Associations between urinary concentrations of bisphenols and serum concentrations of sex hormones among US. Males.
Level 4 - case-series / case-control
Cross-sectional observational study without longitudinal follow-up
PubMed 36550468 · doi:10.1186/s12940-022-00949-6
What was done
Analyzed cross-sectional data from 2,367 adult male participants in the U.S. National Health and Nutrition Examination Survey (NHANES) 2011–2016. Individuals lacking data on urinary bisphenols or serum sex hormones, or taking sex hormone medications, were excluded. Data for bisphenol analogs BPS and BPF were available for a subset of 1,575 participants. Multivariable regression models were used to evaluate associations between urinary bisphenols (BPA, BPS, BPF) and serum sex hormones, including total testosterone (TT), sex hormone-binding globulin (SHBG), and free testosterone (FT).
What was found
Each unit increase in urinary BPF was associated with 0.575 ng/dL higher TT (95% CI: 0.047 to 1.103, P = 0.033), while BPA and BPS showed no significant association with TT. Higher BPA and BPS concentrations were associated with higher SHBG (BPA: β = 0.364, 95% CI: 0.158 to 0.571; BPS: β = 0.250, 95% CI: 0.071 to 0.429), and participants in the highest BPA exposure quartile had 4.072 nmol/L higher SHBG than those in quartile 1 (95% CI: 0.746 to 7.397, P = 0.017; P for trend = 0.005). Both BPA and BPS were negatively associated with FT (Model 2: β = -0.01%, P = 0.0211 for BPA; β = -0.01%, P = 0.0258 for BPS), whereas BPF was positively associated with FT (Model 2: β = 0.0029%, P = 0.0028).
Why it matters
This study provides population-level evidence that both BPA and its common industrial replacements, BPS and BPF, are associated with altered sex hormone and SHBG profiles in adult men, indicating that replacement bisphenols retain potential endocrine-disrupting activity.
Limits
The cross-sectional design cannot establish causality or temporal relationships. Urinary bisphenols have short elimination half-lives, so spot urine samples may not accurately reflect long-term exposure. BPS and BPF were measured in only a subset (1,575 of 2,367) of participants, and unmeasured residual confounding remains possible.
Cited by
- context Adults and adolescents with higher urinary BPA levels have lower testosterone levels and altered estrogen metabolism.