Phthalates, Para-Hydroxybenzoic Acids, Bisphenol-A, and Gonadal Hormones' Effects on Susceptibility to Attention-Deficit/Hyperactivity Disorder

ADHD and Sex Hormones in Females: A Systematic Review

OBJECTIVE

ADHD is a neurodevelopmental condition associated with elevated symptoms of inattention and hyperactivity/impulsivity. Symptoms of ADHD typically persist into adulthood and can impair functioning and overall quality of life. In females (including women and people assigned female at birth), ADHD is under-recognized, and knowledge about the relationship between ADHD symptoms and sex hormones is lacking. This systematic review aimed to synthesize the current evidence investigating the relationship between ADHD symptoms (including medication effects) and sex hormones in females.

METHOD

Searches were conducted within Ovid MEDLINE, Embase, and PsycINFO from 1980 to January 2025. Included studies investigated ADHD symptoms in the context of hormonal changes in females, including studies specifically exploring ADHD and sex hormones, as well as hormonal life stages (puberty, menstrual cycle, and pregnancy). Narrative synthesis was utilized for data extraction, grouping studies by hormonal phase.

RESULTS

A total of 11 studies were included in this review. Evidence was largely suggestive of a relationship between ADHD symptoms and sex hormones in females, specifically in puberty and across the menstrual cycle. Findings were limited by the small number of studies reviewed, often with small sample sizes and considerable diversity in participant populations and outcome measures.

CONCLUSION

Sex hormones and phases related to hormonal changes (such as puberty and the menstrual cycle) may be associated with ADHD symptom changes in females. Further research is needed to understand the relationship between sex hormones and ADHD symptoms and requires investigation of a wider range of hormonal milestones in females, including menopause.

Identification of diagnostic and therapeutic biomarkers for attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric condition among children and adolescents, often associated with a high risk of psychiatric comorbidities. Currently, ADHD diagnosis relies exclusively on clinical presentation and patient history, underscoring the need for clinically relevant, reliable, and objective biomarkers. Such biomarkers may enable earlier diagnosis and lead to improved treatment outcomes. Our research team has focused on identifying potential biomarkers for ADHD by investigating its possible pathomechanisms, with consideration of the aforementioned criteria. Given the significant sex-related differences in ADHD prevalence (male predominance) and the age-related variability in its symptomatology, we explored the role of neuroendocrine systems in ADHD. Specifically, we examined the epigenetic regulation mechanism involved in ADHD pathogenesis and developed a diagnostic model based on peripheral microRNA. Additionally, we investigated the role of microbiota dysbiosis in the pathophysiology of ADHD and provided novel insights into its management. This paper presents a summary of our findings on potential biomarkers for ADHD. By analyzing blood, salivary, and fecal samples, we identified several promising biomarkers that may serve as objective parameters for improving the diagnostic accuracy for ADHD. Further research involving larger cohort studies is required to confirm the reliability of these biomarkers.

Puberty and ADHD: A scoping review and framework for future research

Individuals with ADHD may experience puberty differently from their peers, which has implications for their health and wellbeing. This scoping review characterised and summarised literature reporting quantitative analyses of puberty and ADHD. To identify studies, nine databases (MEDLINE Complete, Web of Science, Embase, PsycInfo, ERIC, CENTRAL, PsycExtra, WHO ICTRP, and ProQuest Dissertations & Theses) were searched using key terms related to puberty/pubertal hormones and ADHD/ADHD traits. From 2795 initial records, 89 studies were eligible. Relevant analyses in included studies were categorised under five topics: 1) pubertal group comparisons between participants with ADHD and control participants; 2) associations between puberty and ADHD; 3) prevalence of ADHD in atypical puberty conditions; 4) ADHD medication effects on puberty; and 5) puberty and co-occurring psychological conditions. With some exceptions, summarised findings for each topic were generally inconsistent, indicating further well-planned primary studies are needed. A framework for future research is provided, recommending methodological improvements, including use of approaches that capture the complexities of puberty and ADHD, more inclusive sampling, and employing theories/models that recognise dynamics between puberty, psychological, social, and other biological factors. Additionally, it is recommended that research priorities in this area are identified in collaboration with key stakeholders, especially the ADHD community.

