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Biochemical Pharmacology Jul 2024Epidemiological evidence links chemical exposure with type 2 diabetes (T2DM) risk and prevalence. Chemical exposure may therefore also limit success of weight loss or... (Meta-Analysis)
Meta-Analysis Review
A systematic review and meta-analysis of environmental contaminant exposure impacts on weight loss and glucose regulation during calorie-restricted diets in preclinical studies: Persistent organic pollutants may impede glycemic control.
Epidemiological evidence links chemical exposure with type 2 diabetes (T2DM) risk and prevalence. Chemical exposure may therefore also limit success of weight loss or restoration of glycemic control during calorie restricted diets. Few human studies examine this hypothesis. This systematic review and clustered meta-analysis examines preclinical evidence that exposure to anthropogenic environmental contaminants impedes weight loss and resumption of glycemic control during calorie restriction. Of five eligible papers from 212 unique citations, four used C57BL/6 mice and one used Sprague Dawley rats. In four the animals received high fat diets to induce obesity and impaired glycemic control. All examined persistent organic pollutants (POPs). Polychlorinated biphenyl (PCB) 77 exposure did not affect final mass (standardised mean difference (SMD) = -0.35 [-1.09, 0.39]; n = 5 (experiments); n = 3 (papers)), or response to insulin in insulin tolerance tests (SMD = -1.54 [-3.25, 0.16] n = 3 (experiments); n = 2 (papers)), but impaired glucose control in glucose tolerance tests (SMD = -1.30 [-1.96, -0.63]; n = 6 (experiments); n = 3 (papers)). The impaired glycemic control following perfluoro-octane sulphonic acid (PFOS) exposure and enhanced mass loss following dichlorodiphenyltrichloroethane (DDT) exposure have not been replicated. Animal studies thus suggest some chemical groups, especially PCB and PFOS, could impair glucose control management during calorie restriction, similar to conclusions from limited existing clinical studies. We discuss the research that is urgently required to inform weight management services that are now the mainstay prevention initiative for T2DM.
Topics: Animals; Mice; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Environmental Exposure; Environmental Pollutants; Glycemic Control; Persistent Organic Pollutants; Weight Loss; Disease Models, Animal; Rats
PubMed: 38782075
DOI: 10.1016/j.bcp.2024.116300 -
Archives of Iranian Medicine Oct 2023Many human diseases such as cancer, neurological diseases, autism and diabetes are associated with exposure to pesticides, especially organochlorine pesticides. However,...
Many human diseases such as cancer, neurological diseases, autism and diabetes are associated with exposure to pesticides, especially organochlorine pesticides. However, pesticide exposure is also associated with cardiovascular disease (CVD) as the leading cause of death worldwide. In this systematic review, results on the link between organochlorine pesticide pollution and CVD were collected from databases (Medline (PubMed), Scopus and Science Direct) in May 2022 from studies published between 2010 and 2022. A total of 24 articles were selected for this systematic review. Sixteen articles were extracted by reviewers using a standardized form that included cross-sectional, cohort, and ecological studies that reported exposure to organochlorine pesticides in association with increased CVD risk. In addition, eight articles covering molecular mechanisms organochlorine pesticides and polychlorinated biphenyls (PCBs) on cardiovascular effects were retrieved for detailed evaluation. Based on the findings of the study, it seems elevated circulating levels of organochlorine pesticides and PCBs increase the risk of coronary heart disease, especially in early life exposure to these pesticides and especially in men. Changes in the regulatory function of peroxisome proliferator-activated γ receptor (PPARγ), reduction of paroxonase activity (PON1), epigenetic changes of histone through induction of reactive oxygen species, vascular endothelial inflammation with miR-expression 126 and miR-31, increased collagen synthesis enzymes in the extracellular matrix and left ventricular hypertrophy (LVH) and fibrosis are mechanisms by which PCBs increase the risk of CVD. According to this systematic review, organochlorine pesticide exposure is associated with increased risk of CVD and CVD mortality through the atherogenic and inflammatory molecular mechanism involving fatty acid and glucose metabolism.
