Chronic Stress in Children and Adolescents: A Review of Biomarkers for Use in Pediatric Research

Hair cortisol determinants in 11-year-old children: Environmental, social and individual factors

INTRODUCTION

Children's exposure to chronic stress is associated with several health problems. Measuring hair cortisol concentration is particularly useful for studying chronic stress but much is unknown about hair cortisol determinants in children and adolescents, and previous research has often not considered the simultaneous exposure of multiple variables. This research is focused on investigating the relationship between environmental, social and individual factors with hair cortisol concentration in children.

METHODS

The data used in this study are from the INMA prospective epidemiological cohort study. The assessment of chronic stress was made on the basis of hair samples taken at the age of 11 years in the INMA-Gipuzkoa cohort (n = 346). A metamodel summarizing the hypothesized relationships among environmental, social and individual factors and hair cortisol concentration was constructed based on previous literature. Structural Equation Modelling was performed to examine the relationships among the variables.

RESULTS

In the general model higher behavioural problems were associated with higher cortisol levels and an inverse relationship between environmental noise and cortisol levels was observed, explaining 5 % of the variance in HCC. Once stratified by sex these associations were only hold in boys, while no significant effect of any of the study variables was related with cortisol levels in girls. Importantly, maternal stress was positively related to behavioural difficulties in children. Finally, higher traffic-related air pollution and lower exposure to neighborhood greenness were related to higher environmental noise.

DISCUSSION

This study highlights that simultaneous exposure to different environmental, social and individual characteristics may determine the concentration of hair cortisol. More research is needed and future studies should include this complex view to better understanding of hair cortisol determinants in children.

The CARING study: Examining biological, behavioral, and genetic mechanisms in the intergenerational transmission of toxic stress

When children experience extreme or persistent stressors (e.g., maltreatment, housing insecurity, intimate partner violence), prolonged elevation of the stress-response system can lead to disrupted development of multiple physiological systems. This response, known as toxic stress, is associated with poor physical and mental health across the life course. Emerging evidence suggests that the effects of toxic stress may be transmitted through generations, but the biological and behavioral mechanisms that link caregivers' childhood history with the health of the children they care for remain poorly understood. The purpose of this report is to describe the research protocol for The CARING (Childhood Adversity and Resilience In the Next Generation) Study, a cross-sectional study of caregivers with children aged 3-5 years designed to (1) examine the intergenerational transmission of toxic stress and protective factors; (2) explore three hypothesized pathways of transmission: parenting, daily routines, stressors, and supports; and (3) explore the extent to which genotypic variation in candidate genes related to caregiving and stress contribute to caregivers' and children's susceptibility to the effects of early childhood experiences (i.e., gene × environment interactions). We expect that findings from this study will provide critical data needed to identify targets for precision health interventions, reduce health disparities related to toxic stress, and prevent cycles of adversity among families at risk.

Leveraging biosocial methods to examine and address structural determinants of health and promote health equity

BACKGROUND

Biosocial approaches in nursing research have largely focused on the ways that social determinants of health influence individual-level outcomes, including symptom management, family and social support, and educational interventions.

PURPOSE

Theoretical, methodological, and practical strategies are needed to expand current biosocial methods for nursing science and focus on upstream, structural determinants of health and the policies that underlie health inequities.

METHODS

This paper summarizes presentations given at the 2023 Council for the Advancement of Nursing Science Advanced Methods Conference, Biosocial Methods to Advance Health Equity, in a panel titled "Individual, community, systems and policy related to biosocial methods."

DISCUSSION

Nurses are uniquely positioned to examine upstream, structural determinants of health by leveraging expertise in biosocial methods, collaborating with interdisciplinary researchers and community members, and advocating for policy change. By conducting theory-grounded biosocial research, nurse researchers can significantly advance scientific knowledge and promote health equity for individuals and communities.

CONCLUSION

Nurse scientists are conducting research using biosocial methods and provide recommendations for expansion of this approach in the field.

Unveiling stress markers: A systematic review investigating psychological stress biomarkers

Psychological stress is a ubiquitous facet of modern life, impacting individuals across diverse contexts and demographics. Understanding its physiological manifestations through biomarkers has gained substantial attention within the scientific community. A comprehensive search was conducted across multiple databases for peer-reviewed articles published within the past decade. Preliminary findings reveal many biomarkers associated with psychological stress across different biological systems, including the hypothalamic-pituitary-adrenal axis, immune system, cardiovascular system, and central nervous system. This systematic review explores psychological, physiological, and biochemical biomarkers associated with stress. Analyzing recent literature, it synthesizes findings across these three categories, elucidating their respective roles in stress response mechanisms. Psychological markers involve subjective assessments like self-reported stress levels, perceived stress scales, or psychometric evaluations measuring anxiety, depression, or coping mechanisms. Physiological markers include heart rate variability, blood pressure, and immune system responses such as cytokine levels or inflammatory markers. Biochemical markers involve hormones or chemicals linked to stress. It includes cortisol, catecholamines, copeptin, salivary amylase, IL-6, and C-reactive protein.

Reversal of Autism Symptoms among Dizygotic Twins through a Personalized Lifestyle and Environmental Modification Approach: A Case Report and Review of the Literature

The prevalence of autism has been increasing at an alarming rate. Even accounting for the expansion of autism spectrum disorder diagnostic (ASD) criteria throughout the 1990's, there has been an over 300% increase in ASD prevalence since the year 2000. The often debilitating personal, familial, and societal sequelae of autism are generally believed to be lifelong. However, there have been several encouraging case reports demonstrating the reversal of autism diagnoses, with a therapeutic focus on addressing the environmental and modifiable lifestyle factors believed to be largely underlying the condition. This case report describes the reversal of autism symptoms among dizygotic, female twin toddlers and provides a review of related literature describing associations between modifiable lifestyle factors, environmental exposures, and various clinical approaches to treating autism. The twins were diagnosed with Level 3 severity ASD "requiring very substantial support" at approximately 20 months of age following concerns of limited verbal and non-verbal communication, repetitive behaviors, rigidity around transitions, and extensive gastrointestinal symptoms, among other common symptoms. A parent-driven, multidisciplinary, therapeutic intervention involving a variety of licensed clinicians focusing primarily on addressing environmental and modifiable lifestyle factors was personalized to each of the twin's symptoms, labs, and other outcome measures. Dramatic improvements were noted within several months in most domains of the twins' symptoms, which manifested in reductions of Autism Treatment Evaluation Checklist (ATEC) scores from 76 to 32 in one of the twins and from 43 to 4 in the other twin. The improvement in symptoms and ATEC scores has remained relatively stable for six months at last assessment. While prospective studies are required, this case offers further encouraging evidence of ASD reversal through a personalized, multidisciplinary approach focusing predominantly on addressing modifiable environmental and lifestyle risk factors.