Association Between Endocrine-Disrupting Chemicals Exposure and Attention-Deficit/Hyperactivity Disorder Symptoms in Children With Attention-Deficit/Hyperactivity Disorder

Objectives

This study investigated the relationship between exposure to endocrine-disrupting chemicals (EDCs), specifically phthalates, bisphenol A, bisphenol F, and bisphenol S, and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms using neuropsychological tests in children diagnosed with ADHD.

Methods

This study included 67 medication-naïve children with ADHD aged 6-16 years. The urinary concentrations of EDCs were measured, and ADHD symptom severity was evaluated using neuropsychological tests and clinical symptom scale measurements. The Jonckheere-Terpstra test, Pearson and Spearman correlation analyses, linear regression models, and multiple regression models were used to examine the relationship between EDC exposure and ADHD symptoms.

Results

A significant correlation was observed between urinary phthalate metabolite concentrations and commission error T-scores in the visual Advanced Test of Attention test. No significant associations were found with other neuropsychological indicators or bisphenol levels.

Conclusion

Phthalate exposure affects impulsivity in children with ADHD, which is consistent with the results of previous studies that used parental surveys. However, bisphenols are not clearly associated with ADHD symptoms, which is consistent with the results of previous studies.

Is exposure to Bisphenol A associated with Attention-deficit hyperactivity disorder (ADHD) and associated executive or behavioral problems in children? A comprehensive systematic review

Numerous studies have investigated environmental risk factors in ADHD, and Bisphenol A (BPA), an endocrine disruptor, is suspected by several reviews. However, the quality of the studies has never been carefully assessed, leading us to rigorously examine associations between BPA exposure and ADHD and associated symptoms in children. Using PRISMA criteria, we conducted a systematic review on the MEDLINE/PubMed, Web of Science, EBSCOhost, PsycINFO, PsycARTICLES and Cochrane databases. We used the ROBINS-E tool to assess the quality, and the GRADE Approach. This study was registered with PROSPERO, CRD42023377150. Out of 10446 screened articles, 46 were included. Unlike pre-existing reviews, most studies failed to find clear links with ADHD or associated symptoms, with a high risk of bias and a very low level of certainty. Our systematic review reveals insufficient evidence regarding the impact of BPA on ADHD, despite some behavioral results that cannot be generalized. Future studies will require improved consideration of confounding factors and more precise sampling methods. This study did not receive specific funding.

Effects of urinary organophosphate flame retardants in susceptibility to attention-deficit/hyperactivity disorder in school-age children

Our previous studies have revealed a correlation between urinary phthalates (PAE) metabolites and parabens and PM2.5 exposure and susceptibility to attention-deficit/hyperactivity disorder (ADHD) in school-age children. Our goal was to examine the relationships between urinary organophosphate flame retardants (OPFRs) and their metabolites and the susceptibility to ADHD in the same cohort of children. We recruited 186 school children, including 132 with ADHD and 54 normal controls, living in southern Taiwan to investigate five OPFRs (1,3-dichloro-2-propyl phosphate (TDCPP), tri-n-butyl phosphate (TnBP), tris (2-chloroethyl) phosphate (TCEP), tris(2-butoxyethyl) phosphate (TBEP), and triphenyl phosphate (TPHP)) and five OPFR metabolites (bis(1,3-dichloro-2-propyl) phosphate (BDCPP), di-n-butyl phosphate (DNBP), bis(2-chloroethyl) hydrogen phosphate (BCEP), di-(2-butoxyethyl) phosphate (DBEP), and diphenyl phosphate (DPHP)) in urine. ADHD patients' behavioral symptoms and neuropsychological function were assessed using the Swanson, Nolan, and Pelham Version IV Scale (SNAP-IV) and the Conners' Continuous Performance Test 3rd Edition (Conners CPT3), respectively. BCEP was predominant among urinary OPFRs and the metabolites in both the ADHD and control groups. ADHD children had significantly higher levels of urinary BDCPP, BCEP, DBEP, DPHP, TCEP, TBEP, TNBP, TPHP, and Σ10OPFR compared to the controls. After controlling for age, gender, body mass index, PM2.5 exposure scenarios, and urinary phthalate metabolites, parabens, bisphenol-A and creatinine, levels of urinary BDCPP, TDCPP, and TBEP in ADHD children showed significant and dose-dependent effects on core behavioral symptoms of inattention. DNBP levels were positively correlated with neuropsychological deficits (CPT detectability, omission, and commission), while urinary DPHP in ADHD children were negatively related to CPT detectability and commission. Hyperactivity and impulsivity were not correlated with urinary OPFRs and their metabolites in ADHD children. In conclusion, the ADHD symptom of inattention and CPT performance may be closely associated with certain urinary OPFRs and their metabolites, independent of urinary PAE metabolites, parabens, and bisphenol-A in school-age-ADHD children.

