Urinary Bisphenol A Concentration and Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women

Lipophilic chemical exposure as a cause of cardiovascular disease

Environmental chemical exposure has been linked to numerous diseases in humans. These diseases include cancers; neurological and neurodegenerative diseases; metabolic disorders including type 2 diabetes, metabolic syndrome and obesity; reproductive and developmental disorders; and endocrine disorders. Many studies have associated the link between exposures to environmental chemicals and cardiovascular disease (CVD). These chemicals include persistent organic pollutants (POPs); the plastic exudates bisphenol A and phthalates; low molecular weight hydrocarbons (LMWHCs); and poly nuclear aromatic hydrocarbons (PAHs). Here it is reported that though the chemicals reported on differ widely in chemical properties and known points of attack in humans, a common link exists between them. All are lipophilic species that are found in serum. Environmentally induced CVD is related to total lipophilic chemical load in the blood. Lipophiles serve to promote the absorption of otherwise not absorbed toxic hydrophilic species that promote CVD.

Obesity and metabolic comorbidities: environmental diseases?

Obesity and metabolic comorbidities represent increasing health problems. Endocrine disrupting compounds (EDCs) are exogenous agents that change endocrine function and cause adverse health effects. Most EDCs are synthetic chemicals; some are natural food components as phytoestrogens. People are exposed to complex mixtures of chemicals throughout their lives. EDCs impact hormone-dependent metabolic systems and brain function. Laboratory and human studies provide compelling evidence that human chemical contamination can play a role in obesity epidemic. Chemical exposures may increase the risk of obesity by altering the differentiation of adipocytes. EDCs can alter methylation patterns and normal epigenetic programming in cells. Oxidative stress may be induced by many of these chemicals, and accumulating evidence indicates that it plays important roles in the etiology of chronic diseases. The individual sensitivity to chemicals is variable, depending on environment and ability to metabolize hazardous chemicals. A number of genes, especially those representing antioxidant and detoxification pathways, have potential application as biomarkers of risk assessment. The potential health effects of combined exposures make the risk assessment process more complex compared to the assessment of single chemicals. Techniques and methods need to be further developed to fill data gaps and increase the knowledge on harmful exposure combinations.

Urinary excretion of phthalate metabolites, phenols and parabens in rural and urban Danish mother-child pairs

Some phthalates, parabens and phenols have shown adverse endocrine disrupting effects in animal studies and are also suspected to be involved in human reproductive problems. However, knowledge about exposure sources and biomonitoring data in different subsets of populations are still scarce. Thus, in this study first morning urine samples were collected from 6 to 11 years Danish children and their mothers. The content of seven parabens, nine phenols and metabolites of eight different phthalates were analysed by LC-MS/MS. Two parabens, six phenols and metabolites from six phthalate diesters were measurable in more than 50%, 75% and 90% of the participants, respectively. Thus the children and their mothers were generally exposed simultaneously to a range of phthalates, phenols and parabens. In general, the levels were low but for several of the compounds extreme creatinine adjusted concentrations 100-500-fold higher than the median level were seen in some participants. Children were significantly higher exposed to bisphenol A (BPA) and some of the phthalates (DiBP, DnBP, BBzP, DEHP and DiNP) than their mothers, whereas mothers were higher exposed to compounds related to cosmetics and personal care products such as parabens (MeP, EtP and n-PrP), benzophenone-3, triclosan and diethyl phthalate. However, a very high correlation between mothers and their children was observed for all chemicals. A high individual exposure to one chemical was often associated with a high exposure to other of the chemicals and the possibility of combination effects of multiple simultaneous exposures cannot be excluded.

