Prenatal and peripubertal phthalates and bisphenol A in relation to sex hormones and puberty in boys

Histopathologic, apoptotic and autophagic, effects of prenatal bisphenol A and/or di(2-ethylhexyl) phthalate exposure on prepubertal rat testis

Bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP) are endocrine-disrupting chemicals (EDCs) used in a wide variety of industrial products as plasticizers. Exposure to EDCs, particularly in mixtures, in prenatal and early postnatal periods may lead to unwanted effects and can cause both developmental and reproductive problems. In this study, we aimed to determine the individual and combined effects of prenatal and lactational exposure to BPA and/or DEHP on testicular histology, apoptosis, and autophagic proteins. Pregnant Sprague-Dawley rats (n = 3) were divided into four groups (control, BPA (50 mg/kg/day), DEHP (30 mg/kg/day), and BPA (50 mg/kg/day) + DEHP (30 mg/kg/day)) and dosed by oral gavage during pregnancy and lactation. The male offspring (n = 6) from each group were chosen randomly, and their testicular examinations were performed on the twelfth week. The results showed that fetal and neonatal exposure to BPA and DEHP could lead to significant testicular histopathological alterations and cause increases in apoptosis markers (as evidenced by increases in caspase 3 and caspase 8 levels; increased TUNEL-positive spermatogonia and TUNEL-positive testicular apoptotic cells) and autophagic proteins (as evidenced by increased LC3 and Beclin levels and decreased p62 levels) in testicular tissue. We can suggest that EDCs cause more dramatic changes in both testicular structure and cell death when there is combined exposure.

Association of phthalate exposure with precocious and delayed pubertal timing in girls and boys: a systematic review and meta-analysis

Exposure to phthalate derivatives has adverse effects on the health and development of humans, especially for children. A growing body of evidence supports the idea that exposure to phthalates can change an individual's physiological set point and the time of puberty in both genders. In this systematic review and meta-analysis, recent studies were evaluated to obtain systematic and regulation results in relation to puberty status and phthalate exposure in girls and boys. We searched English-language papers using Scopus, ISI, and PubMed databases as search engines, with no restriction of time, until the end of July 2019. A comprehensive literature search for an association between phthalate exposure and signs of puberty as well as levels of different types of hormones was carefully performed. Of the 67 studies retained for full-text screening, 39 studies were eligible for data management and extraction. For conducting a meta-analysis, four studies had appropriate effect size and metrics for pooling in the meta-analysis. Our findings revealed that low and high exposure to phthalates could alter pubertal development in both genders; the effects were either early or delayed puberty such as changes in the pubarche, thelarche, and menarche time, as well as in testicular volume. We statistically analyzed the association of pubic-hair development, breast development, and menarche time with exposure to phthalates in girls. For example, the pooled odds ratios of mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) in relation to breast development were (OR: 1.48, 95% CI: 1.11-1.85) and (OR: 1.52, 95% CI: 1.15-1.58) (P-value < 0.001), respectively. In addition, we analyzed the correlation between pubic-hair development and testicular volume with exposure to phthalates in boys. To the best of our knowledge, this is the first systematic review and meta-analysis of its kind for girls and boys. In conclusion, we found that a positive association exists between phthalate exposure and pubertal timing in the pediatric age group. Therefore, prevention of exposure to phthalates and reduction of their use should be underscored in the strategies for primordial prevention of pubertal timing and related consequences.

How to Educate Pregnant Women about Endocrine Disruptors?

Background: Despite mediatization, only half of pregnant women are informed about endocrine disruptors (EDs). We wished to inquire about appropriate environmental health education procedures during pregnancy: Who, when, and how? Methods: The question stems from a comprehensive population health intervention research project. It includes qualitative studies aimed at constructing an educational program in environmental health and an accompanying assessment tool. The validation of a customized questionnaire (PREVED^© for Pregnancy Prevention Endocrine Disruptors) about the knowledge, attitudes, and practices (KAP) of pregnant women regarding exposure to EDs was carried out in a quantitative study. Results: Health education by a prenatal professional with communication skills should take place as early as possible, during the preconception period or early pregnancy, as part of individual consultation or group workshops. In order to customize the discourse and to develop women’s empowerment, concomitant presentation of the risks by the products used in each room and of previous solutions is recommended. Conclusion: Appropriate health education procedures on EDs should be done at every contact but taking the KAP of pregnant women into account first. We propose all educational actions should be accompanied by questioning of the KAP of pregnant women; for example, with questions from the PREVED^© questionnaire.

Onset and tempo of sexual maturation is differentially associated with gestational phthalate exposure between boys and girls in a Mexico City birth cohort

Phthalates are endocrine disrupting compounds commonly found in consumer products, exposure to which may influence reproductive maturation. Effects from exposure in utero on the onset and progression of sexual development are understudied. We examined longitudinal associations between gestational phthalate exposure and sexual maturation at two points in adolescence (8-14, 9-18 years). Gestational exposure was quantified using the geometric mean of 3 trimester-specific urinary phthalate metabolite measurements. Sexual maturation was assessed using Tanner stages and menarche onset for girls and Tanner stages and testicular volume for boys. Generalized estimating equations for correlated ordinal multinomial responses were used to model relationships between phthalates and odds of transitioning to the next Tanner stage, while generalized additive (GA) mixed models were used to assess the odds of menarche. All models were adjusted for child age (centered around the mean), BMI z-score, change in BMI between visits, time (years) between visits (ΔT), and interactions between ΔT and mean-centered child age and the natural log of exposure metabolite concentration. Among girls, a doubling of gestational MBzP concentrations was associated with increased odds of being at a higher Tanner stage for breast development at 8-14 years (OR = 4.62; 95% CI: 1.38, 15.5), but with slower progression of breast development over the follow-up period (OR = 0.65 per year; 95% CI: 0.46, 0.92) after adjustment for child age and BMI z-score. Similar results were found for ∑DEHP levels and breast development. In boys, a doubling of gestational MBP concentrations was associated with lower odds of being at a higher Tanner stage for pubic hair growth at 8-14 years (OR = 0.37; 95% CI: 0.14, 0.95) but with faster progression (OR: 1.28; 95% CI: 0.97, 1.69). These results indicate that gestational phthalate exposures may impact the onset and progression of sexual development, and that these relationships differ between boys and girls.

Association of prenatal exposure to phenols and parabens with birth size: A systematic review and meta-analysis

Phenols and parabens are endocrine-disrupting chemicals and are widely used in daily life products due to their antibacterial action. Previous studies suggest associations of prenatal exposure to phenols and parabens with fetal development; however, such findings are rare and inconsistent. The aim of this review and meta-analysis is to estimate the associations between maternal exposure to phenols and parabens and birth size. We identified 21 relevant studies that met the inclusion criteria through databases of PubMed, Cochrane, EMBASE and Qvid Medline. The last search was in July 3, 2019. The heterogeneity and possibility of publication bias among included studies were assessed by Q-statistic and Begg's test, respectively. Meta-analysis revealed that prenatal exposure to triclosan [number of studies (n) = 12, regression coefficient (β) = -0.04 g; 95% confidence interval (CI): -0.139, 0.059], benzophenone-3 (n = 10, β = -0.001 g; 95% CI: -0.013, 0.012), bisphenol A (n = 9, β = -0.049 g; 95% CI: -0.199, 0.101), 2-4-dichlorophenols (n = 6, β = -14.124 g; 95% CI: -29.971, 1.723), 2-5-dichlorophenols (n = 6, β = -0.061 g; 95% CI: -0.196, 0.074) and parabens were negatively associated with fetal birth weight. Most of them were insignificant. Inconsistent and insignificant associations were detected between exposure to phenols and parabens and other birth outcomes. Subgroup analysis suggested that heterogeneity in our meta-analysis was mainly attributed to the studies conducted in developed countries and samples collected in the second trimester. Insignificant and controversial associations of maternal exposure to phenols and parabens with birth size were observed in our study. The study design and methods of the included studies are inconsistent, and the effects of environmental pollutants on human health are complex. Further cohort studies with large samples and a consistent approach are thus required to evaluate the associations of maternal exposure to phenols and parabens with birth size.

The Impact of Prenatal Exposure to Bisphenol A on Male Reproductive Function

Bisphenol A (BPA) is a recognized xenoestrogen, in that it possesses oestrogenic and anti-androgenic properties. These endocrine-disrupting effects of BPA at the estrogen receptor (ER) occur despite the very low affinity of BPA for the ERβ, which is 10,000 times lower than that of 17-β estradiol, and despite the European regulatory authorities stating that BPA is safe, at usual exposure concentrations, the use of BPA in baby drink bottles was banned in 2011. There exists conflicting evidence from human epidemiological studies as to its influence on adult male reproductive function, although animal data is more convincing. This mini-review will report on the limited epidemiological data from human studies relating early life exposure to BPA on adult male reproductive function. A long term follow-up study from Western Australia using a birth cohort, the Raine Study, demonstrated no adverse associations of antenatal exposure to BPA, and potentially a positive association with antenatal BPA exposure with sperm concentration and motility at 20 years of age, although recent scientific reports suggest traditional measures of BPA exposure may underestimate exposure levels, which makes data interpretation potentially flawed.

