Prenatal concentrations of polychlorinated biphenyls, DDE, and DDT and overweight in children: a prospective birth cohort study

Inheritance of environment-induced phenotypic changes through epigenetic mechanisms

Growing evidence suggests that epigenetic changes through various parental environmental factors alter the phenotypes of descendants in various organisms. Environmental factors, including exposure to chemicals, stress and abnormal nutrition, affect the epigenome in parental germ cells by different epigenetic mechanisms, such as DNA methylation, histone modification as well as small RNAs via metabolites. Some current remaining questions are the causal relationship between environment-induced epigenetic changes in germ cells and altered phenotypes of descendants, and the molecular basis of how the abnormal epigenetic changes escape reprogramming in germ cells. In this review, we introduce representative examples of intergenerational and transgenerational inheritance of phenotypic changes through parental environmental factors and the accompanied epigenetic and metabolic changes, with a focus on animal species. We also discuss the molecular mechanisms of epigenomic inheritance and their possible biological significance.

Dichlorodiphenyltrichloroethane for Malaria and Agricultural Uses and Its Impacts on Human Health

Pesticides are widely used in agriculture and disease control, and dichlorodiphenyltrichloroethane (DDT) is one of the most used pesticides in human history. Besides its significant contributions in pest control in agriculture, DDT was credited as having saved millions of human lives for controlling malaria and other deadly insect-transmitted diseases. Even today, the use of DDT in some countries for malaria control cannot be replaced without endangering people who live there. The recent COVID-19 pandemic has changed our lives and reminded us of the challenges in dealing with infectious diseases, especially deadly ones including malaria. However, DDT and its metabolites are stable, persist long, are found in almost every corner of the world, and their persistent effects on humans, animals, and the environment must be seriously considered. This review will focus on the history of DDT use for agriculture and malaria control, the pathways for the spread of DDT, benefits and risks of DDT use, DDT exposure to animals, humans, and the environment, and the associated human health risks. These knowledge and findings of DDT will benefit the selection and management of pesticides worldwide.

Pesticides and insulin resistance-related metabolic diseases: Evidences and mechanisms

The use of pesticides in the past century has lot helped humankind in improving crops' field and general hygiene level. Nevertheless, there has been countless evidences on the toxic effects of pesticides on the living systems. The link of exposure to pesticides with different human chronic diseases in the context of carcinogenicity, neurotoxicity, developmental toxicity, etc., have been evaluated in various types of studies. There are also some evidences on the link of exposure to pesticides with higher incidence of metabolic diseases associated with insulin resistance like diabetes, obesity, metabolic syndrome, hypertension, polycystic ovary syndrome and chronic kidney diseases. Physiologically, weakening intracellular insulin signaling is considered as a compensatory mechanism for cells to cope with cellular stresses like xenobiotic effects, oxidative stress and inflammatory responses, but it can pathologically lead to a defective cycle with lowered sensitivity of the cells to insulin which happens in metabolic disorders. In this work, the data related to metabolic toxicity of pesticides categorized in the mentioned metabolic diseases with a focus on the effects of pesticides on insulin signaling pathway and the mechanisms of development of insulin resistance will be systematically reviewed and presented.

PCB126 exposure during pregnancy alters maternal and fetal gene expression

Polychlorinated biphenyls (PCBs) are organic pollutants that can have lasting impacts on offspring health. Here, we sought to examine maternal and fetal gene expression differences of aryl hydrocarbon receptor (AHR)-regulated genes in a mouse model of prenatal PCB126 exposure. Female mice were bred and gavaged with 1 µmole/kg bodyweight PCB126 or vehicle control on embryonic days 0 and 14, and maternal and fetal tissues were collected on embryonic day 18.5. Total RNAs were isolated, and gene expression levels were analyzed in both maternal and fetal tissues using the NanoString nCounter system. Interestingly, we found that the expression levels of cytochrome P450 (Cyp)1a1 and Cyp1b1 were significantly increased in response to PCB exposure in the tested maternal and fetal tissues. Furthermore, PCB exposure altered the expression of several other genes related to energy balance, oxidative stress, and epigenetic regulation in a manner that was less consistent across tissue types. These results indicate that maternal PCB126 exposure significantly alters gene expression in both developing fetuses and pregnant dams, and such changes vary in intensity and expressivity depending on tissue type. The altered gene expression may provide insights into pathophysiological mechanisms by which in utero PCB exposures contribute to PCB-induced postnatal metabolic diseases.

Phenylalanine Residues in the Active Site of CYP2E1 Participate in Determining the Binding Orientation and Metabolism-Dependent Genotoxicity of Aromatic Compounds

The composition of amino acids forming the active site of a CYP enzyme is impactful in its substrate selectivity. For CYP2E1, the role of PHE residues in the formation of effective binding orientations for its aromatic substrates remains unclear. In this study, molecular docking and molecular dynamics analysis were performed to reflect the interactions between PHEs in the active site of human CYP2E1 and various aromatic compounds known as its substrates. The results indicated that the orientation of 1-methylpyrene (1-MP) in the active site was highly determined by the presence of PHEs, PHE478 contributing to the binding free energy most significantly. Moreover, by building a random forest model the relationship between each of 19 molecular descriptors of polychlorinated biphenyl (PCB) compounds (from molecular docking, quantum mechanics, and physicochemical properties) and their human CYP2E1-dependent mutagenicityas established mostly in our lab, was investigated. The presence of PHEs did not appear to significantly modify the electronic or structural feature of each bound ligand (PCB), instead, the flexibility of the conformation of PHEs contributed substantially to the effective binding energy and orientation. It is supposed that PHE residues adjust their own conformation to permit a suitablly shaped cavity for holding the ligand and forming its orientation as favorable for a biochemical reaction. This study has provided some insights into the role of PHEs in guiding the interactive adaptation of the active site of human CYP2E1 for the binding and metabolism of aromatic substrates.

Individual Risk Assessment for Population Living on the Territories Long-Term Polluted by Organochlorine Pesticides

The long-term storage of unutilized pesticides raised new problems of long-term environmental contamination. The study presents the results of surveying 151 individuals in 7 villages living close to pesticide-contaminated localities. All individuals have been surveyed concerning their consumption habits and lifestyle characteristics. An assessment of the general exposure risks of the local population was carried out using the analysis of pollutants in food products and the average levels of their consumption in the region. The cohort risk evaluation revealed that the greatest risk was associated with the regular consumption of cucumbers, pears, bell peppers, meat, and milk. The new model to estimate individual risks of long-term pesticide pollution was proposed as a calculation of the combined action of 9 risk factors, including individual genotypes, age, lifestyle, and personal pesticide consumption rates. The analysis of the predictive ability of this model showed that the final score for individual health risks corresponded to the development of chronic diseases. A high level of chromosomal aberrations was evidenced for individual genetic risk manifestations. The combined influence of all risk factors revealed contributions of 24.7% for health status and 14.2% for genetic status, while other impacts go to all unaccounted factors.

Metabolic Consequences of the Water We Drink: A Study Based on Field Evidence and Animal Model Experimentation

The effect of the chronic consumption of water contaminated with residual concentrations of DDT's metabolites (DDD-dichlorodiphenyldichloroethane and DDE-dichlorodiphenyldichloroethylene) found in the environment were evaluated on the biometric, hematological and antioxidant system parameters of the hepatic, muscular, renal and nervous tissues of Wistar rats. The results showed that the studied concentrations (0.002 mg.L^-1 of DDD plus 0.005 mg.L^-1 of DDE) could not cause significant changes in the hematological parameters. However, the tissues showed significant alteration in the activity of the antioxidant system represented by the increase in the activity of the enzymes gluthathione S-transferases in the liver, superoxide dismutase in the kidney, gluthathione peroxidase in the brain, and several changes in enzymatic activity in muscle (SOD, GPx and LPO). The enzymes alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) were also evaluated for the amino acids' metabolism in the liver, with ALT showing a significant increase in the exposed animals. In the integrative analysis of biomarkers (Permanova and PCOA), the studied concentrations showed possible metabolic changes and damage to cellular structures evidenced by increased oxidative stress and body weight gain among the treated animals. This study highlights the need for further studies on the impact of banned pesticides still present in soils that may induce adverse effects in organisms that may prevail in future generations and the environment.

Pesticides as endocrine disruptors: programming for obesity and diabetes

PURPOSE

Exposure to pesticides has been associated with obesity and diabetes in humans and experimental models mainly due to endocrine disruptor effects. First contact with environmental pesticides occurs during critical phases of life, such as gestation and lactation, which can lead to damage in central and peripheral tissues and subsequently programming disorders early and later in life.

METHODS

We reviewed epidemiological and experimental studies that associated pesticide exposure during gestation and lactation with programming obesity and diabetes in progeny.

RESULTS

Maternal exposure to organochlorine, organophosphate and neonicotinoids, which represent important pesticide groups, is related to reproductive and behavioral dysfunctions in offspring; however, few studies have focused on glucose metabolism and obesity as outcomes.

CONCLUSION

We provide an update regarding the use and metabolic impact of early pesticide exposure. Considering their bioaccumulation in soil, water, and food and through the food chain, pesticides should be considered a great risk factor for several diseases. Thus, it is urgent to reformulate regulatory actions to reduce the impact of pesticides on the health of future generations.