Bisphenol A-What Do We Know? A Global or Local Approach at the Public Health Risk Level

BPA has demonstrated enormous multisystem and multi-organ toxicity shown mainly in animal models. Meanwhile, the effects of its exposure in humans still require years of observation, research, and answers to many questions. Even minimal and short-term exposure contributes to disorders or various types of dysfunction. It is released directly or indirectly into the environment at every stage of the product life cycle, demonstrating its ease of penetration into the body. The ubiquity and general prevalence of BPA influenced the main objective of the study, which was to assess the toxicity and health effects of BPA and its derivatives based on the available literature. In addition, the guidelines of various international institutions or regions of the world in terms of its reduction in individual products were checked. Bisphenol A is the most widely known chemical and perhaps even the most studied by virtually all international or national organizations, but nonetheless, it is still controversial. In general, the level of BPA biomonitoring is still too high and poses a potential threat to public health. It is beginning to be widely argued that future toxicity studies should focus on molecular biology and the assessment of human exposure to BPA, as well as its substitutes. The effects of its exposure still require years of observation, extensive research, and answers to many questions. It is necessary to continue to deepen the knowledge and interest of many organizations, companies, and consumers around the world in order to make rational purchases as well as future choices, not only consumer ones.

Early childhood exposures to phthalates in association with attention-deficit/hyperactivity disorder behaviors in middle childhood and adolescence in the ReCHARGE study

BACKGROUND

Early-life exposure to phthalates alters behaviors in animals. However, epidemiological evidence on childhood phthalate exposure and attention-deficit/hyperactivity disorder (ADHD) behaviors is limited.

METHODS

This study included 243 children from the ReCHARGE (Revisiting Childhood Autism Risks from Genetics and Environment) study, who were previously classified as having autism spectrum disorder (ASD), developmental delay, other early concerns, and typical development in the CHARGE case-control study. Twenty phthalate metabolites were measured in spot urine samples collected from children aged 2-5 years. Parents reported on children's ADHD symptoms at ages 8-18 years using Conners-3 Parent Rating Scale. Covariate-adjusted negative binomial generalized linear models were used to investigate associations between individual phthalate metabolite concentrations and raw scores. Weighted quantile sum (WQS) regression with repeated holdout validation was used to examine mixture effects of phthalate metabolites on behavioral scores. Effect modification by child sex was evaluated.

RESULTS

Among 12 phthalate metabolites detected in >75% of the samples, higher mono-2-heptyl phthalate (MHPP) was associated with higher scores on Inattentive (β per doubling = 0.05, 95% confidence interval [CI]: 0.02, 0.08) and Hyperactive/Impulsive scales (β = 0.04, 95% CI: 0.00, 0.07), especially among children with ASD. Higher mono-carboxy isooctyl phthalate (MCiOP) was associated with higher Hyperactivity/Impulsivity scores (β = 0.07, 95% CI: -0.01, 0.15), especially among typically developing children. The associations of the molar sum of high molecular weight (HMW) phthalate metabolites and a phthalate metabolite mixture with Hyperactivity/Impulsivity scores were modified by sex, showing more pronounced adverse associations among females.

