Bisphenol A substitutes and sex hormones in children and adolescents.
Level 4 - case-series / case-control
Cross-sectional survey study
PubMed 33819883 · doi:10.1016/j.chemosphere.2021.130396
What was done
A cross-sectional study evaluated 1,317 participants aged 6 to 19 years to assess associations between exposure to bisphenol A (BPA) and its substitutes (BPF and BPS) and serum sex hormones (total testosterone [TT], estradiol [E2], and sex hormone-binding globulin [SHBG]). Multiple linear regression and restricted cubic splines were used to evaluate linear and non-linear exposure-response relationships across sex-age subgroups.
What was found
Linear associations with BPF or BPS were sporadic, but BPA showed an inverse association with free androgen index (FAI) and E2, and a positive association with SHBG and TT/E2 in female adolescents (no regression coefficients or effect sizes reported in the abstract). Non-linear analyses in female adolescents revealed U-shaped relationships with FAI for BPA (P for non-linearity = 0.03), BPF (P for non-linearity = 0.005), and BPS (P for non-linearity = 0.08). An inverted U-shaped relationship with SHBG was observed for BPA (P for non-linearity = 0.03), BPS (P for non-linearity = 0.01), and BPF (P for non-linearity = 0.01). Associations among males were virtually non-significant.
Why it matters
This study provides human evidence that newer BPA substitutes, BPF and BPS, demonstrate non-linear endocrine-disrupting associations with sex steroid hormones in female adolescents similar to BPA.
Limits
The cross-sectional design cannot establish causality or temporal order. The abstract reports no effect sizes, baseline bisphenol levels, or confidence intervals. Spot measurements of rapidly excreted bisphenols and fluctuating sex hormones may lead to exposure misclassification, and confounding factors such as exact pubertal staging were not detailed.