January 14, 2016
A new study led by researchers from the Children's Hospital of Philadelphia reports an alarming rise in the incidence of kidney stones among American youth, specifically females and African-Americans, in a trend that breaks with the historical pattern of high risk among middle-aged white men.
The study's findings, published Thursday in the Clinical Journal of the American Society of Nephrology, signaled concern for lead author Gregory E. Tasian, a pediatric urologist and epidemiologist at CHOP.
“The emergence of kidney stones in children is particularly worrisome because there is limited evidence on how to best treat children for this condition,” Tasian said. "The fact that stones were once rare and are now increasingly common could contribute to the inappropriate use of diagnostic tests such as CT scans for children with kidney stones -- since healthcare providers historically have not been accustomed to evaluating and treating children with kidney stones.”
Small mineral deposits that form in the kidneys can be caused by a variety of factors and can appear in several forms, but the particularly severe pain symptoms associated with passing them makes the growing prevalence among children an especially problematic medical development.
Tasian added that the condition poses potential long-term health problems for young people, especially young women, who may develop a higher risk for chronic kidney disease, cardiovascular and bone disease.
The 16-year-study, supported by the National Institutes of Health, sought to provide greater clarity on the demographics of a trend that medical experts have noticed but struggled to explain. Between 1997-2012, CHOP researchers analyzed 153,000 child and adult kidney stone patients in South Carolina from a total population of 4.6 million people.
During that period, the risk of kidney stones doubled during childhood among both boys and girls. Adolescents had the greatest increase at 4.7 percent annually, followed by women (3 percent) and African-Americans (2.9 percent). Overall, women saw a 45 percent increase in lifetime risk, while adolescent women had the highest rate of increase among all demographics. Within each five-year period of the study, African-Americans saw a 15 percent higher increase in the incidence of kidney stones than whites.
Among patients between the ages of 10 and 24, females included in the study more frequently developed kidney stones than men. That gender prevalence flipped after the age of 25.
Tasian and his colleagues emphasized that the age, sex and race differences highlighted by the study will require further study. They said several possible factors could be attributed to the increase in kidney stones among youth, including an increase in sodium intake, a decrease in calcium intake and dehydration, which is known to promote the growth of kidney stones.
Tasian previously examined the link between kidney stones and higher daily temperatures in a 2014 study encompassing five U.S. cities. He concluded that climate change may be a contributing factor to the general increase in patients seeking treatment for kidney stones.
The study's authors hope that the patterns found in patients from South Carolina can help physicians and public health officials create targeted prevention strategies for those who are at higher risk for the condition.