Effects of bisphenol A administration to pregnant mice on serum Ca and intestinal Ca absorption

Vitamin D Deficiency Exacerbates Poor Sleep Outcomes with Endocrine-Disrupting Chemicals Exposure: A Large American Population Study

Phthalates and bisphenol A are recognized as the predominant endocrine-disrupting substances (EDCs) in the environment, but their impact on sleep health remains unclear. Vitamin D has often been reported to play a role in sleep health and may be affected by endocrine-disrupting compounds. The study utilized data from 5476 individuals in the NHANES project to investigate the correlation between combined exposure to environmental EDCs and sleep duration through modeling various exposures. Furthermore, it emphasizes the importance of vitamin D in the present scenario. Preliminary analyses suggested that vitamin D-deficient individuals generally slept shorter than individuals with normal vitamin D (p < 0.05). Exposure to Mono-ethyl phthalate (MEP), triclosan (TRS), and Mono-benzyl phthalate (MZP), either alone or in combination, was associated with reduced sleep duration and a greater risk of vitamin D deficiency. Individuals with low vitamin D levels exposed to TRS experienced shorter sleep duration than those with normal vitamin D levels (p < 0.05). TRS and MZP were identified as crucial factors in patient outcomes when evaluating mixed exposures (p < 0.05). The results provide new data supporting a link between exposure to EDCs and insufficient sleep length. Additionally, they imply that a vitamin D shortage may worsen the sleep problems induced by EDCs.

Relationship between endocrine disrupting chemicals (phthalate metabolites, triclosan and bisphenols) and vitamin D in female subjects: An exploratory pilot study

INTRODUCTION

Evidence suggests that endocrine disrupting chemicals (EDCs), commonly used in plastics and personal care products, may be associated with reduced levels of vitamin D. Therefore, this study examined the relationship between phthalate metabolites, 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan; TCS) and bisphenols (BPs) with vitamin D3 (25(OH)D3) and active 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and their relationship to calcium homeostasis.

METHODS

57 female participants (age 31.8 ± 4.6 years; BMI 25.6 ± 3.7 kg/m2) were analyzed for urinary levels of phthalate metabolites, TCS and BPs, and serum levels of 25(OH)D3 and 1,25(OH)2D3, determined by isotope-dilution liquid chromatography tandem mass spectrometry. Serum calcium/calmodulin-dependent (CaM) associated proteins were determined by Slow Off-rate Modified Aptamer (SOMA)-scan.

RESULTS

In the study cohort, 25(OH)D3 and 1,25(OH)2D3 levels were 22.9 ± 11.2 ng/mL and 0.05 ± 0.02 ng/mL, respectively: mono-3-carboxypropyl-phthalate (MCPP) correlated negatively with 25(OH)D3 (ρ = -0.53, p = 0.01). 28 of the 57 women recruited were 25(OH)D3 deficient, <20 ng/mL (50 nmol/L): in this group, mono-iso-butylphthalate (MiBP) and mono-butylphthalate (MBP) negatively correlated with 25(OH)D3; (ρ = -0.47, p = 0.049) and (ρ = -0.64, p = 0.005), respectively. EDCs did not correlate with 1,25(OH)2D3, measures of renal function or CaM proteins.

CONCLUSION

These putative data indicate that MCPP is related to 25(OH)D3, while MiBP and MBP were related to vitamin D deficiency; however, no correlations were observed with TCS and BPs. No phthalate metabolites correlated with 1,25(OH)2D3, CaM associated proteins or renal function, suggesting that effects occur earlier in the vitamin D pathway and not through modulation of cellular calcium flux. The observed correlations are surprisingly strong compared to other predictors of 25(OH)D3, and larger studies adjusting for potential confounders are warranted.

Combination of Bisphenol A and Its Emergent Substitute Molecules Is Related to Heart Disease and Exerts a Differential Effect on Vascular Endothelium

Plastic production, disposal, and recycling systems represent one of the higher challenges for the planet's health. Its direct consequence is the release of endocrine disruptors, such as bisphenol A (BPA), and its emerging substitute molecules, bisphenol F and S (BPF and BPS), into the environment. Consequently, bisphenols are usually present in human biological fluids. Since BPA, BPS, and BPF have structural analogies and similar hormonal activity, their combined study is urgently needed. The present manuscript studied the effect of the mixture of bisphenols (BPmix) in one of the world's largest human cohorts (NHANES cohort). Descriptive and comparative statistics, binomial and multinomial logistic regression, weighted quantile sum regression, quantile g-computation, and Bayesian kernel machine regression analysis determined a positive association between BPmix and heart disease, including confounders age, gender, BMI, ethnicity, Poverty/Income Ratio, and serum cotinine. Endothelial dysfunction is a hallmark of cardiovascular disease; thus, the average ratio of bisphenols found in humans was used to conduct murine aortic endothelial cell studies. The first results showed that BPmix had a higher effect on cell viability than BPA, enhancing its deleterious biological action. However, the flow cytometry, Western blot, and immunofluorescence assays demonstrated that BPmix induces a differential effect on cell death. While BPA exposure induces necroptosis, its combination with the proportion determined in the NHANES cohort induces apoptosis. In conclusion, the evidence suggests the need to reassess research methodologies to study endocrine disruptors more realistically.