CONCLUSION

Exposure to phthalates during early childhood may impact ADHD behaviors in middle childhood and adolescence, particularly among females. Although our findings may not be broadly generalizable due to the diverse diagnostic profiles within our study population, our robust findings on sex-specific associations warrant further investigations.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

BACKGROUND

A growing body of literature investigated childhood exposure to environmental chemicals in association with attention-deficit/hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay (DD), and typical development (TD).

METHODS

A total of 549 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study were administered the Aberrant Behavior Checklist (ABC). This study focused on the ADHD/noncompliance subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in > 70% samples were used to investigate their associations with ADHD symptoms. Negative binomial regression was used for single-chemical analysis, and weighted quantile sum regression with repeated holdout validation was applied for mixture analysis for each chemical class and all chemicals. The mixture analyses were further stratified by diagnostic group.

RESULTS

A phthalate metabolite mixture was associated with higher ADHD/noncompliance scores (median count ratio [CR] = 1.10; 2.5th, 97.5th percentile: 1.00, 1.21), especially hyperactivity/impulsivity (median CR = 1.09; 2.5th, 97.5th percentile: 1.00, 1.25). The possible contributors to these mixture effects were di-2-ethylhexyl phthalate (DEHP) metabolites and mono-2-heptyl phthalate (MHPP). These associations were likely driven by children with ASD as these were observed among children with ASD, but not among TD or those with DD. Additionally, among children with ASD, a mixture of all chemicals was associated with ADHD/noncompliance and hyperactivity/impulsivity, and possible contributors were 3,4-dihydroxy benzoic acid, DEHP metabolites, MHPP, mono-n-butyl phthalate, and cadmium.

CONCLUSIONS

Early childhood exposure to a phthalate mixture was associated with ADHD symptoms, particularly among children with ASD. While the diverse diagnostic profiles limited generalizability, our findings suggest a potential link between phthalate exposure and the comorbidity of ASD and ADHD.

Effect of bisphenol A on the neurological system: a review update

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) and one of the most produced synthetic compounds worldwide. BPA can be found in epoxy resins and polycarbonate plastics, which are frequently used in food storage and baby bottles. However, BPA can bind mainly to estrogen receptors, interfering with various neurologic functions, its use is a topic of significant concern. Nonetheless, the neurotoxicity of BPA has not been fully understood despite numerous investigations on its disruptive effects. Therefore, this review aims to highlight the most recent studies on the implications of BPA on the neurologic system. Our findings suggest that BPA exposure impairs various structural and molecular brain changes, promoting oxidative stress, changing expression levels of several crucial genes and proteins, destructive effects on neurotransmitters, excitotoxicity and neuroinflammation, damaged blood-brain barrier function, neuronal damage, apoptosis effects, disruption of intracellular Ca2+ homeostasis, increase in reactive oxygen species, promoted apoptosis and intracellular lactate dehydrogenase release, a decrease of axon length, microglial DNA damage, astrogliosis, and significantly reduced myelination. Moreover, BPA exposure increases the risk of developing neurologic diseases, including neurovascular (e.g. stroke) and neurodegenerative (e.g. Alzheimer's and Parkinson's) diseases. Furthermore, epidemiological studies showed that the adverse effects of BPA on neurodevelopment in children contributed to the emergence of serious neurological diseases like attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), depression, emotional problems, anxiety, and cognitive disorders. In summary, BPA exposure compromises human health, promoting the development and progression of neurologic disorders. More research is required to fully understand how BPA-induced neurotoxicity affects human health.

Association of bisphenol A with cognitive functions and functionality in adult attention deficit hyperactivity disorder

BACKGROUND

Bisphenol A (BPA) has been linked to attention-deficit/hyperactivity disorder (ADHD) symptoms, but the effects on cognitive functions and functionality in adult ADHD have not been investigated. We investigated the associations between serum BPA with cognitive functions and functionality in adult ADHD patients.

