Urinary bisphenol concentrations and its association with metabolic disorders in the US and Korean populations

Association of metals and bisphenols exposure with lipid profiles and dyslipidemia in Chinese adults: Independent, combined and interactive effects

BACKGROUND

Although studies have assessed the association of metals and bisphenols with lipid metabolism, the observed results have been controversial, and limited knowledge exists about the combined and interactive effects of metals and bisphenols exposure on lipid metabolism.

METHODS

Plasma metals and serum bisphenols concentrations were evaluated in 888 participants. Multiple linear regression and logistic regression models were conducted to assess individual associations of 18 metals and 3 bisphenols with 5 lipid profiles and dyslipidemia risk, respectively. The dose-response relationships of targeted contaminants with lipid profiles and dyslipidemia risk were captured by applying a restriction cubic spline (RCS) function. The bayesian kernel machine regression (BKMR) model was used to assess the overall effects of metals and bisphenols mixture on lipid profiles and dyslipidemia risk. The interactive effects of targeted contaminants on interested outcomes were explored by constructing an interaction model.

RESULTS

Single-contaminant analyses revealed that exposure to iron (Fe), nickel (Ni), copper (Cu), arsenic (As), selenium (Se), strontium (Sr), and tin (Sn) was associated with elevated lipid levels. Cobalt (Co) showed a negative association with high density lipoprotein cholesterol (HDL-C). Bisphenol A (BPA) and bisphenol AF (BPAF) were associated with decreased HDL-C levels, with nonlinear associations observed. Vanadium (V), lead (Pb), and silver (Ag) displayed U-shaped dose-response relationships with most lipid profiles. Multi-contaminant analyses indicated positive trends between contaminants mixture and total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C). The interaction analyses showed that Se-Fe exhibited synergistic effects on LDL-C and non-HDL-C, and Se-Sn showed a synergistic effect on HDL-C.

CONCLUSIONS

Our study suggested that exposure to metals and bisphenols was associated with changes in lipid levels, and demonstrated their combined and interactive effects.

FTO mediates bisphenol F-induced blood-testis barrier impairment through regulating ferroptosis via YTHDF1/TfRc and YTHDF2/SLC7A11 signal axis

Bisphenol F (BPF) has been extensively utilized in daily life, which brings new hazards to male reproductive health. However, the specific functional mechanism is still unclear. Both cell and animal models were utilized for exploring the role of RNA methylation and ferroptosis and its underlying mechanisms in male reproductive injury induced by BPF. In animal model, BPF severely destroyed the integrity of the blood-testis barrier (BTB) and induced ferroptosis. Furthermore, BPF significantly affected the barrier function of TM4 cells and promoted ferroptosis. Importantly, ChIP assays revealed that BPF inhibited AR transcriptional regulation of FTO and FTO expression was downregulated in TM4 cells. Overexpression of FTO prevented the impairment of BTB by inhibiting ferroptosis in TM4 cells. Mechanistically, FTO could significantly down-regulate the m6A modification level of TfRc and SLC7A11 mRNA through MeRIP experiment. RIP experiments showed that YTHDF1 can bind to TfRc mRNA and promote its translation while YTHDF2 could bind to SLC7A11 mRNA and reduce its mRNA stability. Therefore, our results suggest that FTO plays a key role in BPF induced male reproductive toxicity through YTHDF1-TfRc axis and YTHDF2-SLC7A11 axis and may provide new ideas and methods for the prevention and treatment of male reproductive diseases associated with environmental pollutants.

SWATH-MS reveals that bisphenol A and its analogs regulate pathways leading to disruption in insulin signaling and fatty acid metabolism

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC), associated with obesity and insulin resistance. The FDA prohibited the use of BPA-based polycarbonate resins in infant formula packaging; thus, its analogs, viz. Bisphenol S (BPS) and Bisphenol F (BPF) were considered alternatives in epoxy resins, plastics, and food cans. As these analogs might evoke a similar response, we investigated the role of Bisphenols (BPA, BPF, and BPS), on insulin signaling in CHO-HIRc-myc-GLUT4eGFP cells at environmentally relevant concentrations of 2 nM and 200 nM. Insulin signaling demonstrated that Bisphenols reduced phosphorylation of IR and AKT2, GLUT4 translocation, and glucose uptake. This was accompanied by increased oxidative stress. Furthermore, SWATH-MS-based proteomics of 3T3-L1 cells demonstrated that Bisphenol-treated cells regulate proteins in insulin resistance, adipogenesis, and fatty acid metabolism pathways differently. All three Bisphenols induced differentially expressed proteins enriched similar pathways, although their abundance differed for each Bisphenol. This might be due to their varying toxicity level, structural differences, and estrogen-mimetic activity. This study has important implications in addressing health concerns related to EDCs. Given that the analogs of BPA are considered alternatives to BPA, the findings of this study suggest they are equally potent in altering fatty acid metabolism and inducing insulin resistance.

