Urinary concentrations of phthalate biomarkers and weight change among postmenopausal women: a prospective cohort study

Environ Health. 2019 Mar 12;18(1):20. doi: 10.1186/s12940-019-0458-6.


Background: Some phthalates are endocrine disrupting chemicals used as plasticizers in consumer products, and have been associated with obesity in cross-sectional studies, yet prospective evaluations of weight change are lacking. Our objective was to evaluate associations between phthalate biomarker concentrations and weight and weight change among postmenopausal women.

Methods: We performed cross-sectional (N = 997) and longitudinal analyses (N = 660) among postmenopausal Women's Health Initiative participants. We measured 13 phthalate metabolites and creatinine in spot urine samples provided at baseline. Participants' weight and height measured at in-person clinic visits at baseline, year 3, and year 6 were used to calculate body mass index (BMI). We fit multivariable multinomial logistic regression models to explore cross-sectional associations between each phthalate biomarker and baseline BMI category. We evaluated longitudinal associations between each biomarker and weight change using mixed effects linear regression models.

Results: In cross-sectional analyses, urinary concentrations of some biomarkers were positively associated with obesity prevalence (e.g. sum of di (2-ethylhexyl) phthalate metabolites [ΣDEHP] 4th vs 1st quartile OR = 3.29, 95% CI 1.80-6.03 [p trend< 0.001] vs normal). In longitudinal analyses, positive trends with weight gain between baseline and year 3 were observed for mono-(2-ethyl-5-oxohexyl) phthalate, monoethyl phthalate (MEP), mono-hydroxybutyl phthalate, and mono-hydroxyisobutyl phthalate (e.g. + 2.32 kg [95% CI 0.93-3.72] for 4th vs 1st quartile of MEP; p trend < 0.001). No statistically significant associations were observed between biomarkers and weight gain over 6 years.

Conclusions: Certain phthalates may contribute to short-term weight gain among postmenopausal women.

Keywords: Endocrine disruption; Obesity; Phthalates; Postmenopause; Weight change; Women.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Biomarkers / urine
  • Endocrine Disruptors / urine*
  • Environmental Exposure / analysis
  • Environmental Pollutants / urine*
  • Female
  • Humans
  • Middle Aged
  • Phthalic Acids / urine*
  • Postmenopause / urine*
  • Prospective Studies
  • Weight Gain*


  • Biomarkers
  • Endocrine Disruptors
  • Environmental Pollutants
  • Phthalic Acids