Urinary phthalate concentrations are associated with total fat mass in Thai children

Background: Phthalate is one of the endocrine-disrupting chemicals found in many daily consumer products. Chronic exposure to phthalate may associate with obesity and metabolic abnormalities. However, there is limited information showing a direct relationship between phthalate and body compositions. Objectives: To determine the association between urinary phthalate concentration and body composition measure among Thai children. Methods: A cross-sectional analytic study on urinary phthalate concentrations and body composition in elementary school children, aged 6-13 years in Bangkok, was conducted during October 2019 to 2020. Urinary phthalate metabolites; (mono-methyl phthalate-MMP, mono-ethyl phthalate-MEP, mono-buthyl phthalate-MBP, and mono-ethylhexyl phthalate-MEHP), in early morning spot urine samples were measured by liquid chromatography tandem mass spectrometry (LC-MSMS) with a quantitation limit of 1 ng/mL. Phthalate exposures were identified through questionnaires. Body composition was measured by Tanita BC-418 (R). Multivariate logistic regression analysis was performed to determine significant associations. Results: A total of 364 children were enrolled in the study (boy 51.4%). After adjusting for confounders (sex, caregiver educations, family income, BMI-SDS: Body mass index-standard deviation score, TV watching, and exercise frequency), total urinary phthalate concentrations were associated with fat mass 8.24 (0.94, 15.53), trunk percent fat 7.69 (3.26, 12.12), arm percent fat 3.69 (0.47, 6.91), arm fat mass 72.88 (1.08, 144.67), and leg fat mass 17.79 (2.37, 33.22). Conclusions: Higher urinary phthalate concentrations were significantly associated with elevated total fat mass among Thai school-aged children. These findings were not mediated through the degree of obesity defined by BMI. These finding emphasized to be careful when being use phthalate-containing products.