Effects of Bisphenols on Testicular Steroidogenesis

Over the last decades, the adverse effects of human exposure to the so-called "endocrine disruptors" have been a matter of scientific debate and public attention. Bisphenols are synthetic chemicals, widely used in the manufacture of hard plastic products. Bisphenol A (BPA) is one of the best-known environmental toxicants proven to alter the reproductive function in men and to cause other health problems. Consumer concern resulted in "BPA free" products and in the development of bisphenol analogs (BPA-A) to replace BPA in many applications. However, these other bisphenol derivatives seem to have effects similar to those of BPA. Although a number of reviews have summarized the effects of BPA on human reproduction, the purpose of this article is to review the effects of bisphenols on testicular steroidogenesis and to explore their mechanisms of action. Testicular steroidogenesis is a fine-regulated process, and its main product, testosterone (T), has a crucial role in fetal development and maturation and in adulthood for the maintenance of secondary sexual function and spermatogenesis. Contradictory outcomes of both human and animal studies on the effects of BPA on steroid hormone levels may be related to various factors that include study design, dosage of BPA used in in vitro studies, timing and route of exposure, and other confounding factors. We described the main possible molecular target of bisphenols on this complex pathway. We report that Leydig cells (LCs), the steroidogenic testicular component, are highly sensitive to BPA and several mechanisms concur to the functional impairment of these cells.

Sources of clinically significant neonatal intensive care unit phthalate exposure

In the United States each year, more than 300,000 infants are admitted to neonatal intensive care units (NICU) where they are exposed to a chemical-intensive hospital environment during a developmentally vulnerable period. Although multiple studies have demonstrated elevated phthalate biomarkers in NICU patients, specific sources of NICU-based phthalate exposure have not been identified.In this study, premature newborns with birth weight <1500 g were recruited to participate in a prospective environmental health cohort during the NICU hospitalization. Exposure to specific NICU equipment was recorded daily during the NICU hospitalization. One hundred forty-nine urine specimens from 71 infants were analyzed for phthalate metabolites using high-performance liquid chromatography/tandem mass spectrometry.In initial analyses, exposure to medical equipment was directly related to phthalate levels, with DEHP biomarkers 95-132% higher for infants exposed to specific medical equipment types compared to those without that equipment exposure (p < 0.001-0.023). This association was mirrored for clinically relevant phthalate mixtures whether composed of DEHP metabolites or not (p = 0.002-0.007). In models accounting for concurrent equipment use, exposure to respiratory support was associated with DEHP biomarkers 50-136% higher in exposed compared to unexposed infants (p = 0.007-0.036). Phthalate mixtures clinically relevant to neurobehavioral development were significantly associated with non-invasive respiratory support (p = 0.008-0.026). Feeding supplies and intravenous lines were not significantly associated with clinically important phthalate mixtures.Respiratory support equipment may be a significant and clinically relevant NICU source of phthalate exposure. Although manufacturers have altered feeding and intravenous supplies to reduce DEHP exposure, other sources of exposure to common and clinically impactful phthalates persist in the NICU.

Update of the risk assessment of di-butylphthalate (DBP), butyl-benzyl-phthalate (BBP), bis(2-ethylhexyl)phthalate (DEHP), di-isononylphthalate (DINP) and di-isodecylphthalate (DIDP) for use in food contact materials

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP Panel) was asked by the European Commission to update its 2005 risk assessments of di-butylphthalate (DBP), butyl-benzyl-phthalate (BBP), bis(2-ethylhexyl)phthalate (DEHP), di-isononylphthalate (DINP) and di-isodecylphthalate (DIDP), which are authorised for use in plastic food contact material (FCM). Dietary exposure estimates (mean and high (P95)) were obtained by combining literature occurrence data with consumption data from the EFSA Comprehensive Database. The highest exposure was found for DINP, ranging from 0.2 to 4.3 and from 0.4 to 7.0 μg/kg body weight (bw) per day for mean and high consumers, respectively. There was not enough information to draw conclusions on how much migration from plastic FCM contributes to dietary exposure to phthalates. The review of the toxicological data focused mainly on reproductive effects. The CEP Panel derived the same critical effects and individual tolerable daily intakes (TDIs) (mg/kg bw per day) as in 2005 for all the phthalates, i.e. reproductive effects for DBP (0.01), BBP (0.5), DEHP (0.05), and liver effects for DINP and DIDP (0.15 each). Based on a plausible common mechanism (i.e. reduction in fetal testosterone) underlying the reproductive effects of DEHP, DBP and BBP, the Panel considered it appropriate to establish a group-TDI for these phthalates, taking DEHP as index compound as a basis for introducing relative potency factors. The Panel noted that DINP also affected fetal testosterone levels at doses around threefold higher than liver effects and therefore considered it conservative to include it within the group-TDI which was established to be 50 μg/kg bw per day, expressed as DEHP equivalents. The aggregated dietary exposure for DBP, BBP, DEHP and DINP was estimated to be 0.9-7.2 and 1.6-11.7 μg/kg bw per day for mean and high consumers, respectively, thus contributing up to 23% of the group-TDI in the worst-case scenario. For DIDP, not included in the group-TDI, dietary exposure was estimated to be always below 0.1 μg/kg bw per day and therefore far below the TDI of 150 μg/kg bw per day. This assessment covers European consumers of any age, including the most sensitive groups. Based on the limited scope of the mandate and the uncertainties identified, the Panel considered that the current assessment of the five phthalates, individually and collectively, should be on a temporary basis.

The adverse health effects of bisphenol A and related toxicity mechanisms

Bisphenol A (BPA) is an industrial component commonly used in synthesis of polycarbonate plastics, epoxy resin and other polymer materials. Due to its mass productions and widespread applications, the presence of BPA is ubiquitous in the environment. BPA can enter the body via different ways such as digestive tract, respiratory tract and dermal tract. As an endocrine disruptor, BPA has estrogen-like and anti-androgen effects causing damages to different tissues and organs, including reproductive system, immune system and neuroendocrine system, etc. Recently, it has been shown that BPA could induce carcinogenesis and mutagenesis in animal models. Here, the underlying mechanisms of BPA-induced multi-organ toxicity were well summarized, involving the receptor pathways, disruption of neuroendocrine system, inhibition of enzymes, modulation of immune and inflammatory responses, as well as genotoxic and epigenetic mechanisms. The aim of this review is to compile the available current research data regarding BPA and provide an overview of the current status of BPA exposure and relevant health effects covering reproductive, developmental, metabolic, immuno, respiratory, hepatic and renal toxicity and carcinogenesis of BPA. This review provides comprehensive data of BPA toxicity on human health and related mechanisms. We also identify any missing data which should be addressed by further studies.

Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) Project

PURPOSE

The Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) Project is a mother-child pregnancy and birth cohort originally initiated in the mid-1990s to explore: (1) whether enhanced mobilisation of lead from maternal bone stores during pregnancy poses a risk to fetal and subsequent offspring neurodevelopment; and (2) whether maternal calcium supplementation during pregnancy and lactation can suppress bone lead mobilisation and mitigate the adverse effects of lead exposure on offspring health and development. Through utilisation of carefully archived biospecimens to measure other prenatal exposures, banking of DNA and rigorous measurement of a diverse array of outcomes, ELEMENT has since evolved into a major resource for research on early life exposures and developmental outcomes.

PARTICIPANTS

n=1643 mother-child pairs sequentially recruited (between 1994 and 2003) during pregnancy or at delivery from maternity hospitals in Mexico City, Mexico.

FINDINGS TO DATE

Maternal bone (eg, patella, tibia) is an endogenous source for fetal lead exposure due to mobilisation of stored lead into circulation during pregnancy and lactation, leading to increased risk of miscarriage, low birth weight and smaller head circumference, and transfer of lead into breastmilk. Daily supplementation with 1200 mg of elemental calcium during pregnancy and lactation reduces lead resorption from maternal bone and thereby, levels of circulating lead. Beyond perinatal outcomes, early life exposure to lead is associated with neurocognitive deficits, behavioural disorders, higher blood pressure and lower weight in offspring during childhood. Some of these relationships were modified by dietary factors; genetic polymorphisms specific for iron, folate and lipid metabolism; and timing of exposure. Research has also expanded to include findings published on other toxicants such as those associated with personal care products and plastics (eg, phthalates, bisphenol A), other metals (eg, mercury, manganese, cadmium), pesticides (organophosphates) and fluoride; other biomarkers (eg, toxicant levels in plasma, hair and teeth); other outcomes (eg, sexual maturation, metabolic syndrome, dental caries); and identification of novel mechanisms via epigenetic and metabolomics profiling.

