Relationship of serum bisphenol A with diabetes in the Thai population, National Health Examination Survey IV, 2009

Environmental toxicology of bisphenol A: Mechanistic insights and clinical implications on the neuroendocrine system

Bisphenol A (BPA) is a widely used environmental estrogen found in a variety of products, including food packaging, canned goods, baby bottle soothers, reusable cups, medical devices, tableware, dental sealants, and other consumer goods. This substance has been found to have detrimental effects on both the environment and human health, particularly on the reproductive, immune, embryonic development, nervous, endocrine, and respiratory systems. This paper aims to provide a comprehensive review of the effects of BPA on the neuroendocrine system, with a primary focus on its impact on the brain, neurons, oligodendrocytes, neural stem cell proliferation, DNA damage, and behavioral development. Additionally, the review explores the clinical implications of BPA, specifically examining its role in the onset and progression of various diseases associated with the neuroendocrine metabolic system. By delving into the mechanistic analysis and clinical implications, this review aims to serve as a valuable resource for studying the impacts of BPA exposure on organisms.

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.

Association of urinary bisphenols with thyroid function in the general population: a cross-sectional study of an industrial park in China

Bisphenols (BPs) are potential thyroid disruptors that are widely used in many consumer products, leading to their widespread exposure in the general population. Current cross-sectional and case-control studies have found associations between exposure to BPs and serum thyroid function, but the results were contradictory. The objectives of this study are to describe demographic characteristics, BP exposure levels, and thyroid function measurements in potentially exposed and control districts and to investigate the association of urinary BPs with thyroid function. Data were collected from a general population aged 3-79 years (N = 281) recruited by the Zhejiang Human Biomonitoring Program (ZJHBP). The concentrations of 10 kinds of BPs in urine and serum free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), total thyroxine (TT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), thyroglobulin antibodies (TgAb), thyroid peroxidase antibodies (TPOAb), and thyrotropin receptor antibody (TRAb) in serum were measured. Multiple linear regression and weighted quantile sum (WQS) regression were used to estimate the relationship between single and mixed exposure of BPs and thyroid function. Bisphenol A (BPA), bisphenol S (BPS), and bisphenol P (BPP) were detected, respectively, in 82.73%, 94.24%, and 55.40% of the population in the exposed area and 81.69%, 61.27%, and 43.66% of the population in the control area. Among adult females, serum TT3 was negatively associated with urinary BPA (β = -0.033, 95% CI = -0.071, -0.008, P = 0.021). Among minor females, FT4 and Tg levels were negatively associated with the urinary BPA (β = -0.026, 95% CI = -0.051, -0.002, P = 0.032 for FT4; β = -0.129, 95% CI = -0.248, -0.009, P = 0.035 for Tg), and TPOAb was positively associated with urinary BPA (β = 0.104, 95% CI = 0.006, 0.203, P = 0.039). In WQS models, BPs mixture was positively associated with FT3 (βWQS = 0.022, 95% CI = 0.002, 0.042) and TT3 (βWQS = 0.033, 95% CI = 0.004, 0.062), and negatively associated with FT4 (βWQS = -0.024, 95% CI = -0.044, 0.004). We found widespread exposure to BPA, BPS, and BPP in the general population of Zhejiang province and found an association between BPA and thyroid hormones. This association is gender- and age-dependent and needs to be confirmed in further studies.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Association of serum bisphenol A levels with incident overweight and obesity risk and the mediating effect of adiponectin

BACKGROUND

Existing cross-sectional studies indicated a positive association of bisphenol A (BPA) with overweight and obesity. However, the relationship and potential mechanisms underlying this association remain to be elucidated in prospective studies.

OBJECTIVE

This study was designed to investigate whether serum BPA is associated with incident overweight and obesity risk, and to further explore whether adiponectin plays a mediating role in the association.

METHODS

We measured blood BPA and adiponectin in Chinese populations. The association of serum BPA with overweight and obesity risk was evaluated using multivariable logistic regression models. We further examined the mediating effect of adiponectin by causal mediation analysis.

RESULTS

Among 796 participants free of overweight and obesity at baseline, 133 individuals developed overweight and obesity during the follow-up period. Compared with those in the lowest quartile of serum BPA, those in the second and third quartiles were positively associated with incident overweight and obesity risk adjusting for covariates (all P-values < 0.05), whereas this association was not observed in the fourth quartile. Further spline analysis showed an inverted U-shaped dose-response relationship (P_non-linear = 0.04). Furthermore, each unit of serum log₁₀-transformed BPA levels was associated with higher changes in waist-to-height ratio and body roundness index (all P-values < 0.05). Mediation analysis indicated significant indirect effects of adiponectin on the associations of BPA with overweight and obesity prevalence (mediation proportion: 46.08%; P = 0.02), and BMI levels (mediation proportion: 30.32%; P = 0.03).

CONCLUSION

Serum BPA displayed a positive association with incident overweight and obesity risk in a non-monotonic pattern, and adiponectin might mediate the association. Further mechanistic studies are warranted.

Exposure to Bisphenol A Substitutes, Bisphenol S and Bisphenol F, and Its Association with Developing Obesity and Diabetes Mellitus: A Narrative Review

Bisphenol A, a well-known endocrine-disrupting chemical, has been replaced with its analogs bisphenol S (BPS) and bisphenol F (BPF) over the last decade due to health concerns. BPS and BPF are present in relatively high concentrations in different products, such as food products, personal care products, and sales receipts. Both BPS and BPF have similar structural and chemical properties to BPA; therefore, considerable scientific efforts have investigated the safety of their exposure. In this review, we summarize the findings of relevant epidemiological studies investigating the association between urinary concentrations of BPS and/or BPF with the incidence of obesity or diabetes. The results showed that BPS and BPF were detected in many urinary samples at median concentrations ranging from 0.03 to 0.4 µg·L-1. At this exposure level, BPS median urinary concentrations (0.4 µg·L-1) were associated with the development of obesity. At a lower exposure level (0.1-0.03 µg·L-1), two studies showed an association with developing diabetes. For BPF exposure, only one study showed an association with obesity. However, most of the reported studies only assessed BPS exposure levels. Furthermore, we also summarize the findings of experimental studies in vivo and in vitro regarding our aim; results support the possible obesogenic effects/metabolic disorders mediated by BPS and/or BPF exposure. Unexpectedly, BPS may promote worse obesogenic effects than BPA. In addition, the possible mode of action underlying the obesogenic effects of BPS might be attributed to various pathophysiological mechanisms, including estrogenic or androgenic activities, alterations in the gene expression of critical adipogenesis-related markers, and induction of oxidative stress and an inflammatory state. Furthermore, susceptibility to the adverse effects of BPS may be altered by sex differences according to the results of both epidemiological and experimental studies. However, the possible mode of action underlying these sex differences is still unclear. In conclusion, exposure to BPS or BPF may promote the development of obesity and diabetes. Future approaches are highly needed to assess the safety of BPS and BPF regarding their potential effects in promoting metabolic disturbances. Other studies in different populations and settings are highly suggested.

