Publications by authors named "John Meeker"
Concerns persist about the potential impact of prenatal exposure to bisphenols (BP) and their replacement analogues on childhood asthma and allergies. Previous studies on single and small cohorts had limited statistical power, few investigated analogues BPF and BPS, and even fewer examined atopic outcomes. Our objective was to assess whether prenatal exposures to individual environmental bisphenols (BPA, BPF, BPS) influence risk of childhood asthma, allergic rhinitis, and atopic dermatitis.
View Article and Find Full Text PDFBackground: Per- and polyfluoroalkyl substances (PFAS) are fluorinated chemicals linked to adverse pregnancy and birth outcomes. However, the underlying mechanisms, specifically their effects on maternal inflammatory processes, are not well characterized.
Objective: We examined associations between prenatal PFAS exposure and repeated measures of inflammatory biomarkers, including C-reactive protein (CRP) and four cytokines [Interleukin-10 (IL-10), IL-1β, IL-6, and tumor necrosis factor-α (TNF-α)].
Experiencing a hurricane during pregnancy is associated with increased risk of adverse birth outcomes and poor mental health. Pregnant people from marginalized communities are more susceptible to adverse effects, as they have fewer resources to overcome hardships at a time when shelter and nutrition are essential. When Hurricane Maria (HM) devastated Puerto Rico in September 2017, the archipelago was already burdened with high poverty, health disparities, environmental contamination, and fragile utility infrastructure.
View Article and Find Full Text PDFArticle Synopsis
- Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants from sources like traffic and diet, and their effects on neurodevelopmental delay (NDD) have been understudied.
- This study analyzed urine samples from pregnant women in the PROTECT birth cohort to determine the relationship between prenatal PAH exposure and NDD in children at various ages.
- Results indicated that higher PAH exposure generally correlated with lower odds of NDD; however, male children displayed increased odds of delays, particularly in fine motor skills, highlighting a need for further research on sex-specific impacts of PAHs.
Article Synopsis
- Pesticides, particularly chlorpyrifos, may negatively affect respiratory health and contribute to asthma symptoms among low-income, Black children in Baltimore City, with limited existing research on this issue.
- A study involving 148 children with asthma measured various pesticide biomarker concentrations in their urine over a year, linking higher levels of specific biomarkers to increased asthma-related symptoms and healthcare needs.
- Findings indicated that exposure to higher levels of chlorpyrifos (TCPY) was significantly associated with worsened asthma symptoms, including increased coughing, wheezing, and chest tightness, suggesting a potential harmful impact of these pesticides on pediatric respiratory health.
Article Synopsis
- Phthalate exposure is linked to adverse pregnancy outcomes, but the biological mechanisms behind these effects are not completely understood.
- This study analyzed 99 pregnant women and 86 newborns from the PROTECT cohort, using advanced techniques to measure urinary phthalate levels and metabolic profiles in blood plasma.
- Significant associations were found between specific phthalates and metabolic changes in maternal plasma, highlighting the need for more research on phthalate mixtures and their complex effects on both mother and fetus.
Background: Organophosphate esters (OPEs), flame retardants and plasticizers found widely in consumer products, may impact vascularization processes in pregnancy. Yet, the association between maternal exposure to OPEs and both preeclampsia and blood pressure during pregnancy remains understudied.
Methods: Within the LIFECODES Fetal Growth Study (N = 900), we quantified 8 OPE metabolites from maternal urine collected at up to 3 time points during pregnancy and created within-subject geometric means.
Background: Phenols and parabens are two classes of high production volume chemicals that are used widely in consumer and personal care products and have been associated with reproductive harm and pregnancy complications, such as preeclampsia and gestational diabetes. However, studies examining their influence on maternal blood pressure and gestational hypertension are limited.
Objectives: We investigated associations between individual phenols, parabens, and their mixture on maternal blood pressure measurements, including systolic and diastolic blood pressure (SBP and DBP) and hypertension during pregnancy (defined as stage 1 or 2 hypertension), among Puerto Rico PROTECT study participants.