Effects of endocrine disrupting chemicals and their interactions with genetic risk scores on cardiometabolic traits

Ubiquitous non-persistent endocrine disrupting chemicals (EDCs) have inconsistent associations with cardiometabolic traits. Additionally, large-scale genome-wide association studies (GWASs) have yielded many genetic risk variants for cardiometabolic traits and diseases. This study aimed to investigate the associations between a wide range of EDC exposures (parabens, bisphenols, and phthalates) and 14 cardiometabolic traits and whether these are moderated by their respective genetic risk scores (GRSs). Data were from 1074 participants aged 18 years or older of the Lifelines Cohort Study, a large population-based biobank. GRSs for 14 cardiometabolic traits were calculated based on genome-wide significant common variants from recent GWASs. The concentrations of 15 EDCs in 24-hour urine were measured by isotope dilution liquid chromatography tandem mass spectrometry technology. The main effects of trait-specific GRSs and each of the EDC exposures and their interaction effects on the 14 cardiometabolic traits were examined in multiple linear regression. The present study confirmed significant main effects for all GRSs on their corresponding cardiometabolic trait. Regarding the main effects of EDC exposures, 26 out of 280 EDC-trait tests were significant with explained variances ranging from 0.43 % (MMP- estimated glomerular filtration rate (eGFR)) to 2.37 % (PrP-waist-hip ratio adjusted body mass index (WHRadjBMI)). We confirmed the association of MiBP and MBzP with WHRadjBMI and body mass index (BMI), and showed that parabens, bisphenol F, and many other phthalate metabolites significantly contributed to the variance of WHRadjBMI, BMI, high-density lipoprotein (HDL), eGFR, fasting glucose (FG), and diastolic blood pressure (DBP). Only one association between BMI and bisphenol F was nominally significantly moderated by the GRS explaining 0.36 % of the variance. However, it did not survive multiple testing correction. We showed that non-persistent EDC exposures exerted effects on BMI, WHRadjBMI, HDL, eGFR, FG, and DBP. However no evidence for a modulating role of GRSs was found.

Urinary concentrations and elimination half-lives of parabens, benzophenones, bisphenol and triclosan in Japanese young adults

Environmental phenols are widely distributed in the environment and human samples, suggesting potential exposure to these chemicals. We designed an intervention trial with 30 participants over 6 days to assess the urinary concentrations and half-lives of environmental phenols in Japanese young people. The target environmental phenols include three parabens (methyl paraben, ethyl paraben, and propyl paraben), two benzophenones (benzophenone 1 and 3), two bisphenols (bisphenol F and bisphenol S), and triclosan. Throughout the intervention, the participants consumed the same food and drinks and used personal care products provided by the project. The target phenols were measured in urine from the participants using a liquid chromatography-tandem mass spectrometer. We compared the measured concentrations between the study periods to better understand the exposure tendency. Some statistically significant differences were observed. All target analytes were detected in more than 50% of samples collected on Day 0 (the day before the intervention). Methyl paraben was the dominant phenol detected in urine (1640 μg/g-creatinine), followed by ethyl paraben (119 μg/g-creatinine). Downward trends in creatinine-corrected concentrations were observed for all target analytes in some instances. Non-compartment analysis was performed to estimate urinary excretion parameters. The estimated half-lives ranged from 7.69 to 20.3 h. Use of paraben-free products during the intervention period reduced the body burden.

Distribution and potential risk factors of bisphenol a in serum and urine among Chinese from 2004 to 2019

Background

Bisphenol A (BPA) is an oil-derived, large-market volume chemical with endocrine disrupting properties and reproductive toxicity. Moreover, BPA is frequently used in food contact materials, has been extensively researched recently, and widespread exposure in the general population has been reported worldwide. However, national information on BPA levels in general Chinese people is lacking.

