Living on higher ground reduces child neurodevelopment-evidence from South America

Retarded astrogliogenesis in response to hypoxia is facilitated by downregulation of CIRBP

The adverse impacts of chronic hypoxia on maternal and infant health at high altitudes warrant significant attention. However, effective protective measures against the resultant growth restrictions and neurodevelopmental disorders in infants and young children are still lacking. This study investigated the neurodevelopment of mice offspring under hypoxic conditions by exposing pregnant mice to a hypobaric oxygen chamber that simulated the hypobaric hypoxia at an altitude of 4000 m until 28 days after delivery. Our findings suggested that prolonged exposure to hypoxia might result in emotional abnormalities and social disorders in offspring. The significant reduction in astrogliogenesis was a characteristic feature associated with neurodevelopmental disorders induced by hypoxia. Further studies demonstrated that cold-induced RNA-binding protein (CIRBP) was a key transcriptional regulator in astrogliogenesis, which downregulated astrocytic differentiation under hypoxia through its crosstalk with the NFIA. Our study emphasized the crucial role of CIRBP in regulating astrogliogenesis and highlighted its potential as a promising target for therapeutic interventions in neurodevelopmental disorders associated with hypoxia.

The Brain at High Altitude: From Molecular Signaling to Cognitive Performance

The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.

Disparities in the prevalence of screened depression at different altitudes in Peru: A retrospective analysis of the ENDES 2019

INTRODUCTION

Depression is a public health concern, nearing 1.5 million cases and accounting for 9.7% of years lost due to disability. Several factors, including altitude, contribute to its development. Altitude has become a topic for recent research, but its association with depressive symptoms has not been fully clarified. Therefore, this study aimed to determine the association between altitude and depressive symptoms in the Peruvian population.

METHODS

A retrospective, cross-sectional study of the 2019 Demographic and Family Health Survey (ENDES in Spanish) was conducted. The dependent variable, depressive symptoms, was measured using the Patient Health Questionnaire (PHQ-9) and the independent variable, altitude, was categorized into: <1500 meters above sea level (masl), 1500-2499 masl and ≥2500 masl. To evaluate the association between altitude and depressive symptoms, we used Poisson regression model, constructing crude and multiple models.

RESULTS

Of those living at 1500 to 2499 masl and ≥2500 masl, 7.23% and 7.12% had depressive symptoms, respectively. After adjusting for confounding variables, high altitude was found to be associated with depressive symptoms (prevalence ratio adjusted (aPR): 1.38, 95% confidence interval: 1.04-1.84; aPR 1.41, 95% CI: 1.20-1.66).

CONCLUSIONS

A statistically significant association was found between high altitude and depressive symptoms. This may be attributable to hypobaric hypoxia that occurs at high altitudes and its effects on brain function. This study's findings should be considered to identify the population at risk and expand the coverage of preventive and therapeutic measures in high-altitude areas of Peru with poor access to health services.

Optimism and Health Self-Perception-Related Differences in Indigenous Kiwchas of Ecuador at Low and High Altitude: A Cross-Sectional Analysis

Ortiz-Prado, Esteban, Katherine Simbaña-Rivera, Diego Duta, Israel Ochoa, Juan S. Izquierdo-Condoy, Eduardo Vasconez, Kathia Carrasco, Manuel Calvopiña, Ginés Viscor, and Clara Paz. Optimism and health self-perception-related differences in indigenous Kiwchas of Ecuador at low and high altitude: a cross-sectional analysis. High Alt Med Biol 00:000-000, 2021. Background: Living at high altitude causes adaptive responses at every physiological and molecular level within the human body. Emotional and psychological short- or long-term consequences, including mood changes, higher mental overload, and depression prevalence, as well as increased risk to commit suicide have been reported among highlanders. The objective of this report is to explore the differences in self-reported dispositional optimism and health perception among sex-, age-, and genotype-controlled indigenous Kiwcha natives living at two different altitudes. Methods: A cross-sectional analysis of the comparison of means of subscales and summary scores of the 36-item short-form health survey (SF-36) self-reported questionnaire and the Life Orientation Test-Revised was conducted among 219 adults Kiwchas living at low (230 m) and high altitude (3,800 m) in Ecuador. Results: High-altitude dwellers presented lower scores in all the studied dimensions of SF-36 and the total score. Differences were found for the role limitation sphere due to vitality (p = 0.005), mental health (p = 0.002), and social functioning (p = 0.005). In all the cases, participants living at low altitudes scored higher than those living at high altitudes. Lowland women were more optimistic than their high-altitude counterparts. Conclusions: We observe that populations located at high altitudes have more unfavorable self-reported health states. Although our results depict the existence of significant differences in the health status of indigenous peoples living at different altitudes, further studies are needed to explain in depth the sociodemographic and/or environmental factors that might underlie these differences.