Article Synopsis
- The study investigates how prenatal exposure to environmental phenols, which are known to disrupt endocrine functions, impacts fetal growth using ultrasound measurements and delivery data.
- Researchers analyzed data from the LIFECODES Fetal Growth Study, which included 900 births, measuring the effects of 12 different phenols based on urine samples collected during pregnancy.
- Results indicated that certain phenols like triclosan positively correlated with increased fetal weight, while others like methylparaben were linked to a higher risk of small-for-gestational-age births.
Background: Organophosphate esters (OPEs), used ubiquitously as flame retardants and plasticizers in consumer products, are suspected of having developmental toxicity.
Objectives: Our study aimed to estimate associations between prenatal exposure to OPEs and fetal growth, including both ultrasound (head circumference, abdominal circumference, femur length, and estimated fetal weight) and delivery [birth weight -score, small-for-gestational age (SGA), and large-for-gestational age (LGA)] measures of growth.
Methods: In the LIFECODES Fetal Growth Study (2008-2018), an enriched case-cohort of 900 babies born at the small and large ends of the growth spectrum, we quantified OPE biomarkers in three urine samples per pregnant participant and abstracted ultrasound and delivery measures of fetal growth from medical records.
Preterm birth is a leading cause of neonatal mortality and presents significant public health concerns. Environmental chemical exposures during pregnancy may be partially to blame for disrupted delivery timing. Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion, exposure to which occurs via inhalation of cigarette smoke and automobile exhaust, and ingestion of charred meats.
View Article and Find Full Text PDFBackground: Polycyclic aromatic hydrocarbons (PAHs) are endocrine disruptors resulting from incomplete combustion. Pregnancy represents a particularly vulnerable period to such exposures, given the significant influence of hormone physiology on fetal growth and pregnancy outcomes. Maternal thyroid hormones play crucial roles in fetal development and pregnancy outcomes.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates the link between early pregnancy exposure to PFAS (harmful synthetic chemicals) and oxidative stress (OS) biomarkers, considering how fetal sex and maternal race might influence these associations.
- Data from 469 participants revealed a notable increase in the OS biomarker 8-isoprostane with higher PFOS levels, while PFUA showed a negative association; differences in associations were noted based on whether the fetus was male or female.
- The findings suggest that PFAS exposure could adversely impact pregnancy outcomes through oxidative stress pathways, underscoring the need for further research on these effects, especially considering fetal sex.
Background: Phthalate exposure may contribute to hypertensive disorders of pregnancy (HDP), including preeclampsia/eclampsia (PE/E), but epidemiologic studies are lacking.
Objectives: To evaluate associations of pregnancy phthalate exposure with development of PE/E and HDP.
Methods: Using data from 3,430 participants in eight Environmental influences on Child Health Outcomes (ECHO) Program cohorts (enrolled from 1999 to 2019), we quantified concentrations of 13 phthalate metabolites (8 measured in all cohorts, 13 in a subset of four cohorts) in urine samples collected at least once during pregnancy.
Prenatal per- and poly-fluoroalkyl substances (PFAS) exposure may influence gestational outcomes through bioactive lipids─metabolic and inflammation pathway indicators. We estimated associations between prenatal PFAS exposure and bioactive lipids, measuring 12 serum PFAS and 50 plasma bioactive lipids in 414 pregnant women (median 17.4 weeks' gestation) from three Environmental influences on Child Health Outcomes Program cohorts.
View Article and Find Full Text PDFBackground/aim: Heavy metals are known to induce oxidative stress and inflammation, and the association between metal exposure and adverse birth outcomes is well established. However, there lacks research on biomarker profiles linking metal exposures and adverse birth outcomes. Eicosanoids are lipid molecules that regulate inflammation in the body, and there is growing evidence that suggests associations between plasma eicosanoids and pregnancy outcomes.
