Prenatal Exposure to Phthalates and Childhood Body Size in an Urban Cohort

Association of maternal exposure to endocrine disruptor chemicals with cardio-metabolic risk factors in children during childhood: a systematic review and meta-analysis of cohort studies

BACKGROUND

In the present systematic review and meta-analysis, the association of maternal exposure to the endocrine disrupting chemicals (EDCs) with cardio-metabolic risk factors in children during childhood for the first time.

METHOD

The PubMed, Scopus, EMBASE, and Web of Science databases were systematically searched, up to Feb 2023. In total 30 cohort studies had our inclusion criteria. A random-effects model was used for the variables that had considerable heterogeneity between studies. The Newcastle-Ottawa Scale (NOS) tool was used to classify the quality score of studies. All statistical analyses were conducted using Stata 14 and P-value < 0.05 considered as a significant level.

RESULTS

In the meta-analysis, maternal exposure to the EDCs was weakly associated with higher SBP (Fisher_Z: 0.06, CI: 0.04, 0.08), BMI (Fisher_Z: 0.07, CI: 0.06, 0.08), and WC (Fisher_Z: 0.06, CI: 0.03, 0.08) z-scores in children. A significant linear association was found between maternal exposure to the bisphenol-A and pesticides with BMI and WC z-score in children (p < 0.001). Subgroup analysis showed significant linear association of BPA and pesticides, in the urine samples of mothers at the first trimester of pregnancy, with BMI and WC z-score in children from 2-8 years (p < 0.05).

CONCLUSION

Prenatal exposure to the EDCs in the uterine period could increase the risk of obesity in children. Maternal exposure to bisphenol-A and pesticides showed the strongest association with the obesity, especially visceral form, in the next generation.

Understanding risk and causal mechanisms for developing obesity in infants and young children: A National Institutes of Health workshop

Obesity in children remains a major public health problem, with the current prevalence in youth ages 2-19 years estimated to be 19.7%. Despite progress in identifying risk factors, current models do not accurately predict development of obesity in early childhood. There is also substantial individual variability in response to a given intervention that is not well understood. On April 29-30, 2021, the National Institutes of Health convened a virtual workshop on "Understanding Risk and Causal Mechanisms for Developing Obesity in Infants and Young Children." The workshop brought together scientists from diverse disciplines to discuss (1) what is known regarding epidemiology and underlying biological and behavioral mechanisms for rapid weight gain and development of obesity and (2) what new approaches can improve risk prediction and gain novel insights into causes of obesity in early life. Participants identified gaps and opportunities for future research to advance understanding of risk and underlying mechanisms for development of obesity in early life. It was emphasized that future studies will require multi-disciplinary efforts across basic, behavioral, and clinical sciences. An exposome framework is needed to elucidate how behavioral, biological, and environmental risk factors interact. Use of novel statistical methods may provide greater insights into causal mechanisms.

Phthalate exposure and risk of metabolic syndrome components: A systematic review

Metabolic syndrome is a cluster of conditions that increase the risk of cardiovascular disease, i.e. obesity, insulin resistance, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-c) levels and arterial hypertension. Phthalates are environmental chemicals which might influence the risk of the aforementioned disturbances, although the evidence is still controversial. The objective of this work was to synthesize the evidence on the association between human phthalate exposure and metabolic syndrome or any of its components. In this systematic review, the PRISMA guidelines were followed and the literature was search in PubMed, Web of Science and Scopus. Longitudinal and cross-sectional studies were included, the later only if a subclinical marker of disease was evaluated. The methodological quality was assessed with the Newcastle Ottawa Scale and a checklist for Analytical Cross-Sectional Studies developed in the Joanna Briggs Institute. A total of 58 articles were identified that showed high heterogenicity in the specific phthalates assessed, time-window of exposure and duration of follow-up. The quality of the studies was evaluated as high (n = 46, score >7 points) or medium (n = 12, score 4-6). The most frequently studied phthalates were DEHP-MEHP, MBzP and MEP. The evidence revealed a positive association between prenatal (in utero) exposure to most phthalates and markers of obesity in the offspring, but contradictory results when postnatal exposure and obesity were assessed. Moreover, postnatal phthalate exposure showed positive and very consistent associations with markers of diabetes and, to a lesser extent, with triglyceride levels. However, fewer evidence and contradictory results were found for HDL-c levels and markers of hypertension. The suggested mechanisms for these metabolic effects include transcription factor PPAR activation, antagonism of thyroid hormone function, antiandrogenic effects, oxidative stress and inflammation, and epigenetic changes. Nevertheless, as the inconsistency of some results could be related to differences in the study design, future research should aim to standardise the exposure assessment.

Associations between Phthalate Metabolite Concentrations in Follicular Fluid and Reproductive Outcomes among Women Undergoing in Vitro Fertilization/Intracytoplasmic Sperm Injection Treatment

BACKGROUND

Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking.

OBJECTIVES

To investigate the associations between phthalate metabolite concentrations in FF and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic.

METHODS

We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n -butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models.

RESULTS

After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all p for trends < 0.10 ). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites (Σ DEHP ) was associated with a reduction of 9.1% [95% confidence interval (CI): - 17.1 % , - 0.37 % ] and 10.3% (95% CI: - 18.8 % , - 0.94 % ) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth.

DISCUSSION

Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. https://doi.org/10.1289/EHP11998.

Predictors of Phthalate Metabolites Exposure among Healthy Pregnant Women in the United States, 2010-2015

Phthalate use and the concentrations of their metabolites in humans vary by geographic region, race, ethnicity, sex, product use and other factors. Exposure during pregnancy may be associated with detrimental reproductive and developmental outcomes. No studies have evaluated the predictors of exposure to a wide range of phthalate metabolites in a large, diverse population. We examined the determinants of phthalate metabolites in a cohort of racially/ethnically diverse nulliparous pregnant women. We report on urinary metabolites of nine parent phthalates or replacement compounds-Butyl benzyl phthalate (BBzP), Diisobutyl phthalate (DiBP), Diethyl phthalate (DEP), Diisononyl phthalate (DiNP), D-n-octyl phthalate (DnOP), Di-2-ethylhexyl terephthalate (DEHTP), Di-n/i-butyl phthalate (DnBP), Di-isononyl phthalate (DiNP) and Di-(2-ethylhexyl) phthalate (DEHP) from urine collected up to three times from 953 women enrolled in the Nulliparous Mothers To Be Study. Phthalate metabolites were adjusted for specific gravity. Generalized estimating equations (GEEs) were used to identify the predictors of each metabolite. Overall predictors include age, race and ethnicity, education, BMI and clinical site of care. Women who were Non-Hispanic Black, Hispanic or Asian, obese or had lower levels of education had higher concentrations of selected metabolites. These findings indicate exposure patterns that require policies to reduce exposure in specific subgroups.

Prenatal exposure to phthalates and child growth trajectories in the first 24 months of life

BACKGROUND

Phthalates are a class of environmental chemicals with endocrine-disrupting properties. Prenatal phthalate exposure has been associated with adverse developmental outcomes in childhood. However, data assessing the effects of prenatal phthalate exposure on postnatal infant growth trajectories are sparse.

OBJECTIVES

To evaluate the associations of prenatal phthalate exposure with child growth trajectories from birth to 24 months old.

METHODS

Within a Chinese birth cohort study, 1051 mother-offspring pairs were included. Seven phthalate metabolites were quantified in maternal urine collected between weeks 33 and 39 of gestation. The trajectories for weight-for-age z-score (WAZ), length-for-age z-score (LAZ), weight-for-length z-score (WLZ) and head-circumference-for-age z-score (HCZ) were determined by group-based trajectory modeling (GBTM). Multinomial logistic regression and the weighted quantile sum approach (WQS) were used to investigate the association between individual and phthalate mixture exposure and the growth trajectories of four anthropometric metrics.

RESULTS

Five trajectory groups were identified for each anthropometric measure using GBTM. Higher prenatal exposure to several phthalate metabolites (MEHP, MEHHP, MEOHP, MECCP, summed DEHP metabolites, as well as MBP) was associated with child growth trajectories, especially for WAZ and LAZ in the first 24 months of life. The associations were further confirmed by a mixture analysis of phthalate metabolites and a sex-specific effect was observed in the WAZ and LAZ trajectories.

CONCLUSION

Prenatal phthalate exposure had heterogeneous associations with postnatal growth trajectories. More studies are warranted to confirm and elucidate the meaning of our findings.