Nutritional Modulation of Associations between Prenatal Exposure to Persistent Organic Pollutants and Childhood Obesity: A Prospective Cohort Study

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) may contribute to the development of childhood obesity and metabolic disorders. However, little is known about whether the maternal nutritional status during pregnancy can modulate these associations.

OBJECTIVES

The main objective was to characterize the joint associations and interactions between prenatal levels of POPs and nutrients on childhood obesity.

METHODS

We used data from to the Spanish INfancia y Medio Ambiente-Environment and Childhood (INMA) birth cohort, on POPs and nutritional biomarkers measured in maternal blood collected at the first trimester of pregnancy and child anthropometric measurements at 7 years of age. Six organochlorine compounds (OCs) [dichlorodiphenyldichloroethylene, hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH) and polychlorinated biphenyls 138, 153, 180] and four per- and polyfluoroalkyl substances (PFAS) were measured. Nutrients included vitamins (D, B12, and folate), polyunsaturated fatty acids (PUFAs), and dietary carotenoids. Two POPs-nutrients mixtures data sets were established: a) OCs, PFAS, vitamins, and carotenoids (n=660), and b) OCs, PUFAs, and vitamins (n=558). Joint associations of mixtures on obesity were characterized using Bayesian kernel machine regression (BKMR). Relative importance of biomarkers and two-way interactions were identified using gradient boosting machine, hierarchical group lasso regularization, and BKMR. Interactions were further characterized using multivariate regression models in the multiplicative and additive scale.

RESULTS

Forty percent of children had overweight or obesity. We observed a positive overall joint association of both POPs-nutrients mixtures on overweight/obesity risk, with HCB and vitamin B12 the biomarkers contributing the most. Recurrent interactions were found between HCB and vitamin B12 across screening models. Relative risk for a natural log increase of HCB was 1.31 (95% CI: 1.11, 1.54, pInteraction=0.02) in the tertile 2 of vitamin B12 and in the additive scale a relative excess risk due to interaction of 0.11 (95% CI: 0.02, 0.20) was found. Interaction between perfluorooctane sulfonate and β-cryptoxanthin suggested a protective effect of the antioxidant on overweight/obesity risk.

CONCLUSION

These results support that maternal nutritional status may modulate the effect of prenatal exposure to POPs on childhood overweight/obesity. These findings may help to develop a biological hypothesis for future toxicological studies and to better interpret inconsistent findings in epidemiological studies. https://doi.org/10.1289/EHP11258.

Persistent Organic Pollutant Levels in Maternal and Cord Blood Plasma and Breast Milk: Results from the Rio Birth Cohort Pilot Study of Environmental Exposure and Childhood Development (PIPA Study)

Levels of polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) were evaluated in the breast milk and maternal and umbilical cord blood of pregnant women and their newborns in Rio de Janeiro, Brazil. The concentration of 11 PCB and 17 OCP were measured in 135 samples of maternal, and 116 samples of cord blood plasma, as well as 40, 47, and 45 samples of breast milk at 1st, 3rd, and 6th months after birth, respectively, using gas chromatography-mass spectrometry (GC-MS-MS). Women were asked to answer an enrollment questionnaire with reproductive, lifestyle, residential and sociodemographic questions. The most commonly detected OCPs and PCBs in the maternal and cord blood were 4,4'-DDE; β-HCH; ɣ-HCH; and PCB 28. 4,4'-DDE was also the most commonly detected OCP in breast milk samples. Although not statistically significant, ∑DDT levels were higher among women with pregestational BMI ≥ 30, and who were non-white and older (age > 40). Newborns with an Apgar score ≤ 8 at minute 5 of life showed significantly higher levels of ∑DDT in the cord blood. Persistent OCPs and PCBs were still detected in maternal and umbilical cord blood and breast milk, even after decades of their banishment in Brazil. They may pose a risk to maternal, fetal and children's health.

Investigation of obesogenic effects of hexachlorobenzene, DDT and DDE in male rats

Obesity has become a very important public health problem and is increasing globally. Genetics, individual and environmental factors play roles in the etiology of this complex disorder. Recently, several environmental pollutants have been suggested to have obesogenic activities. Peroxisome proliferator activating receptor gamma (PPARγ), uncoupling protein-1 (UCP1) and their expression in white adipose tissue (WAT) and brown adipose tissue (BAT) play key roles in adipogenesis. UCP3 and irisin were reported to play roles in non-shivering thermogenesis. Our primary aim was to investigate obesogenic effects of hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) in rats. In addition, thermoregulatory effects of HCB, DDT and DDE were also investigated by analyzing the levels of Ucp3 and irisin. Thirty-two adult male Sprague-Dawley rats were randomly divided into four groups as control, HCB, DDT and DDE. Animals were administered with organochlorine pesticides (OCPs; 5 mg/kg bw) by oral gavage every other day for five weeks. At the end of the experimental period, the animals were sacrificed, BAT and WAT samples were collected to analyze Pparγ, Ucp1 and Ucp3 levels. Moreover, skeletal muscle samples were collected to examine Ucp3 and irisin levels. Serum glucose, cholesterol and triglyceride levels were also determined. Body weight and core temperature of the animals were not significantly affected by any of the OCP administration. Serum glucose, cholesterol and triglyceride levels were similar among the experimental groups. Pparγ expression was significantly elevated by HCB administration only in WAT (p < 0.05). On the other hand, both Pparγ and Ucp1 expressions were diminished in WAT and BAT (p < 0.01) by DDT treatment, while in WAT, DDE significantly decreased Pparγ expression without altering its expression in BAT (p < 0.001). Ucp3 and irisin levels in skeletal muscle were not altered. Our findings show that both DDT and DDE reduce the browning of WAT by suppressing white adipocytes and thus may have obesogenic activity in male rats without altering thermoregulation. In addition, HCB, DDT and DDE-induced alterations in expression of Pparγ and Ucp1 in WAT implicates differential regulation of adipogenic processes.

Exposure levels of PCDD/Fs and PCBs in human blood and the transplacental transfer characteristics in cord blood of newborns near the industrialized area

Mono-to octa-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in pooled blood from the general population living near a typical industrialized area were investigated. Less chlorinated PCDD/Fs (mean: 2602 pg L^-1) were 7.5 times those of highly chlorinated ones (mean: 349 pg L^-1). The average ΣPCBs and Σdl-PCBs concentrations in human (cord) blood were 2741 (117) and 18 (0.31) ng L^-1, respectively. Higher concentrations of highly chlorinated PCDD/Fs were found in females than in males across different ages. The mean concentrations (and toxic equivalents (TEQs)) of PCDD/Fs were 282 (27) pg L^-1 in males and 312 (32) pg L^-1 in females. The concentrations of the PCDD/Fs and PCBs increased with age for both males and females, which might be caused by the long half-lives of these compounds and decreases in metabolic rates with age as the metabolic of nutrients, food, and also PCDD/Fs and PCBs would trend to slow. The TEQ of total PCDD/Fs and PCBs was higher in blood from orthopedics patients (107 pg L^-1) than other patients. This result may be associated with the bone density and pollutant bioaccumulation. In addition, total concentration of PCDD/Fs and PCBs in blood of women at reproductive age were 6.6 and 37 times the cord blood of newborns, respectively. Positive correlation of PCDD/Fs and PCBs especially for the higher chlorinated compounds between female and cord blood were discovered, which might be caused by the transplacental transfer characteristics and blood barrier for macromolecules and reduce the chemical exposure risks for newborns.

Gene expression signatures in PCB-exposed Slovak children in relation to their environmental exposures and socio-physical characteristics

Our previous gene expression studies in a PCB-exposed cohort of young children in Slovakia revealed that early-life exposures to PCBs and other organochlorine compounds were associated with significant alterations across several pathogenetic pathways. The present study was undertaken to further explore the high-throughput qRT-PCR-based gene expression effects by using TaqMan low-density array (TLDA) for selected genes in a sample of 55 children from the cohort. We analyzed the transcriptional changes of 11 genes in relation to PCB and organochlorine pesticide exposure levels (including DDT, DDE, HCH, and HCB), and to BMI and ethnicity in this cohort. The results indicated an overall downregulation of expression of these genes. Maximum downregulation (in fold change) was observed in the ENTPD3 gene, and the minimum level of downregulation was in CYP2D6. As per our multinomial regression model study, downregulation of LEPR gene was significantly directly correlated with all the exposure variables. Downregulation of APC, ARNT, CYP2D6, LEPR, LRP12, and MYC genes was directly correlated with BMI (kg/m²) of the individuals. Gender-specific differences in gene expression were observed in CYP2D6 (p-value 0.0001) and LEPR (p-value 0.028), while downregulation of CYP2D6 (p-value 0.01), LEPR (p-value 0.02), LRP12 (p-value 0.04), and MYC (p-value 0.02) genes was consistently observed in Roma children compared to Caucasians. The investigation of such health disparities must be emphasized in future research, together with interventions to reduce the health consequences of PCB exposures. In this context, we emphasize the importance of biomarker-based approaches to future research on genetic susceptibility to the effects of these compounds.

