidosis in one patient and treatment with topiramate [Topamax] in two), while almost two-thirds of the cohort had more than one metabolic risk factor for nephrolithiasis.

“Based on these features, we believe that children with a positive family history of stone disease might particularly benefit from referral to a stone clinic that provides multidisciplinary care in order to establish a comprehensive and targeted management plan aimed at preventing future episodes,” said first author Necole M. Streeper, MD.