METHODS

The levels of BPA were measured in 45 adult ADHD patients and 45 well-matched healty controls. The relationship between plastic exposure and BPA was also evaluated. Stroop test and Wisconsin Card Sorting Test were applied for neurocognitive evaluation and participants were compared in basic cognitive functions including planning, organization, abstraction, problem solving, strategy development, set shifting, cognitive flexibility, variants of attention, information processing speed, the ability to change perceptual setup and response under interference. Sheehan disability scale was applied for functionality. The association of BPA with test scores was analyzed statistically.

RESULTS

Serum BPA levels in adult ADHD patients were found to be significantly higher than in healthy controls. There was no relationship between plastic exposure and BPA levels. BPA levels showed a significant effect on functionality in terms of work field. There were significant differences between the groups in terms of cognitive functions. However, no significant correlation was found between BPA levels and cognitive functions.

CONCLUSIONS

BPA is associated with ADHD and affects functionality in the field of work, but larger-scale further studies are needed for its effect on cognitive functions.

Sex differences in children's cognitive functions and phthalates exposure: a meta-analysis

BACKGROUND

Phthalates exposure might affect children's intelligence development. This study aimed to determine (1) whether sex and age affect cognitive function and (2) whether sex differences in cognitive performance are wider with higher phthalate concentrations.

METHODS

Data were collected from PubMed (1998-2022), PROQUEST (1997-2022), and SpringerLink (1995-2022). The study followed the PRISMA process. The included articles were followed by PECO framework. The GRADE applied to assess the certainty of evidence. Of 2422 articles obtained, nine were selected using inclusion criteria. The random-effects model was used to estimate the pooled effects.

RESULTS

Our meta-regression indicated a significant difference between sex differences with age at phthalate concentration assessment (β = -0.25; 95% CI = -0.47, -0.03) and MEHP concentration (β = -0.20; 95% CI = -0.37, -0.03).

CONCLUSIONS

The limitation of the current article is it only provides information on intelligence level rather than other aspects of cognitive function. Thus, the sequelae of phthalate exposure on attention and executive function are still unclear. Our analysis shows significant difference between sex differences in cognitive function scores associated with age at phthalate concentration assessment. Girls might be more resilient in cognitive function at a younger age or during lower concentrations of phthalates metabolites.

IMPACT

This is the first meta-analysis to evaluate the pooled estimates of sex differences in objective cognitive functions among children with phthalate exposure. The female might be a protective factor when exposed to toxic plasticizers while the concentration is low. This study captures the possible role of sex in cognitive functioning and plasticizer exposure through a meta-analysis of children's sex, cognitive scores, and plasticizer exposure.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

Background

Agrowing body of literature investigated childhood exposure to environmental chemicals in association with attention deficit hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay, and typical development.

Methods

A total of 574 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study was administered the Aberrant Behavior Checklist (ABC). This study focused on the Hyperactivity subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in >70% samples were used in statistical analyses. Weighted quantile sum regression for negative binomial outcomes with repeated holdout validation was performed to investigate covariate-adjusted associations between mixtures and ABC scores in 574 children. The mixture analyses were further restricted to 232 children with ASD.

Results

Phthalate metabolite mixtures, weighted for mono-n-butylphthalate (MNBP), mono-2-heptyl phthalate, and mono-carboxy isononyl phthalate, were associated with the Hyperactivity subscale (mean incidence rate ratio [mIRR] = 1.11; 2.5th, 97.5th percentile: 1.00, 1.23), especially the hyperactivity/impulsivity subdomain (mIRR = 1.14; 2.5th, 97.5th percentile: 1.06, 1.26). These associations remained similar after restricting to children with ASD. The inattention subdomain was associated with a phenols/parabens mixture, weighted for several parabens and bisphenols (mIRR = 1.13; 2.5th, 97.5th percentile: 1.00, 1.28) and a total mixture, weighted for 3,4-dihydroxy benzoic acid, MNBR and mono-(2-ethyl-5-carboxypentyl) phthalate (mIRR = 1.11; 2.5th, 97.5th percentile: 1.01,1.25) only among children with ASD.

