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

Understanding the role of endocrine disrupting chemicals as environmental obesogens in the obesity epidemic: A comprehensive overview of epidemiological studies between 2014 and 2024

The prevalence of obesity has reached epidemic proportions worldwide, posing a significant public health concern due to its association with various chronic diseases and healthcare costs. In addition to traditional risk factors such as diet and physical activity, emerging evidence suggests that environmental pollutants, termed obesogens, may contribute to the obesity epidemic. Obesogens are endocrine-disrupting chemicals (EDCs) that can alter lipid homeostasis, promote adipogenesis, and disrupt metabolic regulation, leading to increased adiposity and obesity risk. This review explores available data from human studies published in the last decade, along with the mechanisms underlying obesogenic action, including their effects on adipocyte differentiation, adipose tissue development, and metabolic regulation. Overall, 75 studies were analyzed. Early-life exposure during critical developmental windows has been shown to increase obesity risk later in life, potentially through epigenetic modifications and transgenerational effects. Epidemiological studies provide evidence of associations between prenatal or early-life exposure and increased obesity risk in offspring. Additionally, study found more consistent associations between exposure to some EDCs (including phthalates, parabens, and bisphenols) and obesity or metabolic outcomes in children and women, while results for other chemicals (i.e. PFAS and organochlorine pesticides) were more heterogeneous, especially in adolescents and adults. Key findings indicate consistent associations between phthalate exposure and obesity in children, with mixed results for adults. Future research should focus on elucidating the full spectrum of obesogens, their mechanisms of action, and their implications for obesity risk across generations. This knowledge will inform preventive strategies and public health interventions aimed at addressing the obesity epidemic and its associated health burden.

Maternal per- and polyfluoroalkyl substances exposure, cord blood lipidomics and infant anthropometry: A mediation analysis

Maternal exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with offspring adiposity; however, underlying mechanisms remain unclear. In this study, we quantified 11 PFAS in maternal plasma collected between 12 and 16 gestational weeks and 104 lipid metabolites in the cord blood of 525 mother-infant pairs. Principal components of multiple PFAS compounds, extracted by principal component analysis, were employed to investigate the effect of the PFAS mixture. Infant anthropometric indicators included weight, length, waist/arm circumference, and abdominal/triceps/subscapular skinfold thickness at birth and 6 and 12 months old. Multiple linear regression showed that maternal PFAS exposure was primarily associated with increased glycerophospholipids and decreased fatty acyls and bile acids in cord blood. Four glycerophospholipids (16:0 PI, 16:0-18:1 PI, 18:0-20:4 PI, and 18:0-18:1 PS), fatty acyls (5(S)-HETE, 15(S)-HETE, 13-HDoHE, and dhkPGF2), and bile acids (GCA, TCA, TCDA, and TDCA) partially mediated the positive associations of the first principle component of PFAS compounds (with positive loadings for all PFAS compounds), PFNA, and PFUdA with infant skinfold thickness with mediating proportions ranging from 15.24% to 33.39%. Our findings provide novel insights into mechanisms underlying the effects of maternal PFAS exposure on infant growth.

Novel Approach to Screen Endocrine-Disrupting Chemicals via Endocrine-Enhanced Reduced Human Transcriptome

Endocrine-disrupting chemicals (EDCs) can interfere with multiple pathways and trigger different modes of action. Thus, the traditional EDC in vitro screening processes often require a battery of bioassays to cover multiple target pathways. Here we developed an endocrine-enhanced reduced human transcriptome (ERHT) focused on hormone receptor signaling induced by the EDCs regulating specific genes. ERHT was developed based on 1200 prioritized genes covering 110 endocrine-related biological pathways across eight potential adverse outcomes. The ability of this approach to identify EDCs was derived from machine learning of 1068 dose-dependent transcriptome profiles and enhanced by quantifying chemical-induced critical pathway responses, and thus, it demonstrated excellent classification performance (AUC = 0.84 ± 0.03) in internal cross-validation. We ultimately applied this approach to known EDCs and inactive substances to validate the reliability of this approach. Through external validation on 210 chemicals, the extrapolation accuracy exceeded 80%, demonstrating the outstanding practical performance of this approach. Meanwhile, the pathway responses induced by the same chemical were consistent with the experimental results reported by multiple sequencing platforms, highlighting the robustness of this approach. The above results demonstrate that this approach can provide novel insights for EDCs' high-throughput screening and comprehensive toxic mechanisms through biological pathways.

