Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared with Normal Weight Stone Formers?

To determine if 24-hour urinary parameters in children with nephrolithiasis across four institutions were influenced by body mass index (BMI).

The 24-hour urinary parameters obtained from children with nephrolithiasis between 2000-2013 were stratified by BMI percentile ≥85th and <85th (overweight and obese patients versus healthy weight, respectively). A total of 206 children were included in the study. Exclusion criteria included patients with a history of spina bifida, neurogenic bladder, cerebral palsy and patients on medical treatment before the first 24-hour urine collection.

Overweight and obese patients consisted of 35.4% of the cohort (n=73). Metabolic abnormalities were present in 130 children (63.1%). The most common abnormality present in the <85th percentile was hypercalciuria (32.3%) and in the ≥85th percentile hyperoxaluria (37.0%). Univariable and multivariable analysis revealed that overweight and obese children were more likely to have low urinary volume and elevated uric acid compared to normal weight children.

Although there is a link between stone formation and BMI in adults, no definitive conclusions have been proven in the pediatric literature. Our study indicates that stone forming children who are overweight or obese have low urinary volume and elevated uric acid compared to normal weight stone forming children.

Urology. 2016 Sep 15 [Epub ahead of print]

Gina M Cambareri, Dana W Giel, Aaron P Bayne, Sean Corbett, Elleson Schurtz, Larisa Kovacevic, Troy Sukhu, Michael Yap, George Chiang

UCSD Department of Urology, San Diego, CA, USA. Electronic address: ., Division of Pediatric Urology, University of Tennessee Health Science Center/Le Bonheur Children's Hospital, Memphis, TN, USA., Department of Urology, Oregon Health Sciences University, Portland, OR, USA., Department of Urology, University of Virginia, Charlottesville, VA, USA., Department of Urology, Children's Hospital of Michigan, Detroit, MI, USA., UCSD Department of Urology, San Diego, CA, USA., Rady Children's Specialists of San Diego, UCSD Department of Urology, San Diego, CA, USA.