Urinary Phthalate Metabolites Are Associated with Body Mass Index and Waist Circumference in Chinese School Children

Abstract

BackgroundLab studies have suggested that ubiquitous phthalate exposures are related to obesity, but relevant epidemiological studies are scarce, especially for children.ObjectiveTo investigate the association of phthalate exposures with body mass index (BMI) and waist circumference (WC) in Chinese school children.MethodsA cross-sectional study was conducted in three primary and three middle schools randomly selected from Changning District of Shanghai City of China in 2011–2012. According to the physical examination data in October, 2011, 124 normal weight, 53 overweight, and 82 obese students 8–15 years of age were randomly chosen from these schools on the basis of BMI-based age- and sex-specific criterion. First morning urine was collected in January, 2012, and fourteen urine phthalate metabolites (free plus conjugated) were determined by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Multiple linear regression was used to explore the associations between naturally log-transformed urine phthalate metabolites and BMI or WC.ResultsThe urine specific gravity-corrected concentrations of nine urine phthalate metabolites and five molar sums were positively associated with BMI or WC in Chinese school children after adjustment for age and sex. However, when other urine phthalate metabolites were included in the models together with age and sex as covariables, most of these significant associations disappeared except for mono (2-ethylhexyl) phthalate (MEHP) and monoethyl phthalate (MEP). Additionally, some associations showed sex- or age-specific differences.ConclusionsSome phthalate exposures were associated with BMI or WC in Chinese school children. Given the cross-sectional nature of this study and lack of some important obesity-related covariables, further studies are needed to confirm the associations.

Urinary Excretion of Phthalate Metabolites in School Children of China: Implication for Cumulative Risk Assessment of Phthalate Exposure

“…57 Previous studies in China also showed high urinary concentrations of MnBP and MiBP in the general population or children, 22,30 suggesting that DnBP and DiBP exposure is widespread in China. Since China is one of the largest producers and consumers of DnBP and DiBP globally, 22 exposure to these two phthalates may become an important health issue for Chinese people.…”

“…The distributions of participants by age, sex, body weight, and height in the three sampling regions are listed in The analyses of phthalate metabolites in urine were performed by an Acquity UPLC system coupled to a Xevo TQ-S triple quadrupole mass spectrometer (Waters, Milford, MA, USA) as previously described. 30,38 After an aliquot (1.0 mL) of urine sample was enzymatically hydrolyzed, the phthalate metabolites were separated from other urine components by solid phase extraction (SPE) with an Oasis MAX mixed-mode SPE cartridge (combining reversed-phase and anion-exchange mechanisms, Waters, Milford, MA, USA). Chromatographic separation was achieved using a C18 column (Acquity UPLC BEH C18, 100 mm × 2.1 mm × 1.7 μm).…”

Urinary concentrations of bisphenol A and phthalate metabolites and weight change: a prospective investigation in US women

“…PA is a nonspecific metabolite that can be derived from all phthalate diesters, and all of the phthalates can be ultimately metabolized to PA, so it is a nonspecific metabolite that is not often measured for this reason. 19–23 To be consistent with previous research on phthalates, we excluded PA in calculation of total phthalate metabolite concentration. To test for potential environmental contamination of samples, we compared measurements of urinary concentrations of phthalate metabolites among samples treated with and without β-glucuronidase and sulfatase in a pilot study.…”

Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review

“…The Chinese researchers found that, when age and sex were included in the model, MEHP and MEP were positively associated with BMI and WC. 155 Pesticides and Degradation Products Studies examining prenatal exposures to various pesticides and children's weight have documented inconsistent observations. A detailed discussion can be found in the Supplementary Information.…”