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Background: Cardiometabolic risk factors among youth are rising. Epigenetic age acceleration, a biomarker for aging and disease-risk, has been associated with adiposity in children, but its association with other cardiometabolic risk markers remains understudied. We employed data from the Health Outcomes and Measures of the Environment (HOME) study, a prospective pregnancy and birth cohort in the greater Cincinnati metropolitan area, to examine whether accelerated epigenetic age at birth as well as accelerated epigenetic age and faster pace of biological aging at age 12 years were associated with higher cardiometabolic risk in adolescents. Results: After adjusting for potential confounders, including estimated cell type proportions, epigenetic gestational age acceleration at birth, derived from the Bohlin, Knight, and Haftorn clocks using cord blood DNA methylation data, was not associated with cardiometabolic risk z-scores or individual cardiometabolic risk score components (visceral fat, leptin to adiponectin ratio, HOMA-IR, triglycerides to HDL-C ratio, HbA1c, or systolic blood pressure) at age 12 years. We also did not observe any associations of epigenetic age acceleration, calculated with Horvath's skin and blood, Hannum's, and Wu's epigenetic clocks using peripheral blood at age 12 years, with these same cardiometabolic risk markers. In contrast, faster pace of biological aging was associated with higher cardiometabolic risk [βs (95% CIs)] cardiometabolic risk score 0.25 (0.07, 0.42); visceral fat 0.21 (0.05, 0.38); and hemoglobin A1c 0.23 (0.05, 0.41) per standard deviation increase in pace of biological aging. Faster pace of biological aging was also positively associated with systolic blood pressure, triglycerides to HDL-C ratio, HOMA-IR, and leptin to adiponectin ratio, although these associations were not statistically significant. Conclusions: Our findings provide evidence that faster pace of biological aging was associated with higher cardiometabolic risk score, visceral fat, and HbA1c at age 12 years. Further research is needed to determine whether these associations persist from adolescence through adulthood. [ABSTRACT FROM AUTHOR]

Few methods have been used to characterize repeatedly measured biomarkers of chemical mixtures. We applied latent profile analysis (LPA) to serum concentrations of 4 perfluoroalkyl and polyfluoroalkyl substances (PFAS) measured at 4 time points from gestation to age 12 years. We evaluated the relationships between profiles and z scores of height, body mass index, fat mass index, and lean body mass index at age 12 years (n  = 218). We compared LPA findings with an alternative approach for cumulative PFAS mixtures using g-computation to estimate the effect of simultaneously increasing the area under the receiver operating characteristic curve (AUC) for all PFAS. We identified 2 profiles: a higher PFAS profile (35% of sample) and a lower PFAS profile (relative to each other), based on their average PFAS concentrations at all time points. The higher PFAS profile had generally lower z scores for all outcomes, with somewhat larger effects for males, though all 95% CIs crossed the null. For example, the higher PFAS profile was associated with a 0.50-unit lower (β = −0.50; 95% CI, −1.07 to 0.08) BMI z score among males but not among females (β = 0.04; 95% CI, −0.45 to 0.54). We observed similar patterns with AUCs. We found that a higher childhood PFAS profile and higher cumulative PFAS mixtures may be associated with altered growth in early adolescence. This article is part of a Special Collection on Environmental Epidemiology. [ABSTRACT FROM AUTHOR]

Executive functioning (EF) abilities develop through childhood, but this development can be impacted by various psychosocial environmental influences. Using longitudinal data from the Health Outcome and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort study, we examined if psychosocial environmental factors were significant predictors of EF development. Study participants comprised 271 children and their primary caregivers (98.5% mothers) followed from birth to age 12. We identified four distinct EF developmental trajectory groups comprising a consistently impaired group (13.3%), a descending impairment group (27.7%), an ascending impairment group (9.95%), and a consistently not impaired group (49.1%). Higher levels of maternal ADHD and relational frustration appear to be risk factors for increased EF difficulty over time, while higher family income may serve as a protective factor delaying predisposed EF impairment. Important intervention targets might include teaching positive and effective parenting strategies to mothers whose children are at risk for EF dysfunction. [ABSTRACT FROM AUTHOR]

Short duration of sleep and poor sleep quality have been linked to poor attention and impulse control in children. We aimed to determine the longitudinal predictive value of sleep quantity and quality during early childhood on objective and caregiver-report measures of attention, impulse control, and executive function in children at age 8 years. We used data from the Health Outcomes and Measures of the Environment (HOME) Study, a pregnancy and birth cohort. Caregivers reported on their child's sleep at ages 2, 2.5, 3, 4, and 5 years. Analysis included 410 participants. We used longitudinal growth curve models of early childhood sleep patterns to predict neurobehavioral functioning at age 8 years. Sleep problems did not predict any of our outcome measures at age 8 years. Sleep duration trended shorter as children matured, so predictive models examined both intercept and slope. Children with the least decline in sleep duration across early childhood had fewer impulsive errors at age 8 years on a continuous performance test (unadjusted p = .013; adjusted p = .013). Children with shorter duration of sleep across early childhood had worse caregiver-reported behavioral regulation at age 8 years (unadjusted p = .002; adjusted p = .043). Neither sleep duration slope nor intercept predicted inattention or metacognitive skills at age 8 years (p > .05). Total sleep time across early childhood predicts behavior regulation difficulties in school-aged children. Inadequate sleep during early childhood may be a marker for, or contribute to, poor development of a child's self-regulatory skills. [ABSTRACT FROM AUTHOR]

Background: Prenatal or early childhood secondhand tobacco smoke (SHS) exposure increases obesity risk. However, the potential mechanisms underlying this association are unclear, but obesogenic eating behaviors are one pathway that components of SHS could perturb. Our aim was to assess associations of prenatal and early childhood SHS exposure with adolescent eating behaviors. Methods: Data came from a prospective pregnancy and birth cohort (N = 207, Cincinnati, OH). With multiple informant models, we estimated associations of prenatal (mean of 16 and 26 weeks of gestation maternal serum cotinine concentrations) and early childhood cotinine (average concentration across ages 12, 24, 36, and 48 months) with eating behaviors at age 12 years (Child Eating Behaviors Questionnaire). We tested whether associations differed by exposure periods and adolescent's sex. Models adjusted for maternal and child covariates. Results: We found no statistically significant associations between cotinine measures and adolescent's eating behaviors. Yet, in females, prenatal cotinine was associated with greater food responsiveness (β: 0.23; 95% CI: 0.08, 0.38) and lower satiety responsiveness (β: -0.14; 95% CI: -0.26, -0.02); in males, prenatal and postnatal cotinine was related to lower food responsiveness (prenatal: β: -0.25; 95% CI: -0.04, -0.06; postnatal: β: -0.36; 95% CI: -0.06, -0.11). No significant effect modification by sex or exposure window was found for other eating behaviors. Conclusion: Prenatal and early childhood SHS exposures were not related to adolescent's eating behavior in this cohort; however, biological sex may modify these associations. [ABSTRACT FROM AUTHOR]