Conclusions

Concurrent exposure to phthalate mixtures was associated with hyperactivity in early childhood. Though causal inference cannot be made based on our cross-sectional findings, this study warrants further research on mixtures of larger number of chemicals from multiple classes in association with ADHD-related behaviors in young children.

Association of bisphenol A, bisphenol F, and bisphenol S with ADHD symptoms in children

BACKGROUND

Bisphenol A (BPA) has been linked to attention-deficit/hyperactivity disorder (ADHD) symptoms, but the neurotoxic effects of bisphenol substitutes such as bisphenol F (BPF) and S (BPS) have not been well investigated. We investigated the associations between BPA, BPF, and BPS with ADHD symptoms at multiple time points in children.

METHODS

The levels of BPA (at ages 4, 6, and 8), BPF (at ages 6 and 8), and BPS (at ages 6 and 8) were measured in 619 children. Because of the low detection frequency of BPF and BPS levels, participants were divided into categories (<or ≥ limit of detection (LOD) for BPF; < LOD, ≥ LOD and < median, or ≥ median for BPS). ADHD symptoms were assessed using the ADHD Rating Scale IV (ARS). The relationship between bisphenols and ARS scores was analyzed using Poisson regression models, and generalized additive models and piecewise regression models were further explored for BPA.

RESULTS

BPA was detected in most participants (>97%), whereas BPF and BPS were less frequently detected (age 6: 17.5% for BPF and 42.0% for BPS; age 8: 51.6% for BPF and 73.3% for BPS). Doubling in BPA levels was associated with increased ARS scores by 4.7% (95% confidence intervals [CI]: 0.5, 9.2) at age 6. The association was greater with BPA levels higher than 3.0 μg/g creatinine (24.2% [95% CI: 15.5, 33.6] increase). The BPF ≥ LOD group had 10.8% (95% CI: 1.2, 21.4) higher ARS scores than the BPF < LOD group. The BPS ≥ median group had 11.4% (95% CI: 2.0, 21.7) higher ARS scores than the BPS < LOD group.

CONCLUSION

All bisphenols, in particular those at or above the LOD or median levels, were associated with ADHD symptoms at age 6. Further prospective studies are warranted to determine causal inference.

Genome-wide gene-bisphenol A, F and triclosan interaction analyses on urinary oxidative stress markers

BACKGROUND

Bisphenols and triclosan (TCS) are common endocrine disrupters (EDCs) that may induce oxidative stress. However, there is limited information as to whether these EDCs interact with genetic variants to modify the levels of oxidative stress on a genome-wide scale.

METHODS

We first performed a genome-wide scan among a Chinese population and also measured three urinary EDCs, including bisphenol A (BPA), bisphenol F (BPF) and TCS, and three urinary oxidative stress markers [4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), 8-iso-prostaglandin-F_2α (8-isoPGF_2α) and 8-hydroxy-deoxyguanosine (8-OHdG)]. Subsequently, we examined interactions between three urinary EDCs and nearly 4.6 million genetic variants for three urinary oxidative stress markers by the general linear model.

RESULTS

Urinary BPA, BPF and TCS were positively associated with HNE-MA, 8-isoPGF_2α and 8-OHdG. Significant rs6855040 (4p15.32/between SNORA75B and QDPR)-BPA, rs1112943 (4q35.1/SNX25)-TCS interactions were associated with the 8-isoPGF_2α levels (all P < 5 × 10^-8). In addition, rs4656116 (1p22.3/CACL1), rs16958760 (17p11.2/between USP43 and DHRS7C) and rs11651078 (17p11.2/LOC339260) showed significant gene-TCS interactions with 8-OHdG (all P < 5 × 10^-8). The gene-level analysis found significant interaction between SNX25 and TCS for 8-isoPGF_2α levels (P < 2.12 × 10^-6).

CONCLUSION

Our results identify several gene-EDCs interactions for oxidative stress, highlighting that EDCs may modify the effect of genetic variants on oxidative stress.