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

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

Prenatal exposures to mixtures of endocrine disrupting chemicals and sex-specific associations with children's BMI and overweight at 5.5 years of age in the SELMA study

BACKGROUND

Prenatal exposure to mixtures of endocrine disrupting chemicals (EDC) has the potential to disrupt human metabolism. Prenatal periods are especially sensitive as many developmental processes are regulated by hormones. Prenatal exposure to EDCs has inconsistently been associated with children's body mass index (BMI) and obesity. The objective of this study was to investigate if prenatal exposure to a mixture of EDCs was associated with children's BMI and overweight (ISO-BMI ≥ 25) at 5.5 years of age, and if there were sex-specific effects.

METHODS

A total of 1,105 mother-child pairs with complete data on prenatal EDCs concentrations (e.g., phthalates, non-phthalate plasticizers, phenols, PAH, pesticides, PFAS, organochlorine pesticides, and PCBs), children's measured height and weight, and selected covariates in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study were included in this analysis. The mixture effect of EDCs with children's BMI and overweight was assessed using WQS regression with 100 repeated holdouts. A positively associated WQS index with higher BMI and odds of overweight was derived. Models with interaction term and stratified weights by sex was applied in order to evaluate sex-specific associations.

RESULTS

A significant WQS*sex interaction term was identified and associations for boys and girls were in opposite directions. Higher prenatal exposure to a mixture of EDCs was associated with lower BMI (Mean β = -0.19, 95%CI: -0.40, 0.01) and lower odds of overweight (Mean OR = 0.72, 95%CI: 0.48, 1.04) among girls with borderline significance. However, the association among boys did not reach statistical significance. Among girls, the possible chemicals of concern were MEP, 2-OHPH, BPF, BPS, DPP and PFNA.

CONCLUSION

Prenatal exposure to a mixture of EDCs was associated with lower BMI and overweight among girls, and non-significant associations among boys. Chemicals of concern for girls included phthalates, non-phthalate plasticizers, bisphenols, PAHs, and PFAS.

Associating phthalate exposure during pregnancy with preschooler's FMI, ABSI and BRI trajectories via putative mechanism pathways

Phthalates are well-known obesogens, but a few studies have explored their impacts on the childhood fat mass index (FMI), body shape index (ABSI) and body roundness index (BRI). Information from 2950 participants recruited in the Ma'anshan Birth Cohort was analyzed. The relationships between six maternal phthalate metabolites and their mixture and childhood FMI, ABSI and BRI were investigated. FMI, ABSI and BRI in children aged 3.5 y, 4.0 y, 4.5 y, 5.0 y, 5.5 y and 6.0 y were calculated. The latent class trajectory modeling categorized the FMI trajectories into "rapidly increasing FMI" (4.71%) and "stable FMI" (95.29%) groups; ABSI trajectories were categorized as "decreasing ABSI" (32.74%), "stable ABSI" (46.55%), "slowly increasing ABSI" (13.26%), "moderately increasing ABSI" (5.27%) and "rapidly increasing ABSI" (2.18%) groups; BRI trajectories were categorized as "increasing BRI" (2.82%), "stable BRI" (19.85%), and "decreasing BRI" (77.34%) groups. Prenatal MEP exposure was associated with repeated measurements of FMI (β = 0.111, 95% CI = 0.002-0.221), ABSI (β = 0.145, 95% CI = 0.023-0.268) and BRI (β = 0.046, 95% CI = -0.005-0.097). Compared with each stable trajectory group, prenatal MEP (OR = 0.650, 95% CI = 0.502-0.844) and MBP (OR = 0.717, 95% CI = 0.984-1.015) were linked to a decreased risk of "decreasing BRI" in children; there was a negative relationship between MBP and the "decreasing ABSI" group (OR = 0.667, 95% CI = 0.487-0.914), and MEP increased the risks of "slowly increasing ABSI" (OR = 1.668, 95% CI = 1.210-2.299) and "rapidly increasing ABSI" (OR = 2.522, 95% CI = 1.266-5.024) in children. Phthalate mixture during pregnancy showed significant relationships with all anthropometric indicator trajectories, with MEP and MBP always being of the largest importance. In conclusion, this study suggested that prenatal phthalate coexposure increased the childhood probability of being in higher ABSI and BRI trajectory groups. That is, children were more likely to be obese when they were exposed to higher levels of some phthalate metabolites and their mixture. The low-molecular weight phthalates, including MEP and MBP, contributed the greatest weights.

Phthalates' exposure leads to an increasing concern on cardiovascular health

Being an essential component in the plastics industry, phthalates are ubiquitous in the environment and in everyday life. They are considered environmental contaminants that have been classified as endocrine-disrupting compounds. Despite di-2-ethylhexyl phthalate (DEHP) being the most common plasticizer and the most studied to date, there are many others that, in addition to being widely used in the plastic, are also applied in the medical and pharmaceutical industries and cosmetics. Due to their wide use, phthalates are easily absorbed by the human body where they can disrupt the endocrine system by binding to molecular targets and interfering with hormonal homeostasis. Thus, phthalates exposure has been implicated in the development of several diseases in different age groups. Collecting information from the most recent available literature, this review aims to relate human phthalates' exposure with the development of cardiovascular diseases throughout all ages. Overall, most of the studies presented demonstrated an association between phthalates and several cardiovascular diseases, either from prenatal or postnatal exposure, affecting foetuses, infants, children, young and older adults. However, the mechanisms underlying these effects remain poorly explored. Thus, considering the cardiovascular diseases incidence worldwide and the constant human exposure to phthalates, this topic should be extensively studied to understand the mechanisms involved.

A study on the association of placental and maternal urinary phthalate metabolites

BACKGROUND

Phthalate exposure in pregnancy is typically estimated using maternal urinary phthalate metabolite levels. Our aim was to evaluate the association of urinary and placental tissue phthalates, and to explore the role of maternal and pregnancy characteristics that may bias estimates.

METHODS

Fifty pregnancies were selected from the CANDLE Study, recruited from 2006 to 2011 in Tennessee. Linear models were used to estimate associations of urinary phthalates (2nd, 3rd trimesters) and placental tissue phthalates (birth). Potential confounders and modifiers were evaluated in categories: temporality (time between urine and placenta sample), fetal sex, demographics, social advantage, reproductive history, medication use, nutrition and adiposity. Molar and quantile normalized phthalates were calculated to facilitate comparison of placental and urinary levels.

RESULTS

Metabolites detectable in >80% of both urine and placental samples were MEP, MnBP, MBzP, MECPP, MEOHP, MEHHP, and MEHP. MEP was most abundant in urine (geometric mean [GM] 7.00 ×102 nmol/l) and in placental tissue (GM 2.56 ×104 nmol/l). MEHP was the least abundant in urine (GM 5.32 ×101 nmol/l) and second most abundant in placental tissue (2.04 ×104 nmol/l). In aggregate, MEHP differed the most between urine and placenta (2.21 log units), and MEHHP differed the least (0.07 log units). MECPP was positively associated between urine and placenta (regression coefficient: 0.31 95% CI 0.09, 0.53). Other urine-placenta metabolite associations were modified by measures of social advantage, reproductive history, medication use, and adiposity.

CONCLUSION

Phthalates were ubiquitous in 50 full-term placental samples, as has already been shown in maternal urine. MEP and MEHP were the most abundant. Measurement and comparison of urinary and placental phthalates can advance knowledge on phthalate toxicity in pregnancy and provide insight into the validity and accuracy of relying on maternal urinary concentrations to estimate placental exposures.

IMPACT STATEMENT

This is the first report of correlations/associations of urinary and placental tissue phthalates in human pregnancy. Epidemiologists have relied exclusively on maternal urinary phthalate metabolite concentrations to assess exposures in pregnant women and risk to their fetuses. Even though it has not yet been confirmed empirically, it is widely assumed that urinary concentrations are strongly and positively correlated with placental and fetal levels. Our data suggest that may not be the case, and these associations may vary by phthalate metabolite and associations may be modified by measures of social advantage, reproductive history, medication use, and adiposity.

Early-life exposure to di (2-ethyl-hexyl) phthalate: Role in children with endocrine disorders

Di (2-ethyl-hexyl) phthalate (DEHP), one of endocrine-disrupting chemicals (EDCs), has widespread concern due to its serious health hazards. Exposure to DEHP in the early stage of life affects fetal metabolic and endocrine function, which even would cause genetic lesions. To date, it is widely believed that the increasing incidence of childhood obesity and diabetes in adolescents is related to the impact of DEHP on glucose and lipid homeostasis in children. However, there remains a knowledge gap to recognize these adverse effects. Thus, in this review, besides the exposure routes and levels of DEHP, we further outline the effects of early-life exposure to DEHP on children and potential mechanisms, focusing on the aspect of metabolic and endocrine homeostasis.

