As global warming heats up, kidney stones have joined the hot list for illnesses that merit more attention. The University of Texas predicts that kidney stones will grow even more common in the United States.
Continued global warming will cause the high-risk “kidney-stone belt” in the Southeast to expand to other states, according to researchers from the University of Texas at Dallas and University of Texas Southwestern Medical School.
The link between kidney stones and warm weather is potentially modifiable.
Stone-forming conditions
Inadequate consumption of water is a common cause of kidney stones. Not drinking enough, or a surfeit of sweating or other fluid losses, results in low urine volume. This may produce a situation in which minerals and other substances crystallize in the urine. The small hard stones that develop can cause excruciating pain in the side, back or groin as they pass through the ureters, the tubes leading from your kidneys to your bladder.
Men are four times more likely than women to develop kidney stones. Heredity, a hot dry climate, dietary factors, kidney infections, bone or digestive disorders or certain medications may contribute.
The climate connection
“There is a known geographic variation in stone disease that has been attributed to regional differences in temperature,” says Margaret Pearle, professor of urology at University of Texas Southwestern Medical School. “When people relocate from areas of moderate temperature to areas with warmer climates, a rapid increase in stone risk has been observed.” This has been shown in travelers to the Middle East or North Africa.
In the U.S., the kidney-stone belt consists of the southeastern states of Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. This region has as much as a 50 percent higher rate of stone disease than cooler areas of the country.
Texas research results
Researchers from the University of Texas expect the kidney-stone belt to expand with global warming. One model used by the scientists predicted that the increase will be concentrated in the southern half of the country. Another model pointed to an increase in the upper Midwest.
Taking into account the estimated population growth in those areas, increased temperatures are predicted to cause 2.2 million additional new cases of kidney stones by the year 2050. This represents up to a 30 percent increase in some areas of the country.
People living in high-risk zones for kidney stones will also grow, from 40 percent in 2000, to 56 percent by 2050, and then to 70 percent by 2095.
Plus, medical costs will go up. A 25 percent increase in the cost of caring for kidney stones in the U.S. will bring the sum to $6.5 billion annually by 2050.
The “previously unheralded” link between global warming and kidney stones indicates that “adapting to climate change will be one of the greatest challenges faced by mankind in this century,” the researchers conclude. The University of Texas study was published this summer in the Proceedings of the National Academy of Sciences.
Take-home message
A crucial first step in preventing kidney stones is to drink ample water, especially in warm weather. Other research suggests this can reduce the risk of stones by more than half.
If you’ve had stones before, consult with your doctor about additional measures you can take to keep them from coming back.
For more information: National Kidney and Urologic Diseases Information Clearinghouse, kidney.niddk.nih.gov.
Contact Dr. Elizabeth Smoots at doctor@practicalprevention.com.
&Copy; 2008 Elizabeth S. Smoots
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