(1) Background: Volatile organic compounds (VOCs) are indoor pollutants absorbed by inhalation. The association of several VOCs with lung function in children and adolescents is unknown. (2) Methods: We analyzed 505 participants, 6–17-year-olds from the 2011–2012 National Health and Nutrition Examination Survey. Multiple linear regression models were fitted to estimate the associations of VOC metabolites with spirometry outcomes adjusting for covariates. (3) Results: Urinary metabolites of xylene, acrylamide, acrolein, 1,3-butadiene, cyanide, toluene, 1-bromopropane, acrylonitrile, propylene oxide, styrene, ethylbenzene, and crotonaldehyde were all detected in ≥64.5% of participants. Forced expiratory volume in 1 s (FEV1) % predicted was lower in participants with higher levels of metabolites of acrylamide (β: −7.95, 95% CI: −13.69, −2.21) and styrene (β: −6.33, 95% CI: −11.60, −1.07), whereas the FEV1 to forced vital capacity (FVC) ratio % was lower in children with higher propylene oxide metabolite levels (β: −2.05, 95% CI: −3.49, −0.61). FEV1 % predicted was lower with higher crotonaldehyde metabolite levels only in overweight/obese participants (β: −15.42, 95% CI: −26.76, −4.08) (Pinteraction < 0.001) and with higher 1-bromopropane metabolite levels only in those with serum cotinine > 1 ng/mL (β: −6.26, 95% CI: −9.69, −2.82) (Pinteraction < 0.001). (4) Conclusions: We found novel associations of metabolites for acrylamide, propylene oxide, styrene, 1-bromopropane and crotonaldehyde with lower lung function in children and adolescents. [ABSTRACT FROM AUTHOR]

Thyroid hormones are essential for neurodevelopment. Few studies have considered associations with quantitatively measured autism spectrum disorder (ASD)‐related traits, which may help elucidate associations for a broader population. Participants were drawn from two prospective pregnancy cohorts: the Early Autism Risk Longitudinal Investigation (EARLI), enrolling pregnant women who already had a child with ASD, and the Health Outcomes and Measures of the Environment (HOME) Study, following pregnant women from the greater Cincinnati, OH area. Gestational thyroid‐stimulating hormone (TSH) and free thyroxine (FT4) were measured in mid‐pregnancy 16 (±3) weeks gestation serum samples. ASD‐related traits were measured using the Social Responsiveness Scale (SRS) at ages 3–8 years. The association was examined using quantile regression, adjusting for maternal and sociodemographic factors. 278 participants (132 from EARLI, 146 from HOME) were included. TSH distributions were similar across cohorts, while FT4 levels were higher in EARLI compared to HOME. In pooled analyses, particularly for those in the highest SRS quantile (95th percentile), higher FT4 levels were associated with increasing SRS scores (β = 5.21, 95% CI = 0.93, 9.48), and higher TSH levels were associated with decreasing SRS scores (β = −6.94, 95% CI = −11.04, −2.83). The association between TSH and SRS remained significant in HOME for the 95% percentile of SRS scores (β = −6.48, 95% CI = −12.16, −0.80), but not EARLI. Results for FT4 were attenuated when examined in the individual cohorts. Our results add to evidence that gestational thyroid hormones may be associated with ASD‐related outcomes by suggesting that relationships may differ across the distribution of ASD‐related traits and by familial likelihood of ASD. Lay Summary: The study examined the association between gestational thyroid hormone levels and ASD‐related traits in two pregnancy cohorts. Our results suggested higher levels of gestational free thyroxine levels and lower levels of thyroid‐stimulating hormone were associated with more ASD‐related traits in children, with variations depending on the degree of clinical impairment and the familial likelihood of ASD. [ABSTRACT FROM AUTHOR]

Results of toxicological studies indicate that phthalates and per-/polyfluoroalkyl substances (PFAS), 2 classes of endocrine-disrupting chemicals, may alter the functioning of the hypothalamic-pituitary-adrenocortical (HPA) axis. We evaluated the associations of urinary phthalate metabolites and serum PFAS during gestation and childhood with adolescent hair cortisol concentrations (pg/mg hair) at age 12 years, an integrative marker of HPA axis activity (n  = 205 mother-child pairs; Cincinnati, Ohio; enrolled 2003–2006). We used quantile-based g-computation to estimate associations between mixtures of urinary phthalate metabolites or serum PFAS and hair cortisol. We also examined whether associations of individual phthalate metabolites or PFAS with cortisol varied by the timing of exposure. We found that a 1-quartile increase in all childhood phthalate metabolites was associated with 35% higher adolescent hair cortisol (phthalate mixture ψ = 0.13; 95% confidence interval: 0.03, 0.22); these associations were driven by monoethyl phthalate, monoisobutyl phthalate, and monobenzyl phthalate. We did not find evidence that phthalate metabolites during gestation or serum PFAS mixtures were related to adolescent hair cortisol concentrations. We found suggestive evidence that higher childhood concentrations of individual PFAS were related to higher and lower adolescent hair cortisol concentrations. Our results suggest that phthalate exposure during childhood may contribute to higher levels of chronic HPA axis activity. [ABSTRACT FROM AUTHOR]

(1) Introduction: Epigenetic changes have been proposed as a biologic link between in-utero exposure to maternal smoking and health outcomes. Therefore, we examined if in-utero exposure to maternal smoking was associated with infant DNA methylation (DNAm) of cytosine-phosphate-guanine dinucleotides (CpG sites) in the arginine vasopressin receptor 1A AVPR1a gene. The AVPR1a gene encodes a receptor that interacts with the arginine vasopressin hormone and may influence physiological stress regulation, blood pressure, and child development. (2) Methods: Fifty-two infants were included in this cohort study. Multivariable linear models were used to examine the effect of in-utero exposure to maternal smoking on the mean DNAm of CpG sites located at AVPR1a. (3) Results: After adjusting the model for substance use, infants with in-utero exposure to maternal smoking had a reduction in DNAm at AVPR1a CpG sites by −0.02 (95% CI −0.03, −0.01) at one month of age. In conclusion, in-utero exposure to tobacco smoke can lead to differential patterns of DNAm of AVPR1a among infants. Conclusions: Future studies are needed to identify how gene expression in response to early environmental exposures contributes to health outcomes. [ABSTRACT FROM AUTHOR]

Objective: Excessive gestational weight gain (GWG) has been associated with autism spectrum disorder (ASD). This study sought to examine whether familial susceptibility for autism, intensity of ASD‐related behaviors, or prepregnancy BMI influences the association of GWG with ASD‐related behaviors. Methods: Using data from the Early Autism Risk Longitudinal Investigation (EARLI) study (n = 136), a familial enriched cohort of mothers who had a previous child with ASD, and the Health Outcomes and Measures of the Environment (HOME) study (n = 253), a general population cohort, gestational age and prepregnancy BMI category‐specific GWG z scores were calculated. Caregivers completed the Social Responsiveness Scale (SRS) to assess the presence and severity of ASD‐related traits in children aged 3 to 8 years. Using quantile regression, the association between GWG z scores and ASD‐related behaviors in children was estimated. Results: In HOME, among mothers who had overweight or obesity prepregnancy BMI values, GWG z scores and SRS scores were positively associated in children with more ASD‐related traits (higher SRS scores), but not in children with fewer ASD‐related traits. Similar patterns were observed in EARLI among mothers with prepregnancy obesity. Conclusions: GWG may be associated with autism‐related behaviors among children who have a greater predisposition to these behaviors and who have mothers with prepregnancy overweight or obesity. [ABSTRACT FROM AUTHOR]