The Pediatrician's Role in Protecting Children from Environmental Hazards

Children suffer disproportionately from disease and disability due to environmental hazards, for reasons rooted in their biology. The contribution is substantial and increasingly recognized, particularly due to ever-increasing awareness of endocrine disruption. Regulatory actions can be traced directly to reductions in toxic exposures, with tangible benefits to society. Deep flaws remain in the policy framework in industrialized countries, failing to offer sufficient protection, but are even more limited in industrializing nations where the majority of chemical production and use will occur by 2030. Evidence-based steps for reducing chemical exposures associated with adverse health outcomes exist and should be incorporated into anticipatory guidance.

Endocrine Disruptor Chemicals and Children's Health

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

Combined effects of prenatal phthalate exposure on cardiometabolic risk score among 4- to 7-year-old children: MABC study

There is currently no consensus about the impact of prenatal phthalate exposure on blood pressure and glycolipids in children. Few studies consider the health effects as an integrated indicator. The combined effect of multiple phthalate exposures is often ignored. Based on the Ma'anshan Birth Cohort, 2298 woman-child pairs were included in this study. Maternal urine was collected in each trimester to analyze 6 phthalate metabolites. The overall cardiometabolic risk (CMR) score was calculated based on serum glycolipids and blood pressure for children aged 4-7 years. A higher score represents a less favorable CMR profile. The restricted cubic spline model was used to explore the relationship between prenatal phthalate exposure and childhood CMR score. In addition, the quantile g-computation and the Bayesian kernel machine regression were used to evaluate the combined effect. The MBP exposure in the 1st trimester (MBP-1st) and the MEP-2nd were non-linearly associated with the CMR score (Fnonlinear = 3.28 and 5.60, Pnonlinear = 0.0378 and 0.0038, respectively). The MBP-3rd (Flinear = 5.31, Plinear = 0.0012) and the ∑LMWP-3rd (Flinear = 4.37, Plinear = 0.0045) were negatively associated with the score in a linear manner. The phthalate mixture in the 2nd trimester increased the score (psil = 0.1747, 95% CI = 0.0077-0.3416), with the MEP being the most common [weights = 0.5290; posterior inclusion probability (PIP) = 0.40]. The phthalate mixture in the 3rd trimester decreased the score (psil = -0.2024, 95% CI = -0.4097－0.0048), with the MEHP (weights = -0.5101; PIP = 0.14) and the MBP (weights = -0.3993, PIP = 1.00) being the greatest contributors. In conclusion, the MBP-1st and the MEP-2nd are non-linearly associated with the cardiometabolic risk in children. The MBP-3rd and the ∑LMWP-3rd decrease the childhood risk. The combined exposure to phthalate mixture in the second and third trimester elevates and decreases the risk of childhood cardiometabolism, respectively.

Phthalate metabolite concentrations and effects on albuminuria in the US population

BACKGROUND

The usage pattern of phthalates has changed with the introduction of new alternatives such as 1,2-cyclohexane dicarboxylic acid, diisononyl ester (DINCH) and di-isodecyl phthalate (DiDP). However, the concentrations of these alternatives at the population level and their effects on endothelial function are under-studied.

OBJECTIVES

We examined the concentrations of the new alternatives and their previous counterparts, as well as the associations between phthalate exposure and albuminuria in the general US population.

METHODS

In total, 2672 participants from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 were enrolled in this study, and we obtained data on 19 urinary phthalate metabolites, albumin, and creatinine. The distributions of urinary phthalates were studied by age and sex. Linear and logistic regressions were used to estimate the association between urinary phthalate metabolites and albumin.

RESULTS

The geometric mean of the total phthalate concentrations in males and females was 124.97 and 113.09 ng/mL respectively. The detection rates of most urinary phthalate metabolites were greater than 95 %. The major phthalate metabolites found in the US population were MEP (24.20 %) and MECPTP (23.76 %). More positive relationships between phthalate and micro- plus albuminuria were found in females aged ≥ 60 years group（1.49 (95 % CI: 1.08-1.90), 1.44 (95 % CI: 1.06-1.81), 1.52 (95 % CI: 1.14-1.90), 1.41(95 % CI: 1.04-1.78), 1.29(95 % CI: 1.01-1.58), 1.60(95 % CI: 1.20-2.01), 1.45(95 % CI:1.14-1.77), and 1.55(95 % CI: 1.22-1.87) in MECPP, MEHHP, MEOHP, MEHP, MCPP, MHBP, MHNCH and MCOCH respectively）. In total population, logistic regression showed that all traditional phthalate metabolites were associated with an increased proportion of albuminuria (OR range from 1.19 to 1.40, all p < 0.05). However, three new alternatives were not associated with albuminuria (OR range from 1.01 to 1.05, all p > 0.05), and six new alternatives were associated with an increased proportion of albuminuria (OR range from 1.14 to 1.30, all p < 0.05).

CONCLUSIONS

Children have higher metabolite concentrations than adults. Exposure to certain phthalates may disrupt albuminuria homeostasis, especially in older females. Alternative phthalates may have a lower impact on albuminuria than conventional phthalates. The safety of the new alternatives should be interpreted with caution, as more research is still required.

Prenatal exposure to mixtures of phthalates and phenols and body mass index and blood pressure in Spanish preadolescents

BACKGROUND

Pregnant women are simultaneously exposed to several non-persistent endocrine-disrupting chemicals, which may influence the risk of childhood obesity and cardiovascular diseases later in life. Previous prospective studies have mostly examined single-chemical effects, with inconsistent findings. We assessed the association between prenatal exposure to phthalates and phenols, individually and as a mixture, and body mass index (BMI) and blood pressure (BP) in preadolescents.

METHODS

We used data from the Spanish INMA birth cohort study (n = 1,015), where the 1st and 3rd- trimester maternal urinary concentrations of eight phthalate metabolites and six phenols were quantified. At 11 years of age, we calculated BMI z-scores and measured systolic and diastolic BP. We estimated individual chemical effects with linear mixed models and joint effects of the chemical mixture with hierarchical Bayesian kernel machine regression (BKMR). Analyses were stratified by sex and by puberty status.

RESULTS

In single-exposure models, benzophenone-3 (BP3) was nonmonotonically associated with higher BMI z-score (e.g. Quartile (Q) 3: β = 0.23 [95% CI = 0.03, 0.44] vs Q1) and higher diastolic BP (Q2: β = 1.27 [0.00, 2.53] mmHg vs Q1). Methyl paraben (MEPA) was associated with lower systolic BP (Q4: β = -1.67 [-3.31, -0.04] mmHg vs Q1). No consistent associations were observed for the other compounds. Results from the BKMR confirmed the single-exposure results and showed similar patterns of associations, with BP3 having the highest importance in the mixture models, especially among preadolescents who reached puberty status. No overall mixture effect was found, except for a tendency of higher BMI z-score and lower systolic BP in girls.

CONCLUSIONS

Prenatal exposure to UV-filter BP3 may be associated with higher BMI and diastolic BP during preadolescence, but there is little evidence for an overall phthalate and phenol mixture effect.

Prenatal metal mixture exposure and birth weight: A two-stage analysis in two prospective cohort studies

The understanding of the impact of prenatal exposure to metal mixtures on birth weight is limited. We aimed to identify metal mixture components associated with birth weight and to determine additional pairwise interactions between metals showing such associations. Concentrations of 18 metals were measured using inductively coupled plasma mass spectrometry in urine samples collected in the 3rd trimester from a prenatal cohort (discovery; n = 1849) and the Healthy Baby Cohort (replication; n = 7255) in Wuhan, China. In the discovery set, we used two penalized regression models, i.e., elastic net regression for main effects and a lasso for hierarchical interactions, to identify important mixture components associated with birth weight, which were then replicated. We observed that 8 of the 18 measured metals were retained by elastic net regression, with five metals (vanadium, manganese, iron, cesium, and barium) showing negative associations with Z-scores for birth weight and three metals (cobalt, zinc, and strontium) showing positive associations. In replication set, associations remained significant for vanadium (β = -0.035; 95% confidence interval [CI], -0.059 to -0.010), cobalt (β = 0.073; 95% CI, 0.049 to 0.097), and zinc (β = 0.040; 95% CI, 0.016 to 0.065) after Bonferroni correction. We additionally identified and replicated a single pairwise interaction between iron and copper exposure on birth weight (P < 0.001). Using a two-stage analysis, we identified and replicated individual metals and additional pairwise interactions-associated birth weight. The approach could be used in other studies estimating the effect of complex mixtures on human health.