Methods

This study collected and analyzed 145 (104 in urine and 41 in serum) research articles published between 2004 and 2021 to reflect the BPA internal exposure levels in Chinese populations. The Monte Carlo simulation method is employed to analyze and estimate the data in order to rectify the deviation caused by a skewed distribution.

Results

Data on BPA concentrations in urine and serum were collected from 2006 to 2019 and 2004 to 2019, respectively. Urinary BPA concentrations did not vary significantly until 2017, with the highest concentration occurring from 2018 to 2019 (2.90 ng/mL). The serum BPA concentration decreased to the nadir of 1.07 ng/mL in 2011 and gradually increased to 2.54 ng/mL. Nationally, 18 provinces were studied, with Guangdong (3.50 ng/mL), Zhejiang (2.57 ng/mL), and Fujian (2.15 ng/mL) having the highest urine BPA levels. Serum BPA was investigated in 15 provinces; Jiangsu (9.14 ng/mL) and Shandong (5.80 ng/mL) were relatively high. The results also indicated that males' urine and serum BPA levels were higher than females, while the BPA levels in children were also higher than in adults (p < 0.001). Furthermore, the volume of garbage disposal (r = 0.39, p < 0.05), household sewage (r = 0.34, p < 0.05), and waste incineration content (r = 0.35, p < 0.05) exhibited a strong positive connection with urine BPA levels in Chinese individuals.

Conclusion

Despite using a data consolidation approach, our study found that the Chinese population was exposed to significant amounts of BPA, and males having a higher level than females. Besides, the levels of BPA exposure are influenced by the volume of garbage disposal, household sewage, and waste incineration content.

Sex and Gender Differences on the Impact of Metabolism-Disrupting Chemicals on Obesity: A Systematic Review

Obesity represents an important public health concern, being one of the leading causes of death worldwide. It is a multifactorial disease with many underlying intertwined causes, including genetic, environmental and behavioral factors. Notably, metabolism-disrupting chemicals (MDCs) can alter the set point control of metabolism, affecting the development and function of the adipose tissue. Epidemiological studies have reported associations between human exposure to MDCs and several altered metabolic endpoints. It is also noteworthy that sex and gender represent important risk factors in the development of obesity. Different sex-related biological and physiological characteristics influence individual susceptibility, whereas gender represents a critical component in determining the different exposure scenarios. Although some advancements in the treatment of obesity have been achieved in preclinical and clinical studies, the obesity pandemic continues to increase worldwide. The present study performed a systematic review of recent studies considering the effects of MDCs on obesity, with a specific focus on sex- and gender-related responses. This review highlighted that MDCs could differently affect men and women at different stages of life even though the number of studies evaluating the association between obesity and MDC exposure in relation to sex and gender is still limited. This evidence should urge researchers to carry out studies considering sex and gender differences. This is essential for developing sex-/gender-tailored prevention strategies to improve public health policies and reduce exposure.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Bisphenol S, bisphenol F, bisphenol a exposure and body composition in US adults

Bisphenol S (BPS) and bisphenol F (BPF) are increasingly used to replace bisphenol A (BPA), an endocrine-disrupting chemical with putative obesogenic properties; whether and how BPS and BPF affect adiposity in humans remains to be determined. Therefore, we examined the association of BPA, BPS， and BPF with body composition among US adults. We included 1787 participants aged 20-59 years old in the National Health and Nutrition Examination Survey 2013-2016 who had information on urinary BPA, BPS, and BPF concentrations, and body composition measured using dual-energy x-ray absorptiometry. After full adjustment for potential confounders in linear regression models, BPA was significantly associated with the % body fat of the whole body, arm, and leg, with the β (95% CI) for the highest quartile vs. the lowest quartile of 1.34 (95%CI [0.11, 2.58], P = 0.03), 1.60 (95%CI [0.20, 3.00], P = 0.03), and 1.63 (95%CI [0.24, 3.02], P = 0.02), respectively. No association between BPA and lean mass was found. For BPS, significant associations were found for % body fat of the whole body (β [95% CI] = 1.42 [0.49, 2.36], P = 0.004), trunk (β[95% CI] = 1.92 [0.86, 2.97], P = 0.001), and arm (β [95% CI] = 1.60 [0.49, 2.70], P = 0.01), as well as lean mass of the whole body (β [95% CI] = 2610.6 [1324.3, 3896.8], P < 0.001), trunk (β [95% CI] = 1467.0 [745.3, 2188.7], P < 0.001), arm (β [95% CI] = 113.4 [10.3, 216.5], P = 0.03), and leg (β [95% CI] = 431.5 [219.6, 643.4], P < 0.001), comparing the third quartile vs. the lowest quartile. No significant association was observed between BPF and % body fat and lean mass. Results suggest that higher BPA levels were significantly associated with greater % body fat of the whole body and limbs, and there was suggestive evidence that BPS levels were associated with both % body fat and lean mass of the whole body and body parts in a nonmonotonic relationship.

