Endocrine-Disrupting Chemicals and Insulin Resistance in Children

Investigation of common and unreported parabens alongside other plastic-related contaminants in human milk using non-targeted strategies

Human milk studies analyzing widely used contaminants mainly utilize a targeted approach to screen and quantify a limited number of compounds. While targeted analysis allows health officials to quantify the levels of these chemicals in human milk, it fails to detect the presence of other unknowns that may be of equal importance. Hence, the objective of this study was to apply non-targeted analysis to detect and identify different prevalent contaminants, specifically common or unreported parabens as well as other plastic-related contaminants (PRCs) in human milk. Extracts of 594 human milk samples collected in Canada (Montreal) and South Africa (Vhembe and Pretoria) in 2018-2019 were analyzed using liquid chromatography-mass spectrometry to confirm the presence of methyl, ethyl and propyl parabens. Additional investigations revealed the presence of sulfated species of these parabens, suggesting their conjugation potential in human milk. Further analysis using in-source fragmentation, identified the presence of four other parabens in human milk, including phenyl paraben as well as 2-ethylhexyl 4-hydroxybenzoate, an unusual paraben exclusive to South African samples. Other PRCs that were detected included several phthalate metabolites, per- and poly-fluoroalkyl substances (PFAS) and 1,3 diphenyl guanidine, a tire-related chemical. This is the first study to have used different non-targeted analyses for the detection and confirmation of several common and unusual parabens alongside different PRCs in human milk.

Community-based insights into the connection between endocrine-disrupting chemicals and depressive symptoms

Background

The rising prevalence of depressive disorders has sparked concerns regarding environmental risk factors, particularly exposure to endocrine-disrupting chemicals (EDCs). However, the link between EDC exposure and depressive symptoms remains largely unexplored.

Methods

The Chang Gung Community Medicine Research Center carried out a cross-sectional study across four regions in northeastern Taiwan. Out of 887 participants, 120 subjects were chosen according to their EDC exposure scores. These participants underwent urinary EDC analysis and were evaluated for depressive symptoms through the standardized Hospital Anxiety and Depression Scale - Depression subscale (HADS-D) questionnaire.

Results

Participants with HADS-D scores ≥ 8 exhibited significantly higher EDC exposure score compared to those with lower scores. The correlation analyses identified a notible positive association between urinary monobenzyl phthalate (MBzP) levels and HADS-D scores (r = 0.244, p = 0.007). Multiple regression analysis revealed that MBzP was independently linked to increased HADS-D scores in a positive manner (β ± SE: 0.139 ± 0.050, p = 0.006). Multivariable logistic regression indicated that higher MBzP (OR: 1.150, 95 % CI: 1.036-1.278, p = 0.009) and methylparaben (MP) levels (OR: 1.008, 95 % CI: 1.003-1.013, p < 0.001) showed a significant correlation with the likelihood of HADS-D scores ≥ 8. Receiver operating characteristic curve analysis demonstrated that elevated levels of MBzP, MP and the EDCs exposure score were associated with a greater likelihood of depressive symptoms.

Conclusion

Exposure to EDCs, particularly MBzP and MP, could be associated with a heightened risk of depressive symptoms.

Prenatal exposure to environmental bisphenols over time and their association with childhood asthma, allergic rhinitis and atopic dermatitis in the ECHO consortium

