Higher Urinary Bisphenol A Concentrations Research Articles

Associations of exposure to bisphenol-A or parabens with markers of liver injury/function among US adults in NHANES 2011-2016.

Bisphenol-A (BPA) and parabens are common endocrine-disrupting compounds (EDCs) that are used extensively in consumer products worldwide and are widely found in the environment. The purpose of this study was to comprehensively explore the correlations between urinary BPA/parabens levels and liver injury/function markers. In this cross-sectional study, we used National Health and Nutrition Examination Survey (NHANES) data from 2011 to 2016. The exposure variables were urinary BPA and four urinary parabens [methylparaben (MPB), ethylparaben (EPB), propylparaben (PPB), and butylparaben (BPB)], while the outcome variables were indicators of liver function/injury [alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ ALT, albumin (ALB), total protein (TP), total bilirubin (TBIL), alkaline phosphatase (ALP), and the fibrosis-4 index (FIB-4)]. Multiple linear regression and weighted quantile sum (WQS) regression analyses were applied to explore the relationships between the individual/combined exposure variables and the liver injury/function indicators, respectively. Furthermore, stratified analysis was employed to detect the associations influenced by age and sex. A total of 2,179 adults were eligible for the present analysis. Multivariate linear regression analysis revealed positive associations of EPB with AST, ALT, TP, and FIB-4 scores and negative associations of BPA with TP and ALB. The effects of urinary parabens on adverse outcomes in the liver (AST and ALT) were significant in the female and middle-aged subgroups. In addition, the WQS analysis revealed that the mixture of four compounds was negatively associated with ALB. BPA had the greatest effect on the serum ALB concentration (weight = 0.688). Our present study provided novel evidence of significant associations between BPA or certain parabens and numerous markers of liver injury/function indicators. We found that higher urinary BPA concentrations were associated with worse liver function. Exposure to high EPB/PPB ratios was significantly associated with biomarkers of liver injury.

Serial cross-sectional study for the association between urinary bisphenol A and paediatric obesity: Recent updates using NHANES 2003-2014.

Several studies have reported bisphenol A (BPA) as a potential risk factor for paediatric obesity, but the findings were inconsistent among these studies. Using data from the National Health and Nutrition Examination Survey from 2003 to 2014, we conducted a serial cross-sectional study to examine the association between urinary BPA and paediatric obesity among children aged 6 and 19 years. The association between paediatric obesity and urinary BPA concentrations with or without urinary creatinine adjustments was assessed using multivariable regression and cubic spline models fitted for regression models. We observed decreasing trends in urinary BPA concentrations from 2003 to 2014. The associations between urinary BPA concentrations and obesity were inconsistent across the years of survey and even after different models for urinary creatinine adjustments were used. Children with obesity were positively associated with urinary creatinine concentrations, but was not with creatinine-adjusted models. Furthermore, children with higher urinary BPA concentrations had elevated odds of obesity during 2003 to 2008, whereas these associations were inconsistent during 2009 to 2014. The associations between paediatric obesity and urinary BPA concentrations differed across the years of survey and creatinine adjustments. Further studies are required to assess these discrepancies.

Bisphenol A exposure through receipt handling and its association with insulin resistance among female cashiers

Bisphenol A (BPA) is one of the most widely used chemicals in various consumer products. In thermal papers such as receipts and tickets, BPA is used as a heat-activated developer. Cashiers are therefore suspected to be a vulnerable group of exposure to BPA, but neither contribution of receipt handling to the total body burden of BPA among cashiers, nor related health effects are well characterized. Female cashiers (n = 54) were recruited from seven retail shops of a major supermarket chain in Korea, and urinary levels of BPA and metabolic syndrome (MetS) related biomarkers were measured. In order to estimate the contribution of receipt handling to the body burden of BPA, an intervention was designed on the use of gloves: the subjects were asked not to wear gloves during the work for one week, and in the following week, to wear gloves. Urine samples were collected at pre-shift and post-shift for the first two consecutive days in each week, and urinary BPA concentrations were measured. In cashiers without gloves, about a two-fold increase in urinary BPA concentrations was observed after work-shift. When the cashiers wore gloves, however, urinary BPA levels showed no changes. Higher urinary BPA concentrations were associated with greater levels of fasting insulin and insulin resistance. Our observation shows that receipt handling among the cashiers could double the BPA exposure levels at post-shift compared to those at pre-shift, and use of simple protective equipment such as gloves could effectively reduce the BPA exposure levels.