Topics: Male; Humans; Polychlorinated Biphenyls; Environmental Pollutants; Cardiovascular Diseases; Cross-Sectional Studies; Hydrocarbons, Chlorinated; Pesticides; MicroRNAs; Aryldialkylphosphatase
PubMed: 38310416
DOI: 10.34172/aim.2023.86 -
Prevention Science : the Official... May 2024Exposure to certain chemicals prenatally and in childhood can impact development and may increase risk for attention-deficit/hyperactivity disorder (ADHD). Leveraging a... (Meta-Analysis)
Meta-Analysis Review
Exposure to certain chemicals prenatally and in childhood can impact development and may increase risk for attention-deficit/hyperactivity disorder (ADHD). Leveraging a larger set of literature searches conducted to synthesize results from longitudinal studies of potentially modifiable risk factors for childhood ADHD, we present meta-analytic results from 66 studies that examined the associations between early chemical exposures and later ADHD diagnosis or symptoms. Studies were eligible for inclusion if the chemical exposure occurred at least 6 months prior to measurement of ADHD diagnosis or symptomatology. Included papers were published between 1975 and 2019 on exposure to anesthetics (n = 5), cadmium (n = 3), hexachlorobenzene (n = 4), lead (n = 22), mercury (n = 12), organophosphates (n = 7), and polychlorinated biphenyls (n = 13). Analyses are presented for each chemical exposure by type of ADHD outcome reported (categorical vs. continuous), type of ADHD measurement (overall measures of ADHD, ADHD symptoms only, ADHD diagnosis only, inattention only, hyperactivity/impulsivity only), and timing of exposure (prenatal vs. childhood vs. cumulative), whenever at least 3 relevant effect sizes were available. Childhood lead exposure was positively associated with ADHD diagnosis and symptoms in all analyses except for the prenatal analyses (odds ratios (ORs) ranging from 1.60 to 2.62, correlation coefficients (CCs) ranging from 0.14 to 0.16). Other statistically significant associations were limited to organophosphates (CC = 0.11, 95% confidence interval (CI): 0.03-0.19 for continuous measures of ADHD outcomes overall), polychlorinated biphenyls (CC = 0.08, 95% CI: 0.02-0.14 for continuous measures of inattention as the outcome), and both prenatal and childhood mercury exposure (CC = 0.02, 95% CI: 0.00-0.04 for continuous measures of ADHD outcomes overall for either exposure window). Our findings provide further support for negative impacts of prenatal and/or childhood exposure to certain chemicals and raise the possibility that primary prevention and targeted screening could prevent or mitigate ADHD symptomatology. Furthermore, these findings support the need for regular review of regulations as our scientific understanding of the risks posed by these chemicals evolves.
Topics: Attention Deficit Disorder with Hyperactivity; Humans; Child; Environmental Exposure; Female; Prenatal Exposure Delayed Effects; Pregnancy
PubMed: 38108946
DOI: 10.1007/s11121-023-01601-6 -
Environmental Research Mar 2024Persistent organic pollutants (POPs) are chemicals characterized by their environmental persistence. Evidence suggests that exposure to POPs, which is ubiquitous, is... (Review)
Review
Per- and polyfluoroalkyl substances, polychlorinated biphenyls, organochlorine pesticides, and polybrominated diphenyl ethers and dysregulation of MicroRNA expression in humans and animals-A systematic review.
BACKGROUND
Persistent organic pollutants (POPs) are chemicals characterized by their environmental persistence. Evidence suggests that exposure to POPs, which is ubiquitous, is associated with microRNA (miRNA) dysregulation. miRNA are key regulators in many physiological processes. It is thus of public health concern to understand the relationships between POPs and miRNA as related to health outcomes.
OBJECTIVES
This systematic review evaluated the relationship between widely recognized, intentionally manufactured, POPs, including per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (dichlorodiphenyltrichloroethane [DDT], dichlorodiphenyldichloroethylene [DDE], hexachlorobenzene [HCB]), with miRNA expression in both human and animal studies.
METHODS
We used PubMed and Embase to systematically search the literature up to September 29th, 2023. Search results for human and animal studies were included if they incorporated at least one POP of interest in relation to at least one miRNA. Data were synthesized to determine the direction and significance of associations between POPs and miRNA. We utilized ingenuity pathway analysis to review disease pathways for miRNA that were associated with POPs.