Concerns persist about the potential impact of prenatal exposure to bisphenols (BP) and their replacement analogues on childhood asthma and allergies. Previous studies on single and small cohorts had limited statistical power, few investigated analogues BPF and BPS, and even fewer examined atopic outcomes. Our objective was to assess whether prenatal exposures to individual environmental bisphenols (BPA, BPF, BPS) influence risk of childhood asthma, allergic rhinitis, and atopic dermatitis. Data from the U.S. Environmental Influences on Child Health Outcomes (ECHO) consortium were harmonized on measures of prenatal urinary BPA, BPF and BPS and asthma and allergic rhinitis (ages 5-9 years) and atopic dermatitis (up to age 3 years) from 1905 mother-child pairs that were collected between 1998 and 2017. Across the 2012 federal ban of BPA from certain infant products, median BPA levels decreased from 1.11 ng/ml to 0.86 ng/ml; median BPF levels decreased from 0.51 ng/ml to 0.39 ng/ml; and median BPS levels increased from 0.23 ng/ml to 0.31 ng/ml (dilution adjusted; p < 0.001 for all three median comparisons). Prenatal measures of BPA, BPF, and BPS were unrelated to the risk of childhood asthma, allergic rhinitis, or atopic dermatitis in the total population. Modest sex-dependent effects were observed: only among girls, second tertile levels of BPF was associated with a reduced odds of asthma (odds ratio (OR) 0.27, 95% confidence interval (CI) 0.08, 0.93); a continuous index of prenatal BPS was associated with reduced odds of atopic dermatitis (OR 0.64, 95% CI 0.44, 0.93). The ongoing and changing patterns of exposure to bisphenols in the U.S. population require further study with additional attention to time windows of exposure and co-occurring social determinants of health, to continue to inform current policies and evaluate the importance of limiting exposure to BPA and its analogues on childhood asthma, allergic rhinitis, and atopic dermatitis.

The impact of endocrine-disrupting chemicals on stem cells: Mechanisms and implications for human health

Endocrine-disrupting chemicals (EDCs) are compounds, either natural or man-made, that interfere with the normal functioning of the endocrine system. There is increasing evidence that exposure to EDCs can have profound adverse effects on reproduction, metabolic disorders, neurological alterations, and increased risk of hormone-dependent cancer. Stem cells (SCs) are integral to these pathological processes, and it is therefore crucial to understand how EDCs may influence SC functionality. This review examines the literature on different types of EDCs and their effects on various types of SCs, including embryonic, adult, and cancer SCs. Possible molecular mechanisms through which EDCs may influence the phenotype of SCs are also evaluated. Finally, the possible implications of these effects on human health are discussed. The available literature demonstrates that EDCs can influence the biology of SCs in a variety of ways, including by altering hormonal pathways, DNA damage, epigenetic changes, reactive oxygen species production and alterations in the gene expression patterns. These disruptions may lead to a variety of cell fates and diseases later in adulthood including increased risk of endocrine disorders, obesity, infertility, reproductive abnormalities, and cancer. Therefore, the review emphasizes the importance of raising broader awareness regarding the intricate impact of EDCs on human health.

Potential hazards of bisphenol A on the male reproductive system: Induction of programmed cell death in testicular cells

A common industrial chemical known as bisphenol A (BPA) has been linked to endocrine disruption and can interfere with hormonal signaling pathways in humans and animals. This comprehensive review aims to explore the detrimental consequences of BPA on reproductive organ performance and apoptosis induction, shedding light on the emerging body of evidence from laboratory animal studies. Historically, most studies investigating the connection between BPA and reproductive tissue function have mainly leaned on laboratory animal models. These studies have provided crucial insights into the harmful effects of BPA on several facets of reproduction. This review consolidates an increasing literature that correlates exposure to BPA in the environment with a negative impact on human health. It also integrates findings from laboratory studies conducted on diverse species, collectively bolstering the mounting evidence that environmental BPA exposure can be detrimental to both humans and animals, particularly to reproductive health. Furthermore, this article explores the fundamental processes by which BPA triggers cell death and apoptosis in testicular cells. By elucidating these mechanisms, this review aids a deeper understanding of the complex interactions between BPA and reproductive tissues.

Analysis and remediation of phthalates in aquatic matrices: current perspectives

Phthalic acid esters (PAEs) are high production volume chemicals used extensively as plasticizers, to increase the flexibility of the main polymer. They are reported to leach into their surroundings from plastic products and are now a ubiquitous environmental contaminant. Phthalate levels have been determined in several environmental matrices, especially in water. These levels serve as an indicator of plasticizer abuse and plastic pollution, and also serve as a route of exposure to different species including humans. Reports published on effects of different PAEs on experimental models demonstrate their carcinogenic, teratogenic, reproductive, and endocrine disruptive effects. Therefore, regular monitoring and remediation of environmental water samples is essential to ascertain their hazard quotient and daily exposure levels. This review summarises the extraction and detection techniques available for phthalate analysis in water samples such as chromatography, biosensors, immunoassays, and spectroscopy. Current remediation strategies for phthalate removal such as adsorption, advanced oxidation, and microbial degradation have also been highlighted.