Prenatal single and combined exposure to phthalates associated with girls' BMI trajectory in the first six years

Evidence of the influence of prenatal phthalate exposure on childhood longitudinal obesity markers is limited. Nested on the Ma'anshan birth cohort study, 990 mother-daughter pairs were included. Seven phthalate metabolites were determined in urine collected in each trimester. Each child underwent a physical examination from birth to 6 years of age twelve times. Latent class growth models were used to identify three trajectories of girls' body mass index (BMI). Logistic regression, quantile g-computation and Bayesian kernel machine regression models analyzed the relationships of prenatal exposure to individual and mixed phthalates with girls' body mass index (BMI) trajectory. Compared to the "lowest trajectory" class, prenatal average concentrations of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP, OR_crude = 2.095, 95 % CI = 1.014-4.328) and di(2-ethylhexyl) phthalate (DEHP, OR_crude = 2.336, 95 % CI = 1.022-5.338) during pregnancy were associated with an increased probability of being in the "highest trajectory" class. The average concentration of DEHP (OR_crude = 1.879, 95 % CI = 1.002-3.522) was associated with an increased probability of being in the "moderate trajectory" class. Stratified analyses by trimester of pregnancy mainly showed that third-trimester exposure to monoethyl phthalate (MEP, OR_adjusted = 1.584, 95 % CI = 1.094-2.292), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP, OR_adjusted = 2.885, 95 % CI = 1.367-6.088), MEHHP (OR_adjusted = 2.425, 95 % CI = 1.335-4.407), DEHP (OR_adjusted = 2.632, 95 % CI = 1.334-5.193) and high molecular weight phthalate (OR_adjusted = 2.437, 95 % CI = 1.239-4.792) was associated with an increased probability of being in the "highest trajectory" class. However, the mixture of phthalates was not significantly related to the girl's BMI trajectory. In conclusion, in utero exposure to phthalates, including MEP and DEHP metabolites (MEHHP and MEOHP), was significantly associated with early childhood high BMI trajectories in girls. The third trimester of pregnancy seemed to be the window of vulnerability to phthalate exposure for girls' high BMI trajectory at periods of prenatal development. No evidence supported a significant relationship between combined exposure to phthalate metabolites and girls' high BMI trajectory.

Metabolomics and Data-Driven Bioinformatics Revealed Key Maternal Metabolites Related to Fetal Lethality via Di(2-ethylhexyl)phthalate Exposure in Pregnant Mice

We performed serum metabolome analysis of di(2-ethylhexyl)phthalate (DEHP)-exposed and control pregnant mice. Pregnant mice (n = 5) were fed a DEHP-containing diet (0.1% or 0.2% DEHP) or a normal diet (control) from gestational days 0-18. After maternal exposure to 0.2% DEHP there were no surviving fetuses, indicating its strong fetal lethality. There were no significant differences in the numbers of fetuses and placentas between the 0.1% DEHP and control groups, although fetal viability differed significantly between them, suggesting that maternal exposure to 0.1% DEHP could inhibit fetal growth. Metabolomics successfully detected 169 metabolites in serum. Principal component analysis (PCA) demonstrated that the three groups were clearly separated on PCA score plots. The biological interpretation of PC1 was fetal lethality, whereas PC2 meant metabolic alteration of pregnant mice via DEHP exposure without fetal lethality. In particular, the first component was significantly correlated with fetal viability, demonstrating that maternal metabolome changes via DEHP exposure were strongly related to fetal lethality. Levels of some amino acids were significantly increased in the DEHP-exposed groups, whereas those of some fatty acids, nicotinic acid, and 1,5-anhydroglucitol were significantly decreased in the DEHP groups. DEHP-induced increases in glycine levels could cause fetal neurological disorders, and decreases in nicotinic acid could inhibit fetal growth. In addition, a machine-learning Random forest could determine 16 potential biomarkers of DEHP exposure, and data-driven network analysis revealed that nicotinic acid was the most influential hub metabolite in the metabolic network. These findings will be useful for understanding the effects of DEHP on the maternal metabolome in pregnancy and their relationship to fetal lethality.

Urine Di-(2-ethylhexyl) Phthalate Metabolites Are Independently Related to Body Fluid Status in Adults: Results from a U.S. Nationally Representative Survey

Purpose: Di-(2-ethylhexyl) phthalate (DEHP) has been utilized in many daily products for decades. Previous studies have reported that DEHP exposure could induce renin–angiotensin–aldosterone system activation and increase epithelial sodium channel (ENaC) activity, which contributes to extracellular fluid (ECF) volume expansion. However, there is also no previous study to evaluate the association between DEHP exposure and body fluid status. Methods: We selected 1678 subjects (aged ≥18 years) from a National Health and Nutrition Examination Survey (NHANES) in 2003–2004 to determine the relationship between urine DEHP metabolites and body composition (body measures, bioelectrical impedance analysis (BIA)). Results: After weighing the sampling strategy in multiple linear regression analysis, we report that higher levels of DEHP metabolites are correlated with increases in body measures (body weight, body mass index (BMI), waist circumference), BIA parameters (estimated fat mass, percent body fat, ECF, and ECF/intracellular fluid (ICF) ratio) in multiple linear regression analysis. The relationship between DEHP metabolites and the ECF/ICF ratio was more evident in subjects of younger age (20–39 years old), women, non-Hispanic white ethnicity, and subjects who were not active smokers. Conclusion: In addition to being positively correlated with body measures and body fat, we found that urine DEHP metabolites were positively correlated with ECF and the ECF/ICF ratio in the US general adult population. The finding implies that DEHP exposures might increase ECF volume and the ECF/ICF ratio, which may have adverse health outcomes on the cardiovascular system. Further research is needed to clarify the causal relationship.

Prenatal exposure to phthalate and decreased body mass index of children: a systematic review and meta-analysis

Phthalates are well-known endocrine-disrupting chemicals. Many detrimental health effects of phthalates were investigated, but studies on the association of phthalates with obesity in children showed inconsistent results. Thus, this systematic review and meta-analysis were performed to clarify whether prenatal and postnatal exposures to phthalates are associated with physical growth disturbances in children. We performed the systematic review and meta-analysis following the PRISMA 2020 statement guidelines, and found 39 studies that met our inclusion criteria, including 22 longitudinal and 17 cross-sectional studies. We observed a significant negative association between the prenatal exposure to DEHP and the body mass index (BMI) z-score of the offspring (β = - 0.05; 95% CI: - 0.10, - 0.001) in the meta-analysis, while no significant association between the prenatal exposure to DEHP and the body fat percentage of the offspring was observed (β = 0.01; 95% CI: - 0.41, 0.44). In the systematic review, studies on the association between phthalates exposure in childhood and obesity were inconsistent. Prenatal exposure to phthalates was found to be associated with decreased BMI z-score in children, but not associated with body fat percentage. Our findings suggest that phthalates disturb the normal muscle growth of children, rather than induce obesity, as previous studies have hypothesized.

Obesity II: Establishing causal links between chemical exposures and obesity

Obesity is a multifactorial disease with both genetic and environmental components. The prevailing view is that obesity results from an imbalance between energy intake and expenditure caused by overeating and insufficient exercise. We describe another environmental element that can alter the balance between energy intake and energy expenditure: obesogens. Obesogens are a subset of environmental chemicals that act as endocrine disruptors affecting metabolic endpoints. The obesogen hypothesis posits that exposure to endocrine disruptors and other chemicals can alter the development and function of the adipose tissue, liver, pancreas, gastrointestinal tract, and brain, thus changing the set point for control of metabolism. Obesogens can determine how much food is needed to maintain homeostasis and thereby increase the susceptibility to obesity. The most sensitive time for obesogen action is in utero and early childhood, in part via epigenetic programming that can be transmitted to future generations. This review explores the evidence supporting the obesogen hypothesis and highlights knowledge gaps that have prevented widespread acceptance as a contributor to the obesity pandemic. Critically, the obesogen hypothesis changes the narrative from curing obesity to preventing obesity.

Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

Prenatal Phthalate Exposure and Child Weight and Adiposity from in Utero to 6 Years of Age

BACKGROUND

Prenatal phthalate exposure has been associated with lower birth weight but also higher weight in childhood. Few studies have examined weight or adiposity from birth to childhood and thus cannot assess growth trajectories associated with exposure.

OBJECTIVE

We assessed associations between maternal phthalate exposures in pregnancy and child weight and adiposity measured prenatally through childhood (3-6 years of age).

METHODS

Within The Infant Development and the Environment Study (TIDES), a prospective pregnancy cohort, we analyzed a panel of phthalate metabolites in urine collected at two visits from early and late gestation (N=780). We estimated average phthalate metabolite associations with child weight z-scores from ∼20wk gestation (estimated by ultrasound), birth, and 1, 3, 4, and 6 years of age using linear mixed-effects (LME) models. We also modeled associations with adiposity z-scores from birth (weight for length) and 1, 3, 4, and 6 years of age [body mass index (BMI)] using LME models.