Summary: Background: Eating behaviours are associated with childhood obesity, but their associations with cardiometabolic risk are less clear. Objectives: We evaluated cross‐sectional associations between eating behaviours and cardiometabolic risk among 185 adolescents (age 12.4 ± 0.7 years; 53% female; body mass index (BMI)‐z 0.72 ± 1.37) from Cincinnati, Ohio (HOME Study; enrolled 2003–2006). Methods: Caregivers assessed adolescents' eating behaviours with the Child Eating Behaviour Questionnaire. We computed adolescents' cardiometabolic risk scores based on HOMA‐IR, triglycerides to high‐density lipoprotein cholesterol ratio, adiponectin to leptin ratio, systolic blood pressure, and cross‐sectional area of fat inside the abdominal cavity. Using multivariable linear regression models, we estimated associations of eating behaviour subscales with cardiometabolic risk scores or individual risk components. Results: Emotional overeating (ß = 1.34, 95% CI: 0.67, 2.01), food responsiveness (ß = 0.99, 95% CI: 0.41, 1.57), and emotional undereating (ß = 0.64, 95% CI: 0.08, 1.21) were associated with higher cardiometabolic risk scores. Satiety responsiveness (ß = −0.79, 95% CI: −1.59, 0.00) was associated with lower cardiometabolic risk scores. Adjusting for adolescent BMI‐z at age 12 attenuated these associations, suggesting that adiposity may mediate these associations. Conclusion: Hedonistic eating behaviours were associated with higher cardiometabolic risk in these adolescents. [ABSTRACT FROM AUTHOR]

Background: Anxiety disorders emerge during childhood and adolescence and are frequently preceded by subsyndromal anxiety symptoms. Environmental toxicants, including gestational polybrominated diphenyl ether (PBDE) exposure, are associated with neuropsychiatric sequelae; however, the role of PBDEs as risk factors for anxiety in adolescence is unclear. Methods: Using data from the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort enrolled from 2003 to 2006, we investigated the relationship between gestational serum PBDE concentrations and anxiety symptoms in adolescents (N = 236). We measured five PBDE congeners (PBDE‐28, −47, −99, −100, and −153) at 16 ± 3 weeks of gestation and calculated their sum (∑PBDE). We assessed self‐reported anxiety symptoms using the Screen for Child Anxiety Related Emotional Disorders (SCARED) and depressive symptoms using the Children's Depression Inventory (CDI‐2) at age 12 years. We estimated the associations of maternal PBDE concentrations with child anxiety and depressive symptoms using multivariable linear regression and modified Poisson regression. Covariates included child sex, maternal race, maternal age at delivery, maternal marital status, maternal education, and household income at the 12‐year study visit as well as maternal depressive and anxiety symptoms. Sensitivity analyses were performed to control for maternal lead and mercury at delivery. Results: After adjusting for predetermined covariates, each doubling in maternal PBDE concentrations was associated with increased SCARED scores (e.g., for ∑PBDE, SCARED total score, β = 1.6 95% confidence interval [CI]: 0.3–2.9, p =.019) and a nonsignificant increase in depressive symptoms (e.g., for CDI total score, β =.8, 95% CI: −0.2–1.8, p =.11). Conclusions: Gestational serum PBDE concentrations just before mid‐pregnancy and during a period of active cortical and limbic neurogenesis, synaptogenesis and myelogenesis may be a risk factor for developing anxiety symptoms in early adolescence. [ABSTRACT FROM AUTHOR]

Background: Assessment of bone health in young children has been hampered by limited reference values for bone mineral content (BMC) and areal bone mineral density (aBMD) by dual energy X-ray absorptiometry (DXA). Objectives: To identify age, sex, and population ancestry effects on BMC and aBMD and develop smoothed reference ranges for BMC and aBMD in young children. To quantify precision of bone measurements and influence of height-for-age Z-scores on bone Z-scores. Methods: We recruited 484 healthy children ages 1 to 2 years or 4.5 to 5 years at 2 clinical centers, who were seen once or up to 7 times over a 3-year period. Lumbar spine, distal forearm, and whole-body subtotal (ages ≥ 3 years) BMC and aBMD were measured by DXA. These data were combined with data from the Bone Mineral Density in Childhood Study from children ages 5 to 8.9 years to create the smoothed reference curves. Results: For 1- to 5-year-olds, BMC and aBMD at all skeletal sites increased with age. Age trends differed by sex for BMC and aBMD of the spine, distal one-third radius, ultradistal radius, and by ancestry (Black vs non-Black) for all measures. BMC and aBMD precision (% coefficient of variation) ranged from 1.0% to 4.4%. Height Z-scores were positively associated with bone Z-scores and accounted for 4% to 45% of the variance. Conclusions: We demonstrate the feasibility of bone density measurements in young children and provide robust reference ranges and stature adjustments for calculation of bone Z-scores at multiple skeletal sites to enable bone health assessments. [ABSTRACT FROM AUTHOR]

Objective: The study aimed to identify periods of heightened susceptibility to the effects of pre- and postnatal secondhand tobacco smoke (SHS) exposure on body composition at age 12 years.Methods: The study used data from 217 children from the Health Outcomes and Measures of the Environment (HOME) Study, a prospective cohort in Cincinnati, Ohio. Using multiple informant models, the study estimated associations of maternal serum cotinine (16 and 26 weeks of pregnancy) and child serum cotinine concentrations (at age 12, 24, 36, and 48 months) with measures of body composition obtained with anthropometry and dual-energy x-ray absorptiometry at 12 years. We examined whether there were differences between these associations for pre- and postnatal exposure periods and potential effect measure modification by sex.Results: Postnatal cotinine concentrations were associated with higher weight, BMI, body fat and lean mass, waist circumference, and visceral, android, and gynoid fat. Each 10-fold increase in postnatal cotinine was associated with 76% increased risk of overweight or obesity (95% CI: 1.13-2.75). Associations between prenatal concentrations and measures of body composition at 12 years were generally null.Conclusions: Postnatal exposure to SHS may increase adolescent adiposity and lean mass. Future studies should determine whether early-life exposures to SHS are associated with other cardiometabolic risk markers. [ABSTRACT FROM AUTHOR]

Exposure to phthalates is associated with diminished cognition. It is unknown, however, if disproportionate exposure to phthalates among racial minorities contributes to racial disparities in children's intellectual abilities. Methods: We used data from 253 mother-child pairs in Cincinnati, OH (HOME Study, 2003-2006). We measured urinary concentrations of eleven phthalate metabolites twice during pregnancy and up to six times in childhood. We evaluated children's cognitive abilities at ages 5 and 8 years. Using causal mediation models, we quantified covariate-adjusted direct and indirect effects of race on children's Full Scale IQ scores for individual phthalate metabolite concentrations during gestation and childhood. Results: Average IQ scores among Black children (n = 90) were 7.0-points lower (95% CI: -12, -1.8) than White children (n = 145) after adjustment for socioeconomic factors. Urinary monobenzyl phthalate (MBzP) and monoethyl phthalate (MEP) concentrations during gestation and childhood were higher among Black children. We did not observe compelling evidence that phthalate mediated the race-IQ association, with the exception of MEP. Childhood MEP concentrations partially mediated the race- IQ association. For instance, the disparities in IQ scores between Black and White children would have been reduced by 1.9 points (95% CI: -4.7, 0.7) for each 10-fold reduction in urinary MEP concentrations at age 2 years. Other phthalate metabolite concentrations during pregnancy or childhood did not mediate the race-IQ association. Conclusions: We found that urinary MEP concentrations partly mediated IQ disparities among HOME Study children. Reducing exposure to some phthalates might help reduce IQ disparities among Black and White children. [ABSTRACT FROM AUTHOR]