[Nutritional factors related to insulin resistance in children and adolescents]

Introduction

Insulin resistance is described as a defect in the binding of insulin to its receptor and is associated with several diseases, including obesity and type 2 diabetes. Insulin resistance has been linked to vitamin and mineral deficiencies, especially those involved in oxidative stress. The Mediterranean diet, a diet based on the Healthy Eating Index or the Dietary Approaches to Stop Hypertension (DASH) diet are dietary patterns that have been associated with a lower risk of developing insulin resistance in children. Therefore, a diet rich in antioxidant vitamins and minerals, fiber, calcium, and polyunsaturated fatty acids and low in free sugars, sodium and saturated fatty acids may decrease the risk of insulin resistance in this age group. In addition, other nutritional factors, such as avoiding fast food, eating dinner with the family, not eating while watching TV or eating a sufficient and healthy breakfast on a regular basis seem to be associated with a lower risk of insulin resistance. Therefore, it is important to establish balanced daily eating habits to prevent and treat insulin resistance in schoolchildren and adolescents.

The Hidden Threat: Endocrine Disruptors and Their Impact on Insulin Resistance

The association between Insulin resistance, a global health issue, and endocrine disruptors (EDCs), chemicals interfering with the endocrine system, has sparked concern in the scientific community. This article provides a comprehensive review of the existing literature regarding the intricate relationship between EDCs and insulin resistance. Phthalates, commonly found in consumer products, are well-established EDCs with documented effects on insulin-signaling pathways and metabolic processes. Epidemiological studies have connected phthalate exposure to an increased risk of type 2 diabetes mellitus (T2DM). Perfluoroalkyl substances (PFAS), persistent synthetic compounds, have shown inconsistent associations with T2DM in epidemiological research. However, studies suggest that PFAS may influence insulin resistance and overall metabolic health, with varying effects depending on specific PFAS molecules and study populations. Bisphenol A (BPA), found in plastics and resins, has emerged as a concern for glucose regulation and insulin resistance. Research has linked BPA exposure to T2DM, altered insulin release, obesity, and changes in the mass and function of insulin-secreting β-cells. Triclosan, an antibacterial agent in personal care products, exhibits gender-specific associations with T2DM risk. It may impact gut microbiota, thyroid hormones, obesity, and inflammation, raising concerns about its effects on metabolic health. Furthermore, environmental EDCs like polycyclic aromatic hydrocarbons, pesticides, and heavy metals have demonstrated associations with T2DM, insulin resistance, hypertension, and obesity. Occupational exposure to specific pesticides and heavy metals has been linked to metabolic abnormalities.

A new non-enzymatic biosensor for the determination of bisphenol-A

In this study, a new non-enzymatic carbon paste biosensor was developed for the determination of Bisphenol-A (BPA) based on Multiwalled Carbon Nanotube (MWCNT) modified Myoglobin (Mb). The measurement principle of the biosensor was developed based on the inhibition effect of BPA on the heme group of myoglobin in the presence of hydrogen peroxide. With the designed biosensor, measurements were taken in the potential range of (-0.15 V & +0.65 V) using the differential pulse voltammetry (DPV) method in the medium containing K₄[Fe(CN)₆]. The linear range for BPA was determined to be 100-1000 µM. Response time was calculated as 16 s. The limit of detection was set at 89 μM. As a result, it has been proven that MWCNT modified myoglobin based biosensor is an alternative method that can be used for BPA determination, giving very sensitive and fast results.