FUTURE PLANS

As the ELEMENT mothers and children age, we plan to (1) continue studying the long-term consequences of toxicant exposure during the perinatal period on adolescent and young adult outcomes as well as outcomes related to the original ELEMENT mothers, such as their metabolic and bone health during perimenopause; and (2) follow the third generation of participants (children of the children) to study intergenerational effects of in utero exposures.

TRIAL REGISTRATION NUMBER

NCT00558623.

First trimester maternal exposures to endocrine disrupting chemicals and metals and fetal size in the Michigan Mother-Infant Pairs study

Exposures to endocrine disrupting chemicals and metals are near ubiquitous worldwide, and their potential impact on children is a major public health concern. This pilot study was designed to characterize exposures to phthalates, phenols and metals among pregnant women in the first trimester, and to examine associations with fetal biometrics and birth weight. A total of 41 chemicals and elements were analyzed in urine from 56 mothers with full-term newborns from the Michigan Mother-Infant Pairs study. Bivariate analyses identified predictors of exposure biomarkers. Associations between birth weight, Fenton z-scores and second trimester fetal biometrics with toxicants were examined via multivariable linear regression. An average of 30 toxicants were detected in maternal urine. Fast food consumption was associated with several phthalate metabolites, phenols and metals, and canned food consumption with bisphenol F (P <0.05). Mono (3-carboxypropyl) phthalate was significantly associated with higher birth weight and Fenton z-score while the opposite was observed for bisphenol S. Estimated femur length from ultrasonography was significantly inversely associated with arsenic, barium and lead. While limited by sample size, this study is one of the first to evaluate birth outcomes with respect to emerging endocrine disrupting chemicals and to examine associations between toxicants and fetal biometrics. Exposure assessment was provided by the National Institute of Environmental Health Sciences' Children's Health Exposure Analysis Resource (NIEHS CHEAR), a resource available to children's studies with the goal of combining data across cohorts in an effort to characterize the impact of toxicants on child health from birth and beyond.

Exposure to an environmentally relevant phthalate mixture during prostate development induces microRNA upregulation and transcriptome modulation in rats

Environmental exposure to phthalates during intrauterine development might increase susceptibility to neoplasms in reproductive organs such as the prostate. Although studies have suggested an increase in prostatic lesions in adult animals submitted to perinatal exposure to phthalates, the molecular pathways underlying these alterations remain unclear. Genome-wide levels of mRNAs and miRNAs were monitored with RNA-seq to determine if perinatal exposure to a phthalate mixture in pregnant rats is capable of modifying gene expression expression during prostate development of the filial generation. The mixture contains diethyl-phthalate, di-(2-ethylhexyl)-phthalate, dibutyl-phthalate, di-isononyl-phthalate, di-isobutyl-phthalate, and benzylbutyl-phthalate. Pregnant females were divided into 4 groups and orally dosed daily from GD10 to PND21 with corn oil (Control:C) or the phthalate mixture at three doses (20 μg/kg/d:T1; 200 μg/kg/d:T2; 200 mg/kg/d:T3). The phthalate mixture decreased anogenital distance, prostate weight and decreased testosterone level at the lowest exposure dose at PND22. The mixture also increased inflammatory foci and focal hyperplasia incidence at PND120. miR-184 was upregulated in all treated groups in relation to control and miR-141-3p was only upregulated at the lowest dose. In addition, 120 genes were deregulated at the lowest dose with several of these genes related to developmental, differentiation and oncogenesis. The data indicate that phthalate exposure at lower doses can cause greater gene expression modulation as well as other downstream phenotypes than exposure at higher doses. A significant fraction of the downregulated genes were predicted to be targets of miR-141-3p and miR-184, both of which were induced at the lower exposure doses.

Prenatal bisphenol a and phthalate exposure are risk factors for male reproductive system development and cord blood sex hormone levels

Bisphenol A (BPA) and phthalates can adversely affect the fetal development. However, observational studies on the effects of these chemicals on fetal male reproductive system are still limited. A hundred of umbilical cord blood samples were analyzed for the levels of BPA, di-2-ethylhexyl phthalate (DEHP), mono-2-ethylhexyl phthalate (MEHP), and sex hormones. After birth, male newborns underwent physical examination that included measurements of anogenital distance, stretched penile length (SPL), and penile width. BPA, DEHP and MEHP levels were detectable in ≈99% of cord blood samples. In covariate-adjusted models, cord blood BPA levels were inversely associated with SPL of newborns and positively associated with cord blood estradiol levels. In addition, there was a significant inverse relationship between cord blood DEHP levels and anogenital distance index of newborn males. Our results suggest that in utero BPA and DEHP exposure exerted adverse effects on fetal male reproductive development and cord blood estradiol levels.

Interaction between diet- and exercise-lifestyle and phthalates exposure on sex hormone levels

Phthalate can affect sex hormones secretion. Exercise and diet habits affect sex hormones levels. However, interaction of phthalates exposure and diet or exercise habits with sex hormones is unclear. We enrolled 106 residents aged 11-88 years (48 males and 58 females) from two communities, Wuhan city, China during the winter of 2014 and summer of 2015. Data were collected on socio-demographic characteristics and lifestyle by a questionnaire in two seasons. Participants provided the blood and urine samples over 3 consecutive days for measuring sex hormones and urinary phthalate metabolites. We assessed the associations of urinary phthalate metabolites levels, lifestyle with hormones levels, the interaction of phthalate exposure and lifestyle with hormones levels using multivariate binary logistic regression models. High urinary mono-(2-ethyl-5-oxyhexyl) phthalate (MEOHP) levels and no exercise had an additive interaction on abnormal serum progesterone (PROG) levels in winter as well as on abnormal serum follicle-stimulating hormone (FSH) or luteinizing hormone (LH) levels in summer. High urinary MEOHP levels and red meat intake (>1 time/day) had an additive interaction with abnormal levels of serum FSH only in the winter. Phthalates exposure may confer differential susceptibility to abnormal hormones levels in individuals with no exercise or eating meat >1 time/day.

A repeated measures study of phenol, paraben and Triclocarban urinary biomarkers and circulating maternal hormones during gestation in the Puerto Rico PROTECT cohort

INTRODUCTION

Prenatal exposure to some phenols and parabens has been associated with adverse birth outcomes. Hormones may play an intermediate role between phenols and adverse outcomes. We examined the associations of phenol and paraben exposures with maternal reproductive and thyroid hormones in 602 pregnant women in Puerto Rico. Urinary triclocarban, phenol and paraben biomarkers, and serum hormones (estriol, progesterone, testosterone, sex-hormone-binding globulin (SHBG), corticotropin-releasing hormone (CRH), total triiodothyronine (T3), total thyroxine (T4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH)) were measured at two visits during pregnancy.

METHODS

Linear mixed models with a random intercept were constructed to examine the associations between hormones and urinary biomarkers. Results were additionally stratified by study visit. Results were transformed to hormone percent changes for an inter-quartile-range difference in exposure biomarker concentrations (%Δ).

RESULTS

Bisphenol-S was associated with a decrease in CRH [(%Δ -11.35; 95% CI: -18.71, - 3.33), and bisphenol-F was associated with an increase in FT4 (%Δ: 2.76; 95% CI: 0.29, 5.22). Butyl-, methyl- and propylparaben were associated with decreases in SHBG [(%Δ: -5.27; 95% CI: -9.4, - 1.14); (%Δ: -3.53; 95% CI: -7.37, 0.31); (%Δ: -3.74; 95% CI: -7.76, 0.27)]. Triclocarban was positively associated with T3 (%Δ: 4.08; 95% CI: 1.18, 6.98) and T3/T4 ratio (%Δ: 4.67; 95% CI: -1.37, 6.65), and suggestively negatively associated with TSH (%Δ: -10.12; 95% CI: -19.47, 0.32). There was evidence of susceptible windows of vulnerability for some associations. At 24-28 weeks gestation, there was a positive association between 2,4-dichlorophenol and CRH (%Δ: 9.66; 95% CI: 0.67, 19.45) and between triclosan and estriol (%Δ: 13.17; 95% CI: 2.34, 25.2); and a negative association between triclocarban and SHBG (%Δ: -9.71; 95% CI:-19.1, - 0.27) and between bisphenol A and testosterone (%Δ: -17.37; 95% CI: -26.7, - 6.87).

CONCLUSION

Phenols and parabens are associated with hormone levels during pregnancy. Further studies are required to substantiate these findings.