Sex-specific associations of bisphenol A and its substitutes with body fat distribution among US adults: NHANES 2011-2016

Bisphenol A (BPA) and its structural analogs (bisphenol S (BPS) and bisphenol F (BPF)) are widely consumed endocrine disrupting chemicals that may contribute to the etiology of obesity. To date, few studies have directly investigated the sex-related associations between bisphenols and body fat distribution in adults. In this study, we included 2669 participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 to evaluate and compare sex-specific differences of the associations of BPA, BPS, and BPF with body fat distribution. We found that there were significant positive correlations between BPS and body fat indices (STFAT [adjustedβ=1.94, 95% CI: (0.24, 3.64)], TAF [0.18 (0.04, 0.32)], SAT [0.15 (0.03, 0.27)], android fat mass [0.20 (0.004, 0.40)], BMI [1.63 (0.61, 2.65)], and WC [3.19 (0.64, 5.73)] in the highest quartiles of BPS), but not in BPA and BPF. Stratified analyses suggested that the significant associations of BPS with body fat indices were stronger in women than men (STFAT [adjustedβ=3.75, 95% CI: (1.04, 6.45) vs. adjustedβ=-0.06, 95% CI: (-2.23, 2.11), P for interaction < 0.001], TAF [ 0.32 (0.09, 0.54) vs. 0.01 (-0.17, 0.19), P for interaction < 0.001], SAT [0.27 (0.09, 0.45) vs. 0.01 (-0.14, 0.16), P for interaction < 0.001], android fat mass [0.41 (0.12, 0.71) vs. -0.02 (-0.28, 0.24), P for interaction < 0.001], gynoid fat mass [0.56 (0.11, 1.01) vs. -0.05 (-0.41, 0.31), P for interaction = 0.002], BMI [2.76 (1.08, 4.44) vs. 0.47 (-0.80, 1.74), P for interaction < 0.001], and WC [5.51 (1.44, 9.58) vs. 0.61 (-2.67, 3.88), P for interaction < 0.001]), and positive associations between BPS with fat distribution were also observed in non-smoking women. Our study indicated that in women, higher concentration of urinary BPS was associated with increased body fat accumulation, except for visceral adipose tissue mass. These findings emphasize the role of environmental BPS exposure in the increasing fat deposits, and confirm the need for more prospective cohort studies on a sex-specific manner.

Bisphenol S induces brown adipose tissue whitening and aggravates diet-induced obesity in an estrogen-dependent manner

Bisphenol S (BPS) exposure has been implied epidemiologically to increase obesity risk, but the underlying mechanism is unclear. Here, we propose that BPS exposure at an environmentally relevant dose aggravates diet-induced obesity in female mice by inducing brown adipose tissue (BAT) whitening. We explored the underlying mechanism by which KDM5A-associated demethylation of the trimethylation of lysine 4 on histone H3 (H3K4me3) in thermogenic genes is overactivated in BAT upon BPS exposure, leading to the reduced expression of thermogenic genes. Further studies have suggested that BPS activates KDM5A transcription in BAT by binding to glucocorticoid receptor (GR) in an estrogen-dependent manner. Estrogen-estrogen receptors facilitate the accessibility of the KDM5A gene promoter to BPS-activated GR by recruiting the activator protein 1 (AP-1) complex. These results indicate that BAT is another important target of BPS and that targeting KDM5A-related signals may serve as an approach to counteract the BPS-induced susceptivity to obesity.