Maternal childhood adversity and trauma may elicit biological changes that impact the next generation through epigenetic responses measured in DNA methylation (DNAm). These epigenetic associations could be modified by the early postnatal environment through protective factors, such as early childhood home visiting (HV) programs that aim to mitigate deleterious intergenerational effects of adversity. In a cohort of 53 mother-child pairs recruited in 2015–2016 for the Pregnancy and Infant Development Study (Cincinnati, Ohio), we examined the association between maternal adverse childhood experiences (ACEs) and neonatal DNAm in the secretogranin V gene (SCG5), which is important in neuroendocrine function. We examined prenatal HV as an effect modifier. Mothers completed a questionnaire on ACEs during pregnancy, and infant buccal samples were collected 1 month postpartum. Multivariable linear regression was used to examine the association between maternal ACEs and neonatal DNAm expressed as M-values averaged across 4 cytosine-phosphate-guanine dinucleotide sites. A higher number of maternal ACEs (>3) was associated with a 5.79–percentage-point lower offspring DNAm (95% confidence interval: −10.44, −1.14), and the association was modified by the number of home visits received during pregnancy. In a population of at-risk mother-child dyads, preliminary evidence suggests that maternal ACEs have a relationship with offspring SCG5 DNAm that differs by the amount of prenatal HV. [ABSTRACT FROM AUTHOR]

BACKGROUND: DNA methylation alterations may underlie associations between gestational perfluoroalkyl substances (PFAS) exposure and later-life health outcomes. To the best of our knowledge, no longitudinal studies have examined the associations between gestational PFAS and DNA methylation. OBJECTIVES: We examined associations of gestational PFAS exposure with longitudinal DNA methylation measures at birth and in adolescence using the Health Outcomes and Measures of the Environment (HOME) Study (2003–2006; Cincinnati, Ohio). METHODS: We quantified serum concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoate (PFNA), and perfluorohexane sulfonate (PFHxS) in mothers during pregnancy. We measured DNA methylation in cord blood (푛= 266) and peripheral leukocytes at 12 years of age (푛= 160) using the Illumina HumanMethylation EPIC BeadChip. We analyzed associations between log2-transformed PFAS concentrations and repeated DNA methylation measures using linear regression with generalized estimating equations. We included interaction terms between children’s age and gestational PFAS. We performed Gene Ontology enrichment analysis to identify molecular pathways. We used Project Viva (1999–2002; Boston, Massachusetts) to replicate significant associations. RESULTS: After adjusting for covariates, 435 cytosine–guanine dinucleotide (CpG) sites were associated with PFAS (false discovery rate, 푞< 0.05). Specifically, we identified 2 CpGs for PFOS, 12 for PFOA, 8 for PFHxS, and 413 for PFNA; none overlapped. Among these, 2 CpGs for PFOA and 4 for PFNA were replicated in Project Viva. Some of the PFAS-associated CpG sites annotated to gene regions related to cancers, cognitive health, cardiovascular disease, and kidney function. We found little evidence that the associations between PFAS and DNA methylation differed by children’s age. DISCUSSION: In these longitudinal data, PFAS biomarkers were associated with differences in several CpGs at birth and at 12 years of age in or near genes linked to some PFAS-associated health outcomes. Future studies should examine whether DNA methylation mediates associations between gestational PFAS exposure and health. [ABSTRACT FROM AUTHOR]

Physical examinations to characterize pubertal maturation may be unacceptable for children enrolled in research studies. Studies confirm the utility of pubertal self staging for research, but there has been limited comparison of self examination with hormone biomarkers. Our objective was to assess concordance of pubertal self staging with hormone biomarkers of puberty. Participants were enrolled in the Health Outcomes and Measures of the Environment Study, a longitudinal pregnancy and birth cohort study. At age 12 years, 139 females and 112 males completed pubertal self staging including breast and pubic hair development in females and pubic hair development in males. No clinical physical examination was performed. Hormone concentrations were measured in 102 females and 96 males including serum dehydroepiandrosterone sulfate, luteinizing hormone, and follicle-stimulating hormone in all; estradiol in females; and testosterone in males. Estradiol was significantly associated with female breast stage, even when adjusted for BMI, with geometric least squares means (95%CI) of 13.2 (8.7, 20.2), 38.3 (29.9, 49.1), 59.4 (39.8, 88.6), and 81.2 (45.6, 144) pg/mL for breast stage 1–2, 3, 4, and 5, respectively. Testosterone was significantly associated with male pubic hair stage, with adjusted geometric least squares means (95%CI) of 37.6 (19.9, 71.1), 43.4 (27.7, 68.3), 126 (78.4, 203), 275 (146, 521), and 559 (237, 1319) ng/dL for pubic hair stage 1, 2, 3, 4, and 5, respectively. Self assessed pubertal development was positively associated with hormonal biomarkers of puberty. [ABSTRACT FROM AUTHOR]

Background: Children from socioeconomically disadvantaged families have a markedly elevated risk for impaired cognitive and social-emotional development. Children in poverty experience have a high risk for developmental delays. Poverty engenders disproportionate exposure to psychological adversity which may contribute to impaired offspring development; however the effect may be mitigated by social support and other aspects of resilience. Our objective was to determine the association between maternal stress, adversity and social support and early infant neurobehavior and child behavior at two and three years.Methods: We conducted a longitudinal mother-infant cohort study nested within a regional home visiting program in Cincinnati, Ohio. Four home study visits were completed to collect measures of maternal stress, adversity and social support and infant and child behavior. A measure of infant neurobehavior ('high-arousal' infant) was derived from the NICU Network Neurobehavioral Scale (NNNS) at 1 month and externalizing and internalizing symptoms were measured by the Child Behavior Checklist (CBCL) at 24 and 36 months. Linear and logistic regression identified associations between maternal risk/protective factors and infant and child behavioral measures. We used stratification and multiplicative interaction terms to examine potential interactions.Results: We enrolled n = 55 pregnant mothers and follow 53 mother-offspring dyads at 1 month, 40 dyads at 24 months and 27 dyads at 36 months. Maternal adversity and protective factors were not associated with neurobehavior at one month. However, maternal depression and measures of distress in pregnancy were significantly associated with internalizing and externalizing symptoms at 24 and 36 months.Conclusions: This pilot study established the feasibility of conducting longitudinal research within a community intervention program. In addition, although there were no statistically significant associations between maternal psychosocial factors in pregnancy and infant neurobehavior, there were several associations at 24 months, primarily internalizing symptoms, which persisted through 36 months. Future work will replicate findings within a larger study as well as explore mediators and modifiers of these associations. [ABSTRACT FROM AUTHOR]