RESULTS

For weight, we observed inverse associations between several phthalate metabolites and birth weight z-scores, but no associations were observed with postnatal weight z-scores in LME models. Regarding adiposity, we observed inverse associations between phthalate metabolites and weight-for-length z-scores at birth, but positive associations were observed with BMI z-scores at 3-4 years of age in LME models. For example, mono-ethyl phthalate was associated with a 0.17-unit decrease in birth weight-for-length z-score [95% confidence interval (CI): -0.29, -0.05] and a 0.18-unit increase in 4-years-of-age BMI z-score (95% CI: 0.04, 0.32).

DISCUSSION

We observed associations between prenatal exposure to phthalates and lower weight at birth but not at childhood follow-up visits. However, for adiposity, we observed an interesting pattern of association with low adiposity at delivery as well as high adiposity at 3-4 years of age. Although it is not clear from our results whether these associations occur within the same children, such a pattern of adiposity in early life has been linked to cardiometabolic disease in adulthood and deserves special attention as an outcome in the study of prenatal exposures in the developmental origins of health and disease. https://doi.org/10.1289/EHP10077.

Developmental Exposure to Endocrine Disrupting Chemicals and Its Impact on Cardio-Metabolic-Renal Health

Developmental origin of health and disease postulates that the footprints of early life exposure are followed as an endowment of risk for adult diseases. Epidemiological and experimental evidence suggest that an adverse fetal environment can affect the health of offspring throughout their lifetime. Exposure to endocrine disrupting chemicals (EDCs) during fetal development can affect the hormone system homeostasis, resulting in a broad spectrum of adverse health outcomes. In the present review, we have described the effect of prenatal EDCs exposure on cardio-metabolic-renal health, using the available epidemiological and experimental evidence. We also discuss the potential mechanisms of their action, which include epigenetic changes, hormonal imprinting, loss of energy homeostasis, and metabolic perturbations. The effect of prenatal EDCs exposure on cardio-metabolic-renal health, which is a complex condition of an altered biological landscape, can be further examined in the case of other environmental stressors with a similar mode of action.

Prenatal phthalate exposure associated with age-specific alterations in markers of adiposity in offspring: A systematic review

Childhood obesity and metabolic disorders are of concern and are public health problems globally. Environmental endocrine disruptors, including phthalates, are well known as "obesogens" and "metabolic disruptors". Several studies have investigated the relationships between prenatal phthalate exposure and childhood obesity with inconsistent conclusions. Given the child growth trajectory/pattern as a possible early marker of metabolic disorders, we aimed to assess the effect of prenatal phthalate exposure on offspring growth trajectory. A systematic literature search was conducted using MEDLINE (accessed through PubMed), Web of Science, and CNKI (Chinese National Knowledge Infrastructure) until July 2021. We evaluated the risk of bias for adherence to the prespecified criteria. Fourteen eligible articles were finally included in this systematic review according to the defined PECOS statement. The risk of bias of the included studies was "low" or "probably low", and few were "probably high" and "high". These studies were mostly carried out in the United States (N = 6); others were conducted in China (N = 2), Mexico (N = 2), France (N = 1), Spain (N = 1), Greece (N = 1), and Australia (N = 1) and published from 2015 to 2021. The combined subjects of the 14 studies were 10,396 mother-child pairs. Except for 3 studies not reporting the sex ratio, at least 4001 boys and 3366 girls were included. For the association of prenatal phthalate exposure with an absolute adiposity marker (at a specific visit timepoint), only a few studies were using the same obesity marker as the outcome endpoint and using the same statistical method to explore their associations. However, MEP appeared to be positively associated with several obesity markers, such as the absolute BMI z score, weight-for-age z score, waist circumference, and overweight status. For the association of prenatal phthalate exposure with a repeated measurement of the adiposity marker over the age range, neither associations of adiposity markers with a specific phthalate metabolite nor relationships of a specific adiposity marker with prenatal phthalate exposure were of a consistent result. All four articles reported that phthalate metabolite exposure during pregnancy was associated with children's growth trajectory. Three suggested a sex-specific association between prenatal phthalate exposure and obesity trajectory. In conclusion, the current articles did not show any relationship between prenatal phthalate exposure and children's age-specific outcomes, except for positive associations of prenatal MEP exposure with absolute adiposity markers. However, epidemiological data supported a weak relationship between prenatal phthalate exposure and children's obesity trajectory in a sex-specific manner.

Effect of childhood phthalates exposure on the risk of overweight and obesity: A nested case-control study in China

BACKGROUND

There was growing interest in endocrine disrupting chemicals that might have effect on the obesity epidemic, but few studies on the association of phthalates (PAEs) with childhood overweight and obesity in China based on longitudinal cohort study were available, which was the purpose of the present study.

METHODS

A nested case-control study was conducted in a prospective cohort of 2298 children aged 7-13 years from October 2017 to October 2020 with five waves visits in Xiamen city, China. A total of 829 children remained in the first wave of follow up with collection of urine for measuring seven PAEs metabolites, including mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-iso-butyl phthalate (MiBP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) and mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), utilizing ultra high performance liquid chromatography-triple quadrupole mass spectrometry. Overweight and obesity, defined by WHO classifications, were allocated to the cases group, and those of all normal weight and matched cases with normal weight in each wave of follow-up as two control groups. Logistic regression models after adjusting for confounders were utilized to analyze the effect of PAEs on overweight and obesity in children with divided four groups based on the quartile distribution of each and total PAEs concentration.

RESULTS

The detection rates of children for each PAEs metabolite were 99.4% for MMP, 99.4% for MEP, 99.8% for MBP, 54.5% for MEHP, 84.4% for MEOHP, 99.9% for MEHHP, and 97.2% for MiBP. The geometric mean of concentrations of PAEs, MMP, MEP, MBP, MEHP, MEHHP, and MiBP were 310.085, 34.658, 9.127, 166.347, 7.043, 3.400, 18.571, and 24.093 (ng/ml), respectively. The total PAEs and seven metabolites concentrations were positively associated with childhood BMI Z-Scores with statistically significant slope rates and correlation coefficients, and were higher in the cases group than those in two controls groups in each wave of follow-up. The PAEs concentrations in the cases group was 5.90 (95 %CI: 5.79, 6.01) ng/ml in the first wave of survey, which was higher than those normal controls group (5.68 (95 %CI: 5.61, 5.75) ng/ml, P < 0.001) and matched controls group (5.72 (95 %CI: 5.61, 5.84) ng/ml, P = 0.018). The prevalence and ORs of overweight and obesity increased with quartile group of each and total PAEs concentrations accompanying a dose-response relationship. Compared with the quartile1 reference group with lowest total PAEs concentrations, the ORs of overweight and obesity in quartile2, quartile3 and quartile4 group increased gradually and reached at 1.20 (0.74-1.95), 1.49 (0.93-2.38) and 2.22 (1.41-3.48), respectively (P_trend < 0.001). The strength of the associations between PAEs and overweight and obesity was sex-specific in children.

DISCUSSION

Children in China were extensively exposed to PAEs, and the exposure to PAEs during childhood could significantly increase the risk of overweight and obesity with a dose-response relationship, particularly in girls. While limiting the exposure of PAEs products, the determination of exposure limit of plasticizer should be further strengthened.

Modification of the association by sex between the prenatal exposure to di(2-ethylhexyl) phthalate and fat percentage in a cohort of Mexicans schoolchildren

INTRODUCTION

Children's overweight and obesity are global public health problems, children with obesity have grater obesity risk as adults, thus leading to develop cardiometabolic diseases. Previous studies have found positive and significant associations between the exposure to phthalates and body mass index and body composition.

OBJECTIVE

To evaluate the modification of the association by sex between DEHP exposure during pregnancy and the percentage of body fat in a cohort of Mexican schoolchildren.

MATERIAL AND METHODS

The sample was comprised by children which had previously participated in a POSGRAD longitudinal study. A subsample of 190 mother-children binomials were included. Mothers' DEHP concentrations and its metabolites had been measured in the second trimester of pregnancy: Mono-2-ethylhexyl phthalate (MEHP), Mono-2-ethyl-5-carboxypentyl phthalate (MECPP), Mono-2-ethyl-5-hidroxyhexyl phthalate (MEHHP), and Mono-2-ethyl-5-oxohexyl phthalate (MEOHP). The children's adipose mass was measured at age 8, 9, and 10. Longitudinal data were analyzed using the mixed effects linear regression model, with intercept and random slope, adjusted by important confounders and stratified by sex.