Stress biomarkers and child development in young children in Bangladesh

BACKGROUND

Hundreds of millions of children in low- and middle-income countries are exposed to chronic stressors, such as poverty, poor sanitation and hygiene, and sub-optimal nutrition. These stressors can have physiological consequences for children and may ultimately have detrimental effects on child development. This study explores associations between biological measures of chronic stress in early life and developmental outcomes in a large cohort of young children living in rural Bangladesh.

METHODS

We assessed physiologic measures of stress in the first two years of life using measures of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol and glucocorticoid receptor gene methylation), the sympathetic-adrenal-medullary (SAM) system (salivary alpha-amylase, heart rate, and blood pressure), and oxidative status (F2-isoprostanes). We assessed child development in the first two years of life with the MacArthur-Bates Communicative Development Inventories (CDI), the WHO gross motor milestones, and the Extended Ages and Stages Questionnaire (EASQ). We compared development outcomes of children at the 75th and 25th percentiles of stress biomarker distributions while adjusting for potential confounders using generalized additive models, which are statistical models where the outcome is predicted by a potentially non-linear function of predictor variables.

RESULTS

We analyzed data from 684 children (49% female) at both 14 and 28 months of age; we included an additional 765 children at 28 months of age. We detected a significant relationship between HPA axis activity and child development, where increased HPA axis activity was associated with poor development outcomes. Specifically, we found that cortisol reactivity (coefficient -0.15, 95% CI (-0.29, -0.01)) and post-stressor levels (coefficient -0.12, 95% CI (-0.24, -0.01)) were associated with CDI comprehension score, post-stressor cortisol was associated with combined EASQ score (coefficient -0.22, 95% CI (-0.41, -0.04), and overall glucocorticoid receptor methylation was associated with CDI expression score (coefficient -0.09, 95% CI (-0.17, -0.01)). We did not detect a significant relationship between SAM activity or oxidative status and child development.

CONCLUSIONS

Our observations reveal associations between the physiological evidence of stress in the HPA axis with developmental status in early childhood. These findings add to the existing evidence exploring the developmental consequences of early life stress.

Momentary effects of life stressors on mindfulness and emotion regulation difficulties among adolescents exposed to chronic stressors

Adolescents faced with chronic stressors (e.g., financial instability, interpersonal violence) are at heightened risk for developing mental health problems, likely due in part to stressors that interfere with effective emotion regulation. Although mindfulness may help to act as a buffer against the deleterious effects of life stressors, a relatively untested assumption is that adolescents can maintain mindfulness during periods of stress. This paper explores this assumption by investigating the real-time, dynamic relationships among life stressors, mindfulness, and emotion regulation difficulties among adolescents exposed to chronic stressors. Eighty-one participants who were 10-18 years old (M = 14.33; SD = 2.20; 56% male; 57% Non-Hispanic White) completed ecological momentary assessments (EMA) three times a day for 7 days and contributed a total of 1186 EMA reports. Multilevel structural equation modelling revealed that the presence (vs. absence) of stressors was associated with lower momentary mindfulness and greater momentary emotion regulation difficulties concurrently and prospectively. Stressors with greater severity were also concurrently, but not prospectively, associated with lower momentary mindfulness and greater momentary emotion regulation difficulties. Findings highlight that exposure to life stressors may degrade momentary mindfulness and emotion regulation. Given that mindfulness and emotion regulation are closely associated with mental health, these results also demonstrate one way that stressors may contribute to health disparities at the micro-level. Going forward, it will be important to investigate methods of helping adolescents learn to maintain mindfulness and adaptive emotion regulation in the face of stressful events. This study was preregistered (NCT04927286).

Relationships among Cortisol, Perceived Stress, and Dental Caries Experience in Adolescents and Young Adults

INTRODUCTION

Stress can impact mental and physical health, especially during adolescence and young adulthood, but the extent of its contribution to dental caries is poorly understood. The present study assessed the association between perceived stress, cortisol levels (in hair and saliva), and overall caries experience of adolescents and young adults aged 15-25 years.

METHODS

Hair and saliva samples were obtained from 93 participants free of periodontal disease. Cortisol in hair and saliva was determined using a competitive enzyme-linked immunosorbent assay. Participants completed a perceived stress questionnaire and underwent full-mouth oral examination by a calibrated examiner. Dental caries experience was based on the decayed, missing, and filled teeth (DMFT) index. Sociodemographic variables were also recorded.

RESULTS

There were significantly higher hair cortisol levels and perceived stress scale (PSS) scores in individuals with dental caries experience (DMFT≥1) than in those without (DMFT = 0). However, there was no significant difference in salivary cortisol concentration. A binary logistic regression revealed that higher hair cortisol levels and greater scores on the perceived stress scale were associated with increased odds of having experienced dental caries. In contrast, no significant association was found between salivary cortisol concentration and dental caries. Using multivariable regression models, caries experience was found to be significantly associated with both hair cortisol levels and PSS scores. These associations remained statistically significant even after adjusting for sociodemographic variables.

CONCLUSION

Hair cortisol levels and perceived stress have a significant association with dental caries experience, whereas salivary cortisol concentrations do not.

Variation in diurnal cortisol patterns among the Indigenous Shuar of Amazonian Ecuador

OBJECTIVES

The hypothalamic-pituitary-adrenal (HPA) axis and its primary end product, the glucocorticoid cortisol, are major components of the evolved human stress response. However, most studies have examined these systems among populations in high-income settings, which differ from the high pathogen and limited resource contexts in which the HPA axis functioned for most of human evolution.

METHODS

We investigated variability in diurnal salivary cortisol patterns among 298 Indigenous Shuar from Amazonian Ecuador (147 males, 151 females; age 2-86 years), focusing on the effects of age, biological sex, and body mass index (BMI) in shaping differences in diurnal cortisol production. Saliva samples were collected three times daily (waking, 30 minutes post-waking, evening) for three consecutive days to measure key cortisol parameters: levels at waking, the cortisol awakening response, the diurnal slope, and total daily output.

RESULTS

Age was positively associated with waking levels and total daily output, with Shuar juveniles and adolescents displaying significantly lower levels than adults (p < .05). Sex was not a significant predictor of cortisol levels (p > .05), as Shuar males and females displayed similar patterns of diurnal cortisol production across the life course. Moreover, age, sex, and BMI significantly interacted to moderate the rate of diurnal cortisol decline (p = .027). Overall, Shuar demonstrated relatively lower cortisol concentrations than high-income populations.

CONCLUSIONS

This study expands the documented range of global variation in HPA axis activity and diurnal cortisol production and provides important insights into the plasticity of human stress physiology across diverse developmental and socioecological settings.