RESULTS
Our search identified 38 eligible studies: 9 in humans and 29 in model organisms. PFAS were associated with decreased expression of miR-19, miR-193b, and miR-92b, as well as increased expression of miR-128, miR-199a-3p, and miR-26b across species. PCBs were associated with increased expression of miR-15a, miR-1537, miR-21, miR-22-3p, miR-223, miR-30b, and miR-34a, as well as decreased expression of miR-130a and let-7b in both humans and animals. Pathway analysis for POP-associated miRNA identified pathways related to carcinogenesis.
DISCUSSION
This is the first systematic review of the association of POPs with miRNA in humans and model organisms. Large-scale prospective human studies are warranted to examine the role of miRNA as mediators between POPs and health outcomes.
Topics: Animals; Humans; Polychlorinated Biphenyls; Halogenated Diphenyl Ethers; Prospective Studies; Hydrocarbons, Chlorinated; Environmental Pollutants; Pesticides; MicroRNAs; Fluorocarbons
PubMed: 38056610
DOI: 10.1016/j.envres.2023.117832 -
Frontiers in Endocrinology 2023There are conflicting reports on the association between environmental endocrine disruptors (EEDs) and thyroid cancer. This meta-analysis aimed to elucidate the... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
There are conflicting reports on the association between environmental endocrine disruptors (EEDs) and thyroid cancer. This meta-analysis aimed to elucidate the relationship between EEDs and thyroid cancer.
METHODS
We searched for epidemiological studies on EEDs and thyroid cancer published in PubMed and Web of Science up to December 2022. We then screened the articles that could extract data on EEDs concentration levels in both thyroid cancer patients and healthy controls. We excluded articles that could not calculate effect sizes, focused on other thyroid diseases, or lacked controls. Standardized mean difference (SMD) was calculated to analyze the association between EEDs and thyroid cancer. We measured the heterogeneity among the included studies using I2, assessed publication bias by Egger's and Begg's test, and evaluated article quality using the Newcastle-Ottawa Quality Score (NOS). In the end, fifteen eligible case-control studies were included.
RESULTS
Our comprehensive analysis revealed that polychlorinated biphenyls (PCBs) were negatively associated with thyroid cancer{ SMD = -0.03, 95% confidence interval (CI) = (-0.05, -0.00), P = 0.03}, while polybrominated diphenyl ethers (PBDEs), phthalates (PAEs), and heavy metals were positively associated with thyroid cancer{PBDEs: SMD = 0.14, 95%CI = (0.04, 0.23), P = 0.007; PAEs: SMD = 0.30, 95%CI = (0.02, 0.58), P = 0.04; heavy metals: SMD = 0.21, 95%CI = (0.11, 0.32), P < 0.001}. We did not find a statistically significant relationship between bisphenol A (BPA) and thyroid cancer. Most of the included studies did not show publication bias, except for those on PCBs.
DISCUSSION
Our results indicate that exposure to certain EEDs, such as PBDEs, PAEs, and heavy metals, increases the risk of thyroid cancer. However, further large-scale epidemiological studies and mechanism studies are needed to verify these potential relationships and understand the underlying biological mechanisms.
Topics: Humans; Polychlorinated Biphenyls; Endocrine Disruptors; Halogenated Diphenyl Ethers; Thyroid Neoplasms; Metals, Heavy
PubMed: 38027118
DOI: 10.3389/fendo.2023.1283087 -
Frontiers in Oncology 2023Globally, the burden of breast cancer has increased significantly in recent decades. Emerging evidence suggested that endocrine-disrupting chemicals (EDCs), which have...
BACKGROUND
Globally, the burden of breast cancer has increased significantly in recent decades. Emerging evidence suggested that endocrine-disrupting chemicals (EDCs), which have the potential to interfere with the function of normal hormones, may play a crucial role in this trend. However, the potential relationships were inconsistent in various studies.
OBJECTIVE AND SEARCH METHODS
In our study, we sought to fully evaluate the currently available epidemiological evidence to ascertain whether certain EDC congeners and their metabolites are related to breast cancer risk. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a comprehensive literature search of original peer-reviewed publications in three electronic databases: PubMed, Web of Science, and Embase. Publications that covered xenobiotic EDC exposures and breast cancer-confirmed histological results or antecedent medical records or reporting to health registers were taken into consideration.
