Prenatal manganese biomarkers and operant test battery performance in Mexican children: Effect modification by child sex.

Background: Manganese (Mn) is essential to healthy neurodevelopment, but both Mn deficiency and over-exposure have been linked to prefrontal cortex (PFC) impairments, the brain region that regulates cognitive and neurobehavioral processes responsible for spatial memory, learning, motivation, and time perception. These processes facilitated by attention, inhibitory control, working memory, and cognitive flexibility are often sexually dimorphic and complex, driven by multiple interconnected neurologic and cognitive domains.

Objective: We investigated the role of child sex as an effect modifier of the association between prenatal Mn exposure and performance in an operant testing battery (OTB) that assessed multiple cognitive and behavioral functional domains.

Sex-specific association between prenatal manganese exposure and working memory in school-aged children in Mexico city: An exploratory multi-media approach.

It remains unclear whether manganese (Mn) exposure affects working memory (WM) in a sexually dimorphic manner. Further, no gold standard media exists to measure Mn, suggesting a combined blood and urinary Mn index may better capture the totality of exposure. We investigated the modification effect of child sex on the influence of prenatal Mn exposure on WM in school-age children, exploring two methodological frameworks to integrate exposure estimates across multiple exposure biomarkers.

Prenatal Metal Exposures and Associations with Kidney Injury Biomarkers in Children.

Prenatal exposure to arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) may be nephrotoxic, yet limited studies have examined subclinical kidney injury biomarkers in children. We assessed whether metal exposure in the second trimester (2T), a crucial time of kidney development, is associated with altered urine kidney injury and function biomarkers in preadolescent children. Analyses included 494 children participating in a birth cohort study in Mexico City.

Prenatal and early childhood critical windows for the association of nephrotoxic metal and metalloid mixtures with kidney function.

Introduction: As renal development and maturation processes begin in utero and continue through early childhood, sensitive developmental periods arise during which metal exposures can program subclinical nephrotoxicity that manifests later in life. We used novel dentine biomarkers of established nephrotoxicants including arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), and lithium (Li), and their mixtures, to identify critical windows of exposure-associated kidney function alterations in preadolescents.

Methods: Participants included 353 children in the Programming Research in Obesity Growth, Environment and Social Stressors (PROGRESS) longitudinal birth cohort study based in Mexico City.

Prenatal trace elements mixture is associated with learning deficits on a behavioral acquisition task among young children.

Children are exposed to many trace elements throughout their development. Given their ubiquity and potential to have effects on children's neurodevelopment, these exposures are a public health concern. This study sought to identify trace element mixture-associated deficits in learning behavior using operant testing in a prospective cohort.

Sexually dimorphic associations between prenatal blood lead exposure and performance on a behavioral testing battery in children.

Background: Associations between lead (Pb) and neurodevelopment have been studied widely in the context of global measures of cognitive function, such as IQ. Operant test batteries consist of behavioral tasks that can be used to target discrete cognitive and behavioral mechanisms, which contribute to global cognitive faculties.

Objectives: The goals of this study were to identify Pb-associated deficits in cognitive development and determine the underlying mechanisms involved, utilizing an operant test battery.

Maternal Phthalates Exposure and Blood Pressure during and after Pregnancy in the PROGRESS Study.

Background: Phthalate exposure is ubiquitous and may affect biological pathways related to regulators of blood pressure. Given the profound changes in vasculature during pregnancy, pregnant women may be particularly susceptible to the potential effects of phthalates on blood pressure.

Objectives: We examined associations of phthalate exposure during pregnancy with maternal blood pressure trajectories from mid-pregnancy through 72 months postpartum.

Association between prenatal metal exposure and adverse respiratory symptoms in childhood.

Introduction: Manganese and lead have been cross-sectionally associated with adverse respiratory outcomes in childhood but there is limited data on their combined effects starting in utero. We examined associations between in utero exposure to metals and childhood respiratory symptoms.

Methods: We assessed 633 mother-child dyads enrolled in the Programming Research in Obesity, Growth, Environment, and Social Stressors (PROGRESS) birth cohort in Mexico City.

Prenatal metal mixture concentrations and reward motivation in children.

Reward motivation is a complex umbrella term encompassing the cognitions, emotions, and behaviors involved in the activation, execution, and persistence of goal-directed behavior. Altered reward motivation in children is characteristic of many neurodevelopmental and psychiatric disorders. Previously difficult to operationalize, the Progressive Ratio (PR) task has been widely used to assess reward motivation in animal and human studies, including children.

Prenatal maternal phthalate exposures and trajectories of childhood adiposity from four to twelve years.

Background/aim: Adiposity trajectories reflect dynamic process of growth and may predict later life health better than individual measures. Prenatal phthalate exposures may program later childhood adiposity, but findings from studies examining these associations are conflicting. We investigated associations between phthalate biomarker concentrations during pregnancy with child adiposity trajectories.

Critical windows of perinatal particulate matter (PM) exposure and preadolescent kidney function.

Air pollution exposure, especially particulate matter ≤2.5 μm in diameter (PM), is associated with poorer kidney function in adults and children. Perinatal exposure may occur during susceptible periods of nephron development.

Early childhood fluoride exposure and preadolescent kidney function.

Background: Early-life renal maturation is susceptible to nephrotoxic environmental chemicals. Given the widespread consumption of fluoride and the global obesity epidemic, our main aim was to determine whether childhood fluoride exposure adversely affects kidney function in preadolescence, and if adiposity status modifies this association.

Methods: Our study included 438 children from the PROGRESS cohort.

Nephrotoxic Metal Mixtures and Preadolescent Kidney Function.