Sex-specific associations between maternal exposure to metal mixtures and fetal growth trajectories: A prospective birth cohort study

BACKGROUND

The associations of prenatal metals exposure with birth outcomes have been widely assessed. However, evidence on the associations between metal mixtures and fetal intrauterine growth trajectories is scarce.

OBJECTIVES

This study aimed to explore the associations of metal mixtures with fetal intrauterine growth trajectories overall and by sex.

METHODS

We analyzed data from the Ma'anshan birth cohort, which included a total of 1041 pregnant woman. The concentrations of 12 metals in maternal blood were measured during early pregnancy, and fetal intrauterine growth indicators were standardized and assessed at 16, 23, 30, 34, and 38 weeks of gestation. We used generalized linear regression and linear mixed models to identify the key fetal growth indicator (biparietal diameter (BPD)), and applied GBTM to characterize BPD SD-scores trajectories. To further assess the individual and combined effects of metals, we conducted multivariable logistic regression and repeated holdouts weighted quantile sum (WQS) regression analyses, respectively. Finally, we performed a sex-stratified analysis to explore sex-specific associations.

RESULTS

The sex-stratified multivariable logistic regression analysis indicated that in male fetal, cobalt (Co) (OR: 0.60, 95 % CI: 0.38, 0.92) was negatively associated with the high-growth BPD-SD scores trajectory. In contrast, Co (OR: 2.39, 95 % CI: 1.40, 4.45) showed a positive association in female fetal. Results from the WQS showed that early pregnancy metal mixture exposure was associated with BPD-SD scores at 16, 34, and 38 weeks in female fetal. The results highlighted Zn and Co as key metals associated with high-growth BPD SD-scores trajectory. We also identified a significant interaction between early pregnancy metal mixtures and sex on high-growth BPD SD-scores trajectories. The WQS*sex interaction term had a mean odds ratio of 1.271 (95 % CI: 1.027, 1.619).

CONCLUSION

This study suggests that exposure to prenatal metal mixtures affects fetal intrauterine growth trajectories with sexual dimorphism.

Associations of early life per- and polyfluoroalkyl substances (PFAS) exposure with body mass index and risk of overweight or obesity at age 2-18 years: Mixture analysis in the prospective Boston Birth Cohort

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are a class of widespread persistent chemicals, which may have obesogenic effects during the fetal period. This study investigated the long-term association of maternal plasma PFAS concentrations at delivery and their mixture with child body mass index (BMI) and the risk of Overweight or Obesity (OWO) at the age of 2-18 years.

METHODS

The study included 1189 mother-child dyads from the prospective Boston Birth Cohort. Eight PFAS were measured in maternal plasma samples collected 24-72 h after delivery. Outcomes were BMI Z-score and OWO status of children at 2-18 years. The exposure-outcome associations were evaluated with linear and modified Poisson mixed-effects regression for individual PFAS and Bayesian kernel machine regression and quantile-based g-computation models for PFAS mixture. We explored the effect modification by maternal pre-pregnancy OWO, child age, sex, and race.

RESULTS

Maternal plasma samples had PFAS detection frequencies from 87 % to 100 % and geometric means ranging from 0.11 to 3.67 ng/mL. PFHpS and PFHxS were associated with higher child BMI Z-score. Such associations were stronger in children aged 6-12 years and 13-18 years than in 2-5 years. Stratified by maternal pre-pregnancy OWO, significant associations of the PFAS mixture with child BMI Z-score were only found in children of non-OWO mothers. In children aged 13-18 years, children with both high maternal plasma PFDeA, PFNA, and PFOA concentrations and maternal OWO had the highest risks of OWO compared to children with either only. Such synergistic effects were not found in younger children.

CONCLUSIONS

Early life exposure to individual PFAS and their mixture were associated with a higher risk of childhood OWO, with stronger associations observed in older child age groups and in children of non-OWO mothers. Synergistic effects of PFAS exposures and maternal pre-pregnancy OWO became evident in adolescence.