Combined effects of bisphenol A and diabetes genetic risk score on incident type 2 diabetes: A nested case-control study

Observational studies reported inconsistent results on the association between bisphenol A (BPA) and type 2 diabetes (T2D) risk. Whether genetic factors modified the association remains unclear. The present nested case-control study prospectively investigated the association of BPA with T2D risk, and the interaction and combined effects of diabetes genetic risk score (GRS) and serum BPA on T2D risk. Based on the Dongfeng-Tongji cohort study, 995 incident diabetes cases and 1:1 age- and gender-matched controls were included. T2D was diagnosed based on the American Diabetes Association criteria. Serum BPA concentration was measured at baseline. Diabetes GRS was constructed by 88 diabetes-related SNPs selected from large-scale GWASs. A U-shaped association was observed between serum BPA levels and T2D risk, with the lowest odds of T2D at the serum BPA levels of 1.00 ng/mL (P = 0.001 for nonlinearity). Compared with the middle group, the multivariate-adjusted ORs of T2D in the lowest group and the highest group of serum BPA were 1.52 (95% CI: 1.04, 2.22) and 1.40 (95% CI: 1.08, 1.81), respectively. Both serum BPA levels (β = 0.107, P = 0.001) and weighted-GRS (w-GRS) (β = 0.072, P = 0.02) were significantly associated with baseline FPG levels. Participants with both highest w-GRS and serum BPA levels had highest risk of T2D (OR = 2.53, 95%CI: 1.49, 4.31, P = 0.001) and higher baseline FPG levels (β = 0.218, P = 0.01), compared with those with both lowest w-GRS and serum BPA levels. Non modified effects of serum BPA levels and w-GRS on T2D, baseline FPG levels, and 5-y changes of FPG levels were detected (All P_interaction > 0.05). Our results suggested a U-shaped association between serum BPA levels and T2D risk. Participants with higher serum BPA levels and diabetes genetic risk had higher FPG levels and higher risk of T2D.

Increased bisphenol A levels in Thai children and adolescents with type 1 diabetes mellitus

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) in children and adolescents continues to increase worldwide. The reason for this is unclear. In addition to the role of genetics, bisphenol A (BPA) has been investigated as a possible causal factor for T1DM. This study aimed to determine the correlation between urinary BPA levels and T1DM in Thai children and adolescents.

METHODS

A cross-sectional study was conducted in T1DM patients who were followed at the endocrinology clinic at King Chulalongkorn Memorial Hospital from December 2018 to December 2019 and age-matched healthy controls. Urinary BPA levels were analyzed by high-performance liquid chromatography and adjusted by urine creatinine. Anthropometric data were measured in all participants and clinical data were collected for the T1DM patients. All participants completed a questionnaire regarding possible BPA exposures. Multivariate logistic regression analysis was used to estimate the adjusted odds ratio for T1DM.

RESULTS

Seventy-five T1DM patients and 113 age-matched controls were included in the study. The mean age for T1DM and control groups were 14.8 ± 5.7 and 14.4 ± 6.2 years, respectively. The T1DM group had a significantly higher median (interquartile range) level of adjusted urinary BPA compared to the control (31.50 [7.87, 69.45] vs 10.1 [0, 54.01] μg/g creatinine, P = 0.02). Urinary BPA of 17 μg/g creatinine or more was significantly associated with TIDM, with adjusted odds ratio (95% Confident interval, CI) of 2.38 (1.27, 4.44), P = 0.006.

CONCLUSIONS

Higher urinary BPA level is one of the possible risk factors for T1DM.

Variably methylated retrotransposons are refractory to a range of environmental perturbations

The agouti viable yellow (Avy) allele is an insertional mutation in the mouse genome caused by a variably methylated intracisternal A particle (VM-IAP) retrotransposon. Avy expressivity is sensitive to a range of early-life chemical exposures and nutritional interventions, suggesting that environmental perturbations can have long-lasting effects on the methylome. However, the extent to which VM-IAP elements are environmentally labile with phenotypic implications is unknown. Using a recently identified repertoire of VM-IAPs, we assessed the epigenetic effects of different environmental contexts. A longitudinal aging analysis indicated that VM-IAPs are stable across the murine lifespan, with only small increases in DNA methylation detected for a subset of loci. No significant effects were observed after maternal exposure to the endocrine disruptor bisphenol A, an obesogenic diet or methyl donor supplementation. A genetic mouse model of abnormal folate metabolism exhibited shifted VM-IAP methylation levels and altered VM-IAP-associated gene expression, yet these effects are likely largely driven by differential targeting by polymorphic KRAB zinc finger proteins. We conclude that epigenetic variability at retrotransposons is not predictive of environmental susceptibility.

Concentrations of bisphenol-A in adults from the general population: A systematic review and meta-analysis

BACKGROUND

Human bisphenol-A (BPA) exposure has been linked to adverse health effects even at low doses, which may be of potential public health concern.

OBJECTIVE

To summarize BPA concentrations in general human population and their variability according to sex, geographic area, and analytical method.

METHODS

Systematic review and meta-analysis of studies reporting BPA concentrations in adult human populations. Separate meta-analyses of median values were carried out for BPA in serum, creatinine-adjusted urinary BPA, and unadjusted urinary BPA concentrations using a random-effects model. Cochran's Q-statistic, I² index, 95% prediction intervals (PIs), between-studies standard deviation (τ), and forest plots were applied to verify study heterogeneity. Sensitivity and subgroup analyses and weighted ANOVAs and meta-regressions were conducted. Funnel plots and Egger's tests were used to examine publication bias.