Invisible Hand behind Female Reproductive Disorders: Bisphenols, Recent Evidence and Future Perspectives

Reproductive disorders are considered a global health problem influenced by physiological, genetic, environmental, and lifestyle factors. The increased exposure to bisphenols, a chemical used in large quantities for the production of polycarbonate plastics, has raised concerns regarding health risks in humans, particularly their endocrine-disrupting effects on female reproductive health. To provide a basis for future research on environmental interference and reproductive health, we reviewed relevant studies on the exposure patterns and levels of bisphenols in environmental matrices and humans (including susceptible populations such as pregnant women and children). In addition, we focused on in vivo, in vitro, and epidemiological studies evaluating the effects of bisphenols on the female reproductive system (the uterus, ovaries, fallopian tubes, and vagina). The results indicate that bisphenols cause structural and functional damage to the female reproductive system by interfering with hormones; activating receptors; inducing oxidative stress, DNA damage, and carcinogenesis; and triggering epigenetic changes, with the damaging effects being intergenerational. Epidemiological studies support the association between bisphenols and diseases such as cancer of the female reproductive system, reproductive dysfunction, and miscarriage, which may negatively affect the establishment and maintenance of pregnancy. Altogether, this review provides a reference for assessing the adverse effects of bisphenols on female reproductive health.

Bisphenol A (BPA) and Cardiovascular or Cardiometabolic Diseases

Bisphenol A (BPA; 4,4'-isopropylidenediphenol) is a well-known endocrine disruptor. Most human exposure to BPA occurs through the consumption of BPA-contaminated foods. Cardiovascular or cardiometabolic diseases such as diabetes, obesity, hypertension, acute kidney disease, chronic kidney disease, and heart failure are the leading causes of death worldwide. Positive associations have been reported between blood or urinary BPA levels and cardiovascular or cardiometabolic diseases. BPA also induces disorders or dysfunctions in the tissues associated with these diseases through various cell signaling pathways. This review highlights the literature elucidating the relationship between BPA and various cardiovascular or cardiometabolic diseases and the potential mechanisms underlying BPA-mediated disorders or dysfunctions in tissues such as blood vessels, skeletal muscle, adipose tissue, liver, pancreas, kidney, and heart that are associated with these diseases.

Puerarin Prevents Bisphenol S Induced Lipid Accumulation by Reducing Liver Lipid Synthesis and Promoting Lipid Metabolism in C57BL/6J Mice

Bisphenol S (BPS) is an environmental pollutant that can accumulate in the human body and cause harm. Puerarin (PUE) is a flavonoid with anti-inflammatory and antioxidant effects. In this study, we used 50 mg/kg/d BPS as a poison and PUE as an intervention for model mice for 42 d. BPS exposure significantly increased the levels of the impairment of the mice's liver function, T-CHO, TG, LDL-C, ALT, and AST in the BPS group were significantly increased (p < 0.05). Additionally, BPS exposure caused inflammatory cell infiltration in the mice liver tissue and enhanced oxidative stress response, the level of MDA was significantly increased (p < 0.05). The expression of CD36 and pparγ was stimulated after BPS exposure. Moreover, the expression of cpt1a and cpt1b, which promote fatty acid oxidation, was downregulated. After PUE intervention, the levels of genes and proteins involved in lipid synthesis (PPARγ, SREBP1C, and FASN) and metabolism (Cpt1a, Cpt1b, and PPARα) in mice returned to those of the control group, or much higher than those in the BPS group. Therefore, we hypothesized that BPS causes lipid accumulation in the liver by promoting lipid synthesis and reducing lipid metabolism, whereas PUE reduces lipid synthesis and promotes lipid metabolism. Conclusively, our results imply that long-term exposure to BPS in mice affects liver lipid metabolism and that PUE intervention could maintain the liver function of mice at normal metabolic levels.