Associations of prenatal and concurrent exposure to phenols mixture with anthropometric measures and blood pressure during childhood: A time-varying mixture approach

BACKGROUND

Environmental phenols were recognized as endocrine disrupting chemicals (EDCs). However, their impact on childhood anthropometric measures and blood pressure (BP) is still inconclusive. Limited studies have simultaneously considered prenatal and childhood exposures in analyzing mixtures of phenols.

OBJECTIVE

We investigated the relationships between combined prenatal and childhood exposures (two periodic exposures) to phenol mixtures and anthropometric measure and BP, to further identify the vulnerable periods of phenol exposure and to explore the important individual contribution of each phenol.

METHODS

We analyzed 434 mother-child dyads from the Sheyang Mini Birth Cohort Study (SMBCS). The urinary concentrations of 11 phenolic compounds were measured using gas chromatography tandem mass spectrometry. Generalized linear regression models (GLMs) and hierarchical Bayesian Kernel Machine Regression (hBKMR) were used to examine the effects of individual phenolic compounds at each period and of two periodic exposures.

RESULTS

In the single-chemical analysis, prenatal or childhood exposure to specific phenols, especially Benzopheone-3 (BP3), 4-tert-Octylphenol (4-tOP), and Benzyl paraben (BePB) were associated with BMI z-scores (BAZ), Waist-to-height ratio (WHtR), and BP. In the hBKMR models, two periodic exposures to phenol mixtures had a U-shaped association with WHtR, primarily driven by childhood BePB exposure. Moreover, among the phenol mixtures analysis, childhood 4-tOP exposure was identified as the primary contributor to the positive association with diastolic BP. Concurrent exposure to phenol mixtures resulted in greater susceptibility.

CONCLUSIONS

We found that prenatal and childhood exposure to phenol mixtures might influence childhood obesity and elevate blood pressure levels. Concurrent exposure to 4-tOP may be the primary driver of the positive associations with BP.

Association between phthalates exposure and myocardial damage in the general population: A cross-sectional study

BACKGROUND

Cardiovascular consequences of phthalates exposure have been given increasing attention, but the association of phthalates with subclinical cardiovascular disease (CVD) was unknown. Accordingly, this study aimed to investigate the association between phthalates exposure and high-sensitivity cardiac troponin I (hs-cTnI), a marker of myocardial injury, which was detectable in the subclinical stage of CVD.

METHODS

Participants aged 6 years or older with available urinary phthalates metabolites and serum hs-cTnI concentrations were included in the National Health and Nutrition Examination Survey 2003-2004 cycle. Multivariable linear regression and weighted quantiles sum (WQS) regression were used to assess the association of hs-cTnI with individual phthalates and their co-exposure. Di-2-ethylhexylphthalate (ΣDEHP), high-molecular-weight phthalate (ΣHMWP), and low-molecular-weight phthalate (ΣLMWP) were defined as the molecular sum of phthalates metabolites in urine.

RESULTS

2241 participants were finally included. The percent change of serum hs-cTnI concentrations related to per 1-standard deviation increase of logarithmic urinary phthalates concentrations was 3.4% (0.1-6.7, P = 0.04) for ΣDEHP, 3.6% (0.3-6.9, P = 0.03) for ΣHMWP, and 3.5% (0.2-6.8, P = 0.04) for ΣLMWP. Co-exposure to phthalates metabolites expressed as the WQS index also demonstrated a positive association with hs-cTnI. A similar association pattern was found in the population with no prior CVD.

CONCLUSIONS

This study indicated the potential of phthalates to myocardial injury which may occur even before clinically apparent CVD was identified, emphasizing the significance of reducing phthalates in the prevention of CVD.