CYP1A1, VEGFA and Adipokine Responses of Human Adipocytes Co-exposed to PCB126 and Hypoxia

It is increasingly recognized that hypoxia may develop in adipose tissue as its mass expands. Adipose tissue is also the main reservoir of lipophilic pollutants, including polychlorinated biphenyls (PCBs). Both hypoxia and PCBs have been shown to alter adipose tissue functions. The signaling pathways induced by hypoxia and pollutants may crosstalk, as they share a common transcription factor: aryl hydrocarbon receptor nuclear translocator (ARNT). Whether hypoxia and PCBs crosstalk and affect adipokine secretion in human adipocytes remains to be explored. Using primary human adipocytes acutely co-exposed to different levels of hypoxia (24 h) and PCB126 (48 h), we observed that hypoxia significantly inhibits the PCB126 induction of cytochrome P450 (CYP1A1) transcription in a dose-response manner, and that Acriflavine (ACF)—an HIF1α inhibitor—partially restores the PCB126 induction of CYP1A1 under hypoxia. On the other hand, exposure to PCB126 did not affect the transcription of the vascular endothelial growth factor-A (VEGFA) under hypoxia. Exposure to hypoxia increased leptin and interleukin-6 (IL-6), and decreased adiponectin levels dose-dependently, while PCB126 increased IL-6 and IL-8 secretion in a dose-dependent manner. Co-exposure to PCB126 and hypoxia did not alter the adipokine secretion pattern observed under hypoxia and PCB126 exposure alone. In conclusion, our results indicate that (1) hypoxia inhibits PCB126-induced CYP1A1 expression at least partly through ARNT-dependent means, suggesting that hypoxia could affect PCB metabolism and toxicity in adipose tissue, and (2) hypoxia and PCB126 affect leptin, adiponectin, IL-6 and IL-8 secretion differently, with no apparent crosstalk between the two factors.

Association of Prenatal Exposure to Endocrine-Disrupting Chemicals With Liver Injury in Children

Importance

Prenatal exposures to endocrine-disrupting chemicals (EDCs) may increase the risk for liver injury in children; however, human evidence is scarce, and previous studies have not considered potential EDC-mixture effects. Furthermore, the association between prenatal EDC exposure and hepatocellular apoptosis in children has not been studied previously.

Objective

To investigate associations of prenatal exposure to EDC mixtures with liver injury risk and hepatocellular apoptosis in childhood.

Design, Setting, and Participants

This prospective cohort study used data collected from April 1, 2003, to February 26, 2016, from mother-child pairs from the Human Early-Life Exposome project, a collaborative network of 6 ongoing, population-based prospective birth cohort studies from 6 European countries (France, Greece, Lithuania, Norway, Spain, and the UK). Data were analyzed from April 1, 2021, to January 31, 2022.

Exposures

Three organochlorine pesticides, 5 polychlorinated biphenyls, 2 polybrominated diphenyl ethers (PBDEs), 3 phenols, 4 parabens, 10 phthalates, 4 organophosphate pesticides, 5 perfluoroalkyl substances, and 9 metals.

Main Outcomes and Measures

Child serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and CK-18 were measured at 6 to 11 years of age. Risk for liver injury was defined as having ALT, AST, and/or GGT levels above the 90th percentile. Associations of liver injury or cytokeratin 18 (CK-18) levels with each chemical group among the 45 EDCs measured in maternal blood or urine samples collected in pregnancy were estimated using 2 complimentary exposure-mixture methods: bayesian weighted quantile sum (BWQS) and bayesian kernel machine regression.

Results

The study included 1108 mothers (mean [SD] age at birth, 31.0 [4.7] years) and their singleton children (mean [SD] age at liver assessment, 8.2 [1.6] years; 598 [54.0%] boys). Results of the BWQS method indicated increased odds of liver injury per exposure-mixture quartile increase for organochlorine pesticides (odds ratio [OR], 1.44 [95% credible interval (CrI), 1.21-1.71]), PBDEs (OR, 1.57 [95% CrI, 1.34-1.84]), perfluoroalkyl substances (OR, 1.73 [95% CrI, 1.45-2.09]), and metals (OR, 2.21 [95% CrI, 1.65-3.02]). Decreased odds of liver injury were associated with high-molecular-weight phthalates (OR, 0.74 [95% CrI, 0.60-0.91]) and phenols (OR, 0.66 [95% CrI, 0.54-0.78]). Higher CK-18 levels were associated with a 1-quartile increase in polychlorinated biphenyls (β, 5.84 [95% CrI, 1.69-10.08] IU/L) and PBDEs (β, 6.46 [95% CrI, 3.09-9.92] IU/L). Bayesian kernel machine regression showed associations in a similar direction as BWQS for all EDCs and a nonlinear association between phenols and CK-18 levels.

Conclusions and Relevance

With a combination of 2 state-of-the-art exposure-mixture approaches, consistent evidence suggests that prenatal exposures to EDCs are associated with higher risk for liver injury and CK-18 levels and constitute a potential risk factor for pediatric nonalcoholic fatty liver disease.

Prenatal exposure to multiple organochlorine compounds and childhood body mass index

Background:

Prenatal exposure to organochlorine compounds (OCs) has been associated with increased childhood body mass index (BMI); however, only a few studies have focused on longitudinal BMI trajectories, and none of them used multiple exposure mixture approaches.

Aim:

To determine the association between in-utero exposure to eight OCs and childhood BMI measures (BMI and BMI z-score) at 4 years and their yearly change across 4–12 years of age in 279 Rhea child-mother dyads.

Methods:

We applied three approaches: (1) linear mixed-effect regressions (LMR) to associate individual compounds with BMI measures; (2) Bayesian weighted quantile sum regressions (BWQSR) to provide an overall OC mixture association with BMI measures; and (3)Bayesian varying coefficient kernel machine regressions (BVCKMR) to model nonlinear and nonadditive associations.

Results:

In the LMR, yearly change of BMI measures was consistently associated with a quartile increase in hexachlorobenzene (HCB) (estimate [95% Confidence or Credible interval] BMI: 0.10 [0.06, 0.14]; BMI z-score: 0.02 [0.01, 0.04]). BWQSR results showed that a quartile increase in mixture concentrations was associated with yearly increase of BMI measures (BMI: 0.10 [0.01, 0.18]; BMI z-score: 0.03 [0.003, 0.06]). In the BVCKMR, a quartile increase in dichlorodiphenyldichloroethylene concentrations was associated with higher BMI measures at 4 years (BMI: 0.33 [0.24, 0.43]; BMI z-score: 0.19 [0.15, 0.24]); whereas a quartile increase in HCB and polychlorinated biphenyls (PCB)-118 levels was positively associated with BMI measures yearly change (BMI: HCB:0.10 [0.07, 0.13], PCB-118:0.08 [0.04, 012]; BMI z-score: HCB:0.03 [0.02, 0.05], PCB-118:0.02 [0.002,04]). BVCKMR suggested that PCBs had nonlinear relationships with BMI measures, and HCB interacted with other compounds.

Conclusions:

All analyses consistently demonstrated detrimental associations between prenatal OC exposures and childhood BMI measures.

Nutrition, obesity, and dental development in young adolescents in Chicago

OBJECTIVES

Childhood obesity is a systemic disease with multiple downstream consequences, including shifts in timing of growth and development. It has been documented that children with high body mass index (BMI) show accelerated timing of dental development, but the mechanism for this acceleration is unknown. Prior work has suggested that inflammation and/or nutrition may play a role. We investigate the potential association between diet (caloric intake, macronutrients), obesity, and accelerated dental development.

METHODS

Children and adolescents (age 10-15; n = 112) were recruited from dental clinics at the University of Illinois Chicago. We collected subjects' height, weight, panoramic radiographic records, and each subject filled out a Block Food Frequency Questionnaire.

RESULTS

The only macronutrient level associated with BMI was a negative correlation to Total Fat consumption (p = .01), though this relationship was not significant in the path analysis (p > .05). Regression analyses indicated that BMI (p = .003) and total caloric intake (controlling for BMI; rho = 0.19; p = .04) were both significantly correlated with timing of dental development. However, when a path analysis was conducted, it was revealed that only BMI was statistically significant (p = .008).

CONCLUSIONS

Body mass index percentile, regardless of caloric intake, is positively associated with accelerated dental development. While it is possible that excess caloric intake itself plays a minor role in timing of dental development, we do not see unambiguous evidence for this in our sample. We posit that another mechanism, such as inflammation, may be the link between obesity status and dental development.

Influence of gestational weight gain on the organochlorine pollution content of breast milk

BACKGROUND

Transplacental transfer and breastfeeding are the main transport routes of organic pollutants into children at the beginning of life. Although pollutant transmission through these mechanisms primarily depends on the maternal pollution burden, its impact may be modulated by physiological effects.

OBJECTIVES

We have examined whether gestational weight gain (GWG) exerts an influence on the content of lipophilic low volatile pollutants in breast milk.

RESULTS

Colostrum from mothers from the INMA cohorts of Sabadell and Gipuzkoa (n = 256 and 119, respectively) with low GWG as defined by the Institute of Medicine (IOM) from the US National Academies of Sciences, Engineering and Medicine had significantly higher concentrations of polychlorobiphenyls (PCBs) and 4,4'-DDE than colostrum in mothers who gained weight within IOM recommendations or in those who exceeded this threshold. Statistically significant differences were also found in the colostrum:maternal serum ratios of these compounds. Women with low GWG retained higher pollutant amounts in colostrum. These observations are consistent with previously described higher concentrations of these pollutants in infant cord blood from mothers with low GWG by IOM standards. They indicate that mobilization of lipophilic organic pollutants by metabolic pregnant changes not only leads to higher fetal transfer but to higher accumulation into the mammary system upon low GWG.