Low-dose bisphenol A and estrogen increase ventricular arrhythmias following ischemia-reperfusion in female rat hearts

Bisphenol A (BPA) is an environmental estrogenic endocrine disruptor that may have adverse health impacts on a range of tissue/systems. In previous studies, we reported that BPA rapidly promoted arrhythmias in female rodent hearts through alteration of myocyte calcium handling. In the present study we investigated the acute effects of BPA on ventricular arrhythmias and infarction following ischemia-reperfusion in rat hearts. Rat hearts were subjected to 20 min of global ischemia followed by reperfusion. In female, but not male hearts, acute exposure to 1 nM BPA, either alone or combined with 1 nM 17β-estradiol (E2), during reperfusion resulted in a marked increase in the duration of sustained ventricular arrhythmias. BPA plus E2 increased the duration ventricular fibrillation, and the duration of VF as a fraction of total duration of sustained ventricular arrhythmia. The pro-arrhythmic effects of estrogens were abolished by MPP combined with PHTPP, suggesting the involvements of both ERα and ERβ signaling. In contrast to their pro-arrhythmic effects, BPA and E2 reduced infarction size, agreeing with previously described protective effect of estrogen against cardiac infarction. In conclusion, rapid exposure to low dose BPA, particularly when combined with E2, exacerbates ventricular arrhythmia following IR injury in female rat hearts.

Lifelong exposure to bisphenol a alters cardiac structure/function, protein expression, and DNA methylation in adult mice

Bisphenol A (BPA) is an estrogenizing endocrine disruptor compound of concern. Our objective was to test whether lifelong BPA would impact cardiac structure/function, calcium homeostasis protein expression, and the DNA methylation of cardiac genes. We delivered 0.5 and 5.0 µg/kg/day BPA lifelong from gestation day 11 or 200 µg/kg/day from gestation day 11 to postnatal day 21 via the drinking water to C57bl/6n mice. BPA 5.0 males and females had increased body weight, body mass index, body surface area, and adiposity. Echocardiography identified concentric remodeling in all BPA-treated males. Systolic and diastolic cardiac functions were essentially similar, but lifelong BPA enhanced male and reduced female sex-specific differences in velocity of circumferential shortening and ascending aorta velocity time integral. Diastolic blood pressure was increased in all BPA females. The calcium homeostasis proteins sarcoendoplasmic reticulum ATPase 2a (SERCA2a), sodium calcium exchanger-1, phospholamban (PLB), phospho-PLB, and calsequestrin 2 are important for contraction and relaxation. Changes in their expression suggest increased calcium mobility in males and reduced calcium mobility in females supporting the cardiac function changes. DNA methyltransferase 3a expression was increased in all BPA males and BPA 0.5 females and reduced in BPA 200 females. Global DNA methylation was increased in BPA 0.5 males and reduced in BPA 0.5 females. BPA induced sex-specific altered DNA methylation in specific CpG pairs in the calsequestrin 2 CpG island. These results suggest that continual exposure to BPA impacts cardiac structure/function, protein expression, and epigenetic DNA methylation marks in males and females.

Bisphenol A exposure is associated with low-grade urinary albumin excretion in children of the United States

Urinary bisphenol A (BPA), a widely used biomarker of exposure to BPA, has been associated with cardiometabolic derangements in laboratory studies and with low-grade albuminuria in Chinese adults. Despite the known unique vulnerability of children to environmental chemicals, no studies have examined associations of urinary BPA with albuminuria in children. As exposure to BPA is widespread in the United States population, we examined data from 710 children in the 2009-10 National Health and Nutrition Examination Survey with urinary BPA measurements and first morning urine samples with creatinine values. Controlled for a broad array of sociodemographic and environmental risk factors as well as insulin resistance and elevated cholesterol, children with the highest compared with the lowest quartile of urinary BPA had a significant 0.91 mg/g higher albumin-to-creatinine ratio, adjusted for the urinary BPA concentration. When the multivariable model was reprised substituting continuous measures of BPA, a significant 0.28 mg/g albumin-to-creatinine ratio increase was identified for each log unit increase in urinary BPA. Thus, an association of BPA exposure with low-grade albuminuria is consistent with previous results found in Chinese adults and documents this in children in the United States. Our findings broaden the array of adverse effects of BPA to include endothelial dysfunction as evidenced by the low-grade albuminuria and support proactive efforts to prevent harmful exposures.