Urinary bisphenol A concentration and the risk of central obesity in Chinese adults: A prospective study.

Bisphenol A (BPA) exposure has been associated with diabetes and related metabolic disorders, such as obesity, but studies of the association of urinary BPA concentrations with central obesity risk are limited. The aim of this study was to prospectively investigate the association between urinary BPA and incident central obesity in a Chinese population aged ≥40 years. The study followed 888 participants from Shanghai, China, who did not have central obesity at baseline (in 2009) for 4 years. Concentrations of BPA were measured in baseline morning spot urine samples. Central obesity was defined as waist circumference ≥90 cm in men and ≥80 cm in women. During a mean follow-up of 4 years, 124 (14.0%) participants developed central obesity. Each 1-unit increase in log [BPA] was positively associated with a 2.30-fold risk of incident central obesity (95% confidence interval [CI] 1.39-3.78; P < 0.001) after adjustment for confounders. Compared with the lowest tertile of urinary BPA concentration, Tertiles 2 and 3 were associated with a higher risk of incident central obesity (odds ratios 1.73 [95% CI 1.04-2.88] and 1.81 [95% CI 1.08-3.05], respectively). Stratified analysis showed significant associations of BPA with incident central obesity in women and individuals <60 years of age, with normal weight, non-smokers, non-drinkers, or non-hypertensives. The results indicate that higher urinary BPA concentrations may be associated with a greater risk of incident central obesity in Chinese adults. The study emphasizes the effects of BPA exposure on metabolic risk from a public health perspective.

The consumption of canned food and beverages and urinary Bisphenol A concentrations in NHANES 2003–2008

BackgroundExposure to Bisphenol A (BPA) is ubiquitous and includes dietary and environmental pathways. BPA is rapidly glucuronidated in the body, and both BPA and its conjugates can be readily measured in urine. ObjectivesTo investigate the contribution of canned food and beverages, known sources of BPA contamination, to BPA biomarkers of exposure using dietary and urinary BPA concentration information in a representative sample of the U.S. population. MethodsWe evaluated 7669 NHANES 2003–2008 participants 6 years and older with 24-h dietary recall information and urinary BPA concentrations available. Using linear regression models, we evaluated the associations between recent canned food and beverage consumption and urinary BPA concentrations, adjusting for potential confounders. ResultsWe found 9% of our participants consumed one canned food in the past 24h and 2% consumed two or more canned foods. The consumption of one canned food vs. none was associated with 24% (95% CI 1.11, 1.38) higher urinary BPA concentrations. The consumption of two or more canned foods vs. none was associated with 54% (95% CI 1.27, 1.88) higher urinary BPA concentrations. The consumption of one or more of some specific types of canned foods vs. none were associated with higher urinary BPA concentrations: 41% (95% CI 1.23, 1.63) higher BPA for vegetable and fruit, 70% (95% CI 1.18, 2.44) higher for canned pasta, and 229% (95% CI 1.22, 4.30) higher for canned soup. Canned beverages were not associated with urinary BPA concentrations. ConclusionsCanned food, including some specific types such as canned vegetable and fruit, canned pasta, and canned soup were associated with higher levels of urinary BPA concentrations.