CONCLUSIONS

The present results show that insufficient GWG, besides increasing in utero exposure, also enhances pollutant transfer to infants during breastfeeding which considerably extends the significance of this physiological change for the pollutant children intake in early life.

Prenatal Environmental Exposure to Persistent Organic Pollutants and Indices of Overweight and Cardiovascular Risk in Dutch Adolescents

Persistent organic pollutants (POPs) may have obesogenic effects. Knowledge about the effects of prenatal exposure to POPs on anthropometric measurements and metabolic parameters into adolescence is limited. Therefore, the aim of the current study was to determine whether prenatal environmental exposure to several POPs is associated with indices of overweight and cardiovascular risk in 13–15-year-old children. In this Dutch observational cohort study, 194 mother–infant pairs were included (1998–2002). Maternal pregnancy serum levels of PCBs, OH-PCBs, PBDEs, and other POPs were measured. At follow-up (2014–2016), levels of cholesterol, HDL-C, LDL-C, triglycerides, fasting insulin, fasting glucose, leptin, and adiponectin were measured in their children. The children’s height, weight, waist circumference, hip circumference, and blood pressure were measured. In total, 101 adolescents (14.4 ± 0.8 years; 53.7% of invited) participated of which 55 were boys. Mean BMI was 19.1 ± 3.6 kg/m² and mean BMI z-score 0.13 ± 1.14. Higher prenatal levels of PCBs were associated with lower levels of HDL-C and adiponectin in boys and higher levels of PBDEs with higher triglycerides in girls. We found significant differences by sex in the associations with OH-PCBs, with lower HDL-C and adiponectin, higher LDL-C/HDL-C ratio, fasting glucose, HOMA2-IR, height, and weight for boys. Our study indicates that higher prenatal exposure to PCBs, OH-PCBs, and PBDEs was associated with adolescent levels of some metabolic cardiovascular risk markers and hormones associated with the development of obesity and cardiovascular disease.

Obesogens in Foods

Obesogens, as environmental endocrine-disrupting chemicals, are supposed to have had an impact on the prevalence of rising obesity around the world over the last forty years. These chemicals are probably able to contribute not only to the development of obesity and metabolic disturbances in individuals, but also in their progeny, having the capability to epigenetically reprogram genetically inherited set-up points for body weight and body composition control during critical periods of development, such as fetal, early life, and puberty. In individuals, they may act on myriads of neuro-endocrine–immune metabolic regulatory pathways, leading to pathophysiological consequences in adipogenesis, lipogenesis, lipolysis, immunity, the influencing of central appetite and energy expenditure regulations, changes in gut microbiota–intestine functioning, and many other processes. Evidence-based medical data have recently brought much more convincing data about associations of particular chemicals and the probability of the raised risk of developing obesity. Foods are the main source of obesogens. Some obesogens occur naturally in food, but most are environmental chemicals, entering food as a foreign substance, whether in the form of contaminants or additives, and they are used in a large amount in highly processed food. This review article contributes to a better overview of obesogens, their occurrence in foods, and their impact on the human organism.

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.

Prenatal and childhood exposure to chlordecone and adiposity of seven-year-old children in the Timoun mother-child cohort study in Guadeloupe (French West Indies)

BACKGROUND

Exposure to persistent environmental organic pollutants may contribute to the development of obesity among children. Chlordecone is a persistent organochlorine insecticide with estrogenic properties that was used in the French West Indies (1973-1993) and is still present in the soil and the water and food consumed by the local population. We studied the association between prenatal and childhood exposure to chlordecone and the adiposity of prepubertal children.

METHODS

Within the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies), 575 children had a medical examination at seven years of age, including adiposity measurements. A Structural Equation Modeling approach was used to create a global adiposity score from four adiposity indicators: the BMI z-score, percentage of fat mass, sum of the tricipital and subscapular skinfold thickness, and waist-to-height ratio. Chlordecone concentrations were measured in cord blood at birth and in the children's blood at seven years of age. Models were adjusted for prenatal and postnatal covariates. Sensitivity analyses accounted for co-exposure to PCB-153 and pp'-DDE. Mediation analyses, including intermediate birth outcomes, were conducted.

RESULTS

Prenatal chlordecone exposure tended to be associated with increased adiposity at seven years of age, particularly in boys. However, statistical significance was only reached in the third quartile of exposure and neither linear nor non-linear trends could be formally identified. Consideration of preterm birth or birth weight in mediation analyses did not modify the results, as adjustment for PCB-153 and pp'-DDE co-exposures.

CONCLUSION

Globally, we found little evidence of an association between chlordecone exposure during the critical in utero or childhood periods of development and altered body-weight homeostasis in childhood. Nevertheless, some associations we observed at seven years of age, although non-significant, were consistent with those observed at earlier ages and would be worth investing during further follow-ups of children of the Timoun Mother-Child Cohort Study when they reach puberty.

Prenatal exposure to insecticides and child cardiometabolic risk factors in the VHEMBE birth cohort

As part of malaria control programs, many countries spray dichlorodiphenyltrichloroethane (DDT) or pyrethroid insecticides inside dwellings in a practice called indoor residual spraying that results in high levels of exposure to local populations. Gestational exposure to these endocrine- and metabolism-disrupting chemicals may influence child cardiometabolic health.

Prenatal exposure to persistent organic pollutants as a risk factor of offspring metabolic syndrome development during childhood

Persistent Organic Pollutants (POPs) are exogenous, artificially made chemicals that can disrupt the biological system of individuals and animals. POPs encompass a variety of chemicals including, dioxins, organochlorines (OCs), polychlorinated biphenyl (PCBs), and perfluoroalkyl substances (PFASs) that contain a long half-life and highly resistant to biodegradation. These environmental pollutants accumulate over time in adipose tissues of living organisms and alter various insulin function-related genes. Childhood Metabolic Syndrome (MetS) consists of multiple cardiovascular risk factors, insulin function being one of them. Over the years, the incidence of the syndrome has increased dramatically. It is imperative to explore the role of persistent organic pollutants in the development of Childhood Metabolic Syndrome. Some epidemiological studies have reported an association between prenatal exposure to POPs and offspring MetS development throughout childhood. These findings have been replicated in animal studies in which these pollutants exercise negative health outcomes such as obesity and increased waist circumference. This review discusses the role of prenatal exposure to POPs among offspring who develop MetS in childhood, the latest research on the MetS concept, epidemiological and experimental findings on MetS, and the POPs modes of action. This literature review identified consistent research results on this topic. Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.

Exposure to Endocrine Disrupting Chemicals in Canada: Population-Based Estimates of Disease Burden and Economic Costs

Exposure to endocrine-disrupting chemicals (EDCs) contributes to substantial disease burden worldwide. We aim to quantify the disease burden and costs of EDC exposure in Canada and to compare these results with previously published findings in the European Union (EU) and United States (US). EDC biomonitoring data from the Canadian Health Measures Survey (2007–2011) was applied to 15 exposure–response relationships, and population and cost estimates were based on the 2010 general Canadian population. EDC exposure in Canada (CAD 24.6 billion) resulted in substantially lower costs than the US (USD 340 billion) and EU (USD 217 billion). Nonetheless, our findings suggest that EDC exposure contributes to substantial and costly disease burden in Canada, amounting to 1.25% of the annual Canadian gross domestic product. As in the US, exposure to polybrominated diphenyl ethers was the greatest contributor of costs (8.8 billion for 374,395 lost IQ points and 2.6 billion for 1610 cases of intellectual disability). In the EU, organophosphate pesticides were the largest contributor to costs (USD 121 billion). While the burden of EDC exposure is greater in the US and EU, there remains a similar need for stronger EDC regulatory action in Canada beyond the current framework of the Canadian Environmental Protection Act of 1999.

The Role of Persistent Organic Pollutants in Obesity: A Review of Laboratory and Epidemiological Studies

Persistent organic pollutants (POPs) are considered as potential obesogens that may affect adipose tissue development and functioning, thus promoting obesity. However, various POPs may have different mechanisms of action. The objective of the present review is to discuss the key mechanisms linking exposure to POPs to adipose tissue dysfunction and obesity. Laboratory data clearly demonstrate that the mechanisms associated with the interference of exposure to POPs with obesity include: (a) dysregulation of adipogenesis regulators (PPARγ and C/EBPα); (b) affinity and binding to nuclear receptors; (c) epigenetic effects; and/or (d) proinflammatory activity. Although in vivo data are generally corroborative of the in vitro results, studies in living organisms have shown that the impact of POPs on adipogenesis is affected by biological factors such as sex, age, and period of exposure. Epidemiological data demonstrate a significant association between exposure to POPs and obesity and obesity-associated metabolic disturbances (e.g., type 2 diabetes mellitus and metabolic syndrome), although the existing data are considered insufficient. In conclusion, both laboratory and epidemiological data underline the significant role of POPs as environmental obesogens. However, further studies are required to better characterize both the mechanisms and the dose/concentration-response effects of exposure to POPs in the development of obesity and other metabolic diseases.