View Article and Find Full Text PDFArticle Synopsis
- This study reviews and compares 11 statistical methods for analyzing the health impacts of chemical mixtures, useful for both continuous and binary outcomes in environmental research.* -
- Key findings suggest that the choice of method should align with the analysis goals, with certain methods like Elastic Net and Super Learner showing consistent and superior performance for identifying toxicants and predicting risks.* -
- The research introduces "CompMix," an R package designed to aid practitioners in conducting comprehensive mixtures analysis, offering a streamlined platform for various analytical tasks.*
Exposure to phenols and parabens may contribute to increased maternal inflammation and adverse birth outcomes, but these effects are not well-studied in humans. This study aimed to investigate relationships between concentrations of 8 phenols and 4 parabens with 6 inflammatory biomarkers (C-reactive protein (CRP); matrix metalloproteinases (MMP) 1, 2, and 9; intercellular adhesion molecule-1 (ICAM-1); and vascular cell adhesion molecule-1 (VCAM-1)) measured at two time points in pregnancy in the PROTECT birth cohort in Puerto Rico. Linear mixed models were used, adjusting for covariates of interest.
View Article and Find Full Text PDFArticle Synopsis
- Phthalates, synthetic chemicals found in consumer products, are linked to preterm births, but previous studies have methodological flaws and insufficient data on the effects of alternative phthalate compounds like di-2-ethylhexyl phthalate (DEHP).
- Using data from the NIH's ECHO Program spanning from 1998 to 2022, researchers analyzed the impact of 20 phthalate metabolites on birth outcomes such as gestational age and birth weight, focusing on mother-child pairs with phthalate measurements during pregnancy.
- The study found strong associations between certain phthalates (like phthalic acid and diisononyl phthalate) and negative birth outcomes,
Introduction: Meta-analyses across diverse independent studies provide improved confidence in results. However, within the context of metabolomic epidemiology, meta-analysis investigations are complicated by differences in study design, data acquisition, and other factors that may impact reproducibility.
Objective: The objective of this study was to identify maternal blood metabolites during pregnancy (> 24 gestational weeks) related to offspring body mass index (BMI) at age two years through a meta-analysis framework.
Background: Widespread exposure to organophosphate ester (OPE) flame retardants with potential reproductive toxicity raises concern regarding the impacts of gestational exposure on birth outcomes. Previous studies of prenatal OPE exposure and birth outcomes had limited sample sizes, with inconclusive results.
Objectives: We conducted a collaborative analysis of associations between gestational OPE exposures and adverse birth outcomes and tested whether associations were modified by sex.
Article Synopsis
- Inflammation and oxidative stress play significant roles in pregnancy, but there is limited research on their causal indicators, particularly oxylipins, which are lipid mediators associated with these processes.
- The study analyzed maternal characteristics and their impact on circulating oxylipin levels in 901 singleton pregnancies, focusing on factors like gestational age, prepregnancy BMI, race, and socioeconomic status.
- Findings revealed that various characteristics, such as higher prepregnancy BMI and lower socioeconomic status, were linked to reduced plasma oxylipin levels and increased urinary oxylipins, suggesting a relationship between these factors and oxidative stress and inflammation during pregnancy.
Introduction: N-(phosphonomethyl)glycine, or glyphosate, is a non-selective systemic herbicide widely used in agricultural, industrial, and residential settings since 1974. Glyphosate exposure has been inconsistently linked to neurotoxicity in animals, and studies of effects of gestational exposure among humans are scarce. In this study we investigated relationships between prenatal urinary glyphosate analytes and early childhood neurodevelopment.
View Article and Find Full Text PDFArticle Synopsis
- Synthetic chemicals like bisphenols, parabens, and triclosan may contribute to preterm birth (PTB) and low birth weight (LBW) due to their ability to disrupt hormones and cause oxidative stress.
- A study with 3,619 mother-infant pairs found that higher concentrations of benzophenone-3 and methylparaben during pregnancy were linked to lower birth weight and increased odds of being small for gestational age (SGA).
- The findings suggest that while the effects are concerning, certain compounds like 2,4-dichlorophenol showed an unexpected association with lower odds of low birth weight, indicating complex interactions that need further investigation.