Biomarkers of Stress and Inflammation in Children

Background: Children are increasingly exposed to stressors that can affect their immune function. Given the possible negative effects of stress and inflammation on health, researchers need to use appropriate biomarkers to measure both the effects of stress and subsequent inflammatory responses. Purpose: The purpose of this paper is to briefly review stress and inflammatory pathways, identify biomarkers used to measure chronic stress and chronic inflammation particularly in children in clinical and community settings, and to discuss methodological considerations when measuring stress and inflammation in children. Discussion: Biomarkers of chronic stress can be classified as central, meaning they are made in the brain, or peripheral, meaning they are made in the peripheral tissues in response to central signals. The peripheral biomarker, cortisol, is most frequently used in the community setting. In addition, indirect measures, such as oxytocin, may complement the assessment of stress. Common biomarkers of chronic inflammation in children are C-reactive protein (CRP), TNF-α, and IL-6. Similarly, indirect biomarkers of chronic inflammation, such as IL-2 and IL-1β, may also be considered. Conclusions: Various types of specimens can be used to measure these biomarkers of stress and inflammation including blood, saliva, urine, sweat, hair, nails, and tears. Each type of specimen has different requirements for collection, storage, and assay. Future research would benefit from standardized biomarker levels across age and development in children and incorporation of other biomarkers.

Stress Biomarkers and Child Development in Young Children in Bangladesh

Background

Hundreds of millions of children in low- and middle-income countries are exposed to chronic stressors, such as poverty, poor sanitation and hygiene, and sub-optimal nutrition. These stressors can have physiological consequences for children and may ultimately have detrimental effects on child development. This study explores associations between biological measures of chronic stress in early life and developmental outcomes in a large cohort of young children living in rural Bangladesh.

Methods

We assessed physiologic measures of stress in the first two years of life using measures of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol and glucocorticoid receptor gene methylation), the sympathetic-adrenal-medullary (SAM) system (salivary alpha-amylase, heart rate, and blood pressure), and oxidative status (F2-isoprostanes). We assessed child development in the first two years of life with the MacArthur-Bates Communicative Development Inventories (CDI), the WHO gross motor milestones, and the Extended Ages and Stages Questionnaire (EASQ). We compared development outcomes of children at the 75th and 25th percentiles of stress biomarker distributions while adjusting for potential confounders (hereafter referred to as contrasts) using generalized additive models, which are statistical models where the outcome is predicted by a potentially non-linear function of predictor variables.

Results

We analyzed data from 684 children (49% female) at both 14 and 28 months of age; we included an additional 765 children at 28 months of age. We observed 135 primary contrasts of the differences in child development outcomes at the 75th and 25th percentiles of stress biomarkers, where we detected significant relationships in 5 out of 30 contrasts (17%) of HPA axis activity, 1 out of 30 contrasts (3%) of SAM activity, and 3 out of 75 contrasts (4%) of oxidative status. These findings revealed that measures of HPA axis activity were associated with poor development outcomes. We did not find consistent evidence that markers of SAM system activity or oxidative status were associated with developmental status.

Conclusions

Our observations reveal associations between the physiological evidence of stress in the HPA axis with developmental status in early childhood. These findings add to the existing evidence exploring the developmental consequences of early life stress.

Exploring physical and biological manifestations of burnout and post-traumatic stress disorder symptoms in healthcare workers: a scoping review protocol

INTRODUCTION

The COVID-19 pandemic has strained the mental and physical well-being of healthcare workers (HCW). Increased work-related stress and limited resources have increased symptoms of anxiety, depression, insomnia and post-traumatic stress disorder (PTSD) in this population. Stress-related disorders have been strongly associated with long-term consequences, including cardiometabolic disorders, endocrine disorders and premature mortality. This scoping review aims to explore available literature on burnout, PTSD, and other mental health-associated symptoms in HCW to synthesise relationships with physiological and biological biomarkers that may be associated with increased risk of disease, creating an opportunity to summarise current biomarker knowledge and identify gaps in this literature.

METHODS AND ANALYSIS

This scoping review uses the Arksey and O'Malley six-step scoping review methodology framework. The research team will select appropriate primary sources using a search strategy developed in collaboration with a health sciences librarian. Three reviewers will initially screen the title and abstracts obtained from the literature searches, and two reviewers will conduct independent reviews of full-text studies for inclusion. The research team will be reviewing literature focusing on which burnout and/or PTSD-associated physiological and biological biomarkers have been studied, the methodologies used to study them and the correlations between the biomarkers and HCW experiencing burnout/PTSD. Data extraction forms will be completed by two reviewers for included studies and will guide literature synthesis and analysis to determine common themes.

ETHICS AND DISSEMINATION

This review does not require ethical approval. We expect results from this scoping review to identify gaps in the literature and encourage future research regarding improving biological and physiological biomarker research in HCW. Preliminary results and general themes will be communicated back to stakeholders. Results will be disseminated through peer-reviewed publications, policy briefs and conferences as well as presented to stakeholders to an effort to invest in HCW mental and physical health.

The implications of socioeconomic factors on salivary bioscience methodological variables in a large pediatric multi-site study

Introduction

Salivary bioscience has found increased utilization within pediatric research, given the non-invasive nature of self-collecting saliva for measuring biological markers. With this growth in pediatric utility, more understanding is needed of how social-contextual factors, such as socioeconomic factors or status (SES), influence salivary bioscience in large multi-site studies. Socioeconomic factors have been shown to influence non-salivary analyte levels across childhood and adolescent development. However, less is understood about relationships between these socioeconomic factors and salivary collection methodological variables (e.g., time of saliva collection from waking, time of day of saliva collection, physical activity prior to saliva collection, and caffeine intake prior to saliva collection). Variability in salivary methodological variables between participants may impact the levels of analytes measured in a salivary sample, thus serving as a potential mechanism for non-random systematic biases in analytes.

Methods

Our objective is to examine relationships between socioeconomic factors and salivary bioscience methodological variables within the Adolescent Brain Cognitive Development Study© cohort of children aged 9-10 years old (n = 10,567 participants with saliva samples).

Results

We observed significant associations between household socioeconomic factors (poverty status, education) and salivary collection methodological variables (time since waking, time of day of sampling, physical activity, and caffeine intake). Moreover, lower levels of household poverty and education were significantly associated with more sources of potential bias in salivary collection methodological variables (e.g., longer times since waking, collections later in the day, higher odds of caffeine consumption, and lower odds of physical activity). Consistent associations were not observed with neighborhood socioeconomic factors and salivary methodological variables.