Prenatal exposure to persistent organic pollutants and childhood obesity: A systematic review and meta-analysis of human studies

We conducted a systematic review and meta-analysis of the associations between prenatal exposure to persistent organic pollutants (POPs) and childhood obesity. We focused on organochlorines (dichlorodiphenyltrichloroethane [DDT], dichlorodiphenyldichloroethylene [DDE], hexachlorobenzene [HCB], and polychlorinated biphenyls [PCBs]), perfluoroalkyl and polyfluoroalkyl substances (PFAS), and polybrominated diphenyl ethers (PBDEs) that are the POPs more widely studied in environmental birth cohorts so far. We search two databases (PubMed and Embase) through July/09/2021 and identified 33 studies reporting associations with prenatal organochlorine exposure, 21 studies reporting associations with prenatal PFAS, and five studies reporting associations with prenatal PBDEs. We conducted a qualitative review. Additionally, we performed random-effects meta-analyses of POP exposures, with data estimates from at least three prospective studies, and BMI-z. Prenatal DDE and HCB levels were associated with higher BMI z-score in childhood (beta: 0.12, 95% CI: 0.03, 0.21; I² : 28.1% per study-specific log increase of DDE and beta: 0.31, 95% CI: 0.09, 0.53; I² : 31.9% per study-specific log increase of HCB). No significant associations between PCB-153, PFOA, PFOS, or pentaPBDEs with childhood BMI were found in meta-analyses. In individual studies, there was inconclusive evidence that POP levels were positively associated with other obesity indicators (e.g., waist circumference).

Obesogens in Children-An Uncharted Territory

Obesogens are exogenous chemicals belonging to the group of endocrine-disrupting chemicals and are believed to interfere in obesity development. In children, several chemicals are under investigation, most commonly bisphenol A, phthalates, perfluorinated alkyl substances, and persistent organic pollutants, including organochlorinated pesticides, tributyltin, polychlorinated biphenyls and dioxins. Several associations have been studied between chemical exposure in utero and postnatally. Current opinion among researchers indicates that the obesogen theory is very likely; however, limited published studies show inconsistent support for the obesogenic effects of most substances in children and are limited by difficulty in providing the exact mechanisms of action, nor is their mutual effect in humans known, let alone in children. Existing data indicate that we have only scratched the surface and have much more to learn about obesogens. Hopefully, in the future, more information will provide an opportunity for policy makers to take action and protect public health.

Sex specific associations between in utero exposure to persistent organic pollutants and allergy-related outcomes in childhood: The Rhea Mother-Child Cohort (Crete, Greece)

Accumulating evidence suggests that in utero exposures can influence the development of the immune system. Few studies have investigated whether prenatal exposure to persistent organic pollutants (POPs) is associated with allergy-related phenotypes in childhood, nor explored sex differences. We examined the association between prenatal exposure to POPs and offspring allergic outcomes in early and mid-childhood. We included 682 mother-child pairs from the prospective birth cohort Rhea. We measured dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and 6 polychlorinated biphenyl (PCB) congeners in maternal first trimester serum. Parents completed the questionnaires adapted from the International Study on Asthma and Allergy in Childhood (ISAAC) for allergy-related phenotypes when their children were 4 and 6 years old. We used Poisson regression models to estimate Risk Ratios. Prenatal HCB was associated with increased risk for rhinoconjunctivitis at 6 years (RR (95% CI): 2.5; (1.3, 4.8) for a doubling in the exposure). Among girls, prenatal DDE was associated with increased risk for current wheeze, current asthma and current rhinoconjunctivitis at 4 years (RR (95%CI): 1.4 (0.8, 2.6), 1.6 (1.1, 2.4) and 1.8 (1.0, 3.3) and p-interaction = 0.035, 0.027 and 0.059, respectively), with increased risk for current rhinoconjunctivitis at 6 years (RR (95%CI): 1.7 (0.7, 3.8) and p-interaction = 0.028) and total PCBs were associated with increased risk for current eczema at 4 years (RR (95%CI): 2.1 (1.1, 4.2) and p-interaction = 0.028). In boys, prenatal DDE was associated with decreased risk for current wheeze and current asthma at 4 years. Our findings suggest that even low levels of exposure to POPs prenatally may affect the development of childhood allergy-related outcomes in a sex and age-specific manner.

Network biology approach to human tissue-specific chemical exposome

Human exposure to environmental chemicals is a major contributor to the global disease burden. To characterize the external exposome it is important to assess its chemical components and to study their impact on human health. Biomonitoring studies measure the body burden of environmental chemicals detected in biospecimens from a wide range of the population. The detection of these chemicals in biospecimens (and, hence, human tissues) is considered an important biomarker of human exposure. However, there is no readily available resource that compiles such exposure data for human tissues from published literature, and no studies that explore the patterns in the associations between tissue-specific exposures and human diseases. We present Human Tissue-specific Exposome Atlas (TExAs), a compilation of 380 environmental chemicals detected across 27 human tissues. TExAs is accessible via a user friendly webserver: https://cb.imsc.res.in/texas. We compare the chemicals in TExAs with 55 global chemical regulations, guidelines, and inventories, which represent several categories of the external exposome of humans. Further to understand the potential implications on human health of chemicals detected across human tissues, we employ a network biology approach and explore possible chemical exposure-disease associations. Ensuing analyses reveal the possibilities of disease comorbidities and demonstrate the application of network biology in unraveling complex disease associations due to chemical exposure.

Prenatal exposure to mixtures of persistent endocrine disrupting chemicals and postnatal body size in British girls

BACKGROUND

Endocrine disrupting chemical (EDC) exposure is ubiquitous. EDC exposure during critical windows of development may interfere with the body's endocrine system, affecting growth. Previous human studies have examined one EDC at a time in relation to infant growth. By studying mixtures, the human experience can be better approximated.

AIMS

We investigated the association of prenatal exposure to persistent EDCs (per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs)) as mixtures with postnatal body size among female offspring.

SUBJECTS

We used a sub-sample of the Avon Longitudinal Study of Parents and Children (N = 425), based in the United Kingdom.

STUDY DESIGN

We quantified 52 EDCs in maternal serum collected during pregnancy. We used Bayesian kernel machine regression with a random intercept to examine the association of prenatal concentrations of EDC mixtures with longitudinal postnatal body size measures for each EDC class separately (PFAS, PCBs, and OCPs) and for all three classes combined.

OUTCOME MEASURES

Weight and height measures at 0, 2, 9, and 19 months were obtained by health professionals as part of routine child health surveillance.

RESULTS

The mixture representing all three classes combined (31 chemicals) (n = 301) was inversely associated with postnatal body size. Holding all EDCs in the 31-chemical mixture at the 75th percentile compared to the 50th percentile was associated with 0.15 lower weight-for-age z-score (95% credible interval -0.26, -0.03). Weak inverse associations were also seen for height-for-age and body mass index-for-age scores.

CONCLUSIONS

These results suggest that prenatal exposure to mixtures of persistent EDCs may affect postnatal body size.

Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.

Perinatal exposure to a human relevant mixture of persistent organic pollutants: Effects on mammary gland development, ovarian folliculogenesis and liver in CD-1 mice

The ability of persistent organic pollutants (POPs) with endocrine disrupting properties to interfere with the developing reproductive system is of increasing concern. POPs are transferred from dams to offspring and the high sensitivity of neonates to endocrine disturbances may be caused by underdeveloped systems of metabolism and excretion. The present study aimed to characterize the effect of in utero and lactational exposure to a human relevant mixture of POPs on the female mammary gland, ovarian folliculogenesis and liver function in CD-1 offspring mice. Dams were exposed to the mixture through the diet at Control, Low or High doses (representing 0x, 5000x and 100 000x human estimated daily intake levels, respectively) from weaning and throughout mating, gestation, and lactation. Perinatally exposed female offspring exhibited altered mammary gland development and a suppressed ovarian follicle maturation. Increased hepatic cytochrome P450 enzymatic activities indirectly indicated activation of nuclear receptors and potential generation of reactive products. Hepatocellular hypertrophy was observed from weaning until 30 weeks of age and could potentially lead to hepatotoxicity. Further studies should investigate the effects of human relevant mixtures of POPs on several hormones combined with female reproductive ability and liver function.

Sustained bloodstream release of persistent organic pollutants induced by extensive weight loss after bariatric surgery: Implications for women of childbearing age

BACKGROUND

Lipophilic persistent organic pollutants (POPs) are stored in adipose tissues and released in case of weight loss.

OBJECTIVES

To analyze the kinetics and characteristics of this release during drastic weight loss after bariatric surgery and compare the results in case of women of childbearing age (WCBA) with critical blood concentration thresholds.

METHODS

100 morbidly obese patients (73 women including 53 of childbearing age and 27 men) were screened before and 3, 6 and 12 months after bariatric surgery for serum concentrations of 67 congeners or metabolites of banned or not yet banned organohalogenated persistent pollutants, including highly lipophilic polychlorobiphenyls (PCBs), organochlorine pesticides (OCPs), brominated flame retardants (BFRs), and less lipophilic perfluorinated alkylated substances (PFASs).