Endocrine Disruptor Chemicals and Children's Health

We are all exposed to endocrine-disrupting chemicals (EDCs) starting from embryonic life. The fetus and child set up crucial developmental processes allowing adaptation to the environment throughout life: they are extremely sensitive to very low doses of hormones and EDCs because they are developing organisms. Considering the developmental origin of well-being and diseases, every adult organism expresses consequences of the environment in which it developed. The molecular mechanisms through which the main EDCs manifest their effects and their potential association with endocrine disorders, such as diabetes, obesity, thyroid disease and alteration of adrenal hormones, will be reviewed here. Despite 40 years having passed since the first study on EDCs, little is yet known about them; therefore, our purpose is to take stock of the situation to establish a starting point for further studies. Since there is plenty of evidence showing that exposure to EDCs may adversely impact the health of adults and children through altered endocrine function-suggesting their link to endocrinopathies-it is essential in this context to bear in mind what is already known about endocrine disruptors and to deepen our knowledge to establish rules of conduct aimed at limiting exposure to EDCs' negative effects. Considering that during the COVID-19 pandemic an increase in endocrine disruptor effects has been reported, it will also be useful to address this new phenomenon for better understanding its basis and limiting its consequences.

Combinatorial pathway disruption is a powerful approach to delineate metabolic impacts of endocrine disruptors

The prevalence of metabolic diseases, such as obesity, diabetes, metabolic syndrome and chronic liver diseases among others, has been rising for several years. Epidemiology and mechanistic (in vivo, in vitro and in silico) toxicology have recently provided compelling evidence implicating the chemical environment in the pathogenesis of these diseases. In this review, we will describe the biological processes that contribute to the development of metabolic diseases targeted by metabolic disruptors, and will propose an integrated pathophysiological vision of their effects on several organs. With regard to these pathomechanisms, we will discuss the needs, and the stakes of evolving the testing and assessment of endocrine disruptors to improve the prevention and management of metabolic diseases that have become a global epidemic since the end of last century.

The mediating function of obesity on endocrine-disrupting chemicals and insulin resistance in children

OBJECTIVES

To explore the association of endocrine-disrupting chemicals (EDCs) with insulin resistance (IR) in children as well as whether obesity played a mediation role between EDCs and IR.

METHODS

In this cross-sectional study, the data of 878 subjects were included, and divided into the non-IR group (n=501) and IR group (n=377). The associations of EDC and IR, obesity, abdominal obesity were shown by restricted cubic spline (RCS). Univariate and multivariable logistic analysis were applied to explore the associations between EDCs and IR as well as EDCs and obesity, respectively. Bootstrap coefficient product was used to analyze the medication effect of obesity on EDCs and IR.

RESULTS

RCS showed that increase of benzophenone-3 (BP-3) level was associated with increased risk of IR, obesity and abdominal obesity. After adjusting for confounders, BP-3>100 ng/mL was a risk factor for IR (OR=1.42, 95%CI: 1.11-1.81). In the adjusted model, we found BP-3>100 ng/mL was a risk factor for both obesity (OR=1.52, 95%CI: 1.13-2.04) and abdominal obesity (OR=1.68, 95%CI: 1.11-2.54). The indirect effect of obesity as a mediator on the relationship between BP-3 and IR was 0.038 (95%CI: 0.016-0.090) and the direct effect of obesity as a mediator on the relationship between BP-3 and IR was 0.077 (95%CI: 0.001-0.160). As for abdominal obesity, the indirect effect of it on the relationship between BP-3 and IR was 0.039 (95%CI: 0.007-0.070).

CONCLUSIONS

BP-3 level might be a risk factor for IR and obesity in children, and obesity was a mediator on the relationship between BP-3 and IR in children.

Assessment of Exposure to Di-(2-ethylhexyl) Phthalate (DEHP) Metabolites and Bisphenol A (BPA) and Its Importance for the Prevention of Cardiometabolic Diseases

Exposomics analyses have highlighted the importance of biomonitoring of human exposure to pollutants, even non-persistent, for the prevention of non-communicable diseases such as obesity, diabetes, non-alcoholic fatty liver disease, atherosclerosis, and cardiovascular diseases. Phthalates and bisphenol A (BPA) are endocrine disrupting chemicals (EDCs) widely used in industry and in a large range of daily life products that increase the risk of endocrine and cardiometabolic diseases especially if the exposure starts during childhood. Thus, biomonitoring of exposure to these compounds is important not only in adulthood but also in childhood. This was the goal of the LIFE-PERSUADED project that measured the exposure to phthalates (DEHP metabolites, MEHP, MEHHP, MEOHP) and BPA in Italian mother-children couples of different ages. In this paper we describe the method that was set up for the LIFE PERSUADED project and validated during the proficiency test (ICI/EQUAS) showing that accurate determination of urinary phthalates and BPA can be achieved starting from small sample size (0.5 mL) using two MS techniques applied in cascade on the same deconjugated matrix.