Traditional growing rod for early-onset scoliosis in high-altitude regions: a retrospective study

Background

Children with early-onset scoliosis living in high-altitude areas have severe deformities and poor nutritional status. However, no reports on early-onset scoliosis treatment using traditional growing rods in such children exist. Thus, we analyzed the outcomes of traditional growing rods treatment in such patients and the effect of altitude on therapy.

Methods

Between September 2007 and December 2017, 59 consecutive patients with EOS underwent systematic surgical correction using traditional growing rods. They were divided into the high-altitude and low-altitude groups, and differences in surgical efficacy and complications between the groups were analyzed pre- and postoperatively. Radiographic measurements, including the Cobb angle, thoracic kyphosis, lumbar lordosis, T1–S1 and T1–T12 heights, sagittal and coronal balance, distance between C7PL and sagittal vertical axis, pelvic incidence, sacral slope, and pelvic tilt were assessed preoperatively, postoperatively, and at the last follow-up. Continuous data were analyzed using paired or independent Student’s t tests, and they were compared preoperatively, postoperatively, and at the last follow-up using a repeated measures analysis of variance. Enumerated data were analyzed using the χ² test.

Results

The mean patient age at the initial surgery and mean follow-up duration were 8.9 ± 2.4(5–14) years and 51.91 ± 25.23 months, respectively. Altogether, 234 operations were conducted for all patients with an average interval between operations of 11.4 ± 3.0 months. The average Cobb angle was similar in both groups preoperatively and at the last follow-up, it was significantly different postoperatively. TK was significantly different in all three periods. T1–S1 and T1–T12 heights were significantly different only during the preoperative period. The overall rates of complications and implant-related complications did not differ significantly between the groups.

Conclusions

Deformity in patients with EOS in high-altitude areas was more severe, and treatment using TGRs yielded a satisfactory therapeutic effect.

Exposure to environmental neurotoxic substances and neurodevelopment in children from Latin America and the Caribbean

Environmental (and occupational) exposure to neurotoxic substances is a worldwide problem that can affect children's neurodevelopment (ND). In Latin American and Caribbean (LAC) countries there are over 300 million children living under the threat of neurodevelopmental delays due to toxic environmental exposure. Large industrial centers, intense mining and agricultural activities, along with changing complex ecosystems constitute a mosaic that drives contamination of air, water and the food chain. Neurotoxic contaminants such as pesticides (organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, and manganese fungicides), chemicals of industrial use (phthalates), and metals (Hg, Pb, Al, As, F, Cd, Mo, Mn) are at the center of environmental exposure studies. Exposure to neurotoxic substances singly or in combination with other compounds or socioeconomic stressors (maternal education, socio-economic and nutritional status) intertwined with occupational and para-occupational exposure can affect ND (motor, cognition, behavior) of children. Significant negative effects of pesticides and neurotoxic elements on ND were found in all studied countries, affecting especially the less-privileged children from laboring families. Studies showed that exposures to the neurotoxicants in human milk are secondary to their more lasting effects during prenatal exposure. This review integrates exposure (prenatal and breastfeeding), metabolism, and ND effects of neurotoxicants. It highlights the overwhelming evidence showing that current levels of exposures are hazardous and detrimental to children's ND in LAC countries. The evidence indicates that a reduction in neurotoxicant exposure is essential to protect children's ND. Therefore, it is urgent to adopt policies and actions that prevent and remediate region-specific children's ND issues.