Prenatal bisphenol S exposure induces hepatic lipid deposition in male mice offspring through downregulation of adipose-derived exosomal miR-29a-3p

The increased usage of bisphenol S (BPS) results in wide distribution in pregnant women. In this study, pregnant mice were given multiple-dose BPS during gestation. Results showed that prenatal BPS exposure (50 μg/kg/day) induced increased weight gain, dyslipidemia, higher liver triglyceride (TG), adipocyte hypertrophy, and hepatic lipid deposition in male offspring. Exosomes play important roles in regulating lipid metabolism. Here, serum exosomes and adipose miRNA sequencing of male offspring indicated a remarkable decrease in miR-29a-3p expression. To clarify whether adipocyte-derived exosomes mediate hepatic lipid deposition, exosomes were extracted from BPS-treated adipocytes and co-cultured with hepatocytes. These exosomes could be taken up by hepatocytes and promoted lipid deposition, and notably, exosomal miR-29a-3p was downregulated. Furthermore, miR-29a-3p knockdown in adipocyte-derived exosomes promoted hepatocyte lipid deposition, whereas overexpression led to the opposite effect. Also, the role of miR-29a-3p was demonstrated in hepatocytes by overexpressing or knocking it down. Subsequent studies have shown that miR-29a-3p can promote lipid deposition by directly targeting Col4a1. Taken together, prenatal BPS exposure could lead to lower miR-29a-3p yield in adipocyte-derived exosomes and decrease miR-29a-3p content transported to hepatocytes, which further negatively regulate Col4a1 and promote hepatic lipid deposition. Our findings provided clues to maternal environmental exposure-induced liver metabolic diseases.

Enhancing de novo ceramide synthesis induced by bisphenol A exposure aggravates metabolic derangement during obesity

OBJECTIVE

Exposure to bisphenol A (BPA) has been shown to increase the prevalence of obesity and its related insulin resistance (IR). Ceramide is a sphingolipid known to facilitate the production of proinflammatory cytokines and subsequently exacerbate inflammation and IR during the progression of obesity. Here, we investigated the effects of BPA exposure on ceramide de novo synthesis and whether increased ceramides aggravate adipose tissue (AT) inflammation and obesity-related IR.

METHODS

A population-based case-control study was conducted to explore the relationship between BPA exposure and IR and the potential role of ceramide in AT in obesity. Next, we used mice reared on a normal chow diet (NCD) or a high-fat diet (HFD) to verify the results from the population study and then investigated the role of ceramides in low-level BPA exposure with HFD-induced IR and AT inflammation in mice treated with or without myriocin (an inhibitor of the rate-limiting enzyme in de novo ceramide synthesis).

RESULTS

BPA levels are higher in obese individuals and are significantly associated with AT inflammation and IR. Specific subtypes of ceramides mediated the associations between BPA and obesity, obesity-related IR and AT inflammation in the obesity group. In animal experiments, BPA exposure facilitated ceramide accumulation in AT, activated PKCζ, promoted AT inflammation, increased the expression and secretion of proinflammatory cytokines via the JNK/NF-κB pathway, and lowered insulin sensitivity by disrupting IRS1-PI3K-AKT signaling in mice fed a HFD. Myriocin suppressed BPA-induced AT inflammation and IR.

CONCLUSION

These findings indicate that BPA aggravates obesity-induced IR, which is partly via increased de novo synthesis of ceramides and subsequent promotion of AT inflammation. Ceramide synthesis could be a potential target for the prevention of environmental BPA exposure-related metabolic diseases.

Genetic background in the rat affects endocrine and metabolic outcomes of bisphenol F exposure

Environmental bisphenol compounds like bisphenol F (BPF) are endocrine-disrupting chemicals (EDCs) affecting adipose and classical endocrine systems. Genetic factors that influence EDC exposure outcomes are poorly understood and are unaccounted variables that may contribute to the large range of reported outcomes in the human population. We previously demonstrated that BPF exposure increased body growth and adiposity in male N/NIH heterogeneous stock (HS) rats, a genetically heterogeneous outbred population. We hypothesize that the founder strains of the HS rat exhibit EDC effects that were strain- and sex-dependent. Weanling littermate pairs of male and female ACI, BN, BUF, F344, M520, and WKY rats randomly received either vehicle (0.1% EtOH) or 1.125 mg BPF/l in 0.1% EtOH for 10 weeks in drinking water. Body weight and fluid intake were measured weekly, metabolic parameters were assessed, and blood and tissues were collected. BPF increased thyroid weight in ACI males, thymus and kidney weight in BUF females, adrenal weight in WKY males, and possibly increased pituitary weight in BN males. BUF females also developed a disruption in activity and metabolic rate with BPF exposure. These sex- and strain-specific exposure outcomes illustrate that HS rat founders possess diverse bisphenol-exposure risk alleles and suggest that BPF exposure may intensify inherent organ system dysfunction existing in the HS rat founders. We propose that the HS rat will be an invaluable model for dissecting gene EDC interactions on health.