Effects of bisphenol A on pancreas and thyroid gland of young and adult female Sprague Dawlеy rats

Bisphenol A (BPA), a chemical involved in formation of plastic vessels, is one of the most widespread endocrine disrupting chemicals. The study was designed to investigate the effect of BPA on pancreas and thyroid gland of young and adult female Sprague Dawley rats. The rats were exposed to 330 mg/kg BPA orally every other day for 12 weeks; control rats were exposed orally to ethyl alcohol and corn oil. Samples were collected at 4, 8 and 12 weeks for hormonal, biochemical assays and histopathological examination. The insulin hormone in exposed young rats was decreased, but its level in adult ones was increased; the biochemical assay for blood sugar level showed a significant increase in young rats and decrease in adult ones. T3 hormone was increased in treated young and adult rats; T4 hormone was increased in treated adults, while calcium level was decreased in treated adult rats. The histopathological findings of pancreas revealed vacuolation in its endocrine parts in young rats, while in adult ones there was intralobular fatty infiltration - a typical picture of diabetes. The thyroid gland in treated young female rats showed increased cellularity of parafollicular cells; moreover there was parafollicular haemorrhage, and in adult ones - desquamation in lining epithelium of follicular cells. In conclusion, exposure of young and adult female rats to BPA resulted in changes in the pancreatic and thyroid gland cells manifested by morphological, hormonal and biochemical parameters.

Serum concentration of bisphenol A in elderly cats and its association with clinicopathological findings

OBJECTIVES

Bisphenol A (BPA) has been mentioned as a possible factor contributing to feline hyperthyroidism. Nevertheless, there are no previous studies reporting on the concentration of BPA in feline serum and its association with thyroid function. The objectives of this study were to measure serum BPA concentration in cats aged ⩾7 years, considered as healthy by their owners, and to compare the results with clinicopathological findings.

METHODS

Sixty-nine cats aged ⩾7 years considered as healthy by their owners were enrolled in the study. The concentration of BPA in feline serum was measured using liquid chromatography-tandem mass spectrometry. In all cats, signalment, living environment, diet history, and the results of haematological and biochemical analysis, including thyroxine levels, were available.

RESULTS

The mean serum BPA concentration in feline serum was 1.06 ± 0.908 ng/ml. Significant correlation was found between BPA concentration and haemoglobin (r = 0.3397; P = 0.0043), haematocrit (r = 0.3245; P = 0.0065) and the number of red blood cells (r = 0.2916; P = 0.0151), concentration of total protein (r = 0.2383; P = 0.0486), concentration of calcium (r = 0.3915; P = 0.0009) and level of bilirubin (r = 0.3848; P = 0.0011). No other significant correlations were found. Significant differences (P <0.01) were found between mature (1.28 ± 0.994 ng/ml) and geriatric cats (0.420 ± 0.240 ng/ml), between strictly indoor cats (1.27 ± 0.992 ng/ml) and cats with outdoor access (0.660 ± 0.529 ng/ml), and between cats fed canned food (1.23 ± 0.935 ng/ml) and cats fed non-canned food (0.774 ± 0.795 ng/ml).

CONCLUSIONS AND RELEVANCE

Measurable serum BPA levels were found in all examined samples. The age of the cats was revealed as a significant factor affecting BPA concentration and mature cats had the highest levels. A significantly higher concentration of BPA was found in cats living strictly indoors and in cats fed canned food. No association was found between BPA and thyroid function. Further studies are needed that focus on hyperthyroid cats for better evaluation of this relationship.

Bone Disruption and Environmental Pollutants

BACKGROUND

Endocrine Disrupting Chemicals (EDCs) are ubiquitous and may significantly contribute in environmental pollution, thus contaminating humans and wildlife. Environmental pollutants could interfere with bone homeostasis by means of different mechanisms, which include hormonal imbalance, direct osteoblasts toxicity and enanchment of osteoclasts activity, thus leading to osteopenia or osteoporosis. Among these, bisphenols, dioxins, polycyclic aromatic hydrocarbons, polychlorobiphenyls, poly- and perfluoroalkyls, phthalates, parabens, organotins and cadmium may play a role in bone distuption.

