Could exposure to phthalates speed up or delay pubertal onset and development? A 1.5-year follow-up of a school-based population

Yunhui Zhang; Yang Cao; Huijing Shi; Xiaoxiao Jiang; Yan Zhao; Xin Fang; Changming Xie

doi:10.1016/j.envint.2015.06.005

Could exposure to phthalates speed up or delay pubertal onset and development? A 1.5-year follow-up of a school-based population

Environ Int. 2015 Oct:83:41-9. doi: 10.1016/j.envint.2015.06.005. Epub 2015 Jun 12.

Authors

Yunhui Zhang¹, Yang Cao², Huijing Shi³, Xiaoxiao Jiang¹, Yan Zhao¹, Xin Fang², Changming Xie¹

Affiliations

¹ School of Public Health, Key Laboratory of Public Health Safety, Fudan University, Shanghai 200032, China.
² Unit of Biostatistics, Division of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm 17177, Sweden.
³ School of Public Health, Key Laboratory of Public Health Safety, Fudan University, Shanghai 200032, China. Electronic address: hjshi@fudan.edu.cn.

PMID: 26073845
DOI: 10.1016/j.envint.2015.06.005

Abstract

Purpose: Phthalates may interfere with the timing of pubertal development in adolescence and existing studies have shown inconsistent results. This study aims to assess the associations of pubertal onset and progression with urinary concentrations of phthalate metabolites in school-aged boys and girls.

Methods: Using isotope-dilution liquid chromatography tandem mass spectrometry, we analyzed 6 phthalate metabolites in urine samples of 430 children (222 boys and 208 girls) aged 9.7 ± 2.2 years (age range 6.1 to 13.8 years) at baseline and 18 months of follow-up. The associations of exposures to phthalates with pubertal development such as the testis, breast and pubic hair were evaluated using ordered logistic regression models, adjusting for baseline development stage, current chronological age, current body fat composition, and parental education.

Results: Urinary mono-n-butyl phthalate (MnBP) was associated with a 39% increase in the odds of presenting lower pubic hair development stages in boys, and mono (2-ethylhexyl) phthalate (MEHP) (p < 0.10), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) were associated with 54%-65% increase in the odds of presenting higher breast development stages in girls (p < 0.05), while MEHHP and MEOHP were also associated with a 70% increase in the odds of menarche onset (p < 0.05). After adjusting for potential confounding variables, the associations of girls' pubertal onset with MnBP, MMP, MEP and MEHP were significant. The odds of girls' breast onset were 4 to 10 times higher in high MnBP, MMP, MEP or MEHP exposure group than in low exposure group.

Conclusions: Our findings suggest subtle effects of phthalate metabolites associated with pubertal onset and progression. MnBP exposure may be associated with delayed pubic hair development in boys, while MnBP, MMP, MEP, and MEHP exposures may be associated with breast onset, and MEHP metabolites associated with speedup in breast development progression and earlier menarche onset in girls.

Keywords: Antiandrogenic effect; Environmental endocrine disruptors; Phthalates; Pubertal timing; Sexual maturation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Child
China
Chromatography, Liquid
Cross-Sectional Studies
Environmental Exposure*
Environmental Pollutants / urine*
Female
Follow-Up Studies
Humans
Male
Phthalic Acids / urine*
Prospective Studies
Puberty / drug effects*
Sex Characteristics
Tandem Mass Spectrometry

Substances

Environmental Pollutants
Phthalic Acids