Relationship between bisphenol A and the cardiovascular disease metabolic risk factors in American adults: A population-based study

BACKGROUND

Bisphenol A (BPA) is widely used in personal care and consumer products. However, no study has reported a specific relationship between BPA concentrations and metabolic hazardous elements for cardiovascular diseases (CVDs). Consequently, in this study, we used six years of population-based NHANES data (2011-2016) to analyse the association between BPA concentrations and metabolic risk factors for CVDs.

METHODS

A total of 1467 participants were enrolled in our project. The participants in the study were divided into quartiles based on BPA levels (Q1: ≤0.6 ng/ml, Q2: 0.7-1.2 ng/ml, Q3: 1.3-2.3 ng/ml, Q4: ≥2.4 ng/ml). This study used multiple linear and multivariate logistic regression models to determine the association among BPA concentrations and CVD metabolic risk factors.

RESULTS

When the concentration of BPA was in Q3, fasting glucose concentrations were decreased by 3.87 mg/dl, and 2-h glucose concentrations were decreased by 16.24 mg/dl. When the concentration of BPA was in Q4, fasting glucose concentrations were decreased by 12.15 mg/dl, and diastolic blood pressure was increased by 2.08 mmHg. At the same time, compared to participants in the first quartile (Q1), those from the fourth quartile (Q4) of BPA concentrations had 21% higher odds of hypertension, 30% higher odds of obesity, 30.2% higher odds of central obesity, 4.5% higher odds of elevated HbA₁c, 17% higher odds of elevated non-HDL cholesterol, and 60.8% higher odds of diabetes (compared to the lowest quartile, Q1).

CONCLUSIONS

We found that higher concentrations of BPA were linked with a higher metabolic risk for CVDs. Further regulation of BPA may need to be considered for the prevention of CVDs in adults.

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

Association of urinary bisphenol A with chronic obstructive pulmonary disease-related diseases: evidence from the National Health and Nutrition Examination Survey database (2005-2016)

In vivo and in vitro studies have found that exposure to bisphenol A (BPA) can lead to pulmonary diseases, but there exists little evidence regarding the association between urinary BPA level and chronic obstructive pulmonary disease (COPD)-related diseases in the population. National Health and Nutrition Examination Survey data, from 2005 to 2016, were utilized in this study. Participants who self-reported having emphysema, chronic bronchitis, or COPD were defined as having COPD-related diseases. A multivariate logistic regression analysis was used to analyze the association of urinary BPA with COPD-related diseases in the overall population and according to sex. Three separate models including different covariates were used in our analyses. The association of urinary BPA with COPD-related diseases in different subgroups (age, smoking status, participants belonging to "ever had asthma" and "ever had cardiovascular disease") other than sex was also analyzed. Based on the different models, 9189, 7006, and 6946 participants were used in our study. BPA was found to be significantly associated with COPD-related diseases in all models. The concentration of BPA in urine was significantly associated with COPD-related diseases regardless of whether BPA concentration was treated as a continuous variable (odds ratio (OR): 1.24, 95% confidence interval (CI): 1.11-1.38, in model 3) or as tertiles (OR: 2.01, 95% CI: 1.49-2.72, between the lowest group and highest group, in model 3). This association was significant among male but not female participants. BPA also demonstrated a significant association with emphysema and chronic bronchitis in adults, particularly in males. No significant interaction was found for all the other subgroup analyses. Urinary BPA was associated with COPD-related diseases in adult participants, especially males.

In silico profiling of endocrine-disrupting potential of bisphenol analogues and their halogenated transformation products

Due to its endocrine-disrupting properties, bisphenol A (BPA) is being phased out from plastics, thermal paper and epoxy resins, and its replacements are being introduced into the market. Bisphenols are released into the environment, where they can undergo halogenation. Unlike BPA, the endocrine-disrupting potential of BPA analogues and their halogenated transformation products has not been extensively studied. The aim of this study was to evaluate the endocrine-disrupting potential of 18 BPA analogues and their halogenated derivatives by calculating affinities for 14 human nuclear receptors utilizing the Endocrine Disruptome and VirtualToxLab™ in silico tools. Our simulations identified AR, ERs, and GR as the most favorable targets of bisphenols and their derivatives. Several BPA analogues displayed a higher predicted potential for endocrine disruption than BPA. Our models highlighted BPZ and BPPH as the most hazardous in terms of predicted endocrine activities. Halogenation, in general, was predicted to increase the binding affinity of bisphenols for AR, ERβ, MR, GR, PPARγ, and TRβ. Notably, mono- or 2,2'-di-halogenated bisphenols exhibited the highest potential for endocrine disruption. In vitro corroboration of the obtained results should be the next milestone in evaluating the safety of BPA substitutes and their halogenated transformation products.