Maternal exposure to bisphenol A and anogenital distance throughout infancy: A longitudinal study from Shanghai, China

BACKGROUND

Bisphenol A (BPA) is one of the most common endocrine-disrupting compounds (EDCs) with a ubiquitous presence. Both animal and human studies have reported the association between maternal exposure to BPA and anogenital distance (AGD) in offspring. However, the results are conflicting and the longitudinal effect is unknown. We aimed to examine the effect of maternal exposure to BPA on AGD in offspring in a longitudinal birth cohort from birth to 1 year of age.

METHODS

BPA was assayed using urine samples collected at 12-16 gestational weeks from 982 pregnant participants who later delivered infants. Infants' AGDs (AGDap [anus-penis] and AGDas [anus-scrotum] for boys, AGDac [anus-clitoris] and AGDaf [anus-fourchette] for girls) were measured at birth, and at 6 and 12 months of age. Multiple linear regression analysis was conducted to examine the associations between maternal exposure to BPA and offspring's AGDs. Then generalized estimating equation (GEE) model was applied to make use of the repeated measurements of AGDs and examine the overall effect of maternal exposure to BPA.

RESULTS

Compared to boys with undetected maternal BPA, those with detected BPA were more likely to have shorter AGDap and AGDas at 6 and 12 months. However, the differences were statistically significant for AGDap and AGDas only at 12 months (2.87 and 4.12 mm shorter, respectively). In GEE models, similar patterns were observed. Boys in the higher quartiles were more likely to have shorter AGDap and AGDas than those in the first quartile. However, statistically significant differences were only observed in boys in the third quartile. For girls, these associations were not observed regardless of the timing of measurements (at birth, 6 months and 12 months).

CONCLUSIONS

Maternal exposure to BPA was associated with shortened AGDap and AGDas in boys at age 12 months but not in girls, which suggests a gender specific effect of BPA exposure on offspring's development.

Phthalate Metabolites in Maternal and Cord Plasma and Their Relations to Other Selected Endocrine Disruptors and Steroids

Endocrine disruptors (EDs) are known to have harmful effects on the human endocrine system; special effort is actually given to the exposure during pregnancy. Humans are usually exposed to a mixture of EDs, which may potentiate or antagonize each other, and the combined effect may be difficult to estimate. The main phthalate monoesters monoethyl-, mono-n-butyl-, monoisobutyl-, monobenzyl-, mono-(2-ethylhexyl)-, mono-(2-ethyl-5-hydroxyhexyl)- and mono-(2-ethyl-5-oxohexyl) phthalate were determined in 18 maternal (37th week of pregnancy) and cord plasma samples using liquid chromatography-tandem mass spectrometry. Previously determined levels of selected bisphenols, parabens and steroids were also considered in this study. In cord blood, there were significantly higher mono-n-butyl phthalate levels than in maternal blood (p=0.043). The results of multiple regression models showed that maternal plasma phthalates were negatively associated with cord plasma androstenedione, testosterone and dehydroepiandrosterone and positively associated with estradiol and estriol. For estriol, a cumulative association was also observed for Σbisphenols. To the best of our knowledge, this is the first pilot study evaluating the effect of prenatal exposure by multiple EDs on newborn steroidogenesis. Our results confirmed phthalate accumulation in the fetal area and disruption of fetal steroidogenesis. This preliminary study highlights the negative impacts of in utero EDs exposure on fetal steroidogenesis.

Determinants of Risk Perception Related to Exposure to Endocrine Disruptors during Pregnancy: A Qualitative and Quantitative Study on French Women

Endocrine disruptors (EDCs) are known as environmental exposure factors. However, they are rarely reported by health professionals in clinical practice, particularly during pregnancy, even though they are associated with many deleterious consequences. The objectives of this study were to estimate the risk perception of pregnant women related to EDC exposure and to evaluate its determinants. A qualitative study based on the Health Belief Model was carried out through interviews of pregnant women and focus group with perinatal, environmental health and prevention professionals in 2015 in the city of Poitiers, France. Then, determinants of risk perception were included in a questionnaire administered to 300 women in the perinatal period through a quantitative study. Scores were subsequently calculated. Perception of EDC risk was defined as perceived severity for different stages of the infant’s development and perceived susceptibility to EDC exposure. The determinants reported in the qualitative study were: age, strong maternal figure, socio-professional category, level of knowledge, and involuntariness of exposure. Age and level of knowledge were confirmed in our statistical model as determinants. Mean score of EDC risk perception was 55.0 ± 18.3 on 100 points. Our study should guide healthcare providers when advising pregnant women about EDC and environmental exposure. Our score for perceived EDC risk and assessment of its known determinants may help to assess the impact and the relevance of prevention programs dedicated to reducing exposure to EDC during pregnancy.

Sex Differences in Telomere Length Are Not Mediated by Sex Steroid Hormones or Body Size in Early Adolescence

Telomere length is a biomarker of cell aging that is hypothesized to contribute to women’s greater longevity. Although most previous studies have found no sex difference in telomere length at birth, it is well established that females have longer average telomere length than males during adulthood. Proposed biological mechanisms underlying sex differences in adult telomere length include differences in sex steroid hormones and body size, which emerge during the pubertal transition. The purpose of this study was to examine the total effect of sex on telomere length during early adolescence and to examine estradiol, total testosterone, and body surface area (BSA; a measure of body size) as potential mediators of sex differences in telomere length. Data were from a population-based sample of 126 female and 109 male Hispanic adolescents aged 8 to 14 years from the Early Life Exposures in Mexico to ENvironmental Toxicants (ELEMENT) study. Relative telomere length (T/S ratio) was measured by the quantitative polymerase chain reaction method; sex steroid hormones were measured using an automated chemiluminescent immunoassay, and BSA was calculated using measured height and weight. Adjusting for age and pubertal status, we found that girls had significantly longer telomeres than boys (β = .13; P < .01), but there were no significant indirect effects of sex on telomere length through any of the proposed mediators. We conclude that sex differences in telomere length are evident during early adolescence but are not explained by cross-sectional differences in sex steroid hormones or body size.

Association of Prenatal Urinary Concentrations of Phthalates and Bisphenol A and Pubertal Timing in Boys and Girls

BACKGROUND

Animal studies suggest that phthalates and bisphenol A (BPA), endocrine-disrupting chemicals found in many consumer products, may impact the timing of puberty.

OBJECTIVES

We aimed to determine the association of prenatal exposure to high-molecular-weight phthalates and BPA with pubertal timing in boys and girls participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) longitudinal cohort study.

METHODS

We quantified urinary concentrations of eight phthalate metabolites and BPA at two time points during pregnancy among participating mothers ([Formula: see text]) and conducted clinical Tanner staging of puberty on their children every 9 months between 9 and 13 y of age. We conducted accelerated failure time models and examined the role of child overweight/obese status in this association.

RESULTS

The sum of urinary metabolites of di(2-ethylhexyl) phthalate [Formula: see text], monobenzyl phthalate (MBzP), and BPA were associated with later onset of at least one of the three outcomes assessed in girls (thelarche, pubarche, or menarche) and with earlier onset of at least one of the two outcomes assessed in boys (gondarche and pubarche). We found that monocarboxynonyl phthalate, monocarboxyoctyl phthalate, mono(3-carboxypropyl) phthalate, and BPA were associated with later pubarche and menarche mostly among normal-weight girls but not overweight/obese girls. MBzP was associated with later thelarche in all girls, and [Formula: see text] was associated with later thelarche and menarche in all girls. BPA and all phthalate biomarkers were associated with earlier gonadarche and pubarche in all boys as well as in overweight/obese boys when stratified by weight. Among normal-weight boys, associations with BPA were also inverse, whereas associations with phthalate metabolites were close to the null or positive.

CONCLUSIONS

Several high-molecular-weight phthalates and BPA were associated with later puberty in girls and earlier puberty in boys included in the CHAMACOS cohort study. Childhood overweight/obesity may modify these associations. https://doi.org/10.1289/EHP3424.

Anogenital distance and reproductive outcomes in 9- to 11-year-old boys: the INMA-Granada cohort study

BACKGROUND

Studies examining the association of anogenital distance (AGD), a biomarker of prenatal androgen exposure, with sexual development in children are lacking.

OBJECTIVE

To assess the association between AGD measures and reproductive outcomes, including puberty onset, testicular volume, reproductive hormone levels, and urogenital malformations in boys aged 9-11 years.

MATERIALS AND METHODS

A cross-sectional study was conducted among children belonging to the Spanish Environment and Childhood (INMA) Project, a population-based birth cohort study. The present sample included 279 boys for whom data were available on AGD, pubertal stage, testicular volume, and relevant covariates. Out of the boys with AGD data, 187 provided a blood sample for hormone analysis. AGD was measured from the center of the anus to the base of the scrotum. Pubertal development was assessed according to Tanner stage of genital development (G1-G5), and testicular volume was measured with an orchidometer.