Associations of prenatal exposure to phthalates and their mixture with lung function in Mexican children

Early life phthalates exposure has been associated with adverse respiratory outcomes. However, evidence linking prenatal phthalates exposure and childhood lung function has been inconclusive. Additionally, few studies have examined phthalates exposure as a mixture and explored sexually dimorphic associations. We aimed to investigate sex-specific associations of prenatal phthalates mixtures with childhood lung function using the PROGRESS cohort in Mexico (N = 476). Prenatal phthalate concentrations were measured in maternal urine collected during the 2nd and 3rd trimesters. Children's lung function was evaluated at ages 8-13 years. Individual associations were assessed using multivariable linear regression, and mixture associations were modeled using repeated holdout WQS regression and hierarchical BKMR; data was stratified by sex to explore sex-specific associations. We identified significant interactions between 2nd trimester phthalates mixture and sex on FEV1 and FVC z-scores. Higher 2nd trimester phthalate concentrations were associated with higher FEV1 (β = 0.054, 95 %CI: 0.005, 0.104) and FVC z-scores (β = 0.074, 95 % CI: 0.024, 0.124) in females and with lower measures in males (FEV1, β = -0.017, 95 %CI: -0.066, 0.026; FVC, β = -0.014, 95 %CI: -0.065, 0.030). This study indicates that prenatal exposure to phthalates is related to childhood lung function in a sex-specific manner.

Alterations of gut microbiota and its metabolomics in children with 6PPDQ, PBDE, PCB, and metal(loid) exposure

The composition and metabolites of the gut microbiota can be altered by environmental pollutants. However, the effect of co-exposure to multiple pollutants on the human gut microbiota has not been sufficiently studied. In this study, gut microorganisms and their metabolites were compared between 33 children from Guiyu, an e-waste dismantling and recycling area, and 34 children from Haojiang, a healthy environment. The exposure level was assessed by estimating the daily intake (EDI) of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), 6PPD-quinone (6PPDQ), and metal(loid)s in kindergarten dust. Significant correlations were found between the EDIs of 6PPDQ, BDE28, PCB52, Ni, Cu, and the composition of gut microbiota and specific metabolites. The Bayesian kernel machine regression model showed negative correlations between the EDIs of five pollutants (6PPDQ, BDE28, PCB52, Ni, and Cu) and the composition of gut microbiota. The EDIs of these five pollutants were positively correlated with the levels of the metabolite 2,4-diaminobutyric acid, while negatively correlated with the levels of d-erythro-sphingosine and d-threitol. Our study suggests that exposure to 6PPDQ, BDE28, PCB52, Ni, and Cu in kindergarten dust is associated with alterations in the composition and metabolites of the gut microbiota. These alterations may be associated with children's health.

Determination of pesticide residues in urine by chromatography-mass spectrometry: methods and applications

Introduction

Pollution has emerged as a significant threat to humanity, necessitating a thorough evaluation of its impacts. As a result, various methods for human biomonitoring have been proposed as vital tools for assessing, managing, and mitigating exposure risks. Among these methods, urine stands out as the most commonly analyzed biological sample and the primary matrix for biomonitoring studies.

Objectives

This review concentrates on exploring the literature concerning residual pesticide determination in urine, utilizing liquid and gas chromatography coupled with mass spectrometry, and its practical applications.

Method

The examination focused on methods developed since 2010. Additionally, applications reported between 2015 and 2022 were thoroughly reviewed, utilizing Web of Science as a primary resource.

Synthesis

Recent advancements in chromatography-mass spectrometry technology have significantly enhanced the development of multi-residue methods. These determinations are now capable of simultaneously detecting numerous pesticide residues from various chemical and use classes. Furthermore, these methods encompass analytes from a variety of environmental contaminants, offering a comprehensive approach to biomonitoring. These methodologies have been employed across diverse perspectives, including toxicological studies, assessing pesticide exposure in the general population, occupational exposure among farmers, pest control workers, horticulturists, and florists, as well as investigating consequences during pregnancy and childhood, neurodevelopmental impacts, and reproductive disorders.

Future directions

Such strategies were essential in examining the health risks associated with exposure to complex mixtures, including pesticides and other relevant compounds, thereby painting a broader and more accurate picture of human exposure. Moreover, the implementation of integrated strategies, involving international research initiatives and biomonitoring programs, is crucial to optimize resource utilization, enhancing efficiency in health risk assessment.