RESULTS

Fifteen studies were included in the meta-analysis, totaling 28,353 participants. BPA was detected in over 90% of participants. The pooled creatinine-adjusted urinary BPA concentration was 1.76 μg/g (95% PI: 0.79-2.73), with individual estimates ranging between 1.20 and 2.41. The pooled estimate for unadjusted urinary BPA was 1.91 μg/l (95% PI: 0-3.97), ranging between 0.81 and 3.50, while the pooled estimate for serum BPA was 1.75 μg/l (95% PI: 0-10.58), ranging between 0.34 and 3.76. No differences were found by sex, geographic area or analytical technique. Larger sample sizes were associated with lower BPA concentrations. There was large heterogeneity across studies, whereas data for urinary BPA levels suggested a publication bias affecting research in low exposed populations.

CONCLUSION

This first meta-analysis of human BPA concentrations highlights a widespread population exposure to BPA. Although there was high heterogeneity across studies, the expected range of estimated human BPA concentrations suggests that potential health risks are unlikely. Further studies are warranted to better characterize the epidemiology of human BPA exposure, accounting for ethnic, geographic, individual and environmental variability.

Bisphenol A and its analogues: A comprehensive review to identify and prioritize effect biomarkers for human biomonitoring

Human biomonitoring (HBM) studies have demonstrated widespread and daily exposure to bisphenol A (BPA). Moreover, BPA structural analogues (e.g. BPS, BPF, BPAF), used as BPA replacements, are being increasingly detected in human biological matrices. BPA and some of its analogues are classified as endocrine disruptors suspected of contributing to adverse health outcomes such as altered reproduction and neurodevelopment, obesity, and metabolic disorders among other developmental and chronic impairments. One of the aims of the H2020 European Human Biomonitoring Initiative (HBM4EU) is the implementation of effect biomarkers at large scales in future HBM studies in a systematic and standardized way, in order to complement exposure data with mechanistically-based biomarkers of early adverse effects. This review aimed to identify and prioritize existing biomarkers of effect for BPA, as well as to provide relevant mechanistic and adverse outcome pathway (AOP) information in order to cover knowledge gaps and better interpret effect biomarker data. A comprehensive literature search was performed in PubMed to identify all the epidemiologic studies published in the last 10 years addressing the potential relationship between bisphenols exposure and alterations in biological parameters. A total of 5716 references were screened, out of which, 119 full-text articles were analyzed and tabulated in detail. This work provides first an overview of all epigenetics, gene transcription, oxidative stress, reproductive, glucocorticoid and thyroid hormones, metabolic and allergy/immune biomarkers previously studied. Then, promising effect biomarkers related to altered neurodevelopmental and reproductive outcomes including brain-derived neurotrophic factor (BDNF), kisspeptin (KiSS), and gene expression of nuclear receptors are prioritized, providing mechanistic insights based on in vitro, animal studies and AOP information. Finally, the potential of omics technologies for biomarker discovery and its implications for risk assessment are discussed. To the best of our knowledge, this is the first effort to comprehensively identify bisphenol-related biomarkers of effect for HBM purposes.

Human exposure to bisphenol A through dietary sources and development of diabetes mellitus: a cross-sectional study in Pakistani population

Bisphenol A (BPA) is considered as xenoestrogen, a crucial component utilized for the manufacturing of plastic products. It has a potential to disrupt the endocrine system and induces endocrine-related metabolic disorders. We aimed to investigate the exposure of BPA in Pakistani population and its association with sociodemographic features, dietary habits, and risk factors of diabetes mellitus (DM). This cross-sectional study was conducted on 400 participants among which 61.75% participants were diabetic and 38.25% were non-diabetic. We developed a structured questionnaire, gathered sociodemographic data, and collected their urine and blood samples for the estimation of BPA and various biomarkers as risk factors of DM, respectively. Pearson correlation coefficient was determined for urinary BPA levels and DM risk factors. Urinary BPA values were adjusted for confounders. Sociodemographic data shown that urinary BPA level was significantly higher (p < 0.05) in obese people (BMI > 27) living in semi-urban and industrial areas. BPA was detectable in 75% of study participants. Urinary BPA level was found to be higher in diabetic participants compared with that of non-diabetics. A significant correlation is observed between BPA exposure and DM risk factors. We found that urinary BPA level was correlated with elevated levels of HbA1c (r = 0.6028), HOMA-IR (r = 0.5356), CRP (r = 0.6946), BUN (r = 0.6077), AST (r = 0.5151), FFA (r = 0.5759), TGs (r = 0.5608), and MDA (r = 0.6908). Hence, our study adds to the growing body of evidence supporting the role of BPA exposure as a risk factor for DM and may be associated with higher glycemic index, increased pro-inflammatory and oxidative stress biomarkers, dyslipidemia, and impaired functioning of the liver and kidney. Heating food in plastic containers and consumption of packed food items are the main sources of BPA exposure which are positively associated with DM.

Bisphenol A-induced metabolic disorders: From exposure to mechanism of action

Bisphenol A (BPA) is considered as ubiquitous xenooestrogen and an endocrine disrupting chemical which has deleterious effects on endocrine functions. Human populations are continuously exposed to BPA as it is abundant in daily life. It has been found to be associated with wide range of metabolic disorders notably type 2 diabetes mellitus (DM). Numerous epidemiological studies have been conducted to find its role in development of DM. Experimental studies have found that BPA exposure is associated with pathogenesis of DM and also considered as a risk factor for gestational diabetes. Being a lipophilic compound, BPA is preferably accumulated in adipose tissues where it alters the production of adipokines that play important roles in insulin resistance. BPA induces apoptosis by caspase activation after mitochondrial damage and it impairs insulin signaling pathways by altering associated ion channel activity especially potassium channels. Perinatal exposure of BPA makes offspring more susceptible to develop DM in early years. Epigenetic modifications are the key mechanisms for BPA-induced metabolic re-programming, where BPA alters the expression of DNA methyltransferases involved in methylation of various genes. In this way, DNA methyltransferase controls the expression of numerous genes including genes important for insulin secretion and signaling. Furthermore, BPA induces histone modifications and alters miRNA expression. In this article, we have briefly described the sources of BPA exposure to human being and summarized the evidence from epidemiological studies linking DM with BPA exposure. Additionally, we have also highlighted the potential molecular pathways for BPA-induced DM.