Discussion

Previous literature demonstrates associations between collection methodological variables and measurements of salivary analyte levels, particularly with analytes that are more sensitive to circadian rhythms, pH levels, or rigorous physical activity. Our novel findings suggest that unintended distortions in measured salivary analyte values, potentially resulting from the non-random systematic biases in salivary methodology, need to be intentionally incorporated into analyses and interpretation of results. This is particularly salient for future studies interested in examining underlying mechanisms of childhood socioeconomic health inequities in future analyses.

Participation in an Attachment-Based Home Visiting Program Is Associated with Lower Child Salivary C-Reactive Protein Levels at Follow-Up

OBJECTIVE

Exposure to early childhood adversity is associated with an increased risk for physiological disruption, including increased inflammation. Early interventions that support the mother-child relationship have been shown to potentially buffer negative psychosocial outcomes related to early adversity, but it is unclear whether these interventions have long-term biological effects. We evaluated whether prior participation in Minding the Baby® (MTB), an attachment-based home visiting intervention for young mother-infant dyads living in underserved communities, is associated with lower child salivary inflammatory biomarkers compared with controls at follow-up.

METHODS

Ninety-seven maternal-child dyads (n = 43 intervention and n = 54 controls) enrolled in a follow-up study of the MTB randomized controlled trial, an average of 4.6 years after RCT completion. Children provided salivary specimens. We used adjusted linear regression to examine the relationship between MTB participation and child salivary inflammatory biomarkers (C-reactive protein [CRP], interleukin [IL]-1β, IL-6, IL-8, and TNF-α).

RESULTS

Children were on average 6.6 years old, 48% female, and identified as non-Hispanic/Latino Black/African American (34%) and Hispanic/Latino (63%). Participation in MTB was associated with lower salivary CRP levels (β = -0.31, SE = 0.28, p = 0.003) compared with controls. Participation in MTB was not associated with salivary cytokine levels.

DISCUSSION

Participation in an intensive two-generation home visiting intervention such as MTB may reduce salivary inflammatory biomarkers associated with early childhood adversity. Replication and further research are needed to improve the understanding of the potential for early childhood interventions to buffer the biological embedding of early adversity.

Exploring Physical and Biological Manifestations of Burnout and Post-Traumatic Stress Disorder Symptoms in Healthcare Workers: A Scoping Review Protocol

Introduction

The COVID-19 pandemic has strained the mental and physical well-being of healthcare workers (HCW). Increased work-related stress and limited resources has increased symptoms of anxiety, depression, insomnia, and post-traumatic stress disorder (PTSD) in this population. Stress-related disorders have been strongly associated with long-term consequences including cardiometabolic disorders, endocrine disorders and premature mortality. This scoping review aims to explore available literature on burnout, PTSD, and other mental health-associated symptoms in HCW to synthesize relationships with physiological and biological biomarkers that may be associated with increased risk of disease, creating an opportunity to summarize current biomarker knowledge and identify gaps in this literature.

Methods and Analysis

This scoping review uses the Arksey and O'Malley six-step scoping review methodology framework. The research team will select appropriate primary sources using a search strategy developed in collaboration with a health sciences librarian. Three reviewers will initially screen the title and abstracts obtained from the literature searches, and two reviewers will conduct independent reviews of full-text studies for inclusion. The research team will be reviewing literature focusing on which burnout and/or PTSD-associated physiological and biological biomarkers have been studied, the methodologies used to study them and the correlations between the biomarkers and HCW experiencing burnout/PTSD. Data extraction forms will be completed by two reviewers for included studies and will guide literature synthesis and analysis to determine common themes.

Ethics and Dissemination

This review does not require ethical approval. We expect results from this scoping review to identify gaps in the literature and encourage future research regarding improving biologic and physiologic biomarker research in HCW. Preliminary results and general themes will be communicated back to stakeholders. Results will be disseminated through peer-reviewed publications, policy briefs, and conferences, as well as presented to stakeholders to an effort to invest in HCW mental and physical health.

Strengths and Limitations of This Study

This will be the first scoping review to assess the current understanding of the biologic and physiological impact of burnout on healthcare workers. The target population is restricted to healthcare workers; however, identified research gaps may be used to guide future studies in other high-burnout occupations and industries.This scoping review will be guided by the Arksey and O'Malley six-step methodological framework and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review checklist.Both peer reviewed manuscript and pre-prints/abstracts will be evaluated, but studies that have not been peer reviewed will be notated in the summary table. Conference abstracts are excluded.Preliminary and final themes and results identified by this scoping review will be communicated to stakeholders, including hospital staff and HCW, to ensure agreement with our interpretation and to convey knowledge gained with our population of interest.This review will advance the field's current understanding of mechanisms connecting the burnout and pathogenic stress to biologic and physiologic outcomes in healthcare workers and provide researchers with gaps in the literature to inform opportunities for future research.

Relationships Between Stress-Responsive Biomarkers, ART Adherence, and Viral Suppression Among Adolescent Girls and Young Women Living With HIV in South Africa: An HPTN 068 Analysis

BACKGROUND

Adolescent girls and young women (AGYW) living with HIV who have higher stress levels may be at risk of stress-related biological alterations, which could influence HIV progression and adherence to antiretroviral therapy (ART).

SETTING

We aimed to estimate associations among stress-responsive biomarkers, ART adherence, and viral suppression in AGYW living with HIV in South Africa. We also hypothesized that psychosocial stressors [eg, depression, food insecurity, low socioeconomic status (SES), and HSV-2] would be associated with higher biomarker levels.

METHODS

We used 2018/2019 data from the HIV Prevention Trials Network 068 cohort to assess associations between stress-responsive biomarkers and viral suppression (<1000 copies/mL) and ART adherence measured using dried blood spot cards. Stress-responsive biomarkers included C-reactive protein, herpes simplex virus type 1, and cytomegalovirus infection and reactivation. Associations were estimated using unadjusted log-binomial or ordinal logistic regression models.

RESULTS

In 166 AGYW living with HIV, there was no association between stress-responsive biomarkers and viral suppression or ART adherence. However, increased C-reactive protein levels were associated with higher HSV-2 infection [odds ratio (OR) 1.98; 95% confidence interval (CI) 1.11, 3.52], being a government grant recipient (OR 3.21; 95% CI: 1.30, 7.92), lower food insecurity (OR 0.34; 95% CI: 0.13, 0.90), and increased body mass index (OR 1.07; 95% CI: 1.01, 1.14).

CONCLUSIONS

High prevalence of psychosocial stressors and persistent herpesviruses in AGYW living with HIV has the potential to lead to poorer health outcomes. More research is needed to untangle relationships between economic stability, chronic disease, and chronic stress.

Association between early life adversity and allostatic load in girls with precocious puberty

CONTEXT

The mechanisms underlying the elevated long-term health risk in girls with precocious puberty remain unclear, but might result from physiological wear and tear associated with greater exposure to early life adversity.