Interrelationships among growth hormone, thyroid function, and endocrine-disrupting chemicals on the susceptibility to attention-deficit/hyperactivity disorder

Abnormal growth hormones and thyroid function may be linked to pathophysiology of attention-deficit/hyperactivity disorder (ADHD). Phthalates and bisphenol-A (BPA), two endocrine-disrupting chemicals (EDCs), may affect the human endocrine system. In this study, we aimed to perform a comprehensive investigation of whether growth hormone, thyroid function, and EDCs exhibited differential levels between ADHD patients and healthy controls. In total, 144 children with ADHD and 70 healthy control subjects were enrolled. Their endocrine systems were evaluated using the serum levels of insulin-like growth factor-1 (IGF-1), IGF-binding protein-3 (IGFBP-3), thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and Free T4. The urinary levels of EDCs, including monoethyl phthalate (MEP), mono-methyl phthalate (MMP), monoethylhexyl phthalate (MEHP), mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), and BPA, were also examined. Patients with ADHD had lower IGF-1 levels than healthy controls (p = 0.003), but we observed no significant difference in IGFBP-3, TSH, T3, T4, or Free T4. Compared to the control group, patients with ADHD demonstrated higher MEHP levels (p = 0.043), MnBP (p = 0.033), and MBzP (p = 0.040). Furthermore, MEHP levels (p < 0.001) and BPA levels (p = 0.041) were negatively correlated with IGF-1 levels, while IGF-1 levels were negatively correlated with principal components consisting of ADHD clinical symptoms and neuropsychological performance variables. We suggest that MEHP exposure may be associated with decreased serum levels of IGF-1 and increased risk of ADHD. The mechanism underlying this association may be important for protecting children from environmental chemicals that adversely affect neurodevelopment.

Paracetamol use during pregnancy - a call for precautionary action

Paracetamol (N-acetyl-p-aminophenol (APAP), otherwise known as acetaminophen) is the active ingredient in more than 600 medications used to relieve mild to moderate pain and reduce fever. APAP is widely used by pregnant women as governmental agencies, including the FDA and EMA, have long considered APAP appropriate for use during pregnancy when used as directed. However, increasing experimental and epidemiological research suggests that prenatal exposure to APAP might alter fetal development, which could increase the risks of some neurodevelopmental, reproductive and urogenital disorders. Here we summarize this evidence and call for precautionary action through a focused research effort and by increasing awareness among health professionals and pregnant women. APAP is an important medication and alternatives for treatment of high fever and severe pain are limited. We recommend that pregnant women should be cautioned at the beginning of pregnancy to: forego APAP unless its use is medically indicated; consult with a physician or pharmacist if they are uncertain whether use is indicated and before using on a long-term basis; and minimize exposure by using the lowest effective dose for the shortest possible time. We suggest specific actions to implement these recommendations. This Consensus Statement reflects our concerns and is currently supported by 91 scientists, clinicians and public health professionals from across the globe.

A Review of Recent Studies on Bisphenol A and Phthalate Exposures and Child Neurodevelopment

Purpose of Review: Bisphenol A and phthalate have been found in the environment, as well as in humans. In this narrative review pre- and postnatal bisphenol A and phthalate exposures, their relationship to neurodevelopment, and the behavioral outcomes of children are elucidated, focusing in particular on the recent case-control, cross-sectional, and longitudinal studies. This review also introduces some of the possible mechanisms behind the observed associations between exposures and outcomes. Recent Findings: Although bisphenol A and phthalate exposure have been reported to influence neurobehavioral development in children, there are various kinds of test batteries for child neurodevelopmental assessment at different ages whose findings have been inconsistent among studies. In addition, the timing and number of exposure assessments have varied. Summary: Overall, this review suggests that prenatal exposure to bisphenol A and phthalates may contribute to neurobehavioral outcomes in children. The evidence is still limited; however, Attention Deficit Hyperactivity Disorder (ADHD) symptoms, especially among boys, constantly suggested association with both prenatal and concurrent exposure to bisphenol A. Although there is limited evidence on the adverse effects of prenatal and postnatal bisphenol A and phthalate exposures provided, pregnant women and young children should be protected from exposure based on a precautionary approach.