Historical exposure to non-persistent environmental pollutants and risk of type 2 diabetes in a Spanish sub-cohort from the European Prospective Investigation into Cancer and Nutrition study

BACKGROUND

Environmental factors are believed to account for a substantial burden of type 2 diabetes mellitus (T2DM). Non-persistent environmental pollutants (npEPs) are a group of widely-used chemicals identified as endocrine/metabolic disrupting chemicals and obesogens. The aim of this study was to analyse the potential associations of serum levels of three groups of npEPs with the risk of incident T2DM.

METHODS

This is a longitudinal study within a sub-sample of Granada EPIC-Spain cohort (n = 670). We quantified serum concentrations of 7 npEPs: four parabens (Methylparaben (MP) ethylparaben (EP), propylparaben (PP) and butilparaben (BP); two benzophenones: Benzophenone 1 (BP1), Benzophenone 3 (BP3); and Bisphenol A (BPA). Exposure was assessed by means of chemical analyses of serum samples collected at recruitment, and information on potential confounders was gathered by using validated questionnaires at baseline. Follow-up was performed by review of patients' clinical records. Cox Proportional Hazards Models were used for the statistical analyses.

RESULTS

Median follow-up time was 23 years. There were 182 (27%) incident T2DM diagnoses in our sub-cohort. MP was the most frequently detected npEP, 88.42% samples above the limit of detection, and BP showed the lowest percentage of detection (19.21%). Those individuals within the fourth PP quartile (0.53-9.24 ng/ml) showed a statistically significant increased risk of T2DM (HR = 1.668 p = 0.012), while BP1 concentrations showed an inverse non-significant trend with the risk.

CONCLUSIONS

We evidenced a potential contribution of npEP exposure on T2DM, but no clear trend was observed. However, limitations in relation to exposure estimation might influence our findings and further research is warranted to confirm our results.

Bisphenol-A in the European Prospective Investigation into Cancer and Nutrition cohort in Spain: Levels at recruitment and associated dietary factors

Bisphenol A (BPA) is considered an endocrine disruptor and it is present in numerous products of daily use. The aim of this study was to analyze serum BPA concentrations in a subcohort of the Spanish European Prospective Investigation into Cancer and Nutrition (EPIC), as well as to identify potential predictors of the exposure. The population consisted on 3553 subjects from 4 EPIC-Spain centres and BPA levels were measured in serum samples by UHPLC-MS/MS. Almost 70% of the participants showed detectable BPA values (>0.2 ng/ml), with a geometric mean of 1.19 ng/ml (95% CI: 1.12-1.25). By sex, detectable percentages were similar (p = 0.56) but with higher serum levels in men (1.27 vs 1.11 ng/ml, p = 0.01). Based on the adjusted regression models, a 50 g/day increase in the consumption of added fats and oils were associated with 43% lower BPA serum levels, while sugar and confectionary was associated with 25% higher levels of serum BPA. We evidenced differential exposure levels by province, sex and age, but not by anthropometric or lifestyle characteristics. Further investigation is needed to understand the influence of diet in BPA exposure.

In utero Bisphenol A Exposure Is Linked with Sex Specific Changes in the Transcriptome and Methylome of Human Amniocytes

CONTEXT

Prenatal exposure to bisphenol A (BPA) is linked to obesity and diabetes but the molecular mechanisms driving these phenomena are not known. Alterations in deoxyribonucleic acid (DNA) methylation in amniocytes exposed to BPA in utero represent a potential mechanism leading to metabolic dysfunction later in life.

OBJECTIVE

To profile changes in genome-wide DNA methylation and expression in second trimester human amniocytes exposed to BPA in utero.

DESIGN

A nested case-control study was performed in amniocytes matched for offspring sex, maternal race/ethnicity, maternal age, gestational age at amniocentesis, and gestational age at birth. Cases had amniotic fluid BPA measuring 0.251 to 23.74 ng/mL. Sex-specific genome-wide DNA methylation analysis and RNA-sequencing (RNA-seq) were performed to determine differentially methylated regions (DMRs) and gene expression changes associated with BPA exposure. Ingenuity pathway analysis was performed to identify biologically relevant pathways enriched after BPA exposure. In silico Hi-C analysis identified potential chromatin interactions with DMRs.

RESULTS

There were 101 genes with altered expression in male amniocytes exposed to BPA (q < 0.05) in utero, with enrichment of pathways critical to hepatic dysfunction, collagen signaling and adipogenesis. Thirty-six DMRs were identified in male BPA-exposed amniocytes and 14 in female amniocyte analysis (q < 0.05). Hi-C analysis identified interactions between DMRs and 24 genes with expression changes in male amniocytes and 12 in female amniocytes (P < 0.05).

CONCLUSION

In a unique repository of human amniocytes exposed to BPA in utero, sex-specific analyses identified gene expression changes in pathways associated with metabolic disease and novel DMRs with potential distal regulatory functions.

Exposure to bisphenol A and diabetes risk in Mexican women

Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the production of polycarbonate plastics and epoxy resins, which has been previously linked to diabetes among non-Hispanic populations. As part of a case control study for breast cancer, only controls with BPA information were included in this report. The final sample size comprises 70 self-reported diabetics and 334 non-diabetics. Urinary free bisphenol A (BPA-F) (μg/L) was determined by solid-phase extraction and HPLC/FLD analysis. Logistic regression models were used to evaluate the association between BPA-F and self-reported diabetes. After adjusting by age, urinary BPA-F (4.06-224.53 μg/g creatinine) was associated with diabetes exposure (OR = 1.85; 95% CI 1.04, 3.28) compared with women in the reference category (0.67-4.05 μg/g creatinine). BPA may be an environmental cofactor of diabetes. More studies are needed to confirm this result, especially in Hispanic populations.

Pilot Study on the Effect of Orally Administered Bisphenol A on Glucose and Insulin Response in Nonobese Adults

OBJECTIVE

To determine the effects of varying doses of orally administered BPA on indices of glucose metabolism.

METHODS

Eleven college students (21.0 ± 0.8 years; 24.2 ± 3.9 kg/m2) were randomized in a double-blinded, crossover fashion separated by >1 week to placebo (PL), deuterated BPA at 4 µg/kg body weight (BPA-4), and deuterated BPA at 50 µg/kg body weight (BPA-50). Total BPA, glucose, insulin, and C-peptide were assessed at baseline, minutes 15, 30, 45, 60, and every 30 minutes for 2 hours in response to a glucose tolerance test.