Association of urinary phthalate metabolites with sarcopenia in US adults: NHANES 1999-2006

Phthalates have been extensively detected in environmental and biological matrices. Exposure to phthalates is implicated in various human diseases. In this study, we conducted a cross-sectional study to determine whether urinary phthalate metabolite concentrations were correlated with prevalence of sarcopenia in US adult population. We included 3562 participants with detailed information on skeletal muscle mass and urinary phthalate metabolites based on National Health and Nutrition Examination Survey (NHANES) 1999-2006 data. A total of 7 main phthalate metabolites were analyzed in the urine sample of each participant. Appendicular skeletal muscle mass (ASM) was measured using dual-energy X-ray absorptiometry. Multivariable linear regression models were conducted following adjustment for multiple covariates. ASM adjusted by body mass index (ASM/BMI) was calculated, and sarcopenia was defined as the lowest quintile for ASM/BMI value. Compared with participants in quartile 1, those in quartile 2 of urinary mono-n-butyl phthalate (MnBP) and quartile 4 of urinary monobenzyl phthalate (MBzP) had decreased ASM/BMI. Urinary MnBP in quartile 4, as well as urinary MBzP in quartile 2, was shown to be significantly correlated with higher sarcopenia prevalence. In subgroup analysis, negative association of MBzP with ASM/BMI was observed in both males and females, while this negative association was only observed in males for MnBP. Females with higher urinary monoethyl phthalate (MEP) concentrations had higher sarcopenia risk. Taken together, the present study found several urinary phthalate metabolites were positively associated with sarcopenia prevalence in US adult population. These findings indicated phthalate exposure might be an important environmental risk factor contributing to sarcopenia development.

Early Life Exposure to Food Contaminants and Social Stress as Risk Factor for Metabolic Disorders Occurrence?-An Overview

The global prevalence of obesity has been increasing in recent years and is now the major public health challenge worldwide. While the risks of developing metabolic disorders (MD) including obesity and type 2 diabetes (T2D) have been historically thought to be essentially driven by increased caloric intake and lack of exercise, this is insufficient to account for the observed changes in disease trends. Based on human epidemiological and pre-clinical experimental studies, this overview questioned the role of non-nutritional components as contributors to the epidemic of MD with a special emphasis on food contaminants and social stress. This overview examines the impact of early life adverse events (ELAE) focusing on exposures to food contaminants or social stress on weight gain and T2D occurrence in the offspring and explores potential mechanisms leading to MD in adulthood. Indeed, summing up data on both ELAE models in parallel allowed us to identify common patterns that appear worthwhile to study in MD etiology. This overview provides some evidence of a link between ELAE-induced intestinal barrier disruption, inflammation, epigenetic modifications, and the occurrence of MD. This overview sums up evidence that MD could have developmental origins and that ELAE are risk factors for MD at adulthood independently of nutritional status.

Epigenetic Modifications Associated with Exposure to Endocrine Disrupting Chemicals in Patients with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) remains a significant clinical and public health issue due to its increasing prevalence and the possibility for numerous short- and long-term complications. The growing incidence of GDM seems to coincide with the widespread use of endocrine disrupting chemicals (EDCs). The extensive production and common use of these substances in everyday life has resulted in constant exposure to harmful substances from the environment. That may result in epigenetic changes, which may manifest themselves also after many years and be passed on to future generations. It is important to consider the possible link between environmental exposure to endocrine disrupting chemicals (EDCs) during pregnancy, epigenetic mechanisms and an increased risk for developing gestational diabetes mellitus (GDM). This manuscript attempts to summarize data on epigenetic changes in pregnant women suffering from gestational diabetes in association with EDCs. There is a chance that epigenetic marks may serve as a tool for diagnostic, prognostic, and therapeutic measures.