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) may impair bone accrual and strength via endocrine disruption and nuclear receptor agonism, but human studies are primarily of adults or cross-sectional. OBJECTIVES: We assessed associations of individual PFAS and their mixture during pregnancy with child bone mineral content (BMC) and areal bone mineral density (aBMD) at age 12 y. METHODS: Among 206 mother–child pairs enrolled in a prospective cohort (2003–2006), we quantified perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) in maternal serum collected during gestation or delivery. When children were age 12 y, we performed dual energy X-ray absorptiometry and calculated BMC, aBMD, and bone mineral apparent density (BMAD) 푧-scores for six skeletal sites. We estimated covariate-adjusted 푧-score differences per doubling of individual PFAS using linear regression and assessed the PFAS mixture using quantile g-computation and Bayesian kernel machine regression. We explored whether associations were modified by child's sex or mediated by whole-body lean mass. RESULTS: In covariate-adjusted models, we found that higher maternal serum concentrations of PFOA, PFNA, and the PFAS mixture were associated with lower total hip and forearm (one-third distal radius) BMC 푧-scores in children. Differences in forearm BMC 푧-scores were -0.17 [95% confidence interval (CI): -0.35, 0.01] and -0.24 (95% CI: -0.44, -0.05) per doubling of PFOA and PFNA, respectively, and -0.18 (95% CI: -0.34, -0.02) per quartile increase in the PFAS mixture. Child's sex modified PFOA associations for some skeletal sites; for example, differences in spine BMAD z-score per doubling were -0.31 (95% CI: -0.58, -0.03) among males and 0.07 (95% CI: -0.16, 0.30) among females (modification 푝= 0.04). Except for PFNA among females, these associations were not mediated by whole-body lean mass. DISCUSSION: Maternal PFAS concentrations during pregnancy may be associated with lower bone mineral accrual and strength in early adolescence [ABSTRACT FROM AUTHOR]

Production of organophosphate esters (OPEs), which represent a major flame-retardant class present in consumer goods, has increased over the past 2 decades. Experimental studies suggest that OPEs may be associated with thyroid hormone disruption, but few human studies have examined this association. We quantified OPE metabolites in the urine of 298 pregnant women from Cincinnati, Ohio, in the Health Outcomes and Measures of the Environment Study (enrolled 2003–2006) at 3 time points (16 and 26 weeks' gestation, and at delivery), and thyroid hormones in 16-week maternal and newborn cord sera. Urinary bis(1,3-dichloro-2-propyl)-phosphate concentrations were generally associated with decreased triiodothyronine and thyroxine levels and increased thyroid-stimulating hormone levels in maternal and newborn thyroid hormones in quartile dose–response analyses and multiple informant models. There was weaker evidence for thyroid hormone alterations in association with diphenyl-phosphate and di- n -butyl-phosphate. Bis-2-chloroethyl-phosphate was not associated with alterations in thyroid hormones in any analyses. We did not observe any evidence of effect modification by infant sex. These results suggest that gestational exposure to some OPEs may influence maternal and neonatal thyroid function, although replication in other cohorts is needed. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to examine associations of changes in leptin and adiponectin concentrations from birth to age 12 years with adolescent adiposity and cardiometabolic risk in the Health Outcomes and Measures of Environment (HOME) Study, a prospective birth cohort (Cincinnati, Ohio; N = 166).Methods: Adiposity and cardiometabolic risk factors were assessed at age 12 years using anthropometry, dual-energy x-ray absorptiometry, and fasting serum biomarkers. Cardiometabolic risk scores were calculated by summing age- and sex- standardized z scores for individual cardiometabolic risk factors.Results: Most serum adipocytokine concentrations at birth were not associated with adiposity or cardiometabolic risk outcomes. Leptin and adiponectin concentrations at age 12 years were associated with all outcomes in the expected direction. Adolescents with increasing (β: 4.2; 95% CI: 3.2 to 5.2) and stable (β: 2.2; 95% CI: 1.2 to 3.2) leptin concentrations from birth to age 12 years had higher cardiometabolic risk scores than adolescents with decreasing concentrations (reference group). Adolescents with increasing (e.g., fat mass index = β: -1.04; 95% CI: -1.27 to -0.80) and stable (β: 0.66; 95% CI: -0.92 to -0.40) adiponectin/leptin ratios had more favorable adiposity outcomes than adolescents with decreasing ratios.Conclusions: In this cohort, changes in leptin concentrations and adiponectin/leptin ratios over childhood were associated with adiposity and cardiometabolic risk scores, indicating that adipocytokine concentrations are potential biomarkers for predicting excess adiposity and cardiometabolic risk in adolescence. [ABSTRACT FROM AUTHOR]

Objective: Conduct secondary analyses on longitudinal data to determine if caregiver-reported sleep quantity and sleep problems across early childhood (ages 2 - 5 years) predict their child's attention and executive functioning at age 8 years. Participants and Methods: This study utilized data from the Health Outcomes and Measures of the Environment (HOME) Study. The HOME Study recruited pregnant women from 20032006 within a nine-county area surrounding Cincinnati, OH. Caregivers reported on their child's sleep patterns when children were roughly 2, 2.5, 3, 4, and 5 years of age. Our analysis included 410 participants from the HOME Study where caregivers reported sleep measures on at least 1 occasion or their child completed an assessment of attention and executive functioning at age 8. At each time point, caregiver report on an adapted version of the Child Sleep Habits Questionnaire (CSHQ) was used to determine: (1) total sleep time (TST; "your child's usual amount of sleep each day, combining nighttime sleep and naps") and (2) overall sleep problems (23 items related to difficulties with sleep onset, sleep maintenance, and nocturnal events). Our outcome variables, collected at age 8, included caregiver-report forms and measures of attention and executive functioning. Caregiver report measures included normed scores on the Behavior Rating Inventory of Executive Function, from which we focused on the Behavior Regulation Index (BRIEF BRI) and Metacognition Index (BRIEF MI). Performance based measures included T-scores for Omission and Commission errors on the Conner's Continuous Performance Test, Second Edition (CPT-2) and Standard Scores on the WISC-IV; Working Memory Index (WMI). We used longitudinal growth curve models of early childhood sleep patterns to predict attention and executive functioning at age 8. Predictive analyses were run with and without key covariates: annual household income, child sex and race. To account for general intellectual functioning, we also included covariates children's WISC-IV Verbal Comprehension and Perceptual Reasoning Indexes. Results: Children in our sample were evenly divided by sex; 60% were White. Sleep problems did not show linear or quadratic change over time, so an intercept-only model was used. Sleep problems did not predict any of our outcome measures at age 8 in unadjusted or covariate-adjusted models. As expected, sleep duration was shorter as children matured, so predictive models examined both intercept and slope. Slope was negatively associated with CPT-2 Commissions (unadjusted p=.047; adjusted p=.013); children who showed the least decline in sleep over time had fewer impulsive errors at age 8. The sleep duration intercept was negatively associated with BRIEF BRI (unadjusted p=.002; adjusted p=.043); children who slept less across early childhood had worse parent-reported behavioral regulation at age 8. Neither sleep duration slope nor intercept significantly predicted any other outcomes at age 8 in unadjusted or covariate-adjusted analyses. Conclusions: Total sleep time across early childhood predicts behavior regulation difficulties in later childhood. Inadequate sleep during early childhood may be a marker for or contribute to poor development of a child's self-regulatory skills. [ABSTRACT FROM AUTHOR]

We examined the association between prenatal fish intake and child autism-related traits according to Social Responsiveness Scale (SRS) and cognitive development scores in two US prospective pregnancy cohorts. In adjusted linear regression analyses, higher maternal fish intake in the second half of pregnancy was associated with increased child autism traits (higher raw SRS scores; ß = 5.60, 95%CI 1.76, 12.97). Differences by fish type were suggested; shellfish and large fish species were associated with increases, and salmon with decreases, in child SRS scores. Clear patterns with cognitive scores in the two cohorts were not observed. Future work should further evaluate potential critical windows of prenatal fish intake, and the role of different fish types in association with child autism-related outcomes. [ABSTRACT FROM AUTHOR]

