Paediatric stress: from neuroendocrinology to contemporary disorders

Developmental Neuroendocrinology of Early-Life Stress: Impact on Child Development and Behavior

Our internal balance, or homeostasis, is threatened or perceived as threatened by stressful stimuli, the stressors. The stress system is a highly conserved system that adjusts homeostasis to the resting state. Through the concurrent activation of the hypothalamic-pituitary-adrenal axis and the locus coeruleus/norepinephrine-autonomic nervous systems, the stress system provides the appropriate physical and behavioral responses, collectively termed as "stress response", to restore homeostasis. If the stress response is prolonged, excessive or even inadequate, several acute or chronic stress-related pathologic conditions may develop in childhood, adolescence and adult life. On the other hand, earlylife exposure to stressors has been recognized as a major contributing factor underlying the pathogenesis of non-communicable disorders, including neurodevelopmental disorders. Accumulating evidence suggests that early-life stress has been associated with an increased risk for attention deficit hyperactivity disorder and autism spectrum disorder in the offspring, although findings are still controversial. Nevertheless, at the molecular level, early-life stressors alter the chemical structure of cytosines located in the regulatory regions of genes, mostly through the addition of methyl groups. These epigenetic modifications result in the suppression of gene expression without changing the DNA sequence. In addition to DNA methylation, several lines of evidence support the role of non-coding RNAs in the evolving field of epigenetics. In this review article, we present the anatomical and functional components of the stress system, discuss the proper, in terms of quality and quantity, stress response, and provide an update on the impact of early-life stress on child development and behavior.

The Optimal State Scoring Tool: guidance for interdisciplinary care of infants with severe bronchopulmonary dysplasia and its relation to linear growth

OBJECTIVE

Infants with severe bronchopulmonary dysplasia (sBPD) have complex medical courses. We developed the clinician-rated Optimal State Scoring Tool (OSST) that measures factors relevant to clinical improvement of sBPD and investigated preliminary validity using linear growth outcome and OSST scores in sBPD patients.

METHODS

Tool development process and pilot findings are provided for 13 patients evaluated longitudinally. OSST scores, length measurements, and steroid dependency values were obtained. Changes in OSST scores and lengths were examined using linear mixed-effect models.

RESULTS

OSST scores were significantly correlated with linear growth (95% CI 0.36, 0.57). The steroid-dependent group showed significantly slower rate of linear growth (95% CI 0.74, 1.05) and slower rate of increase in OSST scores (95% CI 0.99, 2.13) compared to the non-steroid-dependent group, with the OSST showing the largest effect size.

CONCLUSION

Pilot data reflect promising evidence for OSST construct validity in monitoring clinical outcomes in sBPD patients.

Glucocorticoid Signaling Pathway: From Bench to Bedside

Glucocorticoids were named by Hans Hugo Bruno Selye, the modern father of stress concepts, for their important role in glucose metabolism [...].

Basic Concepts and Hormonal Regulators of the Stress System

BACKGROUND

Human organisms have to cope with a large number of external or internal stressful stimuli that threaten - or are perceived as threatening - their internal dynamic balance or homeostasis. To face these disturbing forces, or stressors, organisms have developed a complex neuroendocrine system, the stress system, which consists of the hypothalamic-pituitary-adrenal axis and the locus caeruleus/norepinephrine-autonomic nervous system.

SUMMARY

Upon exposure to stressors beyond a certain threshold, the activation of the stress system leads to a series of physiological and behavioral adaptations that help achieve homeostasis and increase the chances of survival. When, however, the stress response to stressors is inadequate, excessive, or prolonged, the resultant maladaptation may lead to the development of several stress-related pathologic conditions. Adverse environmental events, especially during critical periods of life, such as prenatal life, childhood, and puberty/adolescence, in combination with the underlying genetic background, may leave deep, long-term epigenetic imprints in the human expressed genome.