Exposure to metals including lead (Pb), cadmium (Cd), and arsenic (As), may impair kidney function as individual toxicants or in mixtures. However, no single medium is ideal to study multiple metals simultaneously. We hypothesized that multi-media biomarkers (MMBs), integrated indices combining information across biomarkers, are informative of adverse kidney function.

The associations of phthalate biomarkers during pregnancy with later glycemia and lipid profiles.

Background: Pregnancy induces numerous cardiovascular and metabolic changes. Alterations in these sensitive processes may precipitate long-term post-delivery health consequences. Studies have reported associations between phthalates and metabolic complications of pregnancy, but no study has investigated metabolic outcomes beyond pregnancy.

Prenatal blood lead levels and reduced preadolescent glomerular filtration rate: Modification by body mass index.

Background: For the developing kidney, the prenatal period may represent a critical window of vulnerability to environmental insults resulting in permanent nephron loss. Given that the majority of nephron formation is complete in the 3rd trimester, we set out to test whether 1) prenatal lead exposure is associated with decreased preadolescent kidney function and 2) whether preadolescent obesity acts synergistically with early life lead exposure to reduce kidney function.

Methods: Our study included 453 mother-child pairs participating in the PROGRESS birth cohort.

Exosomal miRNAs in urine associated with children's cardiorenal parameters: a cross-sectional study.

The authors sought to examine associations between urinary exosomal miRNAs (exo-miRs), emerging biomarkers of renal health, and cardiorenal outcomes in early childhood. The authors extracted exo-miRs in urine from 88 healthy Mexican children aged 4-6 years. The authors measured associations between 193 exo-miRs and cardiorenal outcomes: systolic/diastolic blood pressure, estimated glomerular filtration rate and urinary sodium and potassium levels.

[Analysis of the national distributionof lead poisoning in 1-4 year-old children.Implications for Mexican public policy].

Objective: To estimate de magnitude of Pb poisoning (≥5μg/dL blood) in 1-4 year old children and to identify the contribution of lead-glazed ceramics use (LGC) as a source of exposure in the 32 Mexican states.

Materials And Methods: Using the results from a sample of capillary blood lead (BPb) we estimated the prevalence of Pb poisoning, it's association with LGC and national distribution.

Results: The national prevalence of Pb poisoning was 17.

Associations between daily ambient temperature and sedentary time among children 4-6 years old in Mexico City.

Background: Sedentary behavior is a worldwide public health concern. There is consistent and growing evidence linking sedentary behavior to mortality and morbidity. Early monitoring and assessment of environmental factors associated with sedentary behaviors at a young age are important initial steps for understanding children's sedentary time and identifying pertinent interventions.

Prenatal maternal phthalate exposures and child lipid and adipokine levels at age six: A study from the PROGRESS cohort of Mexico City.

Background: Prenatal phthalate exposures may affect processes that underlie offspring cardiometabolic health, but findings from studies examining these associations are conflicting. We examined associations between biomarkers of phthalate exposures during pregnancy with child lipid and adipokine levels.

Methods: Data were from 463 mother-child pairs in the PROGRESS cohort of Mexico City.

Early-Life Dietary Cadmium Exposure and Kidney Function in 9-Year-Old Children from the PROGRESS Cohort.

Cadmium (Cd) is a toxic metal associated with adverse health effects, including kidney injury or disease. The aims of this study were to estimate dietary Cd exposure during childhood, and to evaluate the association of early-life dietary Cd with biomarkers of glomerular kidney function in 9-year-old Mexican children. Our study included 601 children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with up to five follow-up food frequency questionnaires from 1 to 9 years of age; and 480 children with measures of serum creatinine, cystatin C, and blood nitrogen urea (BUN), as well as 9-year-old estimated glomerular filtration rate.

Lead Concentrations in Mexican Candy: A Follow-Up Report.

Background: Lead is a neurotoxic metal potentially affecting the developing brain. Children are particularly susceptible since they can absorb between 50% and 100% of ingested lead. There is no safe level for lead, therefore preventing exposure is crucial.

Modification of the effects of prenatal manganese exposure on child neurodevelopment by maternal anemia and iron deficiency.

Background: We evaluated: (1) associations of prenatal manganese (Mn) levels with child neurodevelopment at 4-6 years; (2) effect modification by maternal anemia and iron deficiency; and (3) sex-specific effects.

Methods: We measured blood Mn, hemoglobin, and serum ferritin in mothers at the second trimester, third trimester, and at birth, and in cord blood from a prospective birth cohort in Mexico City (n = 571). McCarthy Scales of Children's Abilities were measured at 4-6 years.

Length of gestation and birth weight are associated with indices of combined kidney biomarkers in early childhood.

Infants born prematurely or with low birth weights are more susceptible to kidney dysfunction throughout their lives. Multiple proteins measured in urine are noninvasive biomarkers of subclinical kidney damage, but few studies have examined the joint effects of multiple biomarkers. We conducted an exploratory study of 103 children in the Programing Research in Obesity, Growth, Environment, and Social Stressors (PROGRESS) longitudinal birth cohort, and measured nine proteins selected a priori in banked spot urine samples collected at ages 4-6.

Identifying critical windows of prenatal particulate matter (PM) exposure and early childhood blood pressure.

Background: Exposure to air pollution is associated with increased blood pressure (BP) in adults and children. Some evidence suggests that air pollution exposure during the prenatal period may contribute to adverse cardiorenal health later in life. Here we apply a distributed lag model (DLM) approach to identify critical windows that may underlie the association between prenatal particulate matter ≤ 2.