[Study of associations between childhood phthalate exposure and physical growth]

Objective: To analyze the associations between childhood phthalic acid esters (PAEs) exposure and physical growth indicators (body height, body weight, BMI), and their gender specific differences. Methods: Based on data from the three-year follow-up (2018-2020) of Xiamen Puberty Development Cohort, this study included 848 children aged 7-13 years for anthropometric examinations (e.g., body height and body weight) and urinary tests for seven PAEs metabolites. Those who had at least two repeated measurements were included in the analysis. Linear mixed effects model was used to analyze the associations between individual PAEs metabolites and body height Z-score, body weight Z-score, and BMI Z-score. Quantile g-computation was used to analyze the mixture exposure effect, stratified by gender. Results: PAEs metabolites were commonly detected in children's urine. In girls, mono-n-butyl phthalate (MnBP) and mono-2-ethylhexyl phthalate (MEHP) were negatively associated with body height Z-score (MnBP: β=-0.023, 95%CI: -0.041- -0.005; MEHP: β=-0.016, 95%CI: -0.029 - -0.003). In boys, the associations between PAEs metabolites and physical growth indicators had no statistical significance. The mixed exposure to PAEs metabolites showed no statistical significant association with body height Z-score, body weight Z-score, or BMI Z-score. Conclusions: There are gender specific differences in the association between childhood exposure to PAEs and physical growth. Exposure to some PAEs (MnBP, MEHP) is negatively associated with the body height of girls.