Associations of per- and polyfluoroalkyl substances (PFAS) and their mixture with risk of rheumatoid arthritis in the U.S. adult population

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are known environmental contaminants with immunosuppressive properties. Their connection to rheumatoid arthritis (RA), a condition influenced by the immune system, is not well studied. This research explores the association between PFAS exposure and RA prevalence.

METHODS

This research utilized data from the NHANES, encompassing a sample of 10,496 adults from the 2003-2018 cycles, focusing on serum levels of several PFAS. The presence of RA was determined based on self-reports. This study used multivariable logistic regression to assess the relationship between individual PFAS and RA risk, adjusting for covariates to calculate odds ratios (ORs). The combined effects of PFAS mixtures were evaluated using BKMR, WQS regression, and quantile g-computation. Additionally, sex-specific associations were explored through stratified analysis.

RESULTS

Higher serum PFOA (OR = 0.88, 95% CI: 0.79, 0.98), PFHxS (OR = 0.91, 95% CI: 0.83, 1.00), PFNA (OR = 0.87, 95% CI: 0.77, 0.98), and PFDA (OR = 0.89, 95% CI: 0.81, 0.99) concentration was related to lower odds of RA. Sex-specific analysis in single chemical models indicated the significant inverse associations were only evident in females. BKMR did not show an obvious pattern of RA estimates across PFAS mixture. The outcomes of sex-stratified quantile g-computation demonstrated that an increase in PFAS mixture was associated with a decreased odds of RA in females (OR: 0.76, 95% CI: 0.62, 0.92). We identified a significant interaction term of the WQS*sex in the 100 repeated hold out WQS analysis. Notably, a higher concentration of the PFAS mixture was significantly associated with reduced odds of RA in females (mean OR = 0.93, 95% CI: 0.88, 0.98).

CONCLUSIONS

This study indicates potential sex-specific associations of exposure to various individual PFAS and their mixtures with RA. Notably, the observed inverse relationships were statistically significant in females but not in males. These findings contribute to the growing body of evidence indicating that PFAS may have immunosuppressive effects.

Prenatal exposure to Per- and polyfluoroalkyl substances and adiposity measures of children at 4 and 6 years: A prospective birth cohort in China

There is growing evidence that prenatal exposure to Per- and polyfluoroalkyl substances (PFAS) was associated with childhood obesity, but evidence on multiple adiposity measures including arm circumference (AC), and waist circumference (WC) among Chinese children is limited. We investigated the associations of prenatal exposure to PFAS with adiposity measures of children at 4 and 6 years of age in the Shanghai-Minhang Birth Cohort Study. A total of 573 mother-child pairs with maternal PFAS concentrations and at least one measurement of adiposity measures of children were included in the present study. Eleven PFAS were assessed in maternal fasting blood samples. Information on children's weight, height, AC, and WC was collected at follow-ups. Weight for age Z score (WAZ), body mass index for age Z score (BMIz), and children overweight were calculated based on the World Health Organization Child Growth Standards. Multivariate linear regression, Poisson regression with robust error variance, and Bayesian Kernel Machine Regression (BKMR) models were used to examine the associations of prenatal exposure to PFAS with children's adiposity measures. Eight PFAS with detection rates above 85 % were included in the analyses. In the multivariate linear regression models, maternal PFNA concentrations were associated with a greater AC (β = 0.29, 95 % Confidence Interval (CI): 0.04-0.55) in 4-year-old children and with an increase in WAZ (β = 0.26, 95 % CI: 0.06-0.46), BMIz (β = 0.31, 95 % CI: 0.09-0.53), AC (β = 0.49, 95 % CI: 0.08-0.90), and WC (β = 1.47, 95 % CI: 0.41-2.52) in 6-year-old children. We also observed the associations of maternal concentrations of PFOS, PFNA, PFUdA, and PFTrDA with the increased risk of children overweight in 6-year-old children. BKMR models further supported the findings from multivariate linear regression and Poisson regression models, and identified PFNA as the most important contributor. Moreover, the associations described above were generally more pronounced in girls. In conclusion, prenatal exposure to PFAS was associated with an increased risk of children's adiposity with a sex-specific manner, and PFNA contributed most to the associations after controlling for the effect of co-exposure to other PFAS compounds, especially among girls at 6 years of age.