RESULTS

We found a differentiated effect by sex, the exposure to DEHP during pregnancy significantly increases the adipose mass in boys. The average increase was 0.058% (p = 0.02) for every 1% variation in MECPP; 0.047% (p = 0.04) in MEHHP; 0.051% (p = 0.03) in MEOHP, and 0.066% (p = 0.007) in MECPP.

CONCLUSIONS

The results suggest an effect differentiated by sex; with boys being the main ones affected by the prenatal exposure to phthalates. However, we cannot rule out effects in girls.

Associations between maternal mono-(2-ethylhexyl) phthalate levels, nuclear receptor gene polymorphisms, and fatty acid levels in pregnant Japanese women in the Hokkaido study

We assessed how the interaction between mono-(2-ethylhexyl) phthalate (MEHP) in maternal sera and the maternal genotypes associated with nuclear receptors affect fatty acid levels in a prospective birth cohort study of pregnant Japanese individuals (n = 437) recruited in Sapporo between 2002 and 2005. We analyzed MEHP and fatty acids using gas chromatography-mass spectrometry. Thirteen single nucleotide polymorphisms of peroxisome proliferator-activated receptor (PPAR) alpha, PPAR gamma (PPARG), PPARG coactivator 1A (PPARGC1A), PPAR delta, constitutive androstane receptor, liver X receptor (LXR) alpha, and LXR beta (LXRB) were analyzed using real-time PCR. Multiple linear regression models were used to confirm the influence of log₁₀-transformed MEHP levels and maternal genotypes on log₁₀-transformed fatty acid levels. When the effects of the interaction between MEHP levels and the maternal PPARGC1A (rs8192678) genotype on oleic acid levels were evaluated, the estimated changes (95 % confidence intervals) in oleic acid levels against MEHP levels, maternal PPARGC1A (rs8192678)-GA/AA genotype, and the interaction between them showed a mean reduction of 0.200 (0.079, 0.322), mean reduction of 0.141 (0.000, 0.283), and mean increase of 0.145 (0.010, 0.281), respectively, after adjusting for the perfluorooctanesulfonate level. The effects of the interaction between MEHP levels and maternal LXRB (rs2303044) genotype on linoleic acid levels was also significant (p_int = 0.010). In conclusion, the interaction between MEHP and the maternal genotypes PPARGC1A (rs8192678) and LXRB (rs2303044) decreased fatty acid levels. Further, the interaction between MEHP and PPARGC1A (rs8192678) may have a greater effect on fatty acid levels than the interaction between PFOS and PPARGC1A.

PERTURBED FACTOR ANALYSIS: ACCOUNTING FOR GROUP DIFFERENCES IN EXPOSURE PROFILES

In this article we investigate group differences in phthalate exposure profiles using NHANES data. Phthalates are a family of industrial chemicals used in plastics and as solvents. There is increasing evidence of adverse health effects of exposure to phthalates on reproduction and neurodevelopment and concern about racial disparities in exposure. We would like to identify a single set of low-dimensional factors summarizing exposure to different chemicals, while allowing differences across groups. Improving on current multigroup additive factor models, we propose a class of Perturbed Factor Analysis (PFA) models that assume a common factor structure after perturbing the data via multiplication by a group-specific matrix. Bayesian inference algorithms are defined using a matrix normal hierarchical model for the perturbation matrices. The resulting model is just as flexible as current approaches in allowing arbitrarily large differences across groups but has substantial advantages that we illustrate in simulation studies. Applying PFA to NHANES data, we learn common factors summarizing exposures to phthalates, while showing clear differences across groups.

Prenatal exposure to phthalate esters and its impact on child development

Endocrine disruptive chemicals (EDCs) cause adverse health effects through interaction with endocrine systems. They are classified by chemical structure, effects on specific endocrine systems, their bioaccumulation and/or persistence in the environment, and/or clinically observable effects. In industrial nations, people are exposed to complex mixtures of many different substances all of which may have multiple and deleterious effects upon the individual. The clinical importance of epigenetic changes caused by the action of EDCs during vulnerable phases of development is currently unclear but of particular relevance. Epidemiological studies are criticized because reproducibility is not always guaranteed. Nevertheless, they remain the method of choice for the development and analysis of suitable model systems. Positive associations, despite of sometimes conflicting results, are the key in the selection of factors that can then be analyzed in model systems in an unbiased way. This article reports EDC-caused effects in the fields of growth and metabolism, neurocognitive development and sexual development and reproduction focusing mainly on phthalates and their metabolites. However, research will have to focus on the interactions of different EDCs and their consequences of prenatal and early life exposure.

Exposure to obesogenic endocrine disrupting chemicals and obesity among youth of Latino or Hispanic origin in the United States and Latin America: A lifecourse perspective

Following a 2019 workshop led by the Center for Global Health Studies at the Fogarty International Center on the topic of childhood obesity prevention and research synergies transpiring from cross-border collaborations, we convened a group of experts in the United States and Latin America to conduct a narrative review of the epidemiological literature on the role of obesogenic endocrine disrupting chemicals (EDCs) in the etiology of childhood obesity among Latino youth in the United States and Latin America. In addition to summarizing and synthesizing results from research on this topic published within the last decade, we place the findings within a lifecourse biobehavioral framework to aid in identification of unique exposure-outcome relationships driven by both biological and behavioral research, identify inconsistencies and deficiencies in current literature, and discuss the role of policy regulations, all with the goal of identifying viable avenues for prevention of early life obesity in Latino/Hispanic populations.

Racial/Ethnic Disparities in Pregnancy and Prenatal Exposure to Endocrine-Disrupting Chemicals Commonly Used in Personal Care Products

Purpose of Review

Endocrine-disrupting chemical (EDC) exposure during pregnancy is linked to adverse maternal and child health outcomes that are racially/ethnically disparate. Personal care products (PCP) are one source of EDCs where differences in racial/ethnic patterns of use exist. We assessed the literature for racial/ethnic disparities in pregnancy and prenatal PCP chemical exposures.

Recent Findings

Only 3 studies explicitly examined racial/ethnic disparities in pregnancy and prenatal exposure to PCP-associated EDCs. Fifty-three articles from 12 cohorts presented EDC concentrations stratified by race/ethnicity or among homogenous US minority populations. Studies reported on phthalates and phenols. Higher phthalate metabolites and paraben concentrations were observed for pregnant non-Hispanic Black and Hispanic women. Higher concentrations of benzophenone-3 were observed in non-Hispanic White women; results were inconsistent for triclosan.

Summary

This review highlights need for future research examining pregnancy and prenatal PCP-associated EDCs disparities to understand and reduce racial/ethnic disparities in maternal and child health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40572-021-00317-5.

Associations between Prenatal Exposure to Phthalates and Timing of Menarche and Growth and Adiposity into Adulthood: A Twenty-Years Birth Cohort Study

Phthalates are ubiquitous environmental chemicals with endocrine disrupting properties and potentially obesogenic effects. We hypothesised that antenatal phthalate exposure may influence growth and adiposity patterns in girls through childhood into adolescence. Among 1342 Raine Study singleton females, 462 had maternal serum and at least one outcome available up to 20 years of age. Individuals’ maternal serum collected at 18 and 34 weeks gestation was pooled and analyzed for concentrations of 32 metabolites of 15 phthalate diesters. Cox regression and linear models were used to determine associations between maternal phthalate levels and age at menarche, change in height and weight z-scores between birth and two years, height from birth to 20 years, BMI from two to 20 years, deviation from mid-parental height at age 20 and DEXA scan measures at age 20. Weak negative associations were detected with some phthalate metabolites and change in height and weight z-score during infancy. Weak positive associations between some of the high molecular weight phthalate metabolites and height z-score were detected during childhood. While still within the normal range, age at menarche was slightly delayed in girls with higher prenatal exposure to the higher molecular weight phthalate metabolites. We derived some associations between prenatal phthalate exposure with early growth patterns and age at menarche.