Benzyl Butyl Phthalate Induced Early lncRNA H19 Regulation in C3H10T1/2 Stem Cell Line

Exposure to endocrine-disrupting chemicals used in plastic manufacturing may contribute to the current obesity and diabetes epidemic. Our previous study demonstrated that benzyl butyl phthalate (BBP) induced adipogenesis in the C3H10T1/2 stem cell line. Here we investigated if BBP deregulated long noncoding RNA H19 and its downstream pathway and whether BBP plays a role in the insulin signaling pathway during adipocyte diiferentiation. Cells treated with an 8 day BBP regimen showed that H19 expression was decreased at day 2 with 50 μM BBP exposure (p < 0.05). However, no significant changes were observed from day 4 to day 8. Expression of miRNA-103/107, H19 regulated miRNAs, was upregulated at day 2 (p < 0.05) but not from day 4 to day 8. Similarly, expression of the let-7 family members (a, b, c, d, f, and g) was also significantly increased at day 2 (p < 0.05 or p < 0.01), except for let-7e. Both let-7 and miRNA-103/107 are targets of H19 and play roles in insulin signaling. Insulin receptor substrate (IRS)-1, one of the key insulin signal transduction regulators, was significantly downregulated from day 2 to day 8 (p < 0.05). Gene expression of insulin receptor (IR) and IRS-2 were not altered by BBP exposure. The ratio of IRS1/IRS2 was significantly decreased from day 2 to day 8. On day 4, phospho-Akt protein expression was significantly decreased (p < 0.05). In conclusion, BBP exposure may lead to metabolic dysregulation by altering vital epigenetic regulators such as lncRNA H19 and its target microRNAs at an earlier stage, which further regulates insulin signaling.

Potential Mechanisms of Bisphenol A (BPA) Contributing to Human Disease

Bisphenol A (BPA) is an organic synthetic compound serving as a monomer to produce polycarbonate plastic, widely used in the packaging for food and drinks, medical devices, thermal paper, and dental materials. BPA can contaminate food, beverage, air, and soil. It accumulates in several human tissues and organs and is potentially harmful to human health through different molecular mechanisms. Due to its hormone-like properties, BPA may bind to estrogen receptors, thereby affecting both body weight and tumorigenesis. BPA may also affect metabolism and cancer progression, by interacting with GPR30, and may impair male reproductive function, by binding to androgen receptors. Several transcription factors, including PPARγ, C/EBP, Nrf2, HOX, and HAND2, are involved in BPA action on fat and liver homeostasis, the cardiovascular system, and cancer. Finally, epigenetic changes, such as DNA methylation, histones modification, and changes in microRNAs expression contribute to BPA pathological effects. This review aims to provide an extensive and comprehensive analysis of the most recent evidence about the potential mechanisms by which BPA affects human health.

Human Erythrocytes Exposed to Phthalates and Their Metabolites Alter Antioxidant Enzyme Activity and Hemoglobin Oxidation

Phthalates used as plasticizers have become a part of human life because of their important role in various industries. Human exposure to these compounds is unavoidable, and therefore their mechanisms of toxicity should be investigated. Due to their structure and function, human erythrocytes are increasingly used as a cell model for testing the in vitro toxicity of various xenobiotics. Therefore, the purpose of our study was to assess the effect of selected phthalates on methemoglobin (metHb), reactive oxygen species (ROS) including hydroxyl radical levels, as well as the activity of antioxidative enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), in human erythrocytes. Erythrocytes were incubated with di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), and their metabolites, i.e., mono-n-butyl phthalate (MBP) and monobenzyl phthalate (MBzP), at concentrations ranging from 0.5 to 100 µg/mL for 6 or 24 h. This study shows that the analyzed phthalates disturbed the redox balance in human erythrocytes. DBP and BBP, at much lower concentrations than their metabolites, caused a statistically significant increase of metHb and ROS, including hydroxyl radical levels, and changed the activity of antioxidant enzymes. The studied phthalates disturbed the redox balance in human erythrocytes, which may contribute to the accelerated removal of these cells from the circulation.