RESULTS

Circulating levels of all chemicals, except PFASs, increased progressively after surgery, reaching after one year an increase between 30 and 139% compared to initial pre-surgical levels; median levels increased for PCB153 from 36.8 to 86.4 ng/g lw (+130%), for dichlorodiphenyldichloroethylene (p,p'-DDE) from 59.8 to 136.1 ng/g lw (+120%), and for hexachlorobenzene (HCB) from 9.8 to 20.3 ng/g lw (+110%). Weight loss averaging 30% of initial body weight at 12 months in both sexes (mean: 40.0 kg for men, 36.1 kg for women), was the main parameter related to the concentration increases (3.1 to 3.6% per kilogram weight loss). They were not dependent on initial BMI, presence of metabolic syndrome or type of surgical procedure but influenced by gender and biochemical properties such as degree of chlorination for PCBs and/or lipophilicity since PFASs did not increase at all. ∑PCB₆ in blood after one year exceeded the critical concentration threshold for 24.5% women of childbearing age (13/53) versus 3.6% (2/53) before surgery.

DISCUSSION

Massive weight loss within the first year following bariatric surgery is associated with a sustained increase of circulating lipophilic POPs. Short- and long-term consequences should be considered, mostly for childbearing age obese women, because of potential health risks for the future fetus and breastfeeding infant.

Prenatal exposure to persistent organic pollutants and markers of obesity and cardiometabolic risk in Spanish adolescents

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) has been linked to cardiometabolic (CM) risk factors in childhood, but there are no studies evaluating the persistence of these associations into adolescence, a period of relevant changes in endocrine-dependent organ systems and rapid increases in lean and fat mass. We examined the associations of prenatal POP exposures with body mass index (BMI) from age 4 to 18 years, and with other CM risk markers in adolescence.

METHODS

We analysed 379 children from the Spanish INMA-Menorca birth cohort study with measured cord blood POP concentrations. We calculated BMI z-scores at ages 4, 6, 11, 14 and 18 years using the WHO growth reference. Body fat % was measured at 11 and 18 years and waist-to-height ratio (WHtR) and blood pressure (BP) at 11, 14 and 18 years. We measured CM biomarkers in fasting blood collected at age 14 years and calculated a CM-risk score as the sum of the sex-, and age-specific z-scores for waist circumference, mean arterial BP, homeostatic model assessment of insulin resistance, fasting blood triglycerides, and high-density lipoprotein cholesterol (HDL-C) (n = 217). Generalised estimating equations and multivariate linear regression models assessed the associations with repeated and single time-point measures, respectively.

RESULTS

Hexachlorobenzene (HCB) exposure in the third tertile, compared to the first tertile, was associated with higher BMI (β = 0.24; 95% CI: 0.01, 0.47) and WHtR z-score (β = 0.27; 95% CI: 0.04, 0.51). A continuous increase in HCB was associated with an elevated body fat % (β per 10-fold increase = 4.21; 95% CI: 0.51, 7.92), systolic BP (β = 0.32; 95% CI: 0.02, 0.64) and diastolic BP z-score (β = 0.32; 95% CI: 0.02, 0.62) across all ages, and with higher CM-risk score (β = 1.59; 95% CI: 0.02, 3.18) and lipid biomarkers (total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C)) at 14 years. Dichlorodiphenyltrichloroethane (p,p'-DDT) exposure was non-monotonically associated with BMI and systolic BP. p,p'-DDE and Σ-polychlorinated biphenyls (PCBs) (sum of congeners 118, 138, 153, 180) were not associated with adiposity or BP. p,p'-DDT exposure was associated with an increased CM-risk score, and ΣPCBs concentrations with LDL-C in all adolescents and with total cholesterol only in girls (p-sex interaction = 0.05).

CONCLUSION

This first longitudinal study from 4 to 18 years suggests that the previously reported POP associations with child BMI persist later in adolescence and that prenatal POP exposures are associated with major risk factors for adult CM syndrome.

Exposure to perfluoroalkyl substances (PFAS) and dyslipidemia, hypertension and obesity in adolescents. The Fit Futures study

BACKGROUND

Prevalence of obesity, hypertension and dyslipidemia has been increasing in children and adolescents worldwide. Exposure to environmental pollutants may contribute to this development. Our aim was to study associations between perfluoroalkyl substances (PFAS) and dyslipidemia, hypertension and obesity in a population-based sample of adolescents.

METHODS

Serum PFAS concentrations were measured in 940 adolescents, mean age 16.4 (SD 1.3) years, from the cross-sectional Fit Futures study by the UHPLC-MS/MS method. The following endpoints were used: hypertension (systolic blood pressure over 130 mmHg and/or diastolic blood pressure over 80 mmHg); obesity (body mass index over 2 z-score, WHO charts for adolescents); dyslipidemia (total cholesterol ≥ 5.17 mmol/L, and/or LDL-cholesterol ≥ 3.36 mmol/l, and/or apolipoprotein B ≥ 1.10 g/L).

RESULTS

Perfluorooctane sulfonate (PFOS), perfluorononanoate (PFNA), perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnDA) serum concentrations were positively associated with apolipoprotein B, total- and LDL cholesterol. The highest vs. lowest quartiles of total PFAS (∑PFAS), PFNA and PFDA concentrations were positively associated with the risk of dyslipidemia: OR 2.24 (95% CI 1.10-4.54), OR 2.30 (95% CI 1.16-4.57) and 2.36 (95% CI 1.08-5.16), respectively. The highest vs. lowest quartiles of ∑PFAS, perfluorohexane sulfonate (PFHxS), PFOS, perfluorooctanoate (PFOA) concentrations were positively associated with the risk of hypertension: OR 1.91 (95% CI 1.12-3.26), OR 2.06 (95% CI 1.16-3.65), 1.86 (95% CI 1.08-3.19) and 2.08 (95% CI 1.17-3.69) respectively. PFHxS and perfluoroheptane sulfonate (PFHpS) concentrations were positively associated with obesity.

CONCLUSIONS

This cross-sectional study showed a possible link between several PFAS and dyslipidemia, hypertension and obesity in Norwegian adolescents.

Maternal seafood intake during pregnancy, prenatal mercury exposure and child body mass index trajectories up to 8 years

Background

Maternal seafood intake during pregnancy and prenatal mercury exposure may influence children’s growth trajectories.

Methods

This study, based on the Norwegian Mother, Father and Child Cohort Study (MoBa), includes 51 952 mother-child pairs recruited in pregnancy during 2002–08 and a subsample (n = 2277) with maternal mercury concentrations in whole blood. Individual growth trajectories were computed by modelling based on child’s reported weight and length/height from 1 month to 8 years. We used linear mixed-effects regression analysis and also conducted discordant-sibling analysis.

Results

Maternal lean fish was the main contributor to total seafood intake in pregnancy and was positively but weakly associated with child body mass index (BMI) growth trajectory. Higher prenatal mercury exposure (top decile) was associated with a reduction in child’s weight growth trajectory, with the estimates ranging from -130 g [95% Confidence Intervals (CI) = -247, -12 g] at 18 months to -608 g (95% CI = -1.102, -113 g) at 8 years. Maternal fatty fish consumption was positively associated with child weight and BMI growth trajectory, but only in the higher mercury-exposed children (P-interaction = 0.045). Other seafood consumption during pregnancy was negatively associated with child weight growth compared with no intake, and this association was stronger for higher mercury-exposed children (P-interaction = 0.004). No association was observed between discordant maternal seafood intake and child growth in the sibling analysis.

Conclusions

Within a population with moderate seafood consumption and low mercury exposure, we found that maternal seafood consumption in pregnancy was associated with child growth trajectories, and the direction of the association varied by seafood type and level of prenatal mercury exposure. Prenatal mercury exposure was negatively associated with child growth. Our findings on maternal seafood intake are likely non-causal.

Adipose Tissue Levels of DDT as Risk Factor for Obesity and Type 2 Diabetes Mellitus

BACKGROUND

Exposure to dichlorodiphenyltrichloroethane (DDT), a potent lipophilic organochlorine pesticide, has long been linked as a risk factor for type 2 diabetes mellitus (T2DM). However, its presence in the adipose tissues of the T2DM subjects has not been explored in the Indian population, where this long-banned pesticide is still in use. The present study was conducted to evaluate the possible association of DDT and its metabolites in obese and non-obese T2DM subjects.

METHODS

Subjects with normal glucose tolerance (n = 50) and T2DM (n = 50) were divided into equal numbers in obese and non-obese groups. Their plasma glucose levels, HbA₁c, and lipid profile were measured. The adipose tissues were collected intraoperatively, and DDT and its metabolites were measured using a gas chromatograph equipped with an electron capture detector.

RESULTS

Obese subjects, irrespective of their glycemic status, and T2DM subjects had higher concentrations of DDT. p, p' DDT was found to increase the odds for diabetes, and o, p' DDT for central obesity. p, p' DDD was also strongly correlated with central obesity, glycemic parameters, and triglycerides.

CONCLUSION

The excess deposition of p, p' DDD, o, p' DDT, and p, p' DDT in obese subjects may proceed to T2DM by disrupting triglycerides and glycemic parameters.

Prenatal exposure to organochlorine pesticides and infant growth: A longitudinal study

BACKGROUND

The association between exposure to organochlorine pesticides (OCPs) and infant growth has been reported contradictorily in previous studies. Few studies have investigated the effects of prenatal exposure to OCPs on infant growth assessed longitudinally at multiple time points.