OBJECTIVE

This study aims to explore early life adversity in girls with precocious puberty and its association with allostatic load.

METHODS

Early life adversity and hair cortisol concentration were measured among 213 girls with precocious puberty (8.21 ± 1.07). Allostatic load score is constructed by using 13 physiological biomarkers representing four systems and hair cortisol concentration. Multivariate linear regression models have estimated the associations between cumulative early life adversity exposure with total and system-specific allostatic load scores. Associations between cumulative early life adversity and the risk of high allostatic load (3 + high-risk biomarkers) were tested using binary logistics regression.

RESULTS

More than two-thirds (67.6%) of girls with central precocious puberty reported two or more early life adversity exposure. Compared to those with no early life adversity exposure, girls who reported early life adversity score ≥ 2 had significantly higher total allostatic load score (β: 1.20-1.64, P < 0.001). Metabolic system was more sensitive to cumulative early life adversity exposure, each form of early life adversity exposure was associated with 0.48-unit increases in metabolic allostatic load score (95%CI: 0.06, 0.90, P = 0.026). Girls reported early life adversity score ≥ 3 were three times more likely to have a high allostatic load compared with those without early life adversity exposure in both unadjusted and adjusted models (OR_adjusted=3.83, 95%CI: 1.17, 12.55, P = 0.001).

CONCLUSION

Multisystem physiological dysregulation is observed in girls with central precocious puberty, which might result from cumulative wear-and-tear associated with early life adversity.

Early childhood stress responses to psychosocial stressors: The state of the science

The aim of this systematic review was to better understand whether and to what extent psychosocial stressors are associated with hypothalamic-pituitary-adrenal axis or autonomic nervous system stress responses in young children (1-6 years of age). Studies were classified by psychosocial stressors from the ecobiodevelopmental model: social and economic resources, maternal mental health, parent-child relationships, and the physical environment. Of the 2388 identified studies, 32 met full inclusion criteria, including over 9107 children. Child physiologic stress responses were measured as hair and urinary cortisol and cortisone, salivary diurnal and reactive cortisol, salivary reactive alpha-amylase, and respiratory sinus arrhythmia. There were 107 identified relations between psychosocial stressors and physiologic stress responses. Nearly two thirds of these relations suggested that children have dysregulated stress responses as either significantly blunted (n = 27) or increased (n = 37); 43 relations were not significant. Children most consistently had significantly dysregulated stress responses if they experienced postnatal maternal depression or anxiety. Some reasons for the mixed findings may be related to characteristics of the child (i.e., moderators) or stressor, how the stress response or psychosocial stressor was measured, unmeasured variables (e.g., caregiving buffering), researcher degrees of freedom, or publication bias.

The Effect of Pythagorean Self-Awareness on Heart Rate Variability, Perceived Stress and Behavior of Preschool Children

Stress is associated with unhealthy habits and non-communicable diseases. It is also linked to communicable diseases due to its impact on immune function. These can be prevented through intervention programs in schools. The aim of this study was to examine the effect of the simplified Pythagorean Self-Awareness Intervention on heart rate variability (HRV) parameters, perceived stress and behaviors of preschool children. The sample of the study consisted of 45 preschool students. A “one group (double) pretest—posttest design” was used, to allow for comparisons of the measurements before and after the intervention. Students were assessed via two questionnaires (“Perceived Stress Scale for Children” (PSS-C) and “Checklist for Screening Behavioral Problems in Preschool Children”) and a photoplethysmographic (PPG) device. The intervention lasted 9 weeks and included practicing of the Pythagorean Self-awareness techniques and the adoption of healthy behaviors. The results showed no statistically significant differences between the two pretests (p > 0.05 for all comparisons) and statistically significant differences between the second pretest and posttest (“Perceived Stress Scale for Children”, (PSS-C) p < 0.0001, “Checklist for Screening Behavioral Problems in Preschool Children” p < 0.0001 and two indices of PPG device: heart rate mean, p < 0.0001, low frequency/very low frequency, p = 0.034). In conclusion, the Pythagorean Self-Awareness Intervention had a beneficial effect on the sample of preschool students examined, as the results showed an improvement in the perceived stress and the HRV parameters tested, and in engaging healthier behaviors, findings that indicate a relaxed psychologic state and a healthier lifestyle.

Strategies to Engage Systematically Marginalized Youth and Their Families in Research Using High-Tech Methods

The purpose of this study was to identify facilitators and barriers for engaging youth and families from a historically and systematically marginalized community in high-tech research. Adapting community-based participatory research principles, 4 focus groups were conducted with 13 youth and 12 parents. Using codebook thematic analysis, 5 facilitator themes (develop skills, ensure health, build understanding, promote safety, and help others, youth-initiated interest) and 4 barrier themes (anxiety and fear, skepticism, confusion, and unfamiliar/unknown experience) were identified. Youth and parent responses informed proposed guidelines for recruiting and engaging families in research using high-tech methods, particularly those from historically and systematically marginalized communities.

School-Related Stressors and the Intensity of Perceived Stress Experienced by Adolescents in Poland

Higher stress reactivity during adolescence is a vulnerability marker of exposure to various environmental stressors. This study aimed to investigate the association between a high level of perceived stress experienced by adolescents and stressful stimuli induced from school environment, peer, and parental relationships. The data used were from a cross-sectional, observational study conducted in a stratified sample of 1846 adolescents (13-18 years) in the Wielkopolska province, Poland. Data were collected through self-administered questionnaires and anthropometric measurements. Perceived stress was assessed using the Perceived Stress Scale (PSS-10). The association of a high level of perceived stress with school-induced exposures was determined using multivariate logistic regression after adjusting for gender, age, height and weight status and interpersonal relationships (STATISTICA 13.1). It was found that girls were over three times more likely than boys to experience a high level of perceived stress. Moreover, girls appeared to be more vulnerable than boys to school-related stressors and weight status, while boys to stressors that can arise from interpersonal relationships. School environment was the only predictor factor of high perceived stress level with a large effect size in both boys (OR = 4.45; 95% CI: 3.11-6.36) and girls (OR = 6.22; 95% CI: 4.18-7.59). Given the findings of the present study, preventive programs are critical to mitigate the effect of stress from school on adolescents' health and well-being.

Potential Socioeconomic Effects of the COVID-19 Pandemic on Neural Development, Mental Health, and K-12 Educational Achievement

The Novel Coronavirus (COVID-19) pandemic can affect more than a child's biological health. Lack of in-person schooling and increased stress can affect neurodevelopment, mental health, and later life outcomes, especially for students who are from low socioeconomic status (SES) households. Insights from neuroscience on child development reveal potential neural mechanisms and educational outcomes likely disrupted by the pandemic-and how this will disproportionally affect low-SES children. Three policies can combat these educational and emotional effects: increased access to online resources, investments in social-emotional health, and increased access to summer/out-of-school learning. Integrating the traditionally separate fields of neuroscience and educational research will be critical for developing and assessing the most impactful policies to improve the well-being and educational achievement of our most disadvantaged children.

