Exploring the association between environmental exposure to phthalates and bisphenol A and changes in reproductive hormones in women: a cross-sectional study

Abstract

Endocrine-disrupting chemicals (EDCs) can harm the female reproductive system by disrupting hormonal balance. This study investigates the association between exposure to EDCs)- specifically, phthalates and bisphenol A (BPA), and serum concentrations of estrogen (ES) and progesterone (P) in women. A comparative analysis was conducted on a group of 90 women, comprising an exposed group (n = 50) and a control group (n = 40). The relationships between 11 urinary phthalate metabolites, BPA, and reproductive hormone levels were analyzed using Spearman correlation, linear regression, and Bayesian Kernel Machine Regression (BKMR). The application of BKMR enabled the modeling of the overall mixture effect of the EDCs. This approach further identified non-linear dose–response relationships and delineated specific lifestyle and behavioral factors that modify the association between EDCs exposure and hormone concentrations. The findings showed that there was a positive association between BPA (β = 0.045; p < 0.05), MBP (β = 0.042; p < 0.05), ∑DEHP (β = 0.041; p < 0.05) with estrogen. Every unit increase in ln-transformed BPA, MBP, and ∑DEHP was associated with 0.045, 0.041, and 0.04 ln-unit increases in estrogen, respectively. Also, there was a positive and significant association between MBP, MEP, and BPA (p < 0.05) with progesterone. The BKMR analysis indicated a significantly positive overall effect on ES and P concentrations with high phthalate metabolites and BPA concentrations. The exposure variables showed that there was a significant positive relationship between smoking, consuming bottled water, drinking bottled beverages, consumption of ready-to-eat foods, and using cosmetics with ∑DEHP and ΒΡΑ (p < 0.05). The findings indicate associations between exposure to phthalates and BPA and hormone imbalances that may compromise women’s health as one of the vulnerable groups.