Obesity in Children Linked to Higher Urinary Bisphenol A

Emma Hitt, PhD

September 18, 2012

September 18, 2012 — Obese children and adolescents have a higher concentration of bisphenol A (BPA) in their urine than their healthy-weight peers, according to the findings of a nationally representative cross-sectional sample.

Leonardo Trasande, MD, MPP, from the Department of Pediatrics and the Department of Environmental Medicine, New York University School of Medicine, and New York University Wagner School of Public Service, New York City, and colleagues report their findings in the September 19 issue of JAMA.

BPA, a known endocrine disruptor, is found in canned foods, liquids packaged in plastic bottles, and other consumer products. Previous studies have shown an association between increased urinary BPA concentrations and obesity in adults.

According to the researchers, in previous studies of the US population, BPA has been detected in the urine of 92.6% of persons aged 6 years or older. A comprehensive cross-sectional study suggests that 99% of BPA exposure comes from food sources. As BPA concentrations in urine do not decline with fasting, and BPA has been detected in adipose tissue, it has been suggested that BPA accumulates in body fat over time.

Recent studies have found a link between increased urinary BPA and an increased risk for obesity, diabetes, cardiovascular disease, and reduced liver function in adults.

In the current study, the authors sought to examine the relationship between urinary BPA and body mass outcomes in children by measuring urinary BPA in a cross-sectional, nationally representative sample of 2838 randomly selected children aged between 6 and 19 years. The data were gathered from the 2003 to 2008 National Health and Nutrition Examination Surveys.

The researchers found that urinary BPA concentration was significantly associated with obesity, with an approximately 2-fold increased risk seen with concentrations in the second, third, and fourth quartiles of urinary BPA concentration compared with the lowest quartile (second quartile: odds ratio [OR], 2.22; 95% confidence interval [CI], 1.53 - 3.23; third quartile: OR, 2.09; 95% CI, 1.48 - 2.95; and fourth quartile: OR, 2.53; 95% CI, 1.72 - 3.74; P < .001 for all comparisons).

In contrast, there was no association found between other environmental chemicals, such as those found in sunscreens and soaps, and childhood obesity. In addition, BPA was not associated with obesity among the black or Hispanic population sample.

"Explanations of the association [between urinary BPA levels and obesity] cannot rule out the possibility that obese children ingest food with higher BPA content or have greater adipose stores of BPA," Dr. Trasande and colleagues write.

The authors add that more research is needed; specifically, longitudinal studies with detailed data "collected at earlier windows of endocrine development (when exposures are more likely to have an effect)."

Dr. Trasande and colleagues recommend that the next steps "could include research conducted among children already enrolled in longitudinal studies, measuring urinary BPA concentrations in banked samples."

The study was supported by the New York University Wagner School of Public Service and the New York University School of Medicine. The authors have disclosed no relevant financial relationships.

JAMA. 2012;308:1113-1121. Abstract