Maternal nutrition during gestation has been investigated for its role in child neurodevelopment. However, little is known about the potential impact of gestational caffeine exposure on child autistic behaviors. Here, we assess the relation between maternal caffeine intake during pregnancy and children's behavioral traits related to Autism Spectrum Disorder (ASD). We harmonized data from two pregnancy cohorts, Early Autism Risk Longitudinal Investigation (EARLI) (n = 120), an enriched-risk cohort of mothers who previously had a child with ASD, from Pennsylvania, Maryland, and Northern California (2009–2012), and the Health Outcomes and Measures of the Environment (HOME) Study (n = 269), a general population cohort from Cincinnati, Ohio (2003–2006). Mothers self-reported caffeine intake twice during pregnancy. Caregivers reported child behavioral traits related to ASD using the Social Responsiveness Scale (SRS) when children were aged 3–8 years. Higher scores indicate more ASD-related behaviors. We estimated covariate-adjusted differences in continuous SRS T-scores per interquartile range increase in caffeine intake. Self-reported caffeine intake during pregnancy was positively associated with SRS T-scores among children in EARLI (β: 2.0; 95% CI -0.1, 4.0), but to a lesser extent in HOME (β: 0.6; 95% CI -0.5, 1.6). In HOME, pre-pregnancy body mass index (BMI) modified the association between caffeine intake and SRS T-scores, where more positive associations were observed among women with higher BMIs. Our findings suggest gestational caffeine intake may represent a marker of vulnerability to childhood ASD-related behaviors. Additional studies are warranted to extend these findings. [ABSTRACT FROM AUTHOR]

Background Epidemiological studies have historically focused on single toxicants, or toxic chemicals, and neurodevelopment, even though the interactions of chemicals and nutrients may result in additive, synergistic, antagonistic, or potentiating effects on neurological endpoints. Investigating the impact of environmentally-relevant chemical mixtures, including heavy metals and endocrine disrupting chemicals (EDCs), is more reflective of human exposures and may result in more refined environmental policies to protect the public. Objective In this review, we provide a summary of epidemiological studies that have analyzed chemical mixtures of heavy metals and EDCs and neurobehavior utilizing multi-chemical models, including frequentist and Bayesian methods. Content Studies investigating chemicals and neurobehavior have the opportunity to not only examine the impact of chemical mixtures, but they can also identify chemicals from a mixture that may play a key role in neurotoxicity, investigate interactive effects, estimate non-linear dose response, and identify potential windows of susceptibility. The examination of neurobehavioral domains is particularly challenging given that traits emerge and change over time and subclinical nuances of neurobehavior are often unrecognized. To date, only a handful of epidemiological studies examining neurodevelopment have utilized multi-pollutant models in the investigation of heavy metals and EDCs. However, these studies were successful in identifying contaminants of importance from the exposure mixtures. Summary and Outlook Investigators are encouraged to broaden their focus to include more environmentally relevant mixtures of chemicals using advanced statistical approaches, particularly to aid in identifying potential mechanisms underlying associations. [ABSTRACT FROM AUTHOR]

Summary: Background: Although sleep duration is a risk factor for obesity in young children, less is known about other aspects of sleep health, including bedtime, on obesity risk. Objective: To determine whether bedtime is associated with body mass index (BMI) z‐score or obesity risk in children ages 2 to 5 years, and to determine if associations are independent of sleep duration. Methods: Cohort analyses were undertaken using three early life obesity prevention trials (POI, INSIGHT, Healthy Beginnings) and a longitudinal cohort study (HOME). Bedtime was assessed by questionnaire and BMI through clinical measurement between 2 and 5 years in 1642 children. Adjusted regression models examined whether BMI z‐score and obesity (BMI z‐score ≥ 2) were associated with bedtime, nocturnal sleep time and 24‐hour sleep time. A discrete mixture model categorized children into bedtime trajectory groups across time points. Results: Bedtime was inconsistently associated with BMI z‐score. Although each hour later of bedtime was associated with greater odds of obesity at ages 3 (OR; 95% CI: 1.05; 1.003, 1.10) and 5 (1.35; 1.08, 1.69) years, odds were attenuated after adjustment for nocturnal or 24‐hour sleep time. Longer nocturnal sleep duration at 2 years was associated with lower odds of obesity (OR 0.90; 0.86, 0.94), as was longer 24‐hour sleep duration at 3 years in girls (0.70; 0.62, 0.78). BMI z‐score and odds of obesity were not significantly different between 'early to bed' and 'late to bed' trajectory groups. Conclusions: Timing of bedtime appears inconsistently related to obesity in young children, possibly via influencing overall sleep duration. [ABSTRACT FROM AUTHOR]

Purpose Environmental chemical exposures may adversely affect an array of adolescent health outcomes. Thus, we used the Health Outcomes and Measures of the Environment (HOME) study, a prospective cohort that recruited pregnant women and conducted longitudinal follow-up on children over the first 12 years of life, to determine if and when chemical exposures affect adolescent health. Participants We recruited 468 pregnant women (age range: 18–45 years) from the Cincinnati, Ohio region to participate in a cohort study between March 2003 and January 2006. Follow-up included two clinic and one home visits during pregnancy, a delivery hospital visit, and four home and six clinic visits when children were aged 4 weeks and 1, 2, 3, 4, 5 and 8 years. Of 441 children available for follow-up, 396 (90%) completed at least one follow-up and 256 (58%) completed the most recent follow-up at 12 years of age (range: 11–14). Findings to date Our new measures include maternal/child report of internalising symptoms, neuroimaging, dual-energy X-ray absorptiometry-derived estimates of lean/adipose tissue and bone mineral density, and cardiometabolic risk biomarkers. We assessed adolescent exposure to perfluoroalkyl substances, phenols, phthalates and flame retardants. Participants completing follow-up at 12 years of age were similar to the original cohort in terms of baseline factors. Most children had typical and expected values for this age on measures of internalising symptoms, body composition, bone density and cardiometabolic risk markers. Notably, 36% and 11% of children had scores indicative of potential anxiety and depressive disorders, respectively. Approximately 35% of children were overweight or obese, with higher prevalence among girls. Thirty-three per cent of children had borderline or high triglyceride concentrations (>90mg/dL). Future plans We will examine associations of early life environmental chemical exposures with adolescent health measures while considering potential periods of heightened susceptibility and mixture effects [ABSTRACT FROM AUTHOR]