RESULTS

After adjusting for potential confounders, logistic regression analysis showed that AGD was positively associated with testicular volume but not with Tanner stage (>G1 vs. G1), serum hormone levels, or undescended testis. Regardless of their age, body mass index, and Tanner stage (G1 or >G1), boys with longer AGD showed increased odds of a testicular volume >3 mL (OR = 1.06, 95%CI = 1.00-1.19 per 10% increment in AGD; and OR = 3.14, 95%CI = 0.99-9.94 for AGD >42 mm vs. <33 mm).

DISCUSSION

Longer AGD was associated with testicular growth, an indicator of gonadarche, but not with other reproductive outcomes.

CONCLUSIONS

Although AGD was positively associated with testicular volume, it remains unclear whether AGD predicts testis size at puberty or is related to puberty onset.

Effects of bisphenol A and its analogs on reproductive health: A mini review

Known endocrine disruptor bisphenol A (BPA) has been shown to be a reproductive toxicant in animal models. Its structural analogs: bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA) are increasingly being used in consumer products. However, these analogs may exert similar adverse effects on the reproductive system, and their toxicological data are still limited. This mini-review examined studies on both BPA and BPA analog exposure and reproductive toxicity. It outlines the current state of knowledge on human exposure, toxicokinetics, endocrine activities, and reproductive toxicities of BPA and its analogs. BPA analogs showed similar endocrine potencies when compared to BPA, and emerging data suggest they may pose threats as reproductive hazards in animal models. While evidence based on epidemiological studies is still weak, we have utilized current studies to highlight knowledge gaps and research needs for future risk assessments.

Bisphenol A and reproductive hormones and cortisol in peripubertal boys: The INMA-Granada cohort

INTRODUCTION

Bisphenol A (BPA) is a well-known endocrine disrupting compound. Although several studies have investigated the effect of BPA exposure and reproductive hormones in humans, results have been inconsistent.

OBJECTIVE

To explore the cross-sectional relationship between bisphenol A (BPA) exposure and reproductive hormones/cortisol among peripubertal boys.

MATERIAL AND METHODS

Urinary BPA and serum hormones were assessed in 172 boys belonging to the INMA "Environment and Childhood" Granada birth cohort in their follow-up at 9-11years of age. BPA concentrations were quantified by liquid chromatography-mass spectrometry, and levels of serum total testosterone (TT), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and cortisol were measured by electrochemiluminescence immunoassay.

RESULT(S)

After adjustment for confounders, linear regression models showed that each natural-log unit increase in urinary BPA concentrations was associated with a 19% increase in geometric mean (GM) serum TT levels, and a 16% decrease in GM serum cortisol levels. When urinary BPA concentrations were categorized in tertiles, boys in the 3rd tertile showed 49% higher TT levels and 23% lower cortisol concentrations compared to boys in the 1st tertile. Additionally, urinary BPA concentrations were also significantly associated with higher TT:LH and TT:cortisol ratios, but not with serum LH or FSH levels.

CONCLUSION(S)

Our results suggest the possible endocrine disrupting potential of BPA during this important period of development. Although action at the testis or pituitary cannot be ruled out, our findings are compatible with a possible involvement of BPA at the adrenal gland, resulting in a differential production of androgens/cortisol. However, given the cross-sectional design of our study, the heterogeneous results reported in the literature, and the scant experimental research on BPA effects at the adrenal gland, the present findings should be interpreted with caution.

Effects of an Environmentally Relevant Phthalate Mixture on Cultured Mouse Antral Follicles

Phthalates are used in building materials, medical devices, and personal care products. Most studies on phthalates have focused on single phthalates, but it is important to study mixtures of phthalates because humans are exposed to such mixtures daily. We tested the hypothesis that phthalate mixture exposure decreases antral follicle growth, compromises steroidogenic capacity, and induces atresia. Antral follicles from adult CD-1 mice were cultured with vehicle control or phthalate mixture (1-500 µg/ml) for 96 h. The mixture was made of 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. During culture, antral follicle diameters were measured every 24 h to monitor growth. After culture, media were subjected to measurements of sex steroid hormones and follicles were subjected to evaluation of gene expression and atresia. The phthalate mixture (100 and 500 µg/ml) decreased antral follicle growth starting at 24 h compared to controls. The mixture at 10, 100, and 500 µg/ml also decreased androstenedione, testosterone, estrone, and estradiol levels compared to control. The mixture (10, 100, and 500 µg/ml) reduced atresia rating, but it induced more oocyte fragmentation compared to control. The phthalate mixture at different doses adversely affected cell cycle regulators, antioxidant enzymes, apoptotic factors, steroidogenic enzymes, and receptors. Collectively, these data indicate that exposure to an environmentally relevant phthalate mixture reduces antral follicle growth, induces oocyte fragmentation, and decreases hormone production by adversely affecting the expression of cell cycle regulators, apoptotic factors, steroidogenic enzymes, and receptors.

High Prenatal Exposure to Bisphenol A Reduces Anogenital Distance in Healthy Male Newborns

OBJECTIVE

To estimate the relationship between cord blood bisphenol A (BPA) levels and anogenital measurements in healthy newborns.

METHODS

Pregnancy and birth history, together with body mass and length data, anogenital measurements, penile measurements and cord blood samples were obtained from healthy newborns. Cord blood concentration of BPA was analyzed by sandwich enzyme-linked immunosorbent assays kit.

RESULTS

Among 130 healthy newborns (72 boys, 58 girls), mean anopenile distance was 45.2±6 mm and anoscrotal distance was 21.9±5.4 mm in boys; mean anoclitoral distance was 33.8±6.6 mm and mean anofourchette distance was 12.2±4.9 mm in girls. Mean cord blood BPA level was 4.75±2.18 ng/mL. 90th percentile value for cord blood BPA was 8.26 ng/mL and the analysis showed a statistically significant correlation between anoscrotal distance and cord blood BPA levels above the 90th percentile (p=0.047) in boys. The changes in anogenital distance in girls were not statistically significant.

CONCLUSION

We showed a significant association between high cord blood BPA levels and shortened anoscrotal distance in male newborns. However, this result should be interpreted with caution since there were no significant external genital abnormalities in our study group.

Sex-Specific Effects of Combined Exposure to Chemical and Non-chemical Stressors on Neuroendocrine Development: a Review of Recent Findings and Putative Mechanisms

PURPOSE OF REVIEW

Environmental toxicants and psychosocial stressors share many biological substrates and influence overlapping physiological pathways. Increasing evidence indicates stress-induced changes to the maternal milieu may prime rapidly developing physiological systems for disruption by concurrent or subsequent exposure to environmental chemicals. In this review, we highlight putative mechanisms underlying sex-specific susceptibility of the developing neuroendocrine system to the joint effects of stress or stress correlates and environmental toxicants (bisphenol A, alcohol, phthalates, lead, chlorpyrifos, and traffic-related air pollution).

RECENT FINDINGS

We provide evidence indicating that concurrent or tandem exposure to chemical and non-chemical stressors during windows of rapid development is associated with sex-specific synergistic, potentiated and reversed effects on several neuroendocrine endpoints related to hypothalamic-pituitary-adrenal axis function, sex steroid levels, neurotransmitter circuits, and innate immune function. We additionally identify gaps, such as the role that the endocrine-active placenta plays, in our understanding of these complex interactions. Finally, we discuss future research needs, including the investigation of non-hormonal biomarkers of stress. We demonstrate multiple physiologic systems are impacted by joint exposure to chemical and non-chemical stressors differentially among males and females. Collectively, the results highlight the importance of evaluating sex-specific endpoints when investigating the neuroendocrine system and underscore the need to examine exposure to chemical toxicants within the context of the social environment.

Concurrent exposures to nonylphenol, bisphenol A, phthalates, and organophosphate pesticides on birth outcomes: A cohort study in Taipei, Taiwan

Prenatal exposure to phenols, phthalates (PAEs), and organophosphate (OP) pesticides may increase the risk of abnormal birth outcomes. However, many previous studies have examined exposure to a limited number of chemical classes or exposure profiles limited to a specific stage of pregnancy. This study aims to characterize the concurrent exposure scenario throughout pregnancy by simultaneously monitoring internal doses of several endocrine-disrupting compounds (EDCs), including 2 phenols (nonylphenol (NP) and bisphenol A (BPA)), 9 PAEs, and 6 OP pesticide metabolites and to assess the relationships between concurrent exposure to EDCs and infant birth weight, length, and head and chest circumference. One hundred and sixty two women provided three spot urine samples at approximately 11 and 26weeks gestation and at delivery. We applied multivariable linear regression and ridge regression models to estimate the effects of separate and correlated exposures. Multivariable linear regression models revealed that women with short birth-length infants had significantly higher urinary second-trimester NP levels (50th percentile, 5.03μg/g creatinine) (β=-0.47cm; 95% CI=-0.93 to -0.01). Similarly significant relationships were observed between second-trimester mono-methyl phthalate (MMP) exposure and short birth length, second-trimester ΣPAEs and short birth length, second-trimester ΣPAEs exposure and reduced head and chest circumference, second-trimester diethylphosphate (DEP) exposure and reduced birth weight and length, and second-trimester ΣDEPs exposure and short birth length. Women with urinary BPA above the 75th percentile or ΣPAEs levels above the 50th percentile in the third trimester had infants with significantly reduced head circumference. These observations suggest that the second trimester may be the critical stage of susceptibility for fetal development. In ridge regression models, for which women with fewer measures for exposure to NP, BPA, MMP, ΣPAEs, DEP and ΣDEPs simultaneously were available, no relationships were found with infant size at birth. Additional studies with larger sample sizes are warranted.

