Associations between urinary concentrations of bisphenols and serum concentrations of sex hormones among US. Males

Abstract

Background Bisphenol A (BPA) exposure and its structural analogs (BPS and BPF) might cause endocrine alterations and adverse physiological effects. Few studies to date have directly explored the association between its structural analogs (BPS, BPF) and sex hormones in adult male participants. Therefore, we aimed to assess the associations between BPA, BPS, BPF, and sex hormones in American adult men. Methods We used data from the U.S. National Health and Nutrition Examination Survey 2011–2016. We excluded participants without data available on sex hormones and urinary bisphenols. Furthermore, participants consuming sex hormone medications were excluded. Multivariable regression models were performed to assess the association between bisphenols and sex hormones. Results In this study, 2367 participants were included. Of 2367, in 1575 participants, the data on BPS and BPF were available. We found that a per unit increase in BPF was associated with 0.575 ng/dL higher total testosterone (TT) (Model 2: 95% CI: 0.047, 1.103, P = 0.033). However, there was no significant association between BPA or BPS and TT. Furthermore, increased BPA and BPS levels were associated with higher levels of sex hormone-binding globulin (SHBG) (Model 2: β = 0.364, 95% CI: 0.158, 0.571; β = 0.25, 95% CI: 0.071, 0.429, respectively). Additionally, participants in the highest BPA exposure quartile (quartile 4) had 4.072 nmol/L higher levels of SHBG than those in quartile 1 (Model 2: 95% CI: 0.746, 7.397, P = 0.017; P for trend =0.005). Both BPA and BPS were negatively associated with free testosterone (FT, nmol/L) after full adjustment (Model 2, β = − 0.01%, P = 0.0211, P = 0.0211; Model 2, β = − 0.01%, P = 0.0258, respectively). However, BPF was positively associated with FT (Model 2, β = 0.0029%, P = 0.0028). Conclusion Our study indicated that exposure to both BPA and its substitutions could alter sex hormone levels. This finding supports the possibility that human exposure to bisphenols at environmental levels might affect the endogenous hormone balance.

Exposure characteristics and cumulative risk assessment of bisphenol A and its substitutes: the Taiwan environmental survey for toxicants 2013

“…In addition, in a study evaluating BPA concentrations in different Asian countries (adults of age ≥ 19, India [ n = 21], Japan [ n = 36]), Korea [ n = 32], Kuwait [ n = 32], Malaysia [ n = 29], and Vietnam [ n = 30]), the GM level (0.67 to 2.53 μg/g Cr) was approximately 4 to 9 times lower than our study (9.79 μg/g Cr) ( 72 ). Furthermore, the median levels of BPF and BPS for adults observed in our study (present study [7.89, 1.96] μg/L) were also 2- to 9-fold higher than those reported through the NHANES 2013–2014 ( 32 ) (USA [0.35, 0.37] μg/L), NHANES 2011–2016 ( 73 ) (USA [0.30, 0.50] μg/L) and the other study (Belgium [0.14, 0.11] μg/L). The above reasons may be caused by the exposure of dietary route ( 74 ) because the exposure of dietary BPA in Taiwan was approximately 100 to 400 times higher than in other countries (Taiwan: 133.79 to 419.26 ng/g (beef, chicken, and pork) vs. Norway: 0.24 ng/g (meat and meat products) ( 75 , 76 ), indicating food insecurity as a predictor of high BPA exposure ( 77 ), and meat products are a major contributor ( 78 ).…”

Association between Urinary BPA Substitutes and Precocious Puberty among Girls: A Single-Exposure and Mixed Exposure Approach from a Chinese Case—Control Study

“…Furthermore, BPS may directly affect the production of GnRH from the brain or directly inhibit pituitary production of gonadotropin hormones [35]. In humans, BPS was related to elevated SHBG and decreased TT in U.S males [31] as well as reduced serum E2, and SHBG in Chinese men [30]. The discrepancies in the results may be caused by differences in species, time of exposure, exposure doses, sex, and sample size among studies.…”

“…This action accelerated the introduction of BPA analogs as BPA substitutes. Some studies have explored the effect of BPA substitutes in humans [17,30,31]. None of these studies assessed the effects of precocious puberty in girls.…”