Purpose: Maternal thyroid function during pregnancy may influence offspring thyroid function, though relations between maternal and child thyroid function are incompletely understood. We sought to characterize relations between maternal, cord and child thyroid hormone concentrations in a population of mother‐child pairs with largely normal thyroid function. Methods: In a prospective birth cohort, we measured thyroid hormone concentrations in 203 mothers at 16 gestational weeks, 273 newborns and 159 children at 3 years among participants in the Health Outcomes and Measures of the Environment (HOME) Study. We used multivariable linear regression to estimate associations of maternal thyroid hormones during pregnancy with cord serum thyroid hormones and also estimated associations of maternal and cord thyroid hormones with child thyroid‐stimulating hormone (TSH). Results: Each doubling of maternal TSH was associated with a 16.4% increase of newborn TSH (95% CI: 3.9%, 30.5%), and each doubling of newborn TSH concentrations was associated with a 10.4% increase in child TSH concentrations at 3 years (95% CI: 0.1%, 21.7%). An interquartile range increase in cord FT4 concentrations was associated with an 11.7% decrease in child TSH concentrations at 3 years (95% CI: −20.2%, −2.3%). Conclusions: We observed relationships between maternal, newborn and child thyroid hormone concentrations in the HOME Study. Our study contributes to understandings of interindividual variability in thyroid function among mother‐child pairs, which may inform future efforts to identify risk factors for thyroid disorders or thyroid‐related health outcomes. [ABSTRACT FROM AUTHOR]

Background: Multiple perspectives on cognitive development, including Cattell's Investment Theory (1963, 1987), suggest that fluid reasoning (Gf) is foundational to the development of academic knowledge and skills. Yet little is known of the role that Gf may play in reading achievement, particularly in comparison with a larger literature demonstrating an influential role of crystallised intelligence (Gc) in word recognition. Given the novelty of word recognition for early readers, it is likely that Gf plays an influential role in literacy acquisition. Method: Using regression‐based mediation analysis, the present study examined performance of preschool children (n = 154) and college‐aged adults (n = 114) on measures of Gf, Gc, phonemic decoding and word recognition. Results: Results show that Gf has a significant direct effect on word recognition among preschoolers but not among adults. Moreover, among preschoolers, Gf exerted an effect indirectly on word recognition through phonemic decoding (i.e., Gf → phonemic decoding →word recognition), as well as through a serial and joint mechanism of Gc and phonemic decoding (i.e., Gf →Gc →phonemic decoding →word recognition). However, among adults, Gf exerted an effect onto word recognition only through this joint and serial mechanism and not singularly through phonemic decoding. Conclusions: Present findings link theories of cognitive development with models of reading development, suggesting that while Gf may both directly and indirectly invest in word recognition during early literacy acquisition, this investment may shift in adulthood such that Gf exerts only indirect effects through crystallised knowledge and skills (i.e., Gc and phonemic decoding). [ABSTRACT FROM AUTHOR]

Early life exposure to air pollution poses a significant risk to brain development from direct exposure to toxicants or via indirect mechanisms involving the circulatory, pulmonary or gastrointestinal systems. In children, exposure to traffic related air pollution has been associated with adverse effects on cognitive, behavioral and psychomotor development. We aimed to determine whether childhood exposure to traffic related air pollution is associated with regional differences in brain volume and cortical thickness among children enrolled in a longitudinal cohort study of traffic related air pollution and child health. We used magnetic resonance imaging to obtain anatomical brain images from a nested subset of 12 year old participants characterized with either high or low levels of traffic related air pollution exposure during their first year of life. We employed voxel-based morphometry to examine group differences in regional brain volume, and with separate analyses, changes in cortical thickness. Smaller regional gray matter volumes were determined in the left pre- and post-central gyri, the cerebellum, and inferior parietal lobe of participants in the high traffic related air pollution exposure group relative to participants with low exposure. Reduced cortical thickness was observed in participants with high exposure relative to those with low exposure, primarily in sensorimotor regions of the brain including the pre- and post-central gyri and the paracentral lobule, but also within the frontal and limbic regions. These results suggest that significant childhood exposure to traffic related air pollution is associated with structural alterations in brain. [ABSTRACT FROM AUTHOR]

Background: The objective was to determine whether infant neurobehavior measured at five post-gestational weeks could predict social and communicative behavior (SCB) through five and eight years. Methods: Infant neurobehavior was assessed using the Neonatal Intensive Care Unit Network Neurobehavioral Scale, and SCB was measured using the Social Responsiveness Scale (SRS). Adjusted linear regression with generalized estimating equations were employed to estimate the association between infant neurobehavior and SCB. Interaction terms and stratification were used to identify potential effect modification by autism spectrum disorder risk factors. Results: The analyses include n = 214 and n = 227 participants who were examined at 5 weeks and followed to 4/5 and 8 years, respectively. Adjusting for maternal age, race, parity, and education as well as gestational age, only the Neonatal Intensive Care Unit Network Neurobehavioral Scale summary score of "attention" (measured at mean 43.9 gestational weeks) was inversely associated with total SRS T-score through 5 years. However, in analyses stratified by maternal age, the inverse association between "attention" and SCB was significant, but only among offspring of women of advanced maternal age (≥35 y); in addition, higher scores of "excitability," "lethargy," and "arousal" were associated with increased total SRS T scores among women of advanced maternal age. The associations were no longer statistically significant at 8 years. Conclusions: Newborns with lower scores on the attention subscale (determined by an ability to localize and track animate and inanimate objects) were more likely to demonstrate deficits in SCB. In addition, infants with increased excitability, lethargy, or increased arousal were more likely to have impaired SCB that persisted through 5 years, but not at 8 years of age. Further work is necessary to identify specific aspects of infant neurobehavior that may affect childhood SCBs. [ABSTRACT FROM AUTHOR]

The variation in childhood social-emotional development within at-risk populations may be attributed in part to epigenetic mechanisms such as DNA methylation (DNAm) that respond to environmental stressors. These mechanisms may partially underlie the degree of vulnerability (and resilience) to negative social-emotional development within adverse psychosocial environments. Extensive research supports an association between maternal adversity and offspring DNAm of the NR3C1 gene, which encodes the glucocorticoid receptor (GR). A gap in knowledge remains regarding the relationship between NR3C1 DNAm, measured in neonatal (1-month of age) buccal cells, and subsequent social-emotional development during infancy and early childhood. We conducted a longitudinal cohort study of n = 53 mother-child dyads (n = 30 with developmental outcomes formed the basis of current study) who were enrolled in a home visiting (HV) program. Higher mean DNAm of the NR3C1 exon 1F promoter was significantly associated with lower 6-month Ages and Stages Questionnaire: Social-Emotional (ASQ:SE) scores—more positive infant social-emotional functioning. A similar trend was observed at 18-months of age in a smaller sample (n = 12). The findings of this pilot study indicate that in a diverse and disadvantaged population, the level of neonatal NR3C1 DNAm is related to later social-emotional development. Limitations and implications for future research are discussed. [ABSTRACT FROM AUTHOR]

Background: Mercury is toxic to the developing brain, but the lowest concentration associated with the development of behavior problems is unclear. The purpose of this study was to examine the association between very low-level mercury exposure during fetal development and behavior problems in children.Methods: We used data from 389 mothers and children in a prospective pregnancy and birth cohort study. We defined mean prenatal mercury concentration as the mean of total whole blood mercury concentrations in maternal samples collected at 16- and 26-weeks of gestation, delivery, and neonatal cord blood samples. We assessed parent-reported child behavior up to five times from two to 8 years of age using the Behavioral Assessment System for Children (BASC-2). At 8 years of age, we assessed self-reported child anxiety using the Spence Children's Anxiety Scale (SCAS). We used multiple linear mixed models and linear regression models to estimate the association between mean prenatal mercury concentrations and child behavior and anxiety, respectively.Results: The median prenatal total blood mercury concentrations was 0.67 μg/L. Overall, we did not find statistically significant associations between mean prenatal mercury concentrations and behavior problems scores, but a 2-fold increase in mercury concentrations at 16-weeks gestation was associated with 0.83 point (95% CI: 0.05, 1.62) higher BASC-2 anxiety scores. Maternal and cord blood mercury concentrations at delivery were associated with parent-reported anxiety at 8 years.Conclusion: We found limited evidence of an association between very-low level prenatal mercury exposure and behaviors in children, with an exception of anxiety. [ABSTRACT FROM AUTHOR]