Leptin as a Biomarker of Stress: A Systematic Review and Meta-Analysis

BACKGROUND

Leptin is a satiety hormone mainly produced by white adipose tissue. Decreasing levels have been described following acute stress.

OBJECTIVE

To conduct a systematic review and meta-analysis to determine if leptin can be a biomarker of stress, with levels decreasing following acute stress.

METHODS

PubMed, Cochrane Library, Embase, and ScienceDirect were searched to obtain all articles studying leptin levels after acute stress on 15 February 2021. We included articles reporting leptin levels before and after acute stress (physical or psychological) and conducted random effects meta-analysis (DerSimonian and Laird approach). We conducted Meta-regressions and sensitivity analyses after exclusion of groups outside the metafunnel.

RESULTS

We included seven articles-four cohort and three case-control studies-(28 groups) from 27,983 putative articles. Leptin levels decreased after the stress intervention (effect size = -0.34, 95%CI -0.66 to -0.02) compared with baseline levels, with a greater decrease after 60 min compared to mean decrease (-0.45, -0.89 to -0.01) and in normal weight compared to overweight individuals (-0.79, -1.38 to -0.21). There was no difference in the overweight population. Sensitivity analyses demonstrated similar results. Levels of leptin after stress decreased with sex ratio-i.e., number of men/women-(-0.924, 95%CI -1.58 to -0.27) and increased with the baseline levels of leptin (0.039, 0.01 to 0.07).

CONCLUSIONS

Leptin is a biomarker of stress, with a decrease following acute stress. Normal-weight individuals and women also have a higher variation of leptin levels after stress, suggesting that leptin may have implications in obesity development in response to stress in a sex-dependent manner.

Maternal Experiences of Racial Discrimination, Child Indicators of Toxic Stress, and the Minding the Baby Early Home Visiting Intervention

BACKGROUND

Racism is a significant source of toxic stress and a root cause of health inequities. Emerging evidence suggests that exposure to vicarious racism (i.e., racism experienced by a caregiver) is associated with poor child health and development, but associations with biological indicators of toxic stress have not been well studied. It is also unknown whether two-generation interventions, such as early home visiting programs, may help to mitigate the harmful effects of vicarious racism.

OBJECTIVE

The purpose of this study was to examine associations between maternal experiences of racial discrimination and child indicators of toxic stress and to test whether relationships are moderated by prior participation in Minding the Baby (MTB), an attachment-based early home visiting intervention.

METHODS

Ninety-seven maternal-child dyads (n = 43 intervention dyads, n = 54 control dyads) enrolled in the MTB Early School Age follow-up study. Mothers reported on racial discrimination using the Experiences of Discrimination Scale. Child indicators of toxic stress included salivary biomarkers of inflammation (e.g., C-reactive protein, panel of pro-inflammatory cytokines), body mass index, and maternally reported child behavioral problems. We used linear regression to examine associations between maternal experiences of racial discrimination and child indicators of toxic stress and included an interaction term between experiences of discrimination and MTB group assignment (intervention vs. control) to test moderating effects of the MTB intervention.

RESULTS

Mothers identified as Black/African American (33%) and Hispanic/Latina (64%). In adjusted models, maternal experiences of racial discrimination were associated with elevated salivary interleukin-6 and tumor necrosis factor-α levels in children, but not child body mass index or behavior. Prior participation in the MTB intervention moderated the relationship between maternal experiences of discrimination and child interleukin-6 levels.

DISCUSSION

Results of this study suggest that racism may contribute to the biological embedding of early adversity through influences on inflammation, but additional research with serum markers is needed to better understand this relationship. Improved understanding of the relationships among vicarious racism, protective factors, and childhood toxic stress is necessary to inform family and systemic-level intervention.

Allostatic Stress and Inflammatory Biomarkers in Transgender and Gender Expansive Youth: Protocol for a Pilot Cohort Study

Background

A growing number of adolescents are coming out as transgender and gender expansive (TGE). These teenagers have been shown to have significantly worse health outcomes than their cisgender peers. Hypotheses to explain this discrepancy are based on increased stress levels surrounding the societal acceptance of gender identity. In this context, elevated allostatic load (AL), which describes the wear and tear sustained by the body in response to repeated exposure to stress, has been associated with adverse long-term health outcomes.

Objective

This protocol aims to measure AL among TGE adolescents compared with their cisgender peers and assess how AL varies depending on psychological stress and perceived societal acceptance.

Methods

This is an observational proof-of-concept pilot study in which AL will be measured by assaying an array of inflammatory cytokines and cortisol in urine, saliva, and hair samples of TGE youth, and these parameters will be compared with those of age-matched control participants. A questionnaire will assess 4 aspects of psychosocial well-being: presence and management of depression and anxiety, gender identity support by family members, gender minority stress, and degree of perceived safety in the surrounding community. Samples and surveys will be collected at 3 visits (baseline, 6 months, and 12 months). This study will incorporate TGE coinvestigators to inform all aspects of design, data collection, and analysis and ensure that practices are carried out in a respectful and sensitive manner.

Results

As of May 2021, the start of data collection for this project has continued to be postponed as a result of the COVID-19 pandemic, which has both impacted the functioning of the clinic and funding requests. We hope to begin participant recruitment and interviews with coinvestigators soon.

Conclusions

We hypothesize that AL will be primarily influenced by psychological well-being and perceived support and that it will be similar in TGE adolescents and in age-matched cisgender control participants when acceptance and perceived support are high. The results of this study have the potential to increase our understanding of the health challenges faced by TGE individuals during adolescence as well as to show that low levels of acceptance may have detrimental health outcomes secondary to elevated ALs; this may lead to the development of a biomarker profile to assess allostatic stress in TGE patients that can be used to guide management.

International Registered Report Identifier (IRRID)

PRR1-10.2196/24100

Racial and Economic Differences in the Risk of Hyperglycemia in Children Hospitalized With Acute Lymphoblastic Leukemia

Background: The underlying mechanism of hyperglycemia in children with acute lymphoblastic leukemia (ALL) is insulin resistance. Although race and economic status have been linked to increased insulin resistance in children, these have not been explored as predictors of hyperglycemia in children with ALL. The objective of this study was to analyze race and income as predictors of hyperglycemia in a diverse sample of children hospitalized with ALL in the United States in the year 2016. Methods: We performed a secondary analysis of 18,077 hospitalizations of White, Black, and Hispanic children under the age of 21 years with ALL contained in a nationally representative database. Multilevel binary logistic regression models were constructed to estimate the relationships between race, median household income, age, sex, and obesity and the odds of hyperglycemia in hospitalized children with ALL. Results: Hyperglycemia occurred during 5.3% of the hospitalizations. Black children were 37% more likely to develop hyperglycemia than White children. The risk for hyperglycemia did not differ between Hispanic and White children. Residing in areas where annual median income was below $54,000 was associated with 1.4-fold increased odds of hyperglycemia, compared to the wealthiest areas. Older children, females, and those diagnosed with obesity were also at increased risk for hyperglycemia. Discussion: An association has been found between treatment-induced hyperglycemia and increased mortality. For this reason, the racial and economic differences in the risk for hyperglycemia identified in this study deserve further consideration.

