The bad news: Kidney stone disease appears to be increasing worldwide. In 2008, 1 out of every 11 Americans will experience a kidney stone at some point in their lives. This is up from 1 out of every 20 Americans in the 1970-80s . This rate has been reported to be even higher in other countries, with 1 out of 7 of Greeks and 1 out of 6 Thai experiencing stones based on reports from 2005 and 1997.
Why is this happening? There are a number of theories on why kidney stones are becoming more common.
1. Rising temperatures worldwide due to climate change
-Higher temperatures results in higher rates of dehydration from perspiration. Dehydration is one of the most common causes of kidney stones.
2. More frequent detection thanks to increased use of CT scans
-There may be more stones sufferers now because we are better at diagnosing kidney stones with the increased use of CT scans. Plain x-rays, more commonly used in the past, have a harder time detecting stones and patients in the past may have been diagnosed with back pain instead.
-As more countries become industrialized, diets have shifted from being vegetable based to being more meat based thanks to rising incomes. In combination with increased salt intake, these shifts in dietary intake increases the risk for forming kidney stones. This is why we recommend that kidney stone formers should moderate their protein and salt intake in order to reduce their risk for future stones.
4. Obesity rates are skyrocketing
-Obesity is another important risk factor for kidney stones. With more and more individuals becoming obese, it is not surprising that kidney stones are also more common.
Romero et al, Kidney Stones: A global picture of prevalence, incidence, and associated risk factors, Reviews in Urology 2010.
Author’s analysis of the National Health and Nutrition Examination Survey, 2007-2008 dataset. Not yet published.