Biphasic modulation of neuro- and interrenal steroidogenesis in juvenile African sharptooth catfish (Clarias gariepinus) exposed to waterborne di-(2-ethylhexyl) phthalate

Receptor (i.e. genomic) and non-receptor (or non-genomic) effects of endocrine toxicology have received limited or almost non-existent attention for tropical species and regions. In the present study, we have evaluated the effects of di-(2-ethylhexyl) phthalate (DEHP) on neuro- and interrenal steroidogenesis of the African catfish (Clarias gariepinus) using molecular, immunochemical and physiological approaches. Juvenile fish (mean weight and length: 5.6±0.6g and 8.2±1.2cm, respectively), were randomly distributed into ten 120L rectangular glass tanks containing 60L of dechlorinated tap water, at 50 fish per exposure group. The fish were exposed to environmentally relevant concentrations of DEHP, consisting of 0 (ethanol solvent control), 10, 100, 200, and 400μg DEHP/L water and performed in two replicates. Brain, liver and head kidney samples were collected at day 3, 7 and 14 after exposure, and analysed for star, p450scc, cyp19a1, cyp17, cyp11β-, 3β-, 17β- and 20β-hsd, and 17β-ohase mRNA expression using real-time PCR. The StAR, P450scc and CYP19 proteins were measured using immunoblotting method, while estradiol-17β (E2) and testosterone (T) were measured in liver homogenate using enzyme immunoassay (EIA). Our data showed a consistent and unique pattern of biphasic effect on star and steroidogenic enzyme genes with increases at low concentration (10μg/L) and thereafter, a concentration-dependent decrease in both the brain and head kidney, that paralleled the expression of StAR, P450scc and CYP19 proteins. Cellular E2 and T levels showed an apparent DEHP concentration-dependent increase at day 14 of exposure. The observed consistency in the current findings and in view of previous reports on contaminants-induced alterations in neuro- and interrenal steroidogenesis, the broader toxicological and endocrine disruptor implication of our data indicate potentials for overt reproductive, metabolic, physiological and general health consequences for the exposed organisms.

Pre-pubertal exposure with phthalates and bisphenol A and pubertal development

OBJECTIVE

Epidemiological studies indicate associations between childhood exposure with phthalates and bisphenol A (BPA) and the pubertal development. We examined associations between the pre-pubertal phthalate and BPA body burden and the longitudinally assessed sexual maturation of eight- to thirteen-year-old children.

METHODS

We started with eight- to ten-year-old children in the baseline study and quantified phthalate metabolites and BPA in 472 urine samples (250 boys; 222 girls; mean age: 8.8 years). Associations between the pubertal development, assessed in three annual follow-up studies by Puberty Development scale questionnaires (PD scales), and the chemical exposure from the baseline visit were longitudinally analyzed with generalized estimation equations.

RESULTS

The number of children with both chemical measures and PD scores (calculated from the PD scales) was 408. In the third follow-up, 49% of the girls and 18% of the boys had reached mid-puberty. For girls, we observed a delayed pubertal development with the di-hexyl-ethyl phthalate (DEHP) metabolites (β: -0.16 to -0.23; p ≤ 0.05 or p ≤ 0.1), mono-n-butyl phthalate (β: -0.15; 95% CI: -0.31; 0.01), mono-benzyl phthalate (β: -0.11; 95% CI: -0,24; -0,01), and mono-ethyl phthalate (MEP) (β: -0.15; 95% CI: -0.28; -0.01). In addition, significant non-linear associations of the DEHP metabolites and BPA with the PD scores were found, when their quadratic effects were included in the GEE models. In boys, no consistent relationships between the PD scores and the chemicals were detected except of an accelerated development with the ∑DEHP metabolites (β: 0.16; 95% CI: -0.02; -0.34).

CONCLUSION

We found indications that pre-pubertal exposures with phthalates and BPA were associated with pubertal timing in children, particularly in girls. For boys, associations were inconsistent, and not necessarily in line with the known anti-androgenicity of some phthalates during prenatal exposure.

Association of Bisphenol A Exposure with Breastfeeding and Perceived Insufficient Milk Supply in Mexican Women

Introduction Estrogen inhibits lactation and bisphenol A (BPA) is a high production environmental estrogen. We hypothesize an inhibitory effect of BPA on lactation and aim to analyze the association between third trimester pregnancy urinary BPA and breastfeeding rates 1 month postpartum. Methods Odds ratios (OR) and 95 % confidence intervals (95 % CI) of breastfeeding and perceived insufficient milk supply (PIM) in relation to maternal peripartum urinary BPA concentrations were calculated in 216 mothers. Results 97.2 % of mothers in the lowest BPA tertile were breastfeeding at 1 month postpartum, compared to 89.9 % in highest (p = 0.01). Adjusted ORs (95 % CI) for not breastfeeding at 1 month were 1.9 (0.3, 10.7) and 4.3 (0.8, 21.6) for second and third BPA tertiles, respectively, compared to the lowest (p = 0.06, trend). 4.2 % reported PIM in the lowest BPA tertile, compared to 8.7 % in the highest (p = 0.03). Adjusted ORs (95 % CI) for PIM were 1.8 (0.4, 7.7) and 2.2 (0.5, 9.5), for the second and third BPA tertiles, respectively, compared to the lowest (p = 0.29, trend). Discussion These results suggest an association between maternal BPA exposure and decreased breastfeeding.

Endocrine Disruptors and Pregnancy: Knowledge, Attitudes and Prevention Behaviors of French Women

Endocrine disrupting chemicals (EDC) are environmental exposure factors that are rarely reported in clinical practice, particularly during pregnancy. This study aimed to describe women's knowledge, attitudes and behaviors towards EDC exposure. A study was conducted in the French Department of Vienne between 2014 and 2016 and comprised semi-structured interviews with pregnant women, a focus group of professionals in perinatology and environmental health, and the administration of a psychosocial questionnaire comprising scores in 300 pregnant or in postpartum period women. The mean score of knowledge was 42.9 ± 9.8 out of 100 (from 13.5 to 75.7). Exposure attitude was determined by risk perception. Mean level of cues to action to reduce their EDC exposure was estimated at 56.9 ± 22.5 out of 100 (from 0 to 100). Anxiety was significantly increased after the questionnaire. Anxiety about EDC was associated with a high score of knowledge (OR = 2.30, 95% CI (1.12-4.71)) and with no pregnancy anxiety (OR = 0.57, 95% CI (0.34-0.95)). Our findings suggest that healthcare providers should consider pregnant women's knowledge and perceptions, possibilities of action, and be careful not to increase their anxiety when advising them about EDC and environmental exposure.

The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes.

First-Trimester Urinary Bisphenol A Concentration in Relation to Anogenital Distance, an Androgen-Sensitive Measure of Reproductive Development, in Infant Girls

INTRODUCTION

Evidence from animal models suggests that prenatal exposure to bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, is associated with adverse reproductive outcomes in females. Exposure during early gestation, a critical period for reproductive development, is of particular concern. Anogenital distance (AGD) is a sensitive biomarker of the fetal hormonal milieu and a measure of reproductive toxicity in animal models. In some studies, the daughters of BPA-exposed dams have shorter AGD than controls. Here, we investigate this relationship in humans.

METHODS

BPA was assayed in first-trimester urine samples from 385 participants who delivered infant girls in a multicenter pregnancy cohort study. After birth, daughters underwent exams that included two measures of AGD (AGD-AC: distance from center of anus to clitoris; AGD-AF: distance from center of anus to fourchette). We fit linear regression models to examine the association between specific gravity-adjusted (SPG-adj) maternal BPA concentrations and infant AGD, adjusting for covariates.

RESULTS

BPA was detectable in 94% of women. In covariate-adjusted models fit on 381 eligible subjects, the natural logarithm of SpG-adj maternal BPA concentration was inversely associated with infant AGD-AC [β=−0.56, 95% confidence interval (CI): −0.97, −0.15]. We observed no association between maternal BPA and infant AGD-AF.