Changes in urinary bisphenol A concentrations associated with placement of dental composite restorations in children and adolescents

BackgroundBisphenol A-glycidyl methacrylate (bis-GMA)–based dental composite restorations may release bisphenol A (BPA). The authors assessed changes in urinary BPA concentrations over a 6-month follow-up period in children and adolescents who received bis-GMA–based restorations. MethodsThe authors collected data from 91 study participants aged 3 to 17 years who needed composite restorations. Participants provided urine samples and information on BPA-related exposures before and at approximately 1 day, 14 days, and 6 months after treatment. The authors used multivariable linear regression models to test associations between the number of surface restorations placed and the changes in urinary BPA concentrations. ResultsParticipants had a mean (standard deviation [SD]) of 1.4 (1.0) for surfaces restored with composite at the first treatment visit and 2.3 (1.6) for surfaces restored during the entire study period. Mean (SD) change in urinary BPA concentrations between pretreatment and day 1 was 1.71 (9.94) nanograms per milliliter overall and 0.87 (5.98) after excluding 1 participant who had 8 surfaces restored at the visit. Overall, the authors observed an association between a greater number of composite surface restorations placed and higher urinary BPA concentrations in the 1-day sample (posterior-occlusal exponentiated coefficients [eβ] = 1.47; 95% confidence interval [CI], 1.18-1.83; P < .001), but the association was attenuated after the authors restricted the sample to the 88 participants who had up to 4 restorations (eβ = 1.19; 95% CI, 0.86-1.64), and they did not observe any association using 14-day (eβ = 0.94; 95% CI, 0.75-1.18) or 6-month (eβ = 0.88; 95% CI, 0.74-1.04) samples. ConclusionsPlacement of bis-GMA–based restorations in children and adolescents may produce transient increases in urinary BPA concentrations that are no longer detectable in urine samples taken approximately 14 days or 6 months after treatment. After placement of a few restorations, increases in urinary BPA concentrations may not be detectable, owing to a high level of variation in background BPA exposure. Practical ImplicationsThese results suggest that leaching of BPA from newly placed composite restorations ceases to be detectable in urine within 2 weeks after restoration placement. The potential human health impact of such short-term exposure remains uncertain.

Oral administration of bisphenol A induces high blood pressure through angiotensin II/CaMKII-dependent uncoupling of eNOS.

Bisphenol A (BPA) is found in human urine and fat tissue. Higher urinary BPA concentrations are associated with arterial hypertension. To shed light on the underlying mechanism, we orally administered BPA (4 nM to 400 μM in drinking water) to 8-wk-old CD11 mice over 30 d. Mice developed dosage-dependent high blood pressure (systolic 130 ± 12 vs. 170 ± 12 mmHg; EC50 0.4 μM), impairment of acetylcholine (AcH)-induced carotid relaxation (0.66 ± 0.08 vs. 0.44 ± 0.1 mm), a 1.7-fold increase in arterial angiotensin II (AngII), an 8.7-fold increase in eNOS mRNA and protein, and significant eNOS-dependent superoxide and peroxynitrite accumulation. AngII inhibition with 0.5 mg/ml losartan reduced oxidative stress and normalized blood pressure and endothelium-dependent relaxation, which suggests that AngII uncouples eNOS and contributes to the BPA-induced endothelial dysfunction by promoting oxidative and nitrosative stress. Microarray analysis of mouse aortic endothelial cells revealed a 2.5-fold increase in expression of calcium/calmodulin-dependent protein kinase II-α (CaMKII-α) in response to 10 nM BPA, with increased expression of phosphorylated-CaMKII-α in carotid rings of BPA-exposed mice, whereas CaMKII-α inhibition with 100 nM autocamptide-2-related inhibitor peptide (AIP) reduced BPA-mediated increase of superoxide. Administration of CaMKII-α inhibitor KN 93 reduced BPA-induced blood pressure and carotid blood velocity in mice, and reverted BPA-mediated carotid constriction in response to treatment with AcH. Given that CaMKII-α inhibition prevents BPA-mediated high blood pressure, our data suggest that BPA regulates blood pressure by inducing AngII/CaMKII-α uncoupling of eNOS.