OBJECTIVES

The purpose of the study was to examine the associations between prenatal exposure to OCPs and infant growth at birth, 6, 12 and 24 months of age, and further to explore the potential sex-specific effects.

METHODS

The study population included 1039 mother-infant pairs who participated in a birth cohort study in Wuhan, China. The weight, length and body mass index (BMI) z-score of infants were measured and calculated at birth, 6, 12 and 24 months of age. The overweight status was defined as BMI z-score ≥ 85th percentile according to the standard of World Health Organization. The concentrations of OCPs were measured in cord serum, including hexachlorocyclohexanes (HCHs, consisted of α-HCH, β-HCH, and γ-HCH), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites: p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE). Generalized linear models were applied to estimate the associations of cord OCPs with infant growth parameters. A group-based semiparametric mixture model was used to estimate growth patterns of infants. Linear-mixed growth curve models were used to examine relationships between predicted growth trajectories and prenatal exposure to OCPs. Weighted quantile sum regression (WQSR) analyses were used to estimate the mixture effects of OCPs on infant growth.

RESULTS

Higher cord serum β-HCH concentrations were associated with higher BMI z-score at 12 [β = 0.07, 95%CI: 0.01, 0.13] and 24 months of age [β = 0.08, 95% CI: 0.02, 0.14]. Similar patterns were observed for relationships of γ-HCH [β = 0.04, 95%CI: 0.01, 0.07] and p,p'-DDT [β = 0.03, 95% CI: 0.00, 0.06] with BMI z-score at 6 and 12 months of age, respectively. However, higher cord serum p,p'-DDE concentrations were associated with a reduction of BMI z-score at 6 months of age [β = -0.07, 95% CI: -0.12, -0.01]. Cord serum β-HCH was also positively associated with the risk of overweight at 12 months of age [RR = 1.16, 95% CI (1.02, 1.33), for the medium vs the lowest tertile]. Among girls, the effects of β-HCH on BMI z-score and overweight status were stronger than boys at 12 and 24 months of age. No statistically significant relationships of other OCPs with infant growth were observed.

CONCLUSIONS

Prenatal exposure to β-HCH was associated with increased BMI z-score and higher risk of overweight status in infants especially at 12 and 24 months of age, which seemed to be stronger in girls.

Health disparities: Intracellular consequences of social determinants of health

Health disparities exist dependent on socioeconomic status, living conditions, race/ethnicity, diet, and exposures to environmental pollutants. Herein, the various exposures contributing to a person's exposome are collectively considered social determinants of health (SDOH), and the SDOH-exposome impacts health more than health care. This review discusses the extent of evidence of the physiologic consequences of these exposures at the intracellular level. We consider how the SDOH-exposome, which captures how individuals live, work and age, induces cell processes that modulate a conceptual "redox rheostat." Like an electrical resistor, the SDOH-exposome, along with genetic predisposition and age, regulate reductive and oxidative (redox) stress circuits and thereby stimulate inflammation. Regardless of the source of the SDOH-exposome that induces chronic inflammation and immunosenescence, the outcome influences cardiometabolic diseases, cancers, infections, sepsis, neurodegeneration and autoimmune diseases. The endogenous redox rheostat is connected with regulatory molecules such as NAD⁺/NADH and SIRT1 that drive redox pathways. In addition to these intracellular and mitochondrial processes, we discuss how the SDOH-exposome can influence the balance between metabolism and regulation of immune responsiveness involving the two main molecular drivers of inflammation, the NLRP3 inflammasome and NF-κB induction. Mitochondrial and inflammasome activities play key roles in mediating defenses against pathogens and controlling inflammation before diverse cell death pathways are induced. Specifically, pyroptosis, cell death by inflammation, is intimately associated with common disease outcomes that are influenced by the SDOH-exposome. Redox influences on immunometabolism including protein cysteines and ion fluxes are discussed regarding health outcomes. In summary, this review presents a translational research perspective, with evidence from in vitro and in vivo models as well as clinical and epidemiological studies, to outline the intracellular consequences of the SDOH-exposome that drive health disparities in patients and populations. The relevance of this conceptual and theoretical model considering the SARS-CoV-2 pandemic are highlighted. Finally, the case of asthma is presented as a chronic condition that is modified by adverse SDOH exposures and is manifested through the dysregulation of immune cell redox regulatory processes we highlight in this review.

Obesity and endocrine-disrupting chemicals

Obesity is now a worldwide pandemic. The usual explanation given for the prevalence of obesity is that it results from consumption of a calorie dense diet coupled with physical inactivity. However, this model inadequately explains rising obesity in adults and in children over the past few decades, indicating that other factors must be important contributors. An endocrine-disrupting chemical (EDC) is an exogenous chemical, or mixture that interferes with any aspect of hormone action. EDCs have become pervasive in our environment, allowing humans to be exposed daily through ingestion, inhalation, and direct dermal contact. Exposure to EDCs has been causally linked with obesity in model organisms and associated with obesity occurrence in humans. Obesogens promote adipogenesis and obesity, in vivo, by a variety of mechanisms. The environmental obesogen model holds that exposure to obesogens elicits a predisposition to obesity and that such exposures may be an important yet overlooked factor in the obesity pandemic. Effects produced by EDCs and obesogen exposure may be passed to subsequent, unexposed generations. This "generational toxicology" is not currently factored into risk assessment by regulators but may be another important factor in the obesity pandemic as well as in the worldwide increases in the incidence of noncommunicable diseases that plague populations everywhere. This review addresses the current evidence on how obesogens affect body mass, discusses long-known chemicals that have been more recently identified as obesogens, and how the accumulated knowledge can help identify EDCs hazards.

Association between prenatal exposure to persistent organic pollutants and neurodevelopment in early life: A mother-child cohort (Shanghai, China)

As common environmental pollutants, persistent organic pollutants (POPs) that are widely applied in industry and agriculture have adverse effects on neurodevelopment. However, evidence on the neurotoxicity of POPs in neural development of offspring is limited. This study explored the relationship between prenatal exposure to POPs and neurodevelopment of 18-month-old toddlers in a mother-child cohort in Shanghai, China. In this study, we determined exposure levels of 37 POPs in cord blood serum collected at the time of delivery. The detection rate of pollutants HCB, β-HCH, and p,p'-DDE was higher than 60%, so these will be discussed in the following analysis. From birth to approximately 18 months, we followed up infants to longitudinally explore whether POPs influenced their language, motor, and cognitive development according to a Bayley-Ⅲ assessment . Based on multivariable regression analyses, the β-HCH concentration in cord serum was negatively related to motor development scores in children at 18 months by adjusting for the covariates, but there was no change in language and cognition. Further piecewise linear regression analysis showed that a cord serum β-HCH concentration greater than 0.2 μg/L had a significantly negative correlation with the motor development scores. p,p'-DDE was positively associated with language development at 18 months before and after adjusting for covariates. But prenatal HCB levels were not associated with any of the Bayley-Ⅲ subscales at 18 months. We concluded that prenatal exposure to β-HCH might have adverse effects on infants' motor development. The minimum harmful concentration of β-HCH was estimated at 0.2 μg/L in cord serum. The unexpected positive association between p,p'-DDT and language development could be due to live birth bias.

Concentrations of persistent organic pollutants in blood of the Spanish population: Temporal trend

The present article reviews the human biomonitoring studies conducted in Spain to assess exposure to persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), polybrominated diphenyl ethers (PBDEs), and per- and poly-fluoroalkyl substances (PFAS). In general terms, important variations in POPs concentrations between Spanish regions and specific populations were observed, while no associations between exposure to POPs and adverse health outcomes were found. Moreover, occupational exposure seems not to be a risk factor with regards to POPs exposure in the Spanish population. The present review highlights the importance of conducting human biomonitoring studies to find possible associations between POPs and adverse health effects.

Chronic depression-like phenotype in male offspring mice following perinatal exposure to naturally contaminated eels with a mixture of organic and inorganic pollutants

Previously, we demonstrated that maternal exposure to high, intermediate, or lowly contaminated European eels with a mixture of chemicals, during pregnancy and lactation, resulted in adult despair-like behavior, selectively in male offspring mice. Here, we investigate if depression-like behavior in offspring males was transient or permanent by monitoring immobility behavior, a measure of behavioral despair, at three distinct stages of life, including young adult (post-natal day (PND) 55), mature adult (PND 200) and middle (PNDs 335-336) age, in the forced swimming (FST) and the tail suspension (TST) tests. Oxidative stress markers including malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were evaluated in the hippocampus, prefrontal cortex, and cerebellum of middle-aged animals. Findings showed a significant enhancement of immobility behavior in the TST performed at young adult age (all p < 0.05) in the FST carried out at mature adult age (all p < 0.001) and in both behavioral tests realized at middle age (all p < 0.05, except one p = 0.06) in mice perinatally exposed to eels compared with non-exposed controls. Antioxidant-related enzyme activities, including SOD and CAT, were only elevated in the hippocampus of middle-aged males perinatally exposed to the two more polluted eels (all p < 0.05). Further, lipid peroxidation, assessed by MDA levels, was not found to be differentially regulated in the selected areas of middle-aged brains of exposed mice (all p > 0.05). Collectively, this suggested limited oxidative metabolism disturbances in middle-aged brains exposed to eels. In summary, our results highlighted that offspring males perinatally exposed to naturally contaminated reared and river eels with persistent organic pollutants (POPs) and heavy metals displayed chronic depression-like phenotype. As extrapolation of data to humans should be done with precaution, retrospective and prospective epidemiological studies are needed to clarify this potential relationship, stressed in our animal model, between maternal polluted fish consumption and chronically low mood in offspring.