CONCLUSION

BPA may have toxic effects on the female reproductive system in humans, as it does in animal models. Higher first-trimester BPA exposure was associated with significantly shorter AGD in daughters, suggesting that BPA may alter the hormonal environment of the female fetus. https://doi.org/10.1289/EHP875.

Impact of phthalate and BPA exposure during in utero windows of susceptibility on reproductive hormones and sexual maturation in peripubertal males

BACKGROUND

Phthalates and BPA are endocrine disrupting chemicals (EDCs) widely used in consumer products. Evidence suggests that phthalate and BPA exposure alters steroid hormone levels in adults, while in utero exposure has been associated with altered fetal reproductive development in boys. However, the impact of exposure during distinct critical windows of in utero development on hormone concentrations and sexual maturation during the pubertal transition has not been examined. The objective of this study was to assess trimester-specific in utero phthalate and BPA exposure in relation to measures of reproductive development among peripubertal boys in a Mexico City birth cohort.

METHODS

We measured maternal urinary phthalate metabolites and BPA during the first, second, and third trimesters of pregnancy. We measured serum levels of testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), inhibin B, and sex hormone-binding globulin (SHBG), and assessed sexual maturation (Tanner staging and testicular volume) among male children at age 8-14 years (n = 109). Linear and logistic regression were used to investigate trimester-specific in utero exposure as predictors of peripubertal hormone levels and sexual maturation, respectively. In sensitivity analyses we evaluated estimated exposure at 7 weeks gestation and rates of change in exposure across pregnancy in relation to outcomes.

RESULTS

Exposure to phthalates during the third trimester was associated with reduced odds of having a Tanner stage >1 for pubic hair development (e.g. MBzP OR = 0.18 per interquartile range (IQR) increase; 95% CI:0.03-0.97) and higher peripubertal SHBG levels (e.g. MBzP 15.2%/IQR; 95% CI:3.2-28%), while first and second trimester phthalates were not. In contrast, exposure to DEHP during the first trimester was associated with higher estradiol (11%/IQR; 95% CI:1.5-22%), while second or third trimester DEHP exposure was not. Sensitivity analyses yielded similar findings.

CONCLUSIONS

Associations between in utero phthalate and BPA exposure and peripubertal measures of male reproductive development are dependent on the timing of that exposure during gestation. These findings suggest that future epidemiological studies relating in utero EDC exposure to pubertal outcomes should consider windows of susceptibility.

Prenatal and childhood exposure to phthalate diesters and sex steroid hormones in 2-, 5-, 8-, and 11-year-old children: A pilot study of the Taiwan Maternal and Infant Cohort Study

Background

Phthalate diesters are commonly used and have been well established as environmental endocrine disruptors. However, few studies have examined their effects on sex steroid hormones in children. We followed children over time to examine the association between pre- and post-natal phthalate exposure and sex steroid hormone levels at 2, 5, 8, and 11 years of age.

Methods

We recruited 430 pregnant women from central Taiwan from 2000 to 2001 and assessed their children at birth, 2, 5, 8, and 11 years of age. We studies children with at least one measurement for both phthalate and hormone levels during each any of the follow-up time point (n = 193). Estradiol, free testosterone, testosterone, and progesterone were measured from venous blood. Three monoesters of di-2-ethylhexyl phthalate (DEHP), mono-benzyl phthalate, mono-n-butyl phthalate, mono-ethyl phthalate, and mono-methyl phthalate were measured in maternal urine collected during the 3rd trimester and child urine collected at each follow-up point. The sum of mono-2-ethylhexyl phthalate (∑MEHP) was calculated by summing the concentrations of the three DEHP monoesters. Generalized estimating equation regression analysis with repeated measures was used to estimate associations between phthalate metabolites and hormone levels.

Results

After adjustment for potential confounders, maternal ∑MEHP level was associated with decreased levels of progesterone in girls (β = −0.309 p = 0.001). The child ∑MEHP concentration was associated with decreased levels of progesterone for girls (β = −0.194, p = 0.003) and with decreased levels of free testosterone for boys (β = −0.124, p = 0.004).

Conclusions

Early-life DEHP exposure may alter sex steroid hormones of children over time, which may pose potential reproductive health risks.

•

Prenatal phthalate exposure was associated with decreased PG levels in girls.

•

Postnatal DEHP exposure was related to decreased free TT in boys and PG in girls.

•

Use of phthalate-containing products in developing children should be limited.

Phthalate exposure and reproductive hormones and sex-hormone binding globulin before puberty - Phthalate contaminated-foodstuff episode in Taiwan

Background

In May 2011, a major incident involving phthalates-contaminated foodstuffs occurred in Taiwan. Di-(2-ethylhexyl) phthalate (DEHP) was added to foodstuffs, mainly juice, jelly, tea, sports drink, and dietary supplements. Concerns arose that normal pubertal development, especially reproductive hormone regulation in children, could be disrupted by DEHP exposure.

Objective

To investigate the association between phthalate exposure and reproductive hormone levels among children following potential exposure to phthalate-tainted foodstuffs.

Methods

A total of 239 children aged <12 years old were recruited from 3 hospitals in north, central, and south Taiwan after the episode. Structured questionnaires were used to collect the frequency and quantity of exposures to 5 categories of phthalate-contaminated foodstuffs to assess phthalate exposure in children. Urine samples were collected for the measurement of phthalate metabolites. The estimated daily intake of DEHP exposure at the time of the contamination incident occurred was calculated using both questionnaire data and urinary DEHP metabolite concentrations. Multiple regression analyses were applied to assess associations between phthalate exposure and reproductive hormone levels in children.

Results

After excluding children with missing data regarding exposure levels and hormone concentrations and girls with menstruation, 222 children were included in the statistical analyses. After adjustment for age and birth weight, girls with above median levels of urinary mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and sum of mono-(2-ethylhexyl) phthalate concentrations had higher odds of above median follicle-stimulating hormone concentrations. Girls with above median estimated average daily DEHP exposures following the contamination episode also had higher odds of sex hormone-binding globulin above median levels.

Conclusions

Phthalate exposure was associated with alterations of reproductive hormone levels in girls.

Exposure to phthalates is associated with lipid profile in peripubertal Mexican youth

Animal models indicate that endocrine disrupting chemicals (EDCs) affect circulating lipid concentrations by interfering with hepatic fatty acid oxidation. Little is known of the relationship between EDC exposure and lipid profile in humans. We measured bisphenol A (BPA) and 9 phthalate metabolites in maternal urine collected at up to three time points during pregnancy as a measure of in utero exposure, and in the child's urine at 8-14 years as a measure of concurrent, peripubertal exposure among 248 participants of a Mexico City pre-birth cohort. We used linear regression to examine relations of BPA and phthalate exposure with peripubertal serum lipids, while also adjusting for child age, sex, and specific gravity. While in utero EDC exposure was not associated with lipid profile, higher concurrent levels of mono-3-carboxypropyl phthalate (MCPP), monoethyl phthalate (MEP), and dibutyl phthalate metabolites (DBP) corresponded with lower total cholesterol and low-density lipoprotein (LDL-C) in boys; e.g., an interquartile range increment in MCPP corresponded with 7.4% (2.0%, 12.8%) lower total cholesterol and 12.7% (3.8%, 21.6%) lower LDL-C. In girls, higher urinary di-2-ethylhexyl phthalate metabolites (ΣDEHP) correlated with lower LDL-C (-7.9% [-15.4%, -0.4%]). Additional longitudinal research is needed to determine whether these associations persist beyond adolescence.

Prenatal di(2-ethylhexyl) phthalate exposure and disruption of adrenal androgens and glucocorticoids levels in cord blood: The Hokkaido Study

Di(2-ethylhexyl) phthalate (DEHP) is known for its endocrine disrupting properties. We previously demonstrated that prenatal DEHP exposure is associated with decreased progesterone levels and testosterone/estradiol ratio in the cord blood. However, evidence of the effects of prenatal DEHP exposure on adrenal androgen and glucocorticoids in infants is scarce. Thus, the objectives of this study were to investigate the association between prenatal DEHP exposure and adrenal androgen and glucocorticoids, and to discuss its effects on steroid hormone profiles in infants. This is part of a birth cohort study: The Hokkaido Study on Environment and Children's Health, Sapporo Cohort. Among the 514 participants, 202 mother-infant pairs with available data on maternal mono(2-ethylhexyl) phthalate (MEHP), adrenal androgen (dehydroepiandrostenedione [DHEA] and androstenedione) and glucocorticoid (cortisol and cortisone) cord blood levels were included in this study. After adjusting for potential confounders, a linear regression analysis showed that maternal MEHP levels were associated with reduced cortisol and cortisone levels and glucocorticoid/adrenal androgen ratio, whereas increased DHEA levels and DHEA/androstenedione ratio. In a quartile model, when comparing the adjusted least square means in the 4th quartile of MEHP with those in the 1st quartile, cortisol and cortisone levels and glucocorticoid/adrenal androgen ratio decreased, whereas DHEA/androstenedione and cortisol/cortisone ratios increased. Significant p-value trends for cortisol and cortisone levels, cortisol/cortisone ratio, and glucocorticoid/adrenal androgen ratio were observed. In combination with the previous results of reduced progesterone levels and testosterone/estradiol ratio, prenatal exposure to DEHP altered the steroid hormone profiles of infants. Further studies investigating the long-term effects of DEHP exposure on growth, neurodevelopment, and gonad and reproductive function are required.