Dental sealants and restorations and urinary bisphenol A concentrations in children in the 2003-2004 National Health and Nutrition Examination Survey

Resin-based dental sealants and composites contain bisphenol A-glycidyl methacrylate, a bisphenol A (BPA) derivative. The authors hypothesized that a greater number of sealants or restorations would be associated with higher urinary BPA concentrations. The authors examined urinary BPA measurements (in nanograms per milliliter) and oral examination data for 1,001 children aged 6 to 19 years from data sets of the 2003-2004 National Health and Nutrition Examination Survey (NHANES). They categorized children according to number of occlusal sealants and number of restorations, with four categories in each of the two groups. They estimated associations by using unadjusted and adjusted tobit regression models. The lowest quartile of BPA concentrations ranged from 0.3 ng/mL to 1.9 ng/mL, whereas the highest quartile ranged from 7.3 ng/mL to 149 ng/mL. In adjusted analysis, children with seven to 16 sealants had geometric mean BPA concentrations 25 percent higher than those of children with no sealants (95 percent confidence interval [CI], -14 percent to 82 percent; P = .23). In adjusted analysis, children with seven to 42 restorations had geometric mean BPA concentrations 20 percent higher than those of children with no restorations (95 percent CI, -6 percent to 53 percent; P = .13). Neither of these adjusted estimates was statistically significant. Though the findings were in the direction hypothesized, the authors did not observe a statistically significant association between a greater number of sealants or restorations and higher urinary BPA concentrations. Additional studies are needed to determine the extent of oral and systemic exposure to BPA from resin-based dental restorative materials over time. Dentists should follow this issue carefully as it develops and as the body of evidence grows. There is insufficient evidence to change practice at this time.

Bisphenol A-associated epigenomic changes in prepubescent girls: a cross-sectional study in Gharbiah, Egypt

BackgroundThere is now compelling evidence that epigenetic modifications link adult disease susceptibility to environmental exposures during specific life stages, including pre-pubertal development. Animal studies indicate that bisphenol A (BPA), the monomer used in epoxy resins and polycarbonate plastics, may impact health through epigenetic mechanisms, and epidemiological data associate BPA levels with metabolic disorders, behavior changes, and reproductive effects. Thus, we conducted an environmental epidemiology study of BPA exposure and CpG methylation in pre-adolescent girls from Gharbiah, Egypt hypothesizing that methylation profiles exhibit exposure-dependent trends.MethodsUrinary concentrations of total (free plus conjugated) species of BPA in spot samples were quantified for 60 girls aged 10 to 13. Genome-wide CpG methylation was concurrently measured in bisulfite-converted saliva DNA using the Infinium HumanMethylation27 BeadChip (N = 46). CpG sites from four candidate genes were validated via quantitative bisulfite pyrosequencing.ResultsCpG methylation varied widely among girls, and higher urinary BPA concentrations were generally associated with less genomic methylation. Based on pathway analyses, genes exhibiting reduced methylation with increasing urinary BPA were involved in immune function, transport activity, metabolism, and caspase activity. In particular, hypomethylation of CpG targets on chromosome X was associated with higher urinary BPA. Using the Comparative Toxicogenomics Database, we identified a number of candidate genes in our sample that previously have been associated with BPA-related expression change.ConclusionsThese data indicate that BPA may affect human health through specific epigenomic modification of genes in relevant pathways. Thus, epigenetic epidemiology holds promise for the identification of biomarkers from previous exposures and the development of epigenetic-based diagnostic strategies.

Dietary and sociodemographic determinants of bisphenol A urine concentrations in pregnant women and children

Bisphenol A (BPA) exposure during early life may have endocrine-disrupting effects, but the dietary and sociodemographic predictors of BPA exposure during pregnancy and childhood remain unclear. Our aim was to evaluate the correlations between, and sociodemographic and dietary predictors of, serial urinary BPA concentrations measured during pregnancy and childhood in a Spanish birth cohort study. BPA was measured in two spot urine samples collected from 479 women during the first and third trimester of pregnancy and in one urine sample from their 4-year old children (n=130). Average dietary intakes were reported in food frequency questionnaires during the first and third pregnancy trimester and at age 4years. Multivariate mixed models and linear regression models were used to estimate associations between sociodemographic and dietary factors and BPA concentrations. A small, but statistically significant correlation was found between serial maternal BPA concentrations measured during pregnancy (r=0.17). Pregnant women who were younger, less-educated, smoked, and who were exposed to second-hand tobacco smoke (SHS) had higher BPA concentrations than others. BPA concentrations were also higher in children exposed to SHS. High consumption of canned fish during pregnancy was associated with 21% [GM ratio=1.21; 95%CI 1.02, 1.44] and 25% [GM ratio=1.25; 95%CI 1.05, 1.49] higher urinary BPA concentrations in the first and third pregnancy trimester, respectively, compared to the lowest consumption group. This study suggests that canned fish may be a major source of BPA during pregnancy in Spain, a country of high canned fish consumption. Further evaluation of specific BPA exposure sources in the sociodemographic group of younger women who smoke, are exposed to SHS, and have a low educational level is needed. Studies identifying sources of exposure would benefit from repeat BPA measurements and questionnaires specifically focused on dietary and packaging sources.