Associations between mixed urinary phenols and parabens metabolites and bone mineral density: Four statistical models

Phenols and parabens widely exist in personal care and consumer products and have been proved to be endocrine disrupting chemicals that could disturb bone metabolism. The current studies focusing on the associations between phenols and parabens with bone mineral density (BMD) drew contradictory conclusions. Considering the bias might be due to not considering the effects of mixed exposure, we conducted the first cross-sectional study to investigate the associations of both single and mixed metabolites of phenols and parabens with BMD in three populations by setting up four models: generalized linear regression model (GLM), weighted quantile sum (WQS) regression model, quantile g-computation (qgcomp) model and Bayesian kernel machine regression (BKMR) model, based on the US National Health and Nutrition Examination Survey (NHANES) database. We found that the association between the mixtures and total femur BMD in men was significantly negative. Bisphenol A (BPA) was shown to play the most important role in this negative association in the BKMR model, and this negative association was also confirmed in the GLM model with β coefficient (95% CI) being -0.02 (-0.04, -0.01). The relationships between the mixtures and femoral neck and trochanter BMD in postmenopausal women were significantly positive. Benzophenone-3 (BP-3) played the most significant role in the positive association with trochanter BMD, as confirmed by the WQS, qgcomp and BKMR models, and this positive association was also verified by the GLM model with β coefficient (95% CI) being 0.01 (0.00, 0.02). In conclusion, the association between the mixed phenols and parabens and BMD was negative in men while was positive in postmenopausal women, which was gender-specific. This study might provide new ideas for the prevention and treatment of osteoporosis and the control of personal care and consumer products containing phenols and parabens in the future.

Ten bisphenol analogs were abundantly found in swine and bovine urines collected from two Chinese farms: concentration profiles and risk evaluation

Bisphenol analogs (BPs) in livestock urine are important biomarkers to reflect the potential contaminants in food products derived from these animals. Nevertheless, little research has been done on their occurrence in farm animal urine. This work investigated ten BPs in swine and bovine urines collected from two Chinese farms. Results showed that all of these ten BPs were frequently detected in swine and bovine urines. The total mean concentration of the ten BPs (ΣBPs) in sow urines was 59.7 ng/mL, which was significantly higher than that of the boar urine with a mean concentration of 37.0 ng/mL (p < 0.05). On the other hand, the corresponding mean concentration of ΣBPs in dairy cattle urine was 59.6 ng/mL, which was significantly higher than that of the beef cattle urine with 37.0 ng/mL (p < 0.05). The respective mean concentration contribution ratios of BPA to ΣBPs in boar, sow, dairy, and beef cattle urines were only 14.9%, 21.4%, 9.0%, and 14.6%, which clearly indicated that BPA was no longer the dominant BP. The average daily urinary excretion rates of ΣBPs by boar, sow, dairy, and beef cattle were 37.0, 59.8, 167.0, and 36.8 times that of human, which suggested that swine and bovine likely encountered high dosage exposure of BPs in the two Chinese livestock farms. Our results showed that feeds and nutritional supplements as unintentionally added contaminants were the main sources of BPs to swine and bovine. As swine and bovine are important food sources for human being, part of BPs exposed to livestock eventually would enter human body via meat or milk. Therefore, quality controls of these feeds or nutritional supplements are quite important in order to guarantee welfare of livestock as well as protect health of our human beings.

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

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.

Bisphenol A analogues in associations with serum hormone levels among reproductive-aged Chinese men

BACKGROUND

Bisphenol A (BPA) as an endocrine disrupting chemical has been shown to alter reproductive endocrine function, but little is known on its analogues such as 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 in negative associations 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 the RCS models, these linear negative associations except 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.