Age and sex-specific relationships between phthalate exposures and obesity in Chinese children at puberty.

Yunhui Zhang,Luxi Li,Xiangzhou Meng,Li Chen,Yan Zhao,Dan Li,Huijing Shi,Lifang Zhao,Antonio Gonzalez-Bulnes

doi:10.1371/journal.pone.0104852

Abstract

ObjectiveTo examine the age and sex-specific associations of urine levels of six mono-phthalates with body size and fat distribution in Chinese children at puberty.Materials and MethodsFour hundred and ninety-three school-aged children (247 boys, 246 girls) were recruited. Obesity related anthropometric indices were measured and body fat proportion (BF%) was calculated. Spot urine samples were collected and phthalate monoesters were detected by an API 2000 electrospray triple quadrupole mass spectrometer (ESI-MS/MS). Associations between phthalate exposure and overweight/obesity measures and their trends were examined by multiple linear regression and Logistic regression analyses, respectively.ResultsDi-2-ethylhexyl phthalate (DEHP) metabolites and monobutyl phthalate (MBP) were found to be the most detectable chemicals. In 8–10 years (yrs) group, concentrations of MEHP and MBP were significantly higher in girls than those in boys. However, concentrations of all phthalate monoesters, except for MEP and MEHP, in 11–13 yrs boys were significantly higher than those in girls. After adjusting for confounders including puberty onset, urinary concentrations of MBP and sum of low molecular-weight phthalate metabolites (∑LMP) were positively associated with boys' obesity in a concentration-effect manner, while concentrations of MEHP, MEHHP and sum of DEHP metabolites (∑MEHP) were negatively associated with girls' obesity. Associations between phthalate exposure levels and BMI z-score changes were age- and sex-specific in school-age children.ConclusionThere are age and sex-specific concentration-effect associations between phthalate exposure and fat distribution in Chinese children. Urinary phthalate levels in 11–13 yrs boys were about 30 percent higher than those in girls, and ∑MEHP levels in younger boys (<10 yrs) were significantly higher than those in elder boys (>10 yrs). Associations were positive for MBP and ∑LMP with both BMI z-score and fat distribution in boys >10 years of age, and negative for ∑MEHP with fat distribution in girls <10 years of age.

Highlights

The rising prevalence of obesity has been of great public health concern in most countries in the world
Associations were positive for monobutyl phthalate (MBP) and gLMP with both body mass index (BMI) z-score and fat distribution in boys .10 years of age, and negative for gMEHP with fat distribution in girls,10 years of age
We excluded 10 marasmus children whose weight for age was lower than 10th percentiles of gender-specific weight distribution

Summary

Introduction

The rising prevalence of obesity has been of great public health concern in most countries in the world. The worldwide prevalence of childhood overweight and obesity had attained 6.7% by 2010 [2]. Obesity is closely linked to many adverse health effects, including type II diabetes, coronary heart disease, ischemic stroke, certain cancers (breast, colon and prostate cancer, etc.) and mortality [5]. 44% of diabetes burden, 23% of ischemic heart disease burden and 7–14% of certain cancer burden are attributable to overweight and obesity [1]. Besides changes in diet and increasing trends of physical inactivity, exposure to environmental pollutants during the critical window period (e.g., perinatal and peripubertal periods) might be one of the risk factors linked to childhood obesity

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Conclusion