Prenatal and postnatal bisphenol A exposure and body mass index in childhood in the CHAMACOS cohort.

Background: Bisphenol A (BPA), a widely used endocrine-disrupting chemical, has been associated with increased body weight and fat deposition in rodents.Objectives: We examined whether prenatal and postnatal urinary BPA concentrations were associated with body mass index (BMI), waist circumference, percent body fat, and obesity in 9-year-old children (n = 311) in the CHAMACOS longitudinal cohort study.Methods: BPA was measured in spot urine samples collected from mothers twice during pregnancy and from children at 5 and 9 years of age.Results: Prenatal urinary BPA concentrations were associated with decreased BMI at 9 years of age in girls but not boys. Among girls, being in the highest tertile of prenatal BPA concentrations was associated with decreased BMI z-score (β = –0.47, 95% CI: –0.87, –0.07) and percent body fat (β = –4.36, 95% CI: –8.37, –0.34) and decreased odds of overweight/obesity [odds ratio (OR) = 0.37, 95% CI: 0.16, 0.91] compared with girls in the lowest tertile. These findings were strongest in prepubertal girls. Urinary BPA concentrations at 5 years of age were not associated with any anthropometric parameters at 5 or 9 years, but BPA concentrations at 9 years were positively associated with BMI, waist circumference, fat mass, and overweight/obesity at 9 years in boys and girls.Conclusions: Consistent with other cross-sectional studies, higher urinary BPA concentrations at 9 years of age were associated with increased adiposity at 9 years. However, increasing BPA concentrations in mothers during pregnancy were associated with decreased BMI, body fat, and overweight/obesity among their daughters at 9 years of age.

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

The endocrine-disrupting chemical bisphenol A (BPA) is widely used in food and beverage packaging. Higher urinary BPA concentrations were cross-sectionally associated with heart disease in National Health and Nutrition Examination Survey (NHANES) 2003-2004 and NHANES 2005-2006, independent of traditional risk factors. We included 758 incident coronary artery disease (CAD) cases and 861 controls followed for 10.8 years from the European Prospective Investigation of Cancer-Norfolk UK. Respondents aged 40 to 74 years and free of CAD, stroke, or diabetes mellitus provided baseline spot urine samples. Urinary BPA concentrations (median value, 1.3 ng/mL) were low. Per-SD (4.56 ng/mL) increases in urinary BPA concentration were associated with incident CAD in age-, sex-, and urinary creatinine-adjusted models (n=1919; odds ratio=1.13; 95% confidence interval, 1.02-1.24; P=0.017). With CAD risk factor adjustment (including education, occupational social class, body mass index category, systolic blood pressure, lipid concentrations, and exercise), the estimate was similar but narrowly missed 2-sided significance (n=1744; odds ratio=1.11; 95% confidence interval, 1.00-1.23; P=0.058). Sensitivity analyses with the fully adjusted model, excluding those with early CAD (<3-year follow-up), body mass index >30, or abnormal renal function or with additional adjustment for vitamin C, C-reactive protein, or alcohol consumption, all produced similar estimates, and all showed associations at P≤0.05. Associations between higher BPA exposure (reflected in higher urinary concentrations) and incident CAD during >10 years of follow-up showed trends similar to previously reported cross-sectional findings in the more highly exposed NHANES respondents. Further work is needed to accurately estimate the prospective exposure-response curve and to establish the underlying mechanisms.