The influence of prenatal exposure to phthalates on subsequent male growth and body composition in adolescence

Phthalates are ubiquitous environmental chemicals with predominantly anti-androgenic, and potentially obesogenic effects. We hypothesised that antenatal phthalate exposure may influence subsequent boy's growth and body composition through childhood and adolescence. Among 1399 singleton males from the Raine Study, 410 had maternal serum and at least one height, BMI or DEXA outcome available after birth and up to 20 years of age. Maternal serum collected at 18 and 34 weeks' gestation was pooled, and analyzed for concentrations of 32 metabolites of 15 phthalate diesters. Their serum concentrations were categorized into undetectable/detectable levels or tertiles. Linear mixed models were used to determine associations between maternal serum phthalate levels and longitudinal height and body mass index (BMI) z-scores in boys from birth to 20 years of age (n = 250 and n = 295 respectively). Linear regression was used to determine associations between maternal phthalate levels and deviation from mid-parental height (n = 177) and DEXA scan outcomes (n = 191) at the 20 year follow-up. Weak positive associations of participants height z-score increase were detected with exposure to some phthalate metabolites in particular to the lower molecular weight phthalate metabolites. Less consistent findings, by mixed model analyses, were detected for BMI and body composition, by dual energy X-ray absorptiometry (DEXA), with some positive associations of phthalate metabolites with BMI and some negative associations with DEXA fat tissue measures, although no consistent findings were evident. In conclusion, we derived some associations of childhood growth with prenatal phthalate exposure, particularly with respect to the lower molecular weight phthalate metabolites.

Increased apoptosis, reduced Wnt/β-catenin signaling, and altered tail development in zebrafish embryos exposed to a human-relevant chemical mixture

A wide variety of anthropogenic chemicals is detected in humans and wildlife and the health effects of various chemical exposures are not well understood. Early life stages are generally the most susceptible to chemical disruption and developmental exposure can cause disease in adulthood, but the mechanistic understanding of such effects is poor. Within the EU project EDC-MixRisk, a chemical mixture (Mixture G) was identified in the Swedish pregnancy cohort SELMA by the inverse association between levels in women at around gestational week ten with birth weight of their children. This mixture was composed of mono-ethyl phthalate, mono-butyl phthalate, mono-benzyl phthalate, mono-ethylhexyl phthalate, mono-isononyl phthalate, triclosan, perfluorohexane sulfonate, perfluorooctanoic acid, and perfluorooctane sulfonate. In a series of experimental studies, we characterized effects of Mixture G on early development in zebrafish models. Here, we studied apoptosis and Wnt/β-catenin signaling which are two evolutionarily conserved signaling pathways of crucial importance during development. We determined effects on apoptosis by measuring TUNEL staining, caspase-3 activity, and acridine orange staining in wildtype zebrafish embryos, while Wnt/β-catenin signaling was assayed using a transgenic line expressing an EGFP reporter at β-catenin-regulated promoters. We found that Mixture G increased apoptosis, suppressed Wnt/β-catenin signaling in the caudal fin, and altered the shape of the caudal fin at water concentrations only 20-100 times higher than the geometric mean serum concentration in the human cohort. These findings call for awareness that pollutant mixtures like mixture G may interfere with a variety of developmental processes, possibly resulting in adverse health effects.

Urinary phthalates and body mass index in preschool children: The MIREC Child Development Plus study

Childhood exposure to phthalates, a class of chemicals with known reproductive and developmental effects, has been hypothesized to increase the risk of obesity, but this association is not well understood in preschool children. We examined the association between urinary concentrations of phthalate metabolites and concurrently measured body mass index (BMI) and skinfolds among children between the ages of two and five years. We collected anthropometric measures and biomonitoring data on approximately 200 children enrolled in the Maternal-Infant Research on Environmental Chemicals Child Development Plus study. We measured 22 phthalate metabolites in children's urine and used the 19 metabolites detected in at least 40% of samples. Our primary outcome was BMI z-scores calculated using the World Health Organization growth standards. Skinfold z-scores were secondary outcomes. We used multivariable linear regression to evaluate the association between tertiles of phthalate concentrations and each anthropometric measure. We also used weighted quantile sum regression to identify priority exposures of concern. Our analytic sample included 189 singleton-born children with complete anthropometric data. Children with concentrations of the parent compound di-n-butyl phthalate (∑DnBP) in the third tertile had 0.475 (95% CI: 0.068, 0.883) higher BMI z-scores than those in the lower tertile. ∑DnBP was identified as a priority exposure in the weighted quantile sum regression BMI model. In this population of Canadian preschool aged children, we identified DnBP as a potential chemical of concern in regard to childhood obesity. Future research with serial phthalate measurements and anthropometric measurements in young children will help confirm these findings.

Life-Time Environmental Chemical Exposure and Obesity: Review of Epidemiological Studies Using Human Biomonitoring Methods

The exponential global increase in the incidence of obesity may be partly attributable to environmental chemical (EC) exposure. Humans are constantly exposed to ECs, primarily through environmental components. This review compiled human epidemiological study findings of associations between blood and/or urinary exposure levels of ECs and anthropometric overweight and obesity indices. The findings reveal research gaps that should be addressed. We searched MEDLINE (PubMed) for full text English articles published in 2006-2020 using the keywords "environmental exposure" and "obesity". A total of 821 articles were retrieved; 102 reported relationships between environmental exposure and obesity indices. ECs were the predominantly studied environmental exposure compounds. The ECs were grouped into phenols, phthalates, and persistent organic pollutants (POPs) to evaluate obesogenic roles. In total, 106 articles meeting the inclusion criteria were summarized after an additional search by each group of EC combined with obesity in the PubMed and Scopus databases. Dose-dependent positive associations between bisphenol A (BPA) and various obesity indices were revealed. Both individual and summed di(2-ethylhexyl) phthalate (DEHP) and non-DEHP metabolites showed inconsistent associations with overweight and obesity indices, although mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), and mono-benzyl phthalate (MBzP) seem to have obesogenic roles in adolescents, adults, and the elderly. Maternal exposure levels of individual POP metabolites or congeners showed inconsistent associations, whereas dichlorodiphenyldichloroethylene (DDE) and perfluorooctanoic acid (PFOA) were positively associated with obesity indices. There was insufficient evidence of associations between early childhood EC exposure and the subsequent development of overweight and obesity in late childhood. Overall, human evidence explicitly reveals the consistent obesogenic roles of BPA, DDE, and PFOA, but inconsistent roles of phthalate metabolites and other POPs. Further prospective studies may yield deeper insights into the overall scenario.

Paternal mixtures of urinary concentrations of phthalate metabolites, bisphenol A and parabens in relation to pregnancy outcomes among couples attending a fertility center

BACKGROUND

Few epidemiologic studies have evaluated the impact of paternal environmental exposures, particularly as mixtures, on couples' pregnancy outcomes.

OBJECTIVE

We investigated whether mixtures of paternal urinary bisphenol A (BPA), paraben, and phthalates were associated with pregnancy outcomes among couples attending a fertility center.

METHODS

We included 210 couples undergoing 300 in vitro fertilization (IVF) between 2004 and 2017 in this prospective analysis. We quantified paternal urinary biomarker concentrations in one sample per cycle using isotope-dilution tandem mass spectrometry. We used principal component analysis (PCA) to identify correlations of biomarker concentrations and multivariable Cox proportional hazards models for discrete survival time to estimate the hazard ratios (HRs) and 95% CIs for the associations between PCA-derived factor scores and probability of failing to achieve a live birth. Interactions were also included in the models to examine strength of associations over three vulnerable periods [embryo transfer to implantation, implantation to clinical pregnancy, and clinical pregnancy to live birth]. Models were adjusted for paternal and maternal ages and body mass indexes, urinary dilution (specific gravity) and year of collection, infertility diagnosis, and other PCA factor scores. Sensitivity analyses with further adjustment for maternal PCA factor scores were performed.

RESULTS

We identified three factors, representing di-2-ethylhexyl phthalate (DEHP) metabolites, BPA and non-DEHP metabolites, and parabens, accounting for 56%, 15% and 10%, respectively, of the total variance explained. An interquartile range (25th and 75th percentiles) increase in the DEHP-related factor score was associated with elevated probability of failing prior to live birth (HR = 1.41, 95% CI: 1.08, 1.81) and the association was stronger between implantation and clinical pregnancy as well as between clinical pregnancy and live birth compared to before implantation. The overall HRs of failure for the BPA/non-DEHP-related and paraben-related factor scores were HR = 1.24 (95% CI: 0.97, 1.59) and HR = 0.99 (95% CI: 0.80, 1.24). We found similar HRs when additionally adjusting for maternal PCA factor scores.

CONCLUSION

Paternal mixtures of urinary concentrations of DEHP metabolites were related to higher infertility treatment failure.

Developmental origins of metabolic diseases

Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.

Phthalate Exposure, Adolescent Health, and the Need for Primary Prevention

Phthalates, a class of endocrine-disrupting chemicals, are used widely in many consumer products, and exposure can interfere with a range of hormonal functions during early life. These disruptions may alter development during late childhood and adolescence. This article discusses the potential effects of phthalate exposure on adiposity, puberty, and neurodevelopment during late childhood and adolescence. It also highlights studies of behavioral interventions to reduce phthalate exposures and the roles of health care professionals and policy makers in preventing phthalate exposure.