A systematic review of the association between sleep health and stress biomarkers in children

Sleep is intimately linked with the stress response system. While the evidence for this connection has been systematically reviewed in the adult literature, to our knowledge no studies have examined this relationship in young children. Recent scientific interest in understanding the effects of adverse environments in early childhood, including an emphasis on understanding the role of sleep, highlights the importance of synthesizing the current evidence on the relationship between sleep and the stress response system in early childhood. The aim of this systematic review is to examine the relationship between sleep health and biomarkers of physiologic stress (neuroendocrine, immune, metabolic, cardiovascular) in healthy children ages 0-12 y. Following PRISMA guidelines, we identified 68 empirical articles and critically reviewed and synthesized the results across studies. The majority of studies included school-age children and reported sleep dimensions of duration or efficiency. Overall, evidence of associations between sleep health and stress biomarkers was strongest for neuroendocrine variables, and limited or inconsistent for studies of immune, cardiovascular, and metabolic outcomes. Gaps in the literature include prospective, longitudinal studies, inclusion of children under the age of 5 y, and studies using objective measures of sleep.

The intergenerational interplay of adversity on salivary inflammation in young children and caregivers

Systemic inflammation links exposure to early childhood adversity to later disease. The associations among adversity and disease risk might in part operate through poor oral hygiene and subsequent periodontal inflammation, which can be measured in saliva. Few studies, however, have examined the association between adversity and salivary inflammation in young children. Further, there is a dearth of literature investigating adverse experiences and salivary inflammation in children and caregivers together, limiting our understanding of the intergenerational, dual effects of adversity on inflammation for both members of the caregiver-child dyad. This study tested child and caregiver adversity and their associations with an inflammatory composite (i.e., IL-6, IL-1β, IL-8, TNF-α) and CRP in 93 preschool-age children and their caregivers. Caregivers reported on their child's experiences of adversity, as well as on their own adverse experiences, using a comprehensive questionnaire synthesized from previous checklists for complete coverage of possible adverse events. Results showed that caregivers' salivary inflammatory markers (i.e., IL-6, IL-1β, IL-8, TNF-α, and CRP) were not significantly correlated with the same five inflammatory markers in children's saliva. Among children, adversity was associated with significantly higher levels of the inflammatory composite, though not CRP. This association was amplified among children whose caregivers also experienced more adversity during adulthood. Among caregivers, childhood adversity and adulthood adversity were each independently associated with significantly higher levels of the inflammatory composite and CRP. The association between caregivers' own childhood adversity and inflammation was amplified among caregivers whose children also experienced more adversity during their childhoods. These findings provide preliminary evidence for the possible dual role of young children's and caregivers' adverse experiences in contributing to salivary inflammation for both members of the dyad, suggesting possible implications for systemic inflammation and future disease.

The longitudinal negative impact of early stressful events on emotional and physical well-being: The buffering role of cardiac vagal development

Early stressful events negatively affect emotional and physical well-being. Cardiac vagal tone (CVT), which is associated with better emotional and physical well-being, usually gradually increase in early childhood. Nonetheless, children's CVT developmental trajectories are greatly variable, such that CVT can increase or decrease across the years. The present study examines the longitudinal effects of early stressful events and the role of 4 years CVT developmental trajectory on children's emotional and physical well-being. Forty-two 4-year-old children were enrolled. Number of stressful events and resting electrocardiogram (ECG) were collected at T1. ECG was registered again after one (T2), two (T3) and three (T4) years. Children's emotional and physical well-being were assessed at T4 through the Child Health and Illness Profile - Child Edition (CHIP-CE). CVT development was calculated as the angular coefficient, reflecting the developmental trajectory of CVT across the four timepoints. Results yielded that higher experienced stressful events predicted poorer emotional and physical well-being after 4 years. The interaction between the number of stressful events and CVT development emerged on physical well-being. Early stressful events negatively affect long-term children's emotional and physical well-being while a positive CVT development seems to mitigate the negative effects of early stressful events on physical well-being.

Experiences of racial discrimination and cardiometabolic risk among Australian children

Cardiometabolic disease is a leading cause of adult morbidity and mortality globally. There is considerable evidence that childhood adversity is associated with markers of cardiometabolic disease risk in childhood, including obesity, blood pressure trajectories, and chronic inflammation. Experiences of racial discrimination may be an important, yet under explored, form of childhood adversity influencing childhood cardiometabolic risk. This study aimed to examine associations between self-reported racial discrimination and cardiometabolic risk markers among children. A total of 124 children (73 female) aged 11.4 years (SD 0.71) participated in the study. Most children (n = 79) identified as being from an Indigenous or an ethnic minority background. Markers of cardiometabolic risk were BMI, waist circumference, weight height ratio, systolic and diastolic blood pressure, and five inflammatory markers (C-reactive protein (CRP), Interleukin (IL)-1β, IL-6, IL-8, and TNF-α). Results showed that two or more reported experiences of racial discrimination were associated with increased BMI z-score (Beta 0.58, 95% CI 0.18, 0.99), waist circumference (Beta 4.91 cm, 95% CI 0.71, 9.1), systolic blood pressure (Beta 2.07 mmHg, 95% CI 0.43, 3.71) and IL-6 (Beta 0.13, 95% CI 0.00, 0.27) and marginally associated with TNF-α (Beta 0.22, 95% CI -0.09, 0.54) after adjusting for socio-demographic covariates. Findings from this study suggest the need to address racism and racial discrimination as important social determinants of cardiometabolic risk and of the inequitable burden of cardiometabolic disease experienced by those from Indigenous and minoritized ethnic backgrounds.

Acceptability and Feasibility of Hair and Salivary Biomarker Collection Among Multiethnic School-Age Children

OBJECTIVE

As noninvasive biological markers gain increasing popularity in pediatric research, it is critical to understand how study participants perceive these measures, especially among groups underrepresented in biobehavioral research, like children and people of color. The purpose of this study was to examine acceptability and feasibility of hair and salivary biomarker collection in an urban community sample of ethnically diverse children (age 4 to 10 years).