METHODS

PubMed/MEDLINE, ISI-web of knowledge and Google scholar databases were searched for medical subject headings terms and free-text word related to the aforementioned classes of chemicals and bone metabolism and remodelling for better clarifying and understanding the main mechanisms of bone disruption.

RESULTS

Several of EDCs act as xenoestrogens. Considering that estrogens play a significant role in regulating bone remodeling, most of these chemicals generate hormonal imbalance with possible detrimental consequences on bone tissue structure and its mechanical and non-mechanical properties.

DISCUSSION

A lot of evidences about bone distruptors came from in vitro studies or animal models, and conduct to equivocal results. In addition, a few data derived form humans and most of these data focused on the impact of EDCs on bone mineral density without considering their influence on long-term fracture risk. Moreover, it should be taken into account that humans are exposed to a mixture of EDCs and the final effect on bone metabolism might be the result of either a synergism or antagonist effects among them. Age of first exposure, cumulative dose exposure over time, and the usually observed non-monotonic dose-response curve for EDCs should be considered as other important variable influencing the final effect on bone metabolism.

CONCLUSION

Taking into account these variables, observational studies are needed to better analyze this issue both for echological purpose and to preserve bone health.

Endocrine Disruptors of the Bisphenol and Paraben Families and Bone Metabolism

After menopause, when estrogen levels decrease, there is room for the activity of anthropogenic substances with estrogenic properties – endocrine disruptors (EDs) – that can interfere with bone remodeling and changes in calcium-phosphate metabolism. Selected unconjugated EDs of the bisphenol group – BPA, BPS, BPF, BPAF, and the paraben family – methyl-, ethyl-, propyl-, butyl-, and benzyl-parabens – were measured by high performance liquid chromatography-tandem mass spectrometry in the plasma of 24 postmenopausal women. Parameters of calcium-phosphate metabolism and bone mineral density were assessed. Osteoporosis was classified in 14 women, and 10 women were put into the control group. The impact of EDs on calcium-phosphate metabolism was evaluated by multiple linear regressions. In women with osteoporosis, concentrations of BPA ranged from the lower limit of quantification (LLOQ) – 104 pg/ml and methyl paraben (MP) from LLOQ – 1120 pg/ml. The alternative bisphenols BPS, BPF and BPAF were all under the LLOQ. Except for MP, no further parabens were detected in the majority of samples. The multiple linear regression model found a positive association of BPA (β=0.07, p<0.05) on calcium (Ca) concentrations. Furthermore, MP (β=-0.232, p<0.05) was negatively associated with C-terminal telopeptide. These preliminary results suggest that these EDs may have effects on calcium-phosphate metabolism.

Urinary BPA and Phthalate Metabolite Concentrations and Plasma Vitamin D Levels in Pregnant Women: A Repeated Measures Analysis

BACKGROUND

In addition to its well-established role in maintaining skeletal health, vitamin D has essential regulatory functions in female reproductive and pregnancy outcomes. Phthalates and bisphenol A (BPA) are endocrine disruptors, and previous research has suggested that these chemical agents may disrupt circulating levels of total 25(OH)D in adults.

OBJECTIVES

We investigated the relationships between repeated measures of urinary phthalate metabolites and BPA and circulating total 25(OH)D in a prospective cohort of pregnant women.

METHODS

The present study population includes participants (n=477) in a nested case-control study of preterm birth drawn from a prospective birth cohort of pregnant women at Brigham and Women's Hospital in Boston, Massachusetts. Urine and blood samples were collected for biomarker measurements at median 10 wk and 26 wk of gestation.

RESULTS

In repeated measures analysis, we observed that an interquartile range (IQR) increase in urinary mono-3-carboxypropyl phthalate (MCPP) was associated with a 4.48% decrease [95% confidence interval (CI): -7.37, -1.58] in total 25(OH)D. We also detected inverse associations for metabolites of di(2-ethylhexyl) phthalate (DEHP) [percent difference (%Δ)=-2.83 to -2.16]. For BPA, we observed a nonsignificant inverse association with total 25(OH)D in the overall population. Our sensitivity analysis revealed that the associations for some metabolites (e.g., MEHP) varied by race/ethnicity, which may reflect potential differences in susceptibility. In agreement with findings from repeated measures analysis, we reported that DEHP metabolites and BPA were significantly associated with an approximate 20% increase in the odds of vitamin D deficiency (≤20 ng/mL) [odds ratio (95% CI): 1.19 (1.06, 1.35) for molar sum of DEHP metabolites and 1.22 (1.01, 1.47) for BPA] at median 10 wk and 26 wk, respectively.