Age-related trends in urinary excretion of bisphenol A in Australian children and adults: evidence from a pooled sample study using samples of convenience

Bisphenol A (BPA or 4,4'-(propane-2,2-diyl)diphenol) is a chemical intermediate in the production of polycarbonate and epoxy resins, and is used in a wide range of applications. BPA has attracted significant attention in the past decade due to its frequency of detection in human populations worldwide, and has demonstrated animal toxicity and potential impact on human health, particularly during critical periods of development. The aim of this study was to perform a preliminary assessment of age-related trends in urinary concentration and to estimate daily excretion of BPA in Australian children (aged >0 to <5 yr) and adults (≥15 to <75 yr). This was achieved using 79 samples pooled by age and gender, created from 868 individual samples of convenience collected as part of routine, community-based pathology testing. Total BPA was analyzed using online solid phase extraction (SPE)-liquid chromatography tandem mass spectrometry (LC-MS/MS) and detected in all samples with a range of 0.65-265 ng/ml. No significant differences were observed between males and females. A urine flow model was constructed from published values and was used to provide an estimate of daily excretion per unit body weight for each pooled sample. The daily excretion estimates ranged from 26.2 to 18,200 ng/kg-d for children, and from 20.1 to 165 ng/kg-d for adults. Urinary concentrations and estimated excretion rates were inversely associated with age, and estimated daily excretion in infants and young children was significantly higher than in adults (geometric mean: 107 and 47.0 ng/kg-d, respectively). Higher excretion of BPA in children may be explained by their higher food consumption relative to body weight compared to adults and adolescents, and may also reflect alternative exposure pathways and sources.

Endocrine-disrupting chemicals and public health protection: a statement of principles from The Endocrine Society

An endocrine-disrupting chemical (EDC) is an exogenous chemical, or mixture of chemicals, that can interfere with any aspect of hormone action. The potential for deleterious effects of EDC must be considered relative to the regulation of hormone synthesis, secretion, and actions and the variability in regulation of these events across the life cycle. The developmental age at which EDC exposures occur is a critical consideration in understanding their effects. Because endocrine systems exhibit tissue-, cell-, and receptor-specific actions during the life cycle, EDC can produce complex, mosaic effects. This complexity causes difficulty when a static approach to toxicity through endocrine mechanisms driven by rigid guidelines is used to identify EDC and manage risk to human and wildlife populations. We propose that principles taken from fundamental endocrinology be employed to identify EDC and manage their risk to exposed populations. We emphasize the importance of developmental stage and, in particular, the realization that exposure to a presumptive "safe" dose of chemical may impact a life stage when there is normally no endogenous hormone exposure, thereby underscoring the potential for very low-dose EDC exposures to have potent and irreversible effects. Finally, with regard to the current program designed to detect putative EDC, namely, the Endocrine Disruptor Screening Program, we offer recommendations for strengthening this program through the incorporation of basic endocrine principles to promote further understanding of complex EDC effects, especially due to developmental exposures.

Associations of Bisphenol A Exposure With Heart Rate Variability and Blood Pressure

Bisphenol A (BPA) is a high-volume production chemical that has been suspected to have adverse health effects. Recent studies have suggested that cardiovascular diseases are associated with the BPA exposure. The aim of present study was to investigate the associations of urinary BPA with heart rate variability and blood pressure. We recruited 560 noninstitutionalized elderly citizens from August 2008 to August 2010 in Seoul. All of the participants were ≥60 years old. The participants took medical examinations ≤5 times. Urinary BPA concentration, heart rate variability, and blood pressure were measured at each time. A total of 1511 observations from 521 participants were included in the analyses. We observed that urinary BPA was associated negatively with the root mean square of successive differences for heart rate and positively with blood pressure. The odds ratio of showing hypertension (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg) was 1.27 (95% CI, 0.85–1.88) in the fourth quartile compared with the first quartile of urinary BPA concentration. When the analyses were restricted to participants who did not report previous history of hypertension (n=258), the odds ratio was increased to 2.35 (95% CI, 1.33–4.17).