METHODS

Ninety-seven mother-child dyads were recruited for a cross-sectional follow up study of the Minding the Baby® home visiting intervention. Children were Hispanic (63%), Black (34%), and multi-racial (3.1%). A conventional content analysis was conducted using two sources of data: (1) mothers' responses to open-ended interview questions on their views and suggestions regarding biomarker collection, and (2) field notes recorded by investigators.

RESULTS

Forty-four percent of mothers reported biomarker-related questions or concerns, including questions about the purpose of biomarker testing, and concerns about cosmetic issues, child discomfort, and future use of biomarker data. Mothers also offered positive feedback and advice for collection. Issues affecting feasibility included children's hair length and style, refusal to participate, and behavioral or developmental issues.

CONCLUSIONS

Hair and salivary biomarker collection was largely acceptable and feasible in this sample. Strategies for promoting ethical and sensitive biomarker collection include respectful explanations and parental involvement, creating a comfortable and safe environment for the child, flexible collection strategies, and attention to development, cultural preferences and perspectives.

Associations Between Maternal Experiences of Discrimination and Biomarkers of Toxic Stress in School-Aged Children

OBJECTIVE

To examine associations between maternal experiences of discrimination and child biomarkers of toxic stress in a multiethnic, urban sample of mothers and children (4-9 years).

METHODS

Data were drawn from a cross-sectional study of maternal-child dyads (N = 54) living in low-income neighborhoods in New Haven, Connecticut, USA. Mothers reported experiences of discrimination. Noninvasive biomarkers of toxic stress were collected to assess neuroendocrine (hair cortisol), immune (salivary cytokines, c-reactive protein), and cardiovascular (blood pressure) functioning in children.

RESULTS

Maternal experiences of discrimination were associated with increased log-transformed salivary interleukin-6 (IL-6) levels in children (β = 0.15, p = 0.02).

CONCLUSIONS

Vicarious racism, or indirect exposure to discrimination experienced by caregivers, is associated with poor health outcomes for children. Immune pathways may be a biological mechanism through which racial discrimination "gets under the skin," but additional research is needed to fully understand these relationships. Uncovering the physiological mechanisms linking vicarious racism with child health is an important step towards understanding possible early roots of racial and ethnic health inequities.

Maternal Adverse Childhood Experiences, Family Strengths, and Chronic Stress in Children

BACKGROUND

Researchers have demonstrated that maternal adverse childhood experiences (ACEs), such as abuse and neglect, are associated with prenatal risk factors and poor infant development. However, associations with child physiologic and health outcomes, including biomarkers of chronic or "toxic" stress, have not yet been explored.

OBJECTIVES

The purpose of this study was to examine the associations among past maternal experiences, current maternal posttraumatic stress disorder (PTSD) symptoms, and children's indicators of exposure to chronic stress in a multiethnic sample of mothers and children at early school age (4 to 9 years).

METHODS

This cross-sectional study included maternal-child dyads (N = 54) recruited from urban community health centers in New Haven, Connecticut. Mothers reported history of ACEs, family strengths, and current PTSD symptoms. Child measures included biomarkers and health and developmental outcomes associated with chronic stress. Correlational and regression analyses were conducted.

RESULTS

Childhood trauma in mothers was associated with higher systolic blood pressure percentile (ρ = .29, p = .03) and behavioral problems (ρ = .47, p = .001) in children, while maternal history of family strengths was associated with lower salivary interleukin (IL)-1β (ρ = -.27, p = .055), salivary IL-6 (ρ = -.27, p = .054), and body mass index z-scores (ρ = -.29, p = .03) in children. Maternal PTSD symptoms were associated with more child behavioral problems (ρ = .57, p < .001) and higher odds of asthma history (ρ = .30, p = .03).

DISCUSSION

Results indicate that past maternal experiences may have important influences on a child's health and affect his or her risk for experiencing toxic stress.

Association between neighbourhood green space and biological markers in school-aged children. Findings from the Generation XXI birth cohort

BACKGROUND

There is considerable literature on the psychological and behavioural benefits of green space. However, less is known about its health-promoting effects, as expressed on biological markers. Additionally, incorporating biomarkers into pediatric research may help elucidate the links between exposures to environmental stressors and lifelong health.

OBJECTIVE

To measure the association between geographical accessibility to green spaces and allostatic load (AL), a measure of biological multi-system dysregulation.

METHODS

We used data from 3108 7-year old children enrolled in Generation XXI, a population-based birth cohort from the Porto Metropolitan Area (Portugal). We computed an AL index based on seven biomarkers representing four regulatory systems: immune/inflammatory system (high sensitivity C-reactive protein); metabolic system (high density lipoprotein; total cholesterol; glycated hemoglobin; waist-hip ratio) and cardiovascular system (systolic and diastolic blood pressure). Accessibility to green spaces was calculated using a Geographic Information System and crude and adjusted associations were estimated using mixed-effects regression models.

RESULTS

Among the 3108 children (51.7% male; mean age 87.3 months), the mean AL index was 0.00 (standard deviation 2.94). Adjusted models showed that having a green space within 400 m and 800 m from the child's school was inversely associated with AL (400 m: beta -0.29 95% CI -0.54 to -0.02; 800 m: -0.29 95% CI -0.51 to -0.07). Also, there was a 12% (0%; 23%) increase in the AL index for every 1 km increase in distance to the nearest green space. No significant associations with AL were observed with residential accessibility to green space or with the presence of a garden at home.

CONCLUSION

We found a cross-sectional negative association between accessibility to green space near schools and AL in children, suggesting that the provision of green space may contribute to improvements in population health beginning early in life.

Associations Between Maternal Caregiving and Child Indicators of Toxic Stress Among Multiethnic, Urban Families

INTRODUCTION

Our purpose was to examine associations between maternal caregiving and child indicators of toxic stress among multiethnic, urban families with children of early school age.

METHOD

We conducted an exploratory cross-sectional analysis of 54 maternal-child dyads. Mothers reported on parenting behaviors and parental reflective functioning (PRF). Child indicators of toxic stress included hair/salivary biomarkers, anthropometric characteristics, and maternally reported health and behavior.

RESULTS

Hostile/coercive parenting behaviors were associated with child externalizing behavioral problems (r = 0.43, p = .001, but lower interleukin (IL) 6 levels (r = 0.31, p = .03). High PRF was associated with fewer child emergency department visits (ρ = -0.43, p = .009), whereas impaired PRF was associated with more behavioral problems (ρ = 0.52, p < .0001).

DISCUSSION

PRF and supportive parenting behaviors may protect against toxic stress among vulnerable families, but additional research is needed to better understand these relationships. Resources are available to help clinicians screen for family risk factors and model responsive caregiving in pediatric settings.