RESULTS

There was a significant condition × time interaction for total BPA (P < 0.001) such that BPA increased more rapidly in BPA-50 than BPA-4 and PL (P = 0.003) and increased more rapidly in BPA-4 than PL (P < 0.001). There were no significant condition × time interactions on glucose, insulin, and C-peptide. Significant condition main effects were observed for glucose such that BPA-50 was significantly lower than PL (P = 0.036) and nearly lower for BPA-4 vs PL (P = 0.056). Significant condition main effects were observed such that insulin in BPA-50 was lower than BPA-4 (P = 0.021), and C-peptide in BPA-50 was lower than BPA-4 (t18 = 3.95; Tukey-adjusted P = 0.003). Glucose, insulin, and C-peptide areas under the curve for the 3-hour profile were significantly lower in BPA-50 vs PL (P < 0.05).

CONCLUSION

Orally administered BPA protocol appeared feasible and has immediate effects on glucose, insulin, and C-peptide concentrations.

Association of urinary concentrations of bisphenols with type 2 diabetes mellitus: A case-control study

Bisphenols, as synthetic chemicals, have been widely detected in environmental and human samples. Epidemiological studies have reported relationships between bisphenol A (BPA) and type 2 diabetes mellitus (T2DM), but results are inconsistent. Additionally, the associations between other bisphenols (i.e., the substitutes of BPA) with T2DM have been scarcely reported. A case-control study was conducted to examine the associations of urinary bisphenols with T2DM by investigating 8 bisphenols in urine samples of 251 T2DM cases and 251 controls and using different statistic models. Urinary bisphenol AF (BPAF) and bisphenol S (BPS) concentrations were significantly positively associated with T2DM in the log-transformed statistical models and adjusted odd ratios (ORs) were separately 4.95 [95% confidence interval (CI): 3.15, 7.79] and 1.73 (95% CI: 1.37, 2.18), which was consistent with the results in categorical models (OR = 2.03; 95% CI: 1.31, 3.15; p = 0.001 for BPAF; OR = 3.83; 95% CI: 2.37, 6.20; p < 0.001 for BPS). In addition, in the categorical models, elevated odds of T2DM were observed in the second BPA quartile (OR = 2.58; 95% CI: 1.38, 4.80) and the third quartile (OR = 1.89; 95% CI: 1.03, 3.46), but not in the fourth quartile, which reflected a nonlinear association between urinary BPA and T2DM. Similarly, only significant positive association with T2DM was found in the second quartile of the sum of bisphenols (OR = 2.07; 95% CI: 1.12, 3.82). In the sensitivity analyses, the associations of bisphenols with T2DM remained consistent except for BPAF in the categorical model. Our study suggested that several urinary bisphenols were positively associated with T2DM.

Effects of bisphenol A on metabolism and evidences of a mode of action mediated through endocrine disruption

Based on rodent studies after prenatal and/or perinatal or adult exposure, there is now evidence that BPA may increase metabolic disturbances eventually leading to type-2 diabetes development via an ED MoA. In particular, BPA has been shown to alter insulin synthesis and/or release by pancreatic β-cells, and insulin signaling within insulin-sensitive organs (i.e., liver, muscle, adipose tissues). This resulted in variations in the expression of specific hepatic or adipose tissue markers, which are indicative of a state of insulin resistance. These effects are considered by experts to be hallmarks of adverse hormonal effects, each leading to insulin resistance within the different insulin-sensitive tissues. Although epidemiological studies are inconclusive, these effects are considered relevant for humans, because similarities exist in homeostatic regulation of insulin production and sensitivity between rodents and humans and because evidence was also shown through in vitro experimental data using human cells or tissues.

Transgenerational effects of maternal bisphenol: a exposure on offspring metabolic health

Exposure to the endocrine disruptor bisphenol A (BPA) is ubiquitous and associated with health abnormalities that persist in subsequent generations. However, transgenerational effects of BPA on metabolic health are not widely studied. In a maternal C57BL/6J mice (F0) exposure model using BPA doses that are relevant to human exposure levels (10 μg/kg/day, LowerB; 10 mg/kg/day, UpperB), we showed male- and dose-specific effects on pancreatic islets of the first (F1) and second generation (F2) offspring relative to controls (7% corn oil diet; control). In this study, we determined the transgenerational effects (F3) of BPA on metabolic health and pancreatic islets in our model. Adult F3 LowerB and UpperB male offspring had increased body weight relative to Controls, however glucose tolerance was similar in the three groups. F3 LowerB, but not UpperB, males had reduced β-cell mass and smaller islets which was associated with increased glucose-stimulated insulin secretion. Similar to F1 and F2 BPA male offspring, staining for markers of T-cells and macrophages (CD3 and F4/80) was increased in pancreas of F3 LowerB and UpperB male offspring, which was associated with changes in cytokine levels. In contrast to F3 BPA males, LowerB and UpperB female offspring had comparable body weight, glucose tolerance and insulin secretion as Controls. Thus, maternal BPA exposure resulted in fewer metabolic defects in F3 than F1 and F2 offspring, and these were sex- and dose-specific.

Bisphenol A is not associated with a 5-year incidence of type 2 diabetes: a prospective nested case-control study

AIMS

The relationship between bisphenol A (BPA) and diabetes remains controversial. This study aims to investigate whether serum BPA level could predict the 5-year incidence of type 2 diabetes (T2D).

METHODS

A nested case-control study was performed among Chinese who participated in the environment, inflammation and metabolic diseases study (2008-2013). Of the 3510 subjects who were free of diabetes, 232 subjects developed diabetes during the 5-year follow-up. Cases and controls were matched for age and gender by a ratio of 1:1. Homoeostasis model assessment was used to estimate basal β-cell function (HOMA-β) and insulin resistance (HOMA-IR). Participants were stratified into tertiles based on low, median and high baseline serum BPA levels. Regression models were used to analyze the relationship between serum BPA concentration and the incidence of T2D.