Urinary bisphenol a concentration and angiography-defined coronary artery stenosis

Background

Bisphenol A is widely used in food and drinks packaging. There is evidence of associations between raised urinary bisphenol A (uBPA) and increased incidence of reported cardiovascular diagnoses.

Methodology/Principal Findings

To estimate associations between BPA exposure and angiographically graded coronary atherosclerosis. 591 patients participating in The Metabonomics and Genomics in Coronary Artery Disease (MaGiCAD) study in Cambridgeshire UK, comparing urinary BPA (uBPA) with grades of severity of coronary artery disease (CAD) on angiography. Linear models were adjusted for BMI, occupational social class and diabetes status. Severe (one to three vessel) CAD was present in 385 patients, 86 had intermediate disease (n = 86) and 120 had normal coronary arteries. The (unadjusted) median uBPA concentration was 1.28 ng/mL with normal coronary arteries, and 1.53 ng/mL with severe CAD. Compared to those with normal coronary arteries, uBPA concentration was significantly higher in those with severe CAD (OR per uBPA SD = 5.96 ng/ml OR = 1.43, CI 1.03 to 1.98, p = 0.033), and near significant for intermediate disease (OR = 1.69, CI 0.98 to 2.94, p = 0.061). There was no significant uBPA difference between patients with severe CAD (needing surgery) and the remaining groups combined.

Conclusions/Significance

BPA exposure was higher in those with severe coronary artery stenoses compared to those with no vessel disease. Larger studies are needed to estimate true dose response relationships. The mechanisms underlying the association remain to be established.

A review of dietary and non-dietary exposure to bisphenol-A

Due to the large number of applications of bisphenol-A (BPA), the human exposure routes are multiple. We aimed to review shortly the food and non-food sources of BPA, and to evaluate their contribution to the human exposure. Food sources discussed here include epoxy resins, polycarbonate and other applications, such as paperboard and polyvinylchloride materials. Among the non-food sources, exposures through dust, thermal paper, dental materials, and medical devices were summarized. Based on the available data for these exposure sources, it was concluded that the exposure to BPA from non-food sources is generally lower than that from exposure from food by at least one order of magnitude for most studied subgroups. The use of urinary concentrations from biomonitoring studies was evaluated and the back-calculation of BPA intake seems reliable for the overall exposure assessment. In general, the total exposure to BPA is several orders of magnitude lower than the current tolerable daily intake of 50 μg/kg bw/day. Finally, the paper concludes with some critical remarks and recommendations on future human exposure studies to BPA.

Lifestyle behaviors associated with exposures to endocrine disruptors

Identifying and characterizing sources of exposure to phthalates and bisphenol A (BPA) have proved challenging due to the presence of multiple co-exposures resulting from a wide variety of home environments and lifestyles. We hypothesized that the consistent lifestyle of an Old Order Mennonite (OOM) community would provide an ideal setting in which to characterize sources of exposure to BPA and phthalates. We obtained urine samples from ten mid-term pregnant OOM women (ages-21-39) to determine concentrations of 9 phthalate metabolites and BPA and collected a self-reported survey of participants' household environment, product use, and lifestyle within a 48-h period prior to urine collection. We compared their metabolite concentrations to pregnant women included in the National Health and Nutrition Examination Survey (NHANES 2007-2008). Although OOM participants reported some use of plastic and fragranced household products, concentrations of metabolites were lower and significantly less for BPA (p=0.002) and phthalate metabolites MEHP (p=0.0215), MiBP (p=0.0020) and MEP (p=0.021), when compared to NHANES pregnant women. Levels of other phthalate metabolites were also lower in this population. Our data suggest three practices that may contribute to these lower levels: (1) consuming mostly homegrown produce (ingestion), (2) no cosmetics and limited use of personal care products, and (3) transportation primarily by sources other than automobiles.