OUTCOMES
The final result of the literature search was 6,498 references, out which we found 67 publications that matched the requirements for meta-analysis and eight publications for qualitative trend synthesis. In this meta-analysis, statistically significant associations revealed that (i) 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p'-DDT) and its major metabolite 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) were somewhat related to a greater risk of breast cancer. However, this relationship only existed in blood serum but not in adipose tissue. (ii) Breast cancer risk was increased by exposure to chlordane and hexachlorocyclohexane. (iii) Five polychlorinated biphenyls (PCB 99, PCB 105, PCB 118, PCB 138, and PCB 183) can increase the risk of breast cancer. (iv) One phthalate congener (BBP) and one per- and polyfluoroalkyl substance congener (PFDoDA) were negatively associated with breast cancer risk. Unfortunately, heterogeneity was not well explained in our review, and a limited number of available prospective studies investigating the associations between EDC exposure and breast cancer were included in our meta-analysis. To elucidate the overall associations, future large, longitudinal epidemiological investigations are needed.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/, identifier CRD 42023420927.
PubMed: 38023188
DOI: 10.3389/fonc.2023.1282651 -
Environmental Health : a Global Access... Nov 2023Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with lowered IQ in children. In some studies, these neurotoxicants impact males and females differently. We aimed to examine the sex-specific effects of exposure to developmental neurotoxicants on intelligence (IQ) in a systematic review and meta-analysis.
METHOD
We screened abstracts published in PsychINFO and PubMed before December 31st, 2021, for empirical studies of six neurotoxicants (lead, mercury, PCBs, PBDEs, OPPs, and phthalates) that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or before age six; and (3) provided effect estimates on general, nonverbal, and/or verbal IQ by sex. We assessed each study for risk of bias and evaluated the certainty of the evidence using Navigation Guide. We performed separate random effect meta-analyses by sex and timing of exposure with subgroup analyses by neurotoxicant.
RESULTS
Fifty-one studies were included in the systematic review and 20 in the meta-analysis. Prenatal exposure to developmental neurotoxicants was associated with decreased general and nonverbal IQ in males, especially for lead. No significant effects were found for verbal IQ, or postnatal lead exposure and general IQ. Due to the limited number of studies, we were unable to analyze postnatal effects of any of the other neurotoxicants.
CONCLUSION
During fetal development, males may be more vulnerable than females to general and nonverbal intellectual deficits from neurotoxic exposures, especially from lead. More research is needed to examine the nuanced sex-specific effects found for postnatal exposure to toxic chemicals.
Topics: Child; Pregnancy; Humans; Male; Female; Polychlorinated Biphenyls; Lead; Sex Characteristics; Halogenated Diphenyl Ethers; Mercury; Insecticides; Organophosphorus Compounds; Prenatal Exposure Delayed Effects
PubMed: 37978510
DOI: 10.1186/s12940-023-01029-z -
Chemosphere Dec 2023This manuscript presents a systematic review of PCB half-lives reported in the scientific literature. The review was completed in accordance with PRISMA guidelines and... (Review)
Review
This manuscript presents a systematic review of PCB half-lives reported in the scientific literature. The review was completed in accordance with PRISMA guidelines and included a review of almost 1000 peer-reviewed publications. In total, 26 articles were found to report half-lives in humans, with the majority of data coming from studies performed in North America on individuals suspected to have been exposed to PCBs. Terminology for reporting PCB half-lives was inconsistent, so we have attempted to consolidate this and recommend using either "apparent half-life" or "intrinsic half-life" in future studies. Within the literature, values for reported half-lives varied considerably for different PCBs. Less chlorinated PCBs generally have shorter half-lives than more chlorinated PCBs. It was interesting to note the large variability of half-lives reported for the same PCB. For example, the reported half-life for PCB 180 varied by nearly 3 orders of magnitude (0.34 years-300 years). Our review identified that the half-lives estimated were largely dependent on the studied cohort. We discuss the importance of PCB body burden, degree of chlorination and PCB structure, gender, age, breastfeeding, BMI, and smoking status on half-life estimations. We also identified significantly shorter half-lives for some PCBs in occupationally exposed individuals compared to results reported from the general population. PCB half-lives are not the same for every PCB or every individual. Therefore, careful consideration is needed when these values are used in human exposure studies.