Prenatal Phthalate Exposures and Body Mass Index Among 4- to 7-Year-old Children: A Pooled Analysis

BACKGROUND

Phthalates are hypothesized to cause obesity, but few studies have assessed whether prenatal phthalate exposures are related to childhood body mass index (BMI).

METHODS

We included 707 children from three prospective cohort studies enrolled in the US between 1998 and 2006 who had maternal urinary phthalate metabolite concentrations measured during pregnancy, and measures of weight and height at ages 4 to 7 years. We calculated age- and sex-standardized BMI z scores and classified children with BMI percentiles ≥85 as overweight/obese. We used mixed effects regression models to estimate associations between a 1 standard deviation increase in natural log phthalate metabolite concentrations and BMI z scores and overweight/obesity. We estimated associations in multiple metabolite models adjusted for confounders, and evaluated heterogeneity of associations by child's sex, race/ethnicity, and cohort.

RESULTS

Mono-3-carboxypropyl phthalate concentrations were positively associated with overweight/obese status in children (odds ratio [95% credible interval] = 2.1 [1.2, 4.0]) but not with BMI z scores (β = -0.02 [-0.15, 0.11]). We did not observe evidence of obesogenic effects for other metabolites. However, monoethyl phthalate and summed di-(2-ethylhexyl) phthalate metabolites (∑DEHP) concentrations were inversely associated with BMI z scores among girls (monoethyl phthalate beta = -0.14 [-0.28, 0.00]; ∑DEHP beta = -0.12 [-0.27, 0.02]).

CONCLUSIONS

Maternal urinary mono-3-carboxypropyl phthalate, a nonspecific metabolite of several phthalates, was positively associated with childhood overweight/obesity. Metabolites of diethyl phthalate and DEHP were associated with lower BMI in girls but not in boys, suggesting that prenatal exposures may have sexually dimorphic effects on physical development.

Computational insights into the molecular interactions of environmental xenoestrogens 4-tert-octylphenol, 4-nonylphenol, bisphenol A (BPA), and BPA metabolite, 4-methyl-2, 4-bis (4-hydroxyphenyl) pent-1-ene (MBP) with human sex hormone-binding globulin

Environmental contamination has been one of the major drawbacks of the industrial revolution. Several man-made chemicals are constantly released into the environment during the manufacturing process and by leaching from the industrial products. As a result, human and animal populations are exposed to these synthetic chemicals on a regular basis. Many of these chemicals have adverse effects on the physiological functions, particularly on the hormone systems in human and animals and are called endocrine disrupting chemicals (EDCs). Bisphenol A (BPA), 4-tert-octylphenol (OP), and 4-nonylphenol (NP) are three high volume production EDCs that are widely used for industrial purposes and are present ubiquitously in the environment. Bisphenol A is metabolized in the human body to a more potent compound (MBP: 4-Methyl-2, 4-bis (4-hydroxyphenyl) pent-1-ene). Epidemiological and experimental studies have shown the three EDCs to be associated with adverse effects on reproductive system in human and animals. Sex hormone-binding globulin (SHBG) is a circulatory protein that binds sex steroids and is a potential target for endocrine disruptors in the human body. The current study was done in order to understand the binding mechanism of OP, BPA, NP, and MBP with human SHBG using in silico approaches. All four compounds showed high binding affinity with SHBG, however, the binding affinity values were higher (more negative) for MBP and NP than for OP and BPA. The four ligands interacted with 19-23 residues of SHBG and a consistent overlapping of the interacting residues for the four ligands with the residues for the natural ligand, dihydrotestosterone (DHT; 82-91% commonality) was shown. The overlapping SHBG interacting residues among DHT and the four endocrine disruptors suggested that these compounds have potential for interference and disruption in the steroid binding function.

Potential Intervention Targets in Utero and Early Life for Prevention of Hormone Related Cancers

Hormone-related cancers have long been thought to be sensitive to exposures during key periods of sexual development, as shown by the vulnerability to such cancers of women exposed to diethylstilbestrol in utero. In addition to evidence from human studies, animal studies using new techniques, such as gene knockout models, suggest that an increasing number of cancers may be hormonally related, including liver, lung, and bladder cancer. Greater understanding of sexual development has also revealed the "mini-puberty" of early infancy as a key period when some sex hormones reach levels similar to those at puberty. Factors driving sex hormones in utero and early infancy have not been systematically identified as potential targets of intervention for cancer prevention. On the basis of sex hormone pathways, we identify common potentially modifiable drivers of sex hormones, including but not limited to factors such as obesity, alcohol, and possibly nitric oxide. We review the evidence for effects of modifiable drivers of sex hormones during the prenatal period and early infancy, including measured hormones as well as proxies, such as the second-to-fourth digit length ratio. We summarize the gaps in the evidence needed to identify new potential targets of early life intervention for lifelong cancer prevention.

Urine bisphenol A and pubertal development in boys

BACKGROUND

Bisphenol A (BPA) is an environmental endocrine disruptor and is found in many consumer products. Animal studies suggest that BPA may perturb pubertal development in males, although studies in humans are limited.

OBJECTIVE

This study investigated the association between BPA exposure and pubertal onset and progression among school-aged boys in Shanghai, China.

METHODS

A total of 671 boys aged 9-18 years from three schools (one elementary, one middle, and one high school) in Shanghai were enrolled in a cross-sectional study. Tanner stages for genital and pubic hair development and testicular volume were assessed by a specifically trained physician. Information concerning spermarche was self-reported. Urine samples were collected to examine peripubertal BPA exposure levels. Associations between BPA exposure and pubertal development, as indicated by the presence of different milestones in early puberty, mid-puberty and late puberty, were assessed using Poisson multivariate regression to derive adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs).

RESULTS

Earlier onset of genital and pubic hair development was observed in boys with moderate BPA exposure compared with those exposed to the least BPA; the adjusted PRs were 1.31 (95%CI:1.03, 1.68) and 1.28 (95%CI:1.02, 1.60) for onset of genital maturation and pubic hair development, respectively. A similar trend was seen for onset of testicular development, although the association was not statistically significant. Conversely, compared with the lowest level of BPA exposure, moderate BPA exposure was associated with delayed presence of the late stage of genital development, with an adjusted PR of 0.78 (95%CI: 0.65, 0.92). A suggestive inverse association was also observed between BPA exposure and late progression of testicular development.

CONCLUSIONS

Our findings indicate an association between peripubertal BPA exposure and earlier pubertal onset, but delayed pubertal progression, in boys. Longitudinal studies of male pubertal development with periodic follow-up are needed to verify these results.

The effect of maternal exposure to endocrine disrupting chemicals on fetal and neonatal development: A review on the major concerns

There is a widespread exposure of general population, including pregnant women and developing fetuses, to the endocrine disrupting chemicals (EDCs). These chemicals have been reported to be present in urine, blood serum, breast milk, and amniotic fluid. Endocrine disruptions induced by environmental toxicants have placed a heavy burden on society, since environmental exposures during critical periods of development can permanently reprogram normal physiological responses, thereby increasing susceptibility to disease later in life-a process known as developmental reprogramming. During development, organogenesis and tissue differentiation occur through a continuous series of tightly-regulated and precisely-timed molecular, biochemical, and cellular events. Humans may encounter EDCs daily and during all stages of life, from conception and fetal development through adulthood and senescence. Nevertheless, prenatal and early postnatal windows are the most critical for proper development, due to rapid changes in system growth. Although there are still gaps in our knowledge, currently available data support the urgent need for health and environmental policies aimed at protecting the public and, in particular, the developing fetus and women of reproductive age. Birth Defects Research (Part C) 108:224-242, 2016. © 2016 Wiley Periodicals, Inc.

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

BACKGROUND

Bisphenol 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.

METHODS

The 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.

RESULTS

Participants 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 [e(β)] = 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 (e(β) = 1.19; 95% CI, 0.86-1.64), and they did not observe any association using 14-day (e(β) = 0.94; 95% CI, 0.75-1.18) or 6-month (e(β) = 0.88; 95% CI, 0.74-1.04) samples.

CONCLUSIONS

Placement 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 IMPLICATIONS

These 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.