CONCLUSIONS

Our results provide suggestive evidence of the potential for environmental exposure to phthalates and/or BPA to disrupt circulating vitamin D levels in pregnancy. https://doi.org/10.1289/EHP1178.

Molecular targets of developmental exposure to bisphenol A in diabesity: a focus on endoderm-derived organs

Several studies associate foetal human exposure to bisphenol A (BPA) to metabolic/endocrine diseases, mainly diabesity. They describe the role of BPA in the disruption of pancreatic beta cell, adipocyte and hepatocyte functions. Indeed, the complexity of the diabesity phenotype is due to the involvement of different endoderm-derived organs, all targets of BPA. Here, we analyse this point delineating a picture of different mechanisms of BPA toxicity in endoderm-derived organs leading to diabesity. Moving from epidemiological data, we summarize the in vivo experimental data of the BPA effects on endoderm-derived organs (thyroid, pancreas, liver, gut, prostate and lung) after prenatal exposure. Mainly, we gather molecular data evidencing harmful effects at low-dose exposure, pointing to the risk to human health. Although the fragmentation of molecular data does not allow a clear conclusion to be drawn, the present work indicates that the developmental exposure to BPA represents a risk for endoderm-derived organs development as it deregulates the gene expression from the earliest developmental stages. A more systematic analysis of BPA impact on the transcriptomes of endoderm-derived organs is still missing. Here, we suggest in vitro toxicogenomics approaches as a tool for the identification of common mechanisms of BPA toxicity leading to the diabesity in organs having the same developmental origin.

Relationships Between Urinary Phthalate Metabolite and Bisphenol A Concentrations and Vitamin D Levels in U.S. Adults: National Health and Nutrition Examination Survey (NHANES), 2005-2010

CONTEXT

Recent research suggests that environmental exposure to endocrine-disrupting chemicals may alter circulating 25-hydroxyvitamin D [25(OH)D] levels in humans. To date, no studies have assessed the associations between phthalates and bisphenol A (BPA) and total 25(OH)D in the U.S. general population.

OBJECTIVE

To explore relationships between urinary concentrations of 11 phthalate metabolites and BPA and serum total 25(OH)D in a representative sample of U.S. adults.

DESIGN

A cross-sectional study.

SETTING

U.S. National Health and Nutrition Examination Survey, 2005-2010.

PATIENTS OR OTHER PARTICIPANTS

U.S. general adult population (aged ≥20 years).

INTERVENTIONS

None Main Outcome Measures: Serum total 25(OH)D measured by liquid chromatography-tandem mass spectrometry.

RESULTS

Metabolites of di(2-ethylhexyl) phthalate (DEHP) were consistently inversely associated with total 25(OH)D in the overall study population and in gender-stratified models. In the overall population, we detected a significant inverse relationship for the molar sum of DEHP metabolites (ΣDEHP), where an interquartile range increase in ΣDEHP was associated with a 1.90% decrease (95% confidence interval [CI], -3.64, -0.17) in total 25(OH)D. A positive association was detected for monoethyl phthalate. For BPA, we found a statistically significant inverse relationship in women, but not in men. In women, an interquartile range increase in urinary BPA was associated with a 3.71% decrease (95% CI, -6.41, -1.02) in total 25(OH)D.

CONCLUSIONS

Overall, our results provide suggestive evidence that environmental exposure to phthalates and BPA may alter circulating levels of total 25(OH)D in adults. Future human and animal studies are required to resolve the direction, temporality, and impact of these relationships.

Neither direct nor developmental exposure to bisphenol A alters the severity of experimental inflammatory colitis in mice

Bisphenol A (BPA) is a high production volume endocrine disrupting chemical that is widely used in many consumer products and prevalent in human biological fluids. Recent studies suggest that BPA is active even at low levels, raising concern about its potential harm to human health. Given that the main route of exposure to BPA is oral, via the consumption of BPA-tainted foods and beverages, intestinal tissues could be particularly vulnerable to BPA-induced changes. A novel examination is reported here of whether oral exposure to BPA affects inflammatory bowel disease (IBD), an immune-mediated disease of the colon, using a mouse model of inflammatory colitis. In addition to direct exposure, the possible contribution of maternal BPA exposure to disease later in life is explored. It was found that daily oral exposure to BPA at the US Environmental Protection Agency described oral reference dose (50 µg/kg/day), either via direct oral route or through maternal sources (i.e. developmental exposure), did not significantly alter disease outcomes of body weight, survival, or colonic pathology. These observations suggest that oral BPA exposure, at this dose and for this exposure duration, has minimal influence on aspects of the inflammatory response that regulate immune mediated diseases of the gastrointestinal tract.