Topics: Female; Humans; Polychlorinated Biphenyls; Half-Life; Breast Feeding; Body Burden; North America; Environmental Pollutants
PubMed: 37832892
DOI: 10.1016/j.chemosphere.2023.140359 -
Annali Di Igiene : Medicina Preventiva... 2023The aim of the present systematic review was to evaluate the correlation between the exposure to environmental and/or occupational pollutants and possible alteration of...
BACKGROUND
The aim of the present systematic review was to evaluate the correlation between the exposure to environmental and/or occupational pollutants and possible alteration of semen quality, focalizing the attention on the studies performed using a biomonitoring approach.
METHODS
The review was conducted from inception to May 11 2023, according to the PRISMA Statement 2020 and using the following databases: Scopus, Pubmed and Web of Science. The protocol was registered on PROSPERO (CRD42023405607). Studies were considered eligible if they reported data about the association between exposure to environmental pollutants and alteration of semen quality using human biomonitoring. The quality assessment was carried out by the use of the Newcastle-Ottawa Quality Assessment Scale.
RESULTS
In total, 21 articles were included, conducted in several countries. The main matrices used for biomonitoring were urine and blood and the most sought-after contaminants were bisphenols, phthalates, pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, heavy metals and other inorganic trace elements. The results of the studies demonstrated a significant positive correlation between the increase of the pollutants' levels in the biological matrices examined and some alterations of the semen quality indicators, such as a decrease in motility, concentration and morphology of the spermatozoa.
CONCLUSIONS
Male fertility can be negatively affected by the exposure to environmental and/or occupational pollutants. Human biomonitoring programs may be considered a useful tool for specific surveillance programs devoted to early highlight subjects who are more exposed to environmental pollutants in order to reduce risk exposure.
Topics: Humans; Male; Environmental Pollutants; Semen Analysis; Occupational Exposure; Semen; Spermatozoa; Environmental Exposure; Environmental Monitoring
PubMed: 37796470
DOI: 10.7416/ai.2023.2581 -
Frontiers in Endocrinology 2023Exposure to endocrine-disrupting chemicals (EDCs) during critical neurodevelopmental windows has been associated with the risk of autistic traits. This systematic review...
AIMS
Exposure to endocrine-disrupting chemicals (EDCs) during critical neurodevelopmental windows has been associated with the risk of autistic traits. This systematic review of epidemiological studies examined the association between maternal exposure to EDCs during pregnancy and the risk of autism spectrum disorder (ASD) in the offspring.
METHODS
We searched PubMed, Web of Science, Scopus, and Google Scholar from inception to November 17, 2022, for studies investigating the association between prenatal exposure to EDCs and outcomes related to ASD. Two independent reviewers screened studies for eligibility, extracted data, and assessed the risk of bias. The review was registered in PROSPERO (CRD42023389386).
RESULTS
We included 27 observational studies assessing prenatal exposure to phthalates (8 studies), polychlorinated biphenyls (8 studies), organophosphate pesticides (8 studies), phenols (7 studies), perfluoroalkyl substances (6 studies), organochlorine pesticides (5 studies), brominated flame retardants (3 studies), dioxins (1 study), and parabens (1 study). The number of examined children ranged from 77 to 1,556, the age at the assessment of autistic traits ranged from 3 to 14 years, and most studies assessed autistic traits using the Social Responsiveness Scale. All but one study was considered to have a low risk of bias. Overall, there was no association between maternal exposure to specific ECDs during pregnancy and the occurrence of autistic traits in offspring.
CONCLUSIONS
Findings from the epidemiological studies evaluated here do not support an association between prenatal exposure to ECDs and the likelihood of autistic traits in later in life. These findings should not be interpreted as definitive evidence of the absence of neurodevelopment effects of EDCs affecting ASD risk, given the limitations of current studies such as representative exposure assessment, small sample sizes, inadequacy to assess sexually dimorphic effects, or the effects of EDC mixtures. Future studies should carefully address these limitations.
Topics: Child; Pregnancy; Female; Humans; Adolescent; Child, Preschool; Endocrine Disruptors; Autism Spectrum Disorder; Prenatal Exposure Delayed Effects; Autistic Disorder; Pesticides; Epidemiologic Studies
PubMed: 37361542
DOI: 10.3389/fendo.2023.1184546