Objective: Whether obesity is associated with childhood cognition is unknown. Given the sensitivity of the developing brain to environmental factors, this study examined whether early-life weight status was associated with children's cognition.Methods: Using data from mother-child pairs enrolled in the Health Outcomes and Measures of the Environment (HOME) Study (2003-2006), children's early-life weight status was assessed using weight-for-length/height standard deviation (SD) scores. A battery of neuropsychological tests was administered to assess cognition, executive function, and visual-spatial abilities at ages 5 and 8 years. Using linear mixed models, associations between early-life weight status and cognition were estimated.Results: Among 233 children, 167 were lean (≤1 SD) and 48 were nonlean (>1 SD). After covariate adjustment, the results suggest that full-scale intelligence quotient scores decreased with a 1-unit increase in weight-for-height SD score (β = -1.4, 95% CI: -3.0 to 0.1). For individual component scores, with a 1-unit increase in weight-for-height SD score, perceptual reasoning (β = -1.7, 95% CI: -3.3 to 0.0) and working memory (β: -2.4, CI: -4.4 to -0.4) scores decreased. Weight status was generally not associated with other cognition measures.Conclusions: Within this cohort of typically developing children, early-life weight status was inversely associated with children's perceptual reasoning and working memory scores and possibly with full-scale intelligent quotient scores. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exposure to triclosan, an endocrine disrupting chemical, may affect thyroid hormone homeostasis and adversely affect neurodevelopment. OBJECTIVE: Using a longitudinal pregnancy and birth cohort, we investigated associations between triclosan exposures during different time windows, and cognitive test scores at 8 y of age in 198 children from the HOME Study. METHODS: We quantified triclosan in urine samples from mother-child pairs up to nine times between the second trimester of gestation and 8 y of age. The Wechsler Intelligence Scale for Children-IV [i.e., Full-Scale Intelligence Quotient (IQ)] assessment was administered to HOME Study children at 8 y of age. We estimated covariate-adjusted triclosan-IQ associations at each visit. We also tested whether associations between triclosan concentrations and cognitive test scores varied among exposure at different time periods. RESULTS: Full-Scale IQ was not significantly associated with urinary triclosan concentrations during gestation or childhood but was significantly associated with a 10-fold increase in maternal urinary triclosan concentration at delivery [-4:5 points (95% CI: -7:0, -2:0)]. Perceptual Reasoning Index (PRI) scores were significantly decreased in association with urinary triclosan concentrations at delivery and at 2 y of age. Associations between repeated triclosan concentrations and cognitive test scores significantly varied among exposure at different time periods for Full-Scale IQ, PRI, Verbal Comprehension Index, and Working Memory (triclosan-visit interaction p=0:04). CONCLUSION: Urinary triclosan concentrations at delivery, but not during mid to late pregnancy and childhood, were associated with significantly lower children's cognitive test scores at 8 y of age in this cohort of U.S. children. [ABSTRACT FROM AUTHOR]

Background: Early-life phthalate exposure may influence child adiposity, but prior studies have not determined if there are periods of enhanced vulnerability to phthalates. Objective: To examine the relationship between child adiposity at 8 y of age and repeated urinary biomarkers of phthalate exposure from gestation through childhood to determine if there are distinct periods of vulnerability. Methods: In 219 mother-child pairs from Cincinnati, Ohio, we quantified nine urinary phthalate metabolites up to two times prenatally and six times from 1-8 y of age. We measured child body mass index (BMI), waist circumference, and percent body fat at 8 y of age. To identify periods of vulnerability, we used two statistical methods to estimate phthalate-adiposity associations at each visit, test differences in phthalate-adiposity associations across visits, and model trajectories of phthalate concentrations for children at different levels of adiposity. Results: Prenatal phthalate concentrations were not associated with excess child adiposity. Monobenzyl phthalate (MBzP) concentrations during pregnancy and childhood were inversely associated with adiposity. The associations of di(2-ethylhexyl) phthalate (∑ DEHP) metabolites and monoethyl phthalate (MEP) with child adiposity depended on the timing of exposure. A 10-fold increase in ∑DEHP at 1 and 5 y was associated with a 2.7% decrease [95% confidence interval (CI): -4.8, -0.5] and 2.9% increase (95% CI: 0.3, 5.5) in body fat, respectively. MEP concentrations at 5 and 8 y of age were associated with higher child adiposity, but earlier childhood concentrations were not. Conclusion: In this cohort, we did not find evidence of an obesogenic effect of prenatal phthalate exposure. Positive associations between postnatal MEP and ∑DEHP concentrations depended on the timing of exposure. https://doi.org/10.1289/EHP1022 [ABSTRACT FROM AUTHOR]

BACKGROUND: Prenatal polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) exposures may influence children's neurodevelopment. OBJECTIVE: We examined the association of prenatal PBDE and PCB exposures with children's reading skills at ages 5 and 8 years, Full-Scale Intelligence Quotient (FSIQ), and externalizing behavior problems at age 8 years. METHODS: From 239 mother-child pairs recruited (2003-2006) in Cincinnati, Ohio, we measured maternal serum PBDE and PCB concentrations, assessed child's reading skills using the Woodcock-Johnson Tests of Achievement III (WJ-III) at age 5 years and the Wide Range Achievement Test-4 (WRAT-4) at age 8 years, tested FSIQ using the Wechsler Intelligence Scale for Children-IV (WISC-IV), and externalizing behavior problems using the Behavioral Assessment System for Children-2 (BASC-2) at age 8 years. We used multiple linear regression to examine the association of prenatal PBDE and PCB concentrations and reading, FSIQ, and externalizing behavior problems after adjusting for covariates. RESULTS: An increase of Sum4PBDEs (BDE-47, BDE-99, BDE-100, and BDE-153) by 10 times was not significantly associated with reading scores at age 5 years at the p = 0.05 level but was inversely associated with Reading Composite scores (β: -6.2, 95% CI: -11.7, -0.6) and FSIQ (β: -5.3, 95% CI: -10.6, -0.02) at age 8 years; it was positively associated with the score for externalizing behavior problems (β: 3.5, 95% CI: -0.1, 7.2) at age 8 years. Prenatal Sum4PCBs (PCB-118, -153, -138-158, and -180) was not significantly associated with a child's reading skills, FSIQ, and externalizing behavior problems. Conclusion: Prenatal PBDE concentration was inversely associated with reading skills and FSIQ and positively associated with externalizing behavior problems at age 8 years. No significant associations were found in prenatal PCB concentration. CITATION: Zhang H, Yolton K, Webster GM, Sjödin A, Calafat AM, Dietrich KN, Xu Y, Xie C, Braun JM, Lanphear BP, Chen A. 2017. Prenatal PBDE and PCB exposures and reading, cognition, and externalizing behavior in children. Environ Health Perspect 125:746-752; http://dx.doi.org/10.1289/EHP478 [ABSTRACT FROM AUTHOR]