Fetal exposure to phthalates and bisphenols and childhood general and organ fat. A population-based prospective cohort study

OBJECTIVES

Fetal exposure to phthalates and bisphenols might have long-lasting effects on growth and fat development. Not much is known about the effects on general and organ fat development in childhood. We assessed the associations of fetal exposure to phthalates and bisphenols with general and organ fat measures in school-aged children.

METHODS

In a population-based, prospective cohort study among 1128 mother-child pairs, we measured maternal urinary phthalate metabolites and bisphenol concentrations in first, second, and third trimester. Offspring body mass index, fat mass index by dual-energy X-ray absorptiometry, and visceral and pericardial fat indices and liver fat fraction were measured by magnetic resonance imaging at 10 years.

RESULTS

After adjustment for confounders and correction for multiple testing, an interquartile range increase in first trimester phthalic acid concentrations remained associated with a 0.14 (95% confidence interval: 0.05, 0.22) standard deviation score increase in pericardial fat index. We also observed tendencies for associations of higher maternal low molecular weight phthalate urinary concentrations in second trimester with childhood pericardial fat index, but these were not significant after adjustment for multiple testing. High molecular weight phthalate, di-2-ethylhexyl phthalate, and di-n-octyl phthalate concentrations were not associated with childhood outcomes. Maternal urinary bisphenol concentrations were not associated with childhood adiposity.

CONCLUSIONS

Maternal first trimester phthalic acid concentrations are associated with increased childhood pericardial fat index at 10 years of age, whereas maternal bisphenol concentrations are not associated with childhood adiposity. We did not find significant sex-specific effects. These findings should be considered as hypothesis generating and need further replication and identification of underlying mechanisms.

The Endocrine Disruption of Prenatal Phthalate Exposure in Mother and Offspring

Phthalates are a group of ubiquitous synthetic endocrine-disrupting chemicals. Fetal and neonatal periods are particularly susceptible to endocrine disorders, which prenatal exposure to phthalates causes. There is increasing evidence concerning the potential endocrine disrupting for phthalate exposure during pregnancy. This article aims to review the endocrine impairment and potential outcomes of prenatal phthalate exposure. Prenatal exposure phthalates would disrupt the levels of thyroid, sex hormone, and 25-hydroxyvitamin D in pregnant women or offspring, which results in preterm birth, preeclampsia, maternal glucose disorders, infant cryptorchidism, infant hypospadias, and shorter anogenital distance in newborns, as well as growth restriction not only in infants but also in early adolescence and childhood. The relationship of prenatal phthalate exposure with maternal and neonatal outcomes in human beings was often sex-specific associations. Because of the potentially harmful influence of prenatal phthalate exposure, steps should be taken to prevent or reduce phthalate exposure during pregnancy.

Residential neighborhood features associated with objectively measured walking near home: Revisiting walkability using the Automatic Context Measurement Tool (ACMT)

Many distinct characteristics of the social, natural, and built neighborhood environment have been included in walkability measures, and it is unclear which measures best describe the features of a place that support walking. We developed the Automatic Context Measurement Tool, which measures neighborhood environment characteristics from public data for any point location in the United States. We explored these characteristics in home neighborhood environments in relation to walking identified from integrated GPS, accelerometer, and travel log data from 681 residents of King Country, WA. Of 146 neighborhood characteristics, 92 (63%) were associated with walking bout counts after adjustment for individual characteristics and correction for false discovery. The strongest built environment predictor of walking bout count was housing unit count. Models using data-driven and a priori defined walkability measures exhibited similar fit statistics. Walkability measures consisting of different neighborhood characteristic measurements may capture the same underlying variation in neighborhood conditions.

Endocrine disruption and obesity: A current review on environmental obesogens

Obesity represents an important public health concern because it substantially increases the risk of multiple chronic diseases and thereby contributing to a decline in both quality of life and life expectancy. Besides unhealthy diet, physical inactivity and genetic susceptibility, environmental pollutants also contribute to the rising prevalence of obesity epidemic. An environmental obesogen is defined as a chemical that can alter lipid homeostasis to promote adipogenesis and lipid accumulation whereas an endocrine disrupting chemical (EDC) is defined as a synthetic chemical that can interfere with the endocrine function and cause adverse health effects. Many obesogens are EDCs that interfere with normal endocrine regulation of metabolism, adipose tissue development and maintenance, appetite, weight and energy balance. An expanding body of scientific evidence from animal and epidemiological studies has begun to provide links between exposure to EDCs and obesity. Despite the significance of environmental obesogens in the pathogenesis of metabolic diseases, the contribution of synthetic chemical exposure to obesity epidemic remains largely unrecognised. Hence, the purpose of this review is to provide a current update on the evidences from animal and human studies on the role of fourteen environmental obesogens in obesity, a comprehensive view of the mechanisms of action of these obesogens and current green and sustainable chemistry strategies to overcome chemical exposure to prevent obesity. Designing of safer version of obesogens through green chemistry approaches requires a collaborative undertaking to evaluate the toxicity of endocrine disruptors using appropriate experimental methods, which will help in developing a new generation of inherently safer chemicals.

•

Many environmental obesogens are endocrine disrupting chemicals that interfere with normal endocrine regulation of metabolism.

•

Understanding the role of environmental obesogens in the epidemics of obesity is in an infant stage.

•

Green chemistry approach aims to design a safer version of these chemicals by understanding their hazardous effects.

•

Further studies are necessary to fully establish the hazardous effects of obesogens and their association to human obesity.

Urinary Concentrations of Phthalate Metabolite Mixtures in Relation to Serum Biomarkers of Thyroid Function and Autoimmunity among Women from a Fertility Center

BACKGROUND

Although previous epidemiological studies have explored associations of phthalate metabolites with thyroid function, no studies to date have assessed associations of mixtures with thyroid function and autoimmunity among potentially susceptible subgroups such as subfertile women.

OBJECTIVE

We aimed to explore associations of mixtures of urinary phthalate metabolites with serum markers of thyroid function and autoimmunity.

METHODS

This cross-sectional study included 558 women attending a fertility center who provided one spot urine and one blood sample at enrollment (2005-2015). We quantified urinary concentrations of eight phthalate metabolites using mass spectrometry, and biomarkers of thyroid function [thyroid-stimulating hormone (TSH), free and total thyroxine (fT4, TT4) and triiodothyronine (fT3, TT3), and autoimmunity [thyroid peroxidase and thyroglobulin antibodies (TPOAb and TgAb, respectively)] in serum using electrochemiluminescence assays. We applied principal component analysis (PCA) and Bayesian kernel machine regression (BKMR) to identify the main patterns of urinary phthalate metabolites. We used linear mixed models to assess the association between PCA-derived factor scores in quintiles and serum thyroid function and autoimmunity, adjusting for age, body mass index (BMI), specific gravity (SG), and, for the PCA, other factor scores.

RESULTS

We observed two factors using PCA, one representing the di(2-ethylhexyl) (DEHP) and another non-DEHP metabolites. Compared to women in the lowest quintile of the DEHP factor scores, women in the highest quintile had significantly lower serum concentrations of fT4, TT4, fT3, and TT3 [absolute difference: -0.62; 95% confidence interval (CI): -0.12, -0.01; p=0.04; absolute difference: -8.31; 95% CI: -13.8, -2.85; p=0.003; absolute difference: -0.37; 95% CI: 0.54, -0.19; p<0.0001; and absolute difference: -0.21; 95% CI: -0.32, -0.10; p=0.003, respectively]. Using BKMR, we observed that mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was the primary contributor to these negative associations. DEHP and non-DEHP factor scores were not associated with serum TSH, TgAb, or TPOAb.

CONCLUSIONS

Mixtures of urinary DEHP metabolites were inversely associated with serum biomarkers of thyroid function but not with autoimmunity, which were within normal ranges for healthy adult women. https://doi.org/10.1289/EHP6740.

Endocrine-Disrupting Chemicals and Insulin Resistance in Children

The purpose of this article is to review the evidence linking background exposure to endocrine-disrupting chemicals (EDCs) with insulin resistance in children. Although evidence in children is scarce since very few prospective studies exist even in adults, evidence that EDCs might be involved in the development of insulin resistance and related diseases such as obesity and diabetes is accumulating. We reviewed the literature on both cross-sectional and prospective studies in humans and experimental studies. Epidemiological studies show a statistical link between exposure to pesticides, polychlorinated bisphenyls, bisphenol A, phthalates, aromatic polycyclic hydrocarbides, or dioxins and insulin resistance.