Bisphenol a Analogues in Associations with Serum Hormone Levels Among Reproductive-Aged Chinese Men

Abstract

Background: Bisphenol A (BPA) as an endocrine-disrupting chemical has been shown to alter reproductive endocrine function, but little is known on its analogues including bisphenol F (BPF) and bisphenol S (BPS) with increasing usage and exposure.

Objective: To explore the associations between exposures to BPA, BPF and BPS and serum reproductive hormones among reproductive-aged Chinese men.

Methods: We measured BPA, BPF and BPS concentrations in repeated urine samples and multiple reproductive hormones in the serum samples collected from 462 men attending an infertility clinic in Wuhan, China. Linear regression models were applied to assess the associations between averaged urinary BPA, BPF and BPS levels and serum hormone concentrations, and restricted cubic spline (RCS) models were further utilized to explore potential non-linear associations. We also examined potential modifying effects by age and body mass index (BMI).

Results: There was little evidence of associations between BPA exposure and altered reproductive hormones. However, we found that elevated BPF and BPS exposures were negatively associated with estrogen (E2) levels and E2/T (total testosterone) ratio (all P for trends < 0.05), and that elevated BPS exposure was negatively associated with SHBG levels (P for trend = 0.09). Based on RCS models, these linear negative associations except for that between BPS exposure and E2/T ratio were further confirmed. In stratified analyses, BPF and BPS exposures in relation to reduced E2 and E2/T ratio were more pronounced among men aged > 30 years, whereas their associations with reduced SHBG levels were more pronounced among men aged ≤ 30. Also, BPS exposure in negative association with FSH only emerged among men with BMI ≥ 24 kg/m2 (P for interaction = 0.03).

Conclusion: BPF and BPS exposures were negatively associated with male serum E2, E2/T ratio and SHBG levels, and these associations varied by age and BMI.

Note:
Funding Information: This study was supported by the National Natural Science Foundation of China (No.81872585), the Chongqing Science and Technology Bureau, China (2019cstc-jbky-01702) and National Key Research and Development Plan of China (No. 2018YFC1004201)

Declaration of Interests: None.

Ethics Approval Statement: The study was approved by the Ethics Committee of Tongji Medical College. Signed informed consent was obtained.

Keywords: Bisphenols, Bisphenol A, Bisphenol F, Bisphenol S, Men, Reproductive hormones