Urologists and nephrologists have long suspected that obesity also increases the risk of kidney stones in children. This connection is already known in adults. American researchers have now been able to show in a study that this also applies to children.
Scientists at Children’s Hospital Los Angeles have taken a new approach to assessing whether there is a link between the development of kidney stones and obesity in children. The team led by S. Scott Sparks, MD, and Arthi Hannallah, MD, studied 221 children with kidney stones at Children’s Hospital Los Angeles from 2007 to 2021.
Starting from puberty, being overweight has a strong influence on stone formation
The US researchers grouped the patients according to pubertal status (before puberty, during puberty, and after puberty) and compared their body mass indices with those of age-matched adolescents without kidney stones. The results were clear: Healthy children with kidney stones who had reached or completed puberty were more likely to have a significantly higher body mass index (BMI) than age-matched children without kidney stones.
dr Sparks, who along with nephrologist Dr. Nadine Khouzam, MD, who leads the Comprehensive Stone Program at Children’s Hospital Los Angeles, presented the findings at the fall meeting of the Society for Pediatric Urology in December. dr Khouzam was also an author of the article.
“These elevated BMIs are very similar to what we see in the adult population,” he explained. “By accounting for pubertal status, we were able to demonstrate a connection that clinicians have long suspected.”
The idea for the study design came from Dr. Hannallah, a pediatric urology fellow at Children’s Hospital Los Angeles.
“Part of the challenge in studying kidney stones was that children vary so much in terms of age and stage of development,” he said. “We hypothesized that we would find elevated BMIs in patients with stones from the onset of puberty, and we did.”
In contrast, the study found that prepubertal children with kidney stones did not have significantly higher BMIs than the control group. “The stones may be more likely to be caused by other conditions, such as spina bifida, in younger patients,” Dr. Chispas suggested. “That’s not always true, but it can be a factor.”
The study only looked at healthy children with stones, not young patients whose stones were caused by specific medical conditions.
Nutrition has an impact: socially disadvantaged families have less access to healthy food
dr Sparks also presented a second paper from the team, which found that children with kidney stones were more likely to come from low socioeconomic households. Even more concerning was that young patients from families living at or near the poverty line were much more likely to need surgery for their stones.
Even the types of stones differed according to socioeconomic level. The wealthier children tended to have calcium oxalate stones, while the less wealthy children had struvite stones, which are more related to diet. The experts looked at what a lack of access to healthy food has to do with the risk of kidney stones in children.
“All of these studies go hand in hand,” said Dr. Chispas. “We see that obesity is a risk factor for stone formation in children. And we know that lower socioeconomic status is associated with higher rates of obesity and obesity-related diseases. […]”
Kidney stones in children have increased in recent decades
Understanding these risk factors is important because kidney stones in children have increased in recent decades. The Comprehensive Stone Program at Children’s Hospital Los Angeles opened in 2016 and has grown rapidly, with the number of patients more than doubling.
The clinic takes a multidisciplinary approach, with patients able to see nephrologists and urologists, as well as a nutritionist and nurses.
Sources: Newswise, Children’s Hospital Los Angeles, Society for Pediatric Urology (Fall Meeting 1, 2)