RESULTS

At baseline, no significant difference in serum BPA concentration was observed between patients with T2D and controls [1.3 (0.3, 3.7) vs. 1.6 (0.4, 3.9) μmol/L, P = 0.199]; serum BPA concentration was positively associated with fasting plasma glucose (r = 0.27, P < 0.001); however, neither HOMA-β nor HOMA-IR correlated with serum BPA concentration. During the follow-up, baseline BPA levels could not predict the 5-year T2D incidence, whether or not adjusted for the potential confounders such as body mass index and blood pressure. [Low BPA tertile was the reference, OR 0.66 (95% CI 0.30, 1.44) for median, OR 0.93 (95% CI 0.41, 2.13) for high.] CONCLUSION: BPA is not associated with a 5-year T2D incidence. These data do not support previous cross-sectional study that BPA exerted a detrimental effect on glucose metabolism.

Serum Phthalate and Triclosan Levels Have Opposing Associations With Risk Factors for Gestational Diabetes Mellitus

Certain phthalates and bisphenol A (BPA) have been associated with insulin resistance and type 2 diabetes in non-pregnant adults, but studies of gestational diabetes mellitus (GDM) have reported conflicting results for phthalates and no associations with BPA. Our aim was to investigate the relationship between maternal serum levels of phthalate metabolites and phenols at 10-17 weeks of gestation and glucose homeostasis at 28 weeks of gestation. 232 women aged ≥16 years without type 1 or 2 diabetes with singleton male pregnancies were recruited from a single UK maternity centre between 2001 and 2009 as part of a prospective observational study (Cambridge Baby Growth Study). Serum levels of 16 phthalate metabolites and 9 phenols (including BPA) were measured using liquid chromatography/tandem mass spectrometry. Oral glucose tolerance tests were performed at 28 weeks. 47/232 (20.3%) women had GDM. First-trimester triclosan (TCS) was inversely associated with incident GDM (adjusted odds ratio per log increase in concentration 0.54, 95% confidence interval 0.34-0.86, p = 0.010). Amongst women without GDM, first-trimester mono-(2-ethylhexyl) phthalate and mono(carboxyisooctyl) phthalate levels were positively associated with 120-min plasma glucose (adjusted β 0.268 and 0.183, p = 0.0002 and 0.010, respectively) in mid-pregnancy. No other monotonic associations were detected between phthalate or phenol levels and fasting or stimulated plasma glucose, β-cell function, insulin resistance, or 60-min disposition index. Our results support a glycaemia-raising effect of phthalates during pregnancy, consistent with findings in non-pregnant populations and suggest a possible protective effect of exposure to TCS against GDM.

Immune System: An Emerging Player in Mediating Effects of Endocrine Disruptors on Metabolic Health

The incidence of metabolic disorders like type 2 diabetes and obesity continues to increase. In addition to the well-known contributors to these disorders, such as food intake and sedentary lifestyle, recent research in the exposure science discipline provides evidence that exposure to endocrine-disrupting chemicals like bisphenol A and phthalates via multiple routes (e.g., food, drink, skin contact) also contribute to the increased risk of metabolic disorders. Endocrine-disrupting chemicals (EDCs) can disrupt any aspect of hormone action. It is becoming increasingly clear that EDCs not only affect endocrine function but also adversely affect immune system function. In this review, we focus on human, animal, and in vitro studies that demonstrate EDC exposure induces dysfunction of the immune system, which, in turn, has detrimental effects on metabolic health. These findings highlight how the immune system is emerging as a novel player by which EDCs may mediate their effects on metabolic health. We also discuss studies highlighting mechanisms by which EDCs affect the immune system. Finally, we consider that a better understanding of the immunomodulatory roles of EDCs will provide clues to enhance metabolic function and contribute toward the long-term goal of reducing the burden of environmentally induced diabetes and obesity.

Sex- and Dose-Specific Effects of Maternal Bisphenol A Exposure on Pancreatic Islets of First- and Second-Generation Adult Mice Offspring

BACKGROUND

Exposure to the environmental endocrine disruptor bisphenol A (BPA) is ubiquitous and associated with the increased risk of diabetes and obesity. However, the underlying mechanisms remain unknown. We recently demonstrated that perinatal BPA exposure is associated with higher body fat, impaired glucose tolerance, and reduced insulin secretion in first- (F1) and second-generation (F2) C57BL/6J male mice offspring.

OBJECTIVE

We sought to determine the multigenerational effects of maternal bisphenol A exposure on mouse pancreatic islets.

METHODS

Cellular and molecular mechanisms underlying these persistent changes were determined in F1 and F2 adult offspring of F0 mothers exposed to two relevant human exposure levels of BPA (10μg/kg/d-LowerB and 10mg/kg/d-UpperB).

RESULTS

Both doses of BPA significantly impaired insulin secretion in male but not female F1 and F2 offspring. Surprisingly, LowerB and UpperB induced islet inflammation in male F1 offspring that persisted into the next generation. We also observed dose-specific effects of BPA on islets in males. UpperB exposure impaired mitochondrial function, whereas LowerB exposure significantly reduced β-cell mass and increased β-cell death that persisted in the F2 generation. Transcriptome analyses supported these physiologic findings and there were significant dose-specific changes in the expression of genes regulating inflammation and mitochondrial function. Previously we observed increased expression of the critically important β-cell gene, Igf2 in whole F1 embryos. Surprisingly, increased Igf2 expression persisted in the islets of male F1 and F2 offspring and was associated with altered DNA methylation.

CONCLUSION

These findings demonstrate that maternal BPA exposure has dose- and sex-specific effects on pancreatic islets of adult F1 and F2 mice offspring. The transmission of these changes across multiple generations may involve either mitochondrial dysfunction and/or epigenetic modifications. https://doi.org/10.1289/EHP1674.

