ESPE Abstracts

Background: Humans are exposed to a variety of endocrine disruptors (EDs), including phthalates and phenol substitutes, in daily life. Previous studies have suggested the association between individual EDs and the risk of obesity, however, studies on the effects of multiple EDs have been extremely limited. We investigated the associations of urinary 12 phthalates, 3 polycyclic aromatic hydrocarbons, and 26 phenol substitutes with adiposity measures in Korean girls.

Methods: A total of 75 girls, aged 7 to 8 years old (28 obese and 47 controls), were recruited. Anthropometric indices, such as body mass index (BMI) and waist circumferences (WC), were also determined. The urinary concentrations of phthalates and phenol substitutes were measured using column switching coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results: Obese girls had higher urinary concentrations of nonylphenol (0.42 vs. 0.26 ng/mL), 2,5-dichlorophenol (0.69 vs. 0.41 ng/mL), and benzophenone-3 (1.93 vs. 0.95 ng/mL) after adjusting for log-transformed urinary creatinine (P<0.05), while other EDs monitored were not significantly different by obesity. After adjusting for all the covariates, girls in the highest quartile of nonylphenol and 2,5-dichlorophenol had significantly higher weight (mean difference-6.35 kg), BMI (3.24 kg/m²), and WC (8.23 cm), compared with those in the lowest quartile. After adjusting for covariates, the girls in a higher nonylphenol quartile showed a significantly higher odds ratio (OR) for general obesity (OR: 7.1 for quartile 3; 10.1 for quartile 4). and central obesity (OR: 9.2 for quartile 3; 10.7 for quartile 4) than those in the lowest quartile (P-for-trend <0.01). No statistical significance was observed in adjusted OR for obesity by quartiles of urinary 2,5-dichlorophenol levels.

Conclusion: We demonstrated a positive association between urinary nonylphenol and obesity in girls. Longitudinal studies with larger sample sizes are needed to confirm and elucidate our results.