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.

Oxidative Stress in NAFLD: Role of Nutrients and Food Contaminants

Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. NAFLD involves a large spectrum of clinical conditions. These range from steatosis, a benign liver disorder characterized by the accumulation of fat in hepatocytes, to non-alcoholic steatohepatitis (NASH), which is characterized by inflammation, hepatocyte damage, and liver fibrosis. NASH can further progress to cirrhosis and hepatocellular carcinoma. The etiology of NAFLD involves both genetic and environmental factors, including an unhealthy lifestyle. Of note, unhealthy eating is clearly associated with NAFLD development and progression to NASH. Both macronutrients (sugars, lipids, proteins) and micronutrients (vitamins, phytoingredients, antioxidants) affect NAFLD pathogenesis. Furthermore, some evidence indicates disruption of metabolic homeostasis by food contaminants, some of which are risk factor candidates in NAFLD. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrial damage have been reported to be causative in NAFLD initiation and progression. The aim of this review is to provide an overview of the contribution of nutrients and food contaminants, especially pesticides, to oxidative stress and how they may influence NAFLD pathogenesis.

Persistent organic pollutants exposure in newborn dried blood spots and infant weight status: A case-control study of low-income Hispanic mother-infant pairs

Persistent organic pollutants (POPs) are believed to alter metabolic homeostasis during fetal development, leading to childhood obesity. However, limited studies have explored how fetal chemical exposures relate to birth and infant weight outcomes in low-income Hispanic families at the highest risk of obesity. Therefore, we sought to determine associations between neonatal POPs exposure measured in newborn dried blood spots (DBS) and prenatal diet quality, birth weight, and overweight status at 18 months old. We conducted a case-control study nested within the Starting Early Program randomized controlled trial comparing POPs concentrations in infants with healthy weight (n = 46) and overweight status (n = 52) at age 18 months. Three categories of POPs, organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and perfluoroalkyl substances (PFASs) were measured in archived newborn DBS. We assessed correlations between prenatal diet quality and neonatal POPs concentrations. Multivariable regression analyses examined associations between POPs (dichotomized at the mean) and birth weight z-score and weight status at 18 months, controlling for confounders. Seven of eight chemicals had detectable levels in greater than 94% of the sample. Higher protein, sodium and refined grain intake during pregnancy were correlated with lower POPs in newborn DBS. We found that high concentrations of perfluorooctanesulfonate (unstandardized coefficient [B]: -0.62, 95% confidence interval [CI]: -0.96 to -0.29) and perfluorohexanesulfate (B: -0.65, 95% CI: -0.99 to -0.31) were related to lower birth weight z-scores compared to those with low concentrations. We did not find associations between PBDEs, OCPs, and the other PFASs with birth weight z-scores, or between any POPs and weight status at 18 months. In conclusion, two PFASs were associated with lower birth weight, an important indicator of child health and growth, although direct associations with infant overweight status were not found. Whether neonatal POPs exposures contribute to economic and ethnic disparities in early obesity remains unclear.

Perinatal exposure to a dietary pesticide cocktail does not increase susceptibility to high-fat diet-induced metabolic perturbations at adulthood but modifies urinary and fecal metabolic fingerprints in C57Bl6/J mice

BACKGROUND

We recently demonstrated that chronic dietary exposure to a mixture of pesticides at low-doses induced sexually dimorphic obesogenic and diabetogenic effects in adult mice. Perinatal pesticide exposure may also be a factor in metabolic disease etiology. However, the long-term consequences of perinatal pesticide exposure remain controversial and largely unexplored.

OBJECTIVES

Here we assessed how perinatal exposure to the same low-dose pesticide cocktail impacted metabolic homeostasis in adult mice.

METHODS

Six pesticides (boscalid, captan, chlopyrifos, thiachloprid, thiophanate, and ziram) were incorporated in food pellets. During the gestation and lactation periods, female (F0) mice were fed either a pesticide-free or a pesticide-enriched diet at doses exposing them to the tolerable daily intake (TDI) level for each compound, using a 1:1 body weight scaling from humans to mice. All male and female offsprings (F1) were then fed the pesticide-free diet until 18 weeks of age, followed by challenge with a pesticide-free high-fat diet (HFD) for 6 weeks. Metabolic parameters, including body weight, food and water consumption, glucose tolerance, and urinary and fecal metabolomes, were assessed over time. At the end of the experiment, we evaluated energetic metabolism and microbiota activity using biochemical assays, gene expression profiling, and ¹H NMR-based metabolomics in the liver, urine, and feces.

RESULTS

Perinatal pesticide exposure did not affect body weight or energy homeostasis in 6- and 14-week-old mice. As expected, HFD increased body weight and induced metabolic disorders as compared to a low-fat diet. However, HFD-induced metabolic perturbations were similar between mice with and without perinatal pesticide exposure. Interestingly, perinatal pesticide exposure induced time-specific and sex-specific alterations in the urinary and fecal metabolomes of adult mice, suggesting long-lasting changes in gut microbiota.

CONCLUSIONS

Perinatal pesticide exposure induced sustained sexually dimorphic perturbations of the urinary and fecal metabolic fingerprints, but did not significantly influence the development of HFD-induced metabolic diseases.

Lactational exposure to polychlorinated biphenyls is higher in overweight /obese women and associated with altered infant growth trajectory: A pilot study

•

Human milk levels of PCBs are higher in mothers with overweight and obesity.

•

Lactational exposure to PCBs is associated with alterations in development.

•

Lactational expsures to PCBs in human milk are associated with slower infant growth patterns.

Background

Infant exposure to environmental chemicals, such as polychlorinated biphenyls (PCBs), may contribute to developmental programming of long-term metabolic disease risk. PCBs persist given their lipophilicity and long half-lives, allowing them to bio-accumulate in adipose tissue. These compounds can then be excreted into maternal milk resulting in infant exposure.

Objective

To determine the level of PCBs in milk from mothers with pre-pregnancy overweight and obese (OW/OB) versus normal weight status (NW) and evaluate the association of milk PCB levels with infant growth over the first 6 months of life.

Methods

A pilot study of a subset of milk samples from mothers with NW (pre-pregnancy body mass index (BMI) < 25 kg/m², n = 11) and OW/OB (pre-pregnancy BMI ≥ 25 kg/m², n = 8) were examined approximately 2-weeks postpartum. PCB congeners 138 + 163, 132 + 153, 180, and the sum were measured using gas chromatography/mass spectrometry and adjusted for milk fat content. Infant growth was monitored from birth to 6 months for weight-for-age (WFA), length-for-age (LFA), weight-for-length (WFL), head circumference-for-age (HCA), and associations with milk PCB content determined using linear mixed modeling.

Results

Total milk fat content did not differ by maternal weight status (p = 0.88). Milk from mothers with OW/OB had significantly higher PCB sum (p = 0.02) and PCB 138 + 163 (p = 0.03). PCB 132 + 153 (β −0.0008, p = 0.0218), PCB 180 (β −0.0010, p = 0.0279), and PCB sum (β −0.0006, p = 0.0138) were negatively associated with HCA Z-score growth to 6 months. PCB 180 was negatively associated with infant WFA (β −0.0015, p = 0.0058) and WFL Z-score (β −0.0016, p = 0.0263) to 6 months. There were no associations of PCB sum content with WFL, LFA, WFL Z-score over the first 6 months of life.

Conclusions

Maternal overweight and obesity are associated with higher levels of total PCB congeners (132, 138, 153, 163, 180) in human milk. PCB congeners have negative associations with infant head circumference and weight trajectory over the first 6 months of life.

Insight into the transplacental transport mechanism of methoxylated polybrominated diphenyl ethers using a BeWo cell monolayer model

Methoxylated polybrominated diphenyl ethers (MeO-PBDEs), a type of emerging environmental contaminants, can accumulate through the food chain and eventually enter the human body. For pregnant women, these chemicals may be transplacentally transported to their fetuses, causing early intrauterine exposure. This study was designed to explore the transport process and characteristics of MeO-PBDEs using a BeWo cell monolayer model to simulate the placental barrier effect. Concentration-dependent transplacental transport indicates that the transport of MeO-PBDEs may be dominated by passive diffusion within the studied concentration range. According to the apparent permeability coefficients, MeO-BDE congeners investigated can be classified as poorly transported compounds, with the exception of MeO-BDE28. Time-dependent transplacental transport was observed (R² = 0.97-0.99), which showed that the intracellular accumulation of MeO-PBDEs followed pseudo-first-order kinetics process. The transport process of MeO-PBDEs in the BeWo cell assay was not found to be sensitive to the pH of 6.5-7.4. An efflux transporter, breast cancer resistance protein, may be involved in the transport process of some MeO-PBDE congeners, and influx transporters, including organic anion transporters and organic cation transporters, may also be involved in the transport process. Although the present results indicated the possible transplacental transport mechanism, more molecular biological studies should be conducted to advance the understanding of the transport mechanisms.