Association of Anemia with Neurodevelopmental Disorders in a Nationally Representative Sample of US Children

OBJECTIVE

To examine the associations of anemia with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and learning disability in US children.

STUDY DESIGN

We included children and adolescents aged 3-17 years from the National Health Interview Survey (NHIS), 1997-2018. Information about physician-diagnosed history of anemia, ASD, ADHD, and learning disability was reported by a parent or guardian. Multiple logistic regression with sample weights was used to estimate the ORs and 95% CIs of neurodevelopmental disorders according to the presence of anemia.

RESULTS

Of the total population of 213 893 children aged 3-17 years (mean age [SE], 10.01 [0.01] years), 2379 were reported to have a diagnosis of anemia, for a weighted prevalence of 1.06% (95% CI, 1.01-1.12). The prevalence of ASD was 1.94% (95% CI, 1.20-2.68) among children with anemia and 1.07% (95% CI, 1.01-1.14) among those without anemia. The corresponding prevalences were 12.24% (95% CI, 10.47-14.00) and 7.73% (95% CI, 7.58-7.88) for ADHD and 15.03% (95% CI, 13.08-16.99) and 7.75% (95% CI, 7.39-7.70) for learning disability, respectively. Compared with those without anemia, children with anemia were more likely to have neurodevelopmental disorders, with an aOR of 2.07 (95% CI, 1.39-3.08) for ASD, 1.84 (95% CI, 1.55-2.19) for ADHD, and 2.22 (95% CI, 1.90-2.60) for learning disability.

CONCLUSIONS

In a nationally representative sample of US children, we found significant associations between anemia and neurodevelopmental disorders including ASD, ADHD, and learning disability. Further investigation is warranted to assess the causality and elucidate the underlying mechanisms.

Hypoxia and connectivity in the developing vertebrate nervous system

The developing nervous system depends upon precise regulation of oxygen levels. Hypoxia, the condition of low oxygen concentration, can interrupt developmental sequences and cause a range of molecular, cellular and neuronal changes and injuries. The roles and effects of hypoxia on the central nervous system (CNS) are poorly characterized, even though hypoxia is simultaneously a normal component of development, a potentially abnormal environmental stressor in some settings, and a clinically important complication, for example of prematurity. Work over the past decade has revealed that hypoxia causes specific disruptions in the development of CNS connectivity, altering axon pathfinding and synapse development. The goals of this article are to review hypoxia's effects on the development of CNS connectivity, including its genetic and molecular mediators, and the changes it causes in CNS circuitry and function due to regulated as well as unintended mechanisms. The transcription factor HIF1α is the central mediator of the CNS response to hypoxia (as it is elsewhere in the body), but hypoxia also causes a dysregulation of gene expression. Animals appear to have evolved genetic and molecular responses to hypoxia that result in functional behavioral alterations to adapt to the changes in oxygen concentration during CNS development. Understanding the molecular pathways underlying both the normal and abnormal effects of hypoxia on CNS connectivity may reveal novel insights into common neurodevelopmental disorders. In addition, this Review explores the current gaps in knowledge, and suggests important areas for future studies.

Summary: The nervous system's exposure to hypoxia has developmental and clinical relevance. In this Review, the authors discuss the effects of hypoxia on the development of the CNS, and its long-term behavioral and neurodevelopmental consequences.

UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level

Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0 yr old, 129 ± 9 cm, 27 ± 8 kg, 14 girls) Sherpa children (3,800 m, Nepal) and 25 (9.9 ± 0.7 yr old, 143 ± 7 cm, 34 ± 6 kg, 14 girls) age-matched sea level children (344 m, Canada) during supine rest. Resting gas exchange, blood pressure, oxygen saturation and heart rate were assessed. Despite comparable age, height and weight were lower (both P < 0.01) in Sherpa compared with sea level children. Mean arterial pressure, heart rate, and ventilation were similar, whereas oxygen saturation (95 ± 2 vs. 99 ± 1%, P < 0.01) and end-tidal Pco₂ (24 ± 3 vs. 36 ± 3 Torr, P < 0.01) were lower in Sherpa children. Global cerebral blood flow was ∼30% lower in Sherpa compared with sea level children. This was reflected in a lower ICA flow (283 ± 108 vs. 333 ± 56 ml/min, P = 0.05), VA flow (78 ± 26 vs. 118 ± 35 ml/min, P < 0.05), and MCA velocity (72 ± 14 vs. 88 ± 14 cm/s, P < 0.01). CCA flow was similar between Sherpa and sea level children (425 ± 92 vs. 441 ± 81 ml/min, P = 0.52). Scaling flow and oxygen uptake for differences in vessel diameter and body size, respectively, led to the same findings. A lower cerebral blood flow in Sherpa children may reflect specific cerebral hemodynamic adaptations to chronic hypoxia.NEW & NOTEWORTHY Cerebral blood flow is lower in Sherpa children compared with children residing at sea level; this may reflect a cerebral hemodynamic pattern, potentially due to adaptation to a hypoxic environment.

Differences in early cognitive and receptive-expressive neurodevelopment by ancestry and underlying pathways in Brazil and Argentina

We examine disparities in early child cognitive and receptive-expressive skills by ethnic ancestry among infants aged 3-24 months from Brazil and Argentina. We employ unique data on the neurodevelopment of children who were seeking routine well-child care at a set of pediatric clinics in these countries. The sample included children who had normal birth outcomes and no major health complications, allowing us to focus on variation in neurodevelopment among children without major physical health limitations. The physicians attending the pediatric clinics were trained in administering the Bayley Infant Neurodevelopmental Screener, a standardized instrument used to screen an infant's risk of neurodevelopmental problems on various domains of abilities. We evaluate disparities in overall neurodevelopmental scores and risk for neurodevelopmental problems as well as in cognitive functioning and receptive-expressive neurodevelopment. We also examine the extent to which household demographic and socioeconomic characteristics and geographic location explain these disparities. We find large gaps in both cognitive and receptive-expressive neurodevelopment by ancestry. In Brazil, children of African ancestry have lower scores on both cognitive and receptive-expressive domains and on overall neurodevelopment than children of European ancestry. In Argentina, children of Native ancestry have lower scores on these outcomes than children of European ancestry. These gaps however are largely explained by differences in geographic location and household characteristics, highlighting the importance of policies that reduce socioeconomic and geographic disparities in social capital and economic development for eliminating ethnic disparities in infant neurodevelopment.

Improving Knowledge about Children's Environmental Health in Northwest China

The main purpose of this study was to identify policy maker opinions and attitudes towards children’s environmental health (CEH), potential barriers to child-specific protective legislation and implementation in northwest China, and evaluate knowledge and attitudes about CEH before and after an educational conference. We conducted seventy-two interviews with regional officials, researchers and non-governmental organization representatives from five provinces, and surveyed participants (forty-seven) before and after an educational conference in northwest China about CEH. Interviews identified general consensus among participants of the adverse effects of air pollution on children, yet few participants knew of policies to protect them. Barriers identified included limited funding and enforcement, weak regional governments and absence of child-specific policy-making. After the conference, substantially greater self-efficacy was identified for lead, mercury, air pollution and polychlorinated biphenyls (+0.57–0.72 on a 1–5 Likert scale, p = 0.002–0.013), and the scientific knowledge for the role of environment in children’s health (+0.58, p = 0.015), and health care provider control (+0.52, p = 0.025) were rated more strongly. We conclude that policy makers in Northwest China appreciate that children are uniquely vulnerable, though additional regulations are needed to account for that vulnerability. Further research should examine effectiveness of the intervention on a larger scale and scope, and evaluate the usefulness of such interventions in translating research into improved care/reduced exposure to environmental hazards.