The role of polycarbonate monomer bisphenol-A in insulin resistance

Bisphenol A (BPA) is a synthetic unit of polycarbonate polymers and epoxy resins, the types of plastics that could be found in essentially every human population and incorporated into almost every aspect of the modern human society. BPA polymers appear in a wide range of products, from liquid storages (plastic bottles, can and glass linings, water pipes and tanks) and food storages (plastics wraps and containers), to medical and dental devices. BPA polymers could be hydrolyzed spontaneously or in a photo- or temperature-catalyzed process, providing widespread environmental distribution and chronic exposure to the BPA monomer in contemporary human populations. Bisphenol A is also a xenoestrogen, an endocrine-disrupting chemical (EDC) that interferes with the endocrine system mimicking the effects of an estrogen and could potentially keep our endocrine system in a constant perturbation that parallels endocrine disruption arising during pregnancy, such as insulin resistance (IR). Gestational insulin resistance represents a natural biological phenomenon of higher insulin resistance in peripheral tissues of the pregnant females, when nutrients are increasingly being directed to the embryo instead of being stored in peripheral tissues. Gestational diabetes mellitus may appear in healthy non-diabetic females, due to gestational insulin resistance that leads to increased blood sugar levels and hyperinsulinemia (increased insulin production from the pancreatic beta cells). The hypothesis states that unnoticed and constant exposure to this environmental chemical might potentially lead to the formation of chronic low-level endocrine disruptive state that resembles gestational insulin resistance, which might contribute to the development of diabetes. The increasing body of evidence supports the major premises of this hypothesis, as exemplified by the numerous publications examining the association of BPA and insulin resistance, both epidemiological and mechanistic. However, to what extent BPA might contribute to the development of diabetes in the modern societies still remains unknown. In this review, I discuss the chemical properties of BPA and the sources of BPA contamination found in the environment and in human tissues. I provide an overview of mechanisms for the proposed role of bisphenol A in insulin resistance and diabetes, as well as other related diseases, such as cardiovascular diseases. I describe the transmission of BPA effects to the offspring and postulate that gender related differences might originate from differences in liver enzyme levels, such as UDP-glucuronosyltransferase, which is involved in BPA processing and its elimination from the organism. I discuss the molecular mechanisms of BPA action through nuclear and membrane-bound ER receptors, non-monotonic dose response, epigenetic modifications of the DNA and propose that chronic exposure to weak binders, such as BPA, may mimic the effects of strong binders, such as estrogens.

Adipose Tissue as a Site of Toxin Accumulation

We examine the role of adipose tissue, typically considered an energy storage site, as a potential site of toxicant accumulation. Although the production of most persistent organic pollutants (POPs) was banned years ago, these toxicants persist in the environment due to their resistance to biodegradation and widespread distribution in various environmental forms (e.g., vapor, sediment, and water). As a result, human exposure to these toxicants is inevitable. Largely due to their lipophilicity, POPs bioaccumulate in adipose tissue, resulting in greater body burdens of these environmental toxicants with obesity. POPs of major concern include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), and polybrominated biphenyls and diphenyl ethers (PBBs/PBDEs), among other organic compounds. In this review, we (i) highlight the physical characteristics of toxicants that enable them to partition into and remain stored in adipose tissue, (ii) discuss the specific mechanisms of action by which these toxicants act to influence adipocyte function, and (iii) review associations between POP exposures and the development of obesity and diabetes. An area of controversy relates to the relative potential beneficial versus hazardous health effects of toxicant sequestration in adipose tissue. © 2017 American Physiological Society. Compr Physiol 7:1085-1135, 2017.

Bisphenol A (BPA) in the serum of pet dogs following short-term consumption of canned dog food and potential health consequences of exposure to BPA

Bisphenol A (BPA) is a widely present endocrine disruptor chemical found in many household items. Moreover, this chemical can bioaccumulate in various terrestrial and aquatic sources; thereby ensuring continual exposure of animals and humans. For most species, including humans, diet is considered the primary route of exposure. However, there has been little investigation whether commercial-brands of dog foods contain BPA and potential health ramifications of BPA-dietary exposure in dogs. We sought to determine BPA content within dog food, whether short-term consumption of these diets increases serum concentrations of BPA, and potential health consequences, as assessed by potential hematological, serum chemistry, cortisol, DNA methylation, and gut microbiome changes, in dogs associated with short-term dietary exposure to BPA. Fourteen healthy privately-owned dogs were used in this study. Blood and fecal samples were collected prior to dogs being placed for two-weeks on one of two diets (with one considered to be BPA-free), and blood and fecal samples were collected again. Serum/plasma samples were analyzed for chemistry and hematology profiles, cortisol concentrations, 5-methylcytosine in lymphocytes, and total BPA concentrations. Fecal samples were used for microbiome assessments. Both diets contained BPA, and after two-weeks of being on either diet, dogs had a significant increase in circulating BPA concentrations (pre-samples=0.7±0.15ng/mL, post-samples=2.2±0.15ng/mL, p<0.0001). Elevated BPA concentrations positively correlated with increased plasma bicarbonate concentrations and associated with fecal microbiome alterations. Short-term feeding of canned dog food increased circulating BPA concentrations in dogs comparable to amounts detected in humans, and greater BPA concentrations were associated with serum chemistry and microbiome changes. Dogs, who share our internal and external environments with us, are likely excellent indicators of potential human health concerns to BPA and other environmental chemicals. These findings may also have relevance to aquatic and terrestrial wildlife.

The association between bisphenol A exposure and type-2 diabetes: a world systematic review

The present study was conducted to systematically review, analyze, and interpret all the relevant evidence in the literature on the possible link between exposure to bisphenol A (BPA) and the risk of type-2 diabetes mellitus (T2DM). We developed a comprehensive search strategy and used it to search Web of Science, Scopus, PubMed, and Google Scholar up to March 31, 2016, producing 3108 hits, of which 13 original papers were included. Findings of these studies were quite controversial; few studies indicated a significant positive association between BPA exposure and T2DM, while some other failed to detect such a relationship. Overall, it can be suggested that chance is unlikely the plausible explanation for the observed association between BPA exposure and T2DM. This was mainly because even in the negative studies some clues could be found in favor of a statistically significant relationship between BPA and T2DM. Additionally, some of the studies had shortcomings in defining the exposure and outcome measures, which, if present, might have led to underestimating the relationship between BPA exposure and T2DM. The theoretical plausibility of such a relationship found earlier in animal studies also supports this point. However, more definitive answer requires the conduct of future longitudinal studies, in which the possible association between BPA exposure and T2DM is assessed over much longer periods of time with more temporally robust BPA measurements. In addition, it would be quite beneficial if future studies be conducted in areas where data is still lacking (e.g., South America, Australia/Oceania, and Europe). Graphical abstract ᅟ.

Serum bisphenol A as a predictor of chronic kidney disease progression in primary hypertension: a 6-year prospective study

OBJECTIVE

Hypertensive nephropathy is one of the major causes of chronic kidney disease (CKD). Bisphenol A (BPA) is associated with elevated blood pressure and urinary albuminuria. The aim of this study is to evaluate the association between serum BPA with the progression of CKD in patients with primary hypertension.

METHODS

In this prospective study, 302 patients with primary hypertension were followed up for 6 years (195 men and 107 women, 65.29 ± 9.78 years at baseline). The baseline values of serum BPA were measured. Renal function was measured as estimated glomerular filtration rate (eGFR) calculated by the Chronic Kidney Disease Epidemiology Collaboration creatinine-cystatin C equation (eGFRcr-cys). Regression models were used to calculate associations of serum BPA with the annual change in eGFR and the risk of CKD progression.

RESULTS

Baseline serum BPA concentration was 0.61(0.26, 2.44) ng/ml and was significantly negatively correlated with the annual change in eGFR (R = -0.197, P < 0.001). After adjusting for clinical factors, baseline serum BPA level had a significant negative association with the annual change in eGFR (β = -0.132, P = 0.007). Univariate logistic regression analysis showed that the baseline age, SBP, eGFR, and serum BPA levels were predictors of CKD stage 3 or greater. In multivariate logistic regression analysis, patients with high serum BPA levels exhibited a five-fold increased risk of developing CKD stage 3 or greater compared with patients with low serum BPA levels [odds ratio 4.79 (95% confidence interval 1.81, 14.25), P = 0.004].

CONCLUSION

Serum BPA may be a predictor of CKD progression in patients with primary hypertension.

Serum bisphenol A and progression of type 2 diabetic nephropathy: a 6-year prospective study

AIMS

Bisphenol A (BPA) is associated with diabetes and cardiovascular diseases. The aim of our study was to evaluate whether serum BPA could predict the progression of chronic kidney disease (CKD) in patients with type 2 diabetes (T2D).

METHODS

In this prospective study, a total of 121 patients with T2D and estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m(2) were followed up for 6 years. The baseline values of serum BPA were measured. Renal function was measured as eGFR calculated by the Chronic Kidney Disease Epidemiology Collaboration creatinine-cystatin C equation. Development of CKD was defined as eGFR < 60 mL/min/1.73 m(2) at the last follow-up. Regression models were used to analyze the associations of serum BPA with the change in eGFR and the risk of CKD development.

RESULTS

Baseline serum BPA concentration was 0.40 (0.17, 1.40) ng/mL. Duration of T2D, baseline waist circumference, systolic blood pressure, diastolic blood pressure, fasting plasma glucose, and serum BPA level were significantly negatively associated with the annual change and percentage change in eGFR. After adjusting for clinical factors, baseline serum BPA level had a significant negative association with the annual change in eGFR (β = -0.371, P < 0.001) and percentage change in eGFR (β = -0.391, P = <0.001). Multivariate logistic regression analysis showed that patients with high levels of serum BPA exhibited about a sevenfold increased risk of developing CKD compared to patients with low levels of serum BPA [odds ratio (OR) 6.65 (95 % CI 1.47, 30.04), P = 0.014].

CONCLUSION

Serum BPA may be a predictor of CKD in patients with T2D.

Human Bisphenol A Exposure and the "Diabesity Phenotype"

Bisphenol A (BPA), a known endocrine disruptor, is a food contaminant suspected of being a contributing factor to the present-day increase in obesity, diabetes, and cardiovascular disease. This issue is of increasing interest in the field of diabetes research and has become a matter of concern for regulatory agencies and food industries. Recently, the number of studies involving BPA has increased exponentially, but there are still many gaps in the knowledge of the relationship between actual BPA exposure and cardiometabolic risk and of the modalities of food intake exposure, all of which prevents sound judgments concerning the risks to human health. This review focuses on the association between human exposure to BPA and obesity, thyroid function, diabetes, insulin resistance, metabolic syndrome, cardiovascular diseases, and BPA content in food. Many cross-sectional studies support, sometimes contradictorily, an adverse effect of BPA exposure on obesity, diabetes, and cardiovascular diseases. Few prospective studies support an adverse effect of BPA exposure on such pathologies. Moreover, no intervention studies have been conducted to evaluate the causality of such associations. This is mainly due to lack of an appropriate database of BPA content in foods, thus hindering any estimation of the usual dietary BPA intake.

Can exposure to environmental chemicals increase the risk of diabetes type 1 development?

Type 1 diabetes mellitus (T1DM) is an autoimmune disease, where destruction of beta-cells causes insulin deficiency. The incidence of T1DM has increased in the last decades and cannot entirely be explained by genetic predisposition. Several environmental factors are suggested to promote T1DM, like early childhood enteroviral infections and nutritional factors, but the evidence is inconclusive. Prenatal and early life exposure to environmental pollutants like phthalates, bisphenol A, perfluorinated compounds, PCBs, dioxins, toxicants, and air pollutants can have negative effects on the developing immune system, resulting in asthma-like symptoms and increased susceptibility to childhood infections. In this review the associations between environmental chemical exposure and T1DM development is summarized. Although information on environmental chemicals as possible triggers for T1DM is sparse, we conclude that it is plausible that environmental chemicals can contribute to T1DM development via impaired pancreatic beta-cell and immune-cell functions and immunomodulation. Several environmental factors and chemicals could act together to trigger T1DM development in genetically susceptible individuals, possibly via hormonal or epigenetic alterations. Further observational T1DM cohort studies and animal exposure experiments are encouraged.

Association of serum bisphenol a with hypertension in thai population

Objective. The present study aimed to examine the association between serum BPA and hypertension and evaluated whether it was influenced by estradiol level. Methods. A subsample of 2588 sera randomly selected from the Thai National Health Examination Survey IV, 2009, was measured for serum BPA and estradiol. Logistic regression was used to examine the association controlling for age, sex, diabetes, body mass index, and estradiol level. Results. Compared with the lowest quartile, the adjusted odds ratio (AOR) of hypertension for the fourth quartile of serum BPA was 2.16 (95% CI 1.31, 3.56) in women and 1.44 (0.99, 2.09) in men. There was no interaction between serum BPA and estradiol level. For analysis using log(BPA) as a continuous variable, the AOR per unit change in log(BPA) was 1.09 (95% CI 1.02, 1.16). Among postmenopausal women, the AOR for the fourth quartile of BPA was 2.33 (95% CI 1.31, 4.15) and, for premenopausal women, it was 2.12 (95% CI 0.87, 5.19). Conclusion. Serum BPA was independently associated with hypertension in women and was not likely to be affected by estrogen; however, its mechanism related to blood pressure needs further investigation.