KEY MESSAGES

In this review, we describe the components of the stress system and its functional interactions with other homeostatic systems of the organism; we present the hormonal regulators of the stress response, and we discuss the development of stress-related pathologies.

The Human Glucocorticoid Receptor Beta: From Molecular Mechanisms to Clinical Implications

Glucocorticoids play a fundamental role in a plethora of cellular processes and physiologic functions through binding on a ubiquitously expressed receptor, the glucocorticoid receptor (GR), which functions as a ligand-activated transcription factor influencing the transcription rate of numerous genes in a positive or negative fashion. For many years, we believed that the pleiotropic actions of glucocorticoids were mediated by a single GR protein expressed by the NR3C1 gene. Nowadays, we know that the NR3C1 gene encodes 2 main receptor isoforms, the GRα and the GRβ, through alternative splicing of the last exons. Furthermore, the alternative initiation of GR mRNA translation generates 8 distinct GRα and possibly 8 different GRβ receptor isoforms. The tremendous progress of cellular, molecular, and structural biology in association with the data explosion provided by bioinformatics have enabled a deeper understanding of the role of GRβ in cellular homeostasis. In this review article, I will provide an update on the cellular properties and functions of hGRβ and summarize the current knowledge about the evolving role of the beta isoform of glucocorticoid receptor in endocrine physiology, pathophysiology, and beyond.

Difference in Hair Cortisol Concentrations between Obese and Non-Obese Children and Adolescents: A Systematic Review

Childhood obesity has been linked to physical and psychological comorbidities that can be carried into adulthood. A bidirectional link between body weight and the stress system appears to exist, as cortisol may affect the regulation of appetite, while adiposity can affect cortisol secretion. Among the biological tissues used to evaluate cortisol concentrations, scalp hair can provide retrospective measures. The aim of this systematic review was to investigate the difference in hair cortisol concentrations between obese and non-obese minors ≤ 19 years of age. Children and adolescents with genetic, somatic or psychiatric comorbidities were excluded. The work was conducted following the PRISMA guidelines, using prespecified search terms in the Pubmed database. The initial search yielded 56 studies, while the last step of the screening procedure concluded in 9 observational studies. Among them, the results could be characterized as inconclusive. Five of them demonstrated significantly higher hair cortisol concentrations in obese children and adolescents than normal weight subjects. On the contrary, the remaining four found no statistically significant differences in hair cortisol concentrations between obese and non-obese subjects. Different methodologies applied, and confounding factors could explain the inconsistency in the findings. Further research is needed to provide more solid results.

Comparison of Hospital Consultation and Summer Camp Lifestyle Intervention Programs for Sustained Body Weight Loss in Overweight/Obese Greek Children

Two lifestyle intervention programs of a health initiative named "Evrostia" were conducted at (a) an outpatient obesity clinic of a children's hospital and (b) summer camp (SC), respectively. Thirty overweight/obese children were randomly selected to participate in each intervention arm to assess the efficacy of the SC intervention and its possible superiority over usual hospital consultation (HC) practice. There was a statistically significant decrease in body weight (BW), and body mass index (BMI) in both programs. A higher duration of reduced BW was observed in the SC compared to HC intervention. Regarding the nutritional behavior, there was a significant increase in the consumption of breakfast, fruit and vegetables, and a reduction in the consumption of beverages and sweets in the SC group. A significant increase in the hours of weekly physical activity was also observed in children of the SC program. The comparison between the two lifestyle intervention programs showed that the SC program improved nutritional behaviors and physical activity and promoted longer preservation of BW loss than that of the HC program. Thus, the holistic and experiential approach of the SC program was more successful in the treatment of overweight and obesity in children than a conventional HC program.

Primary Generalized Glucocorticoid Resistance and Hypersensitivity Syndromes: A 2021 Update

Glucocorticoids are the final products of the neuroendocrine hypothalamic-pituitary-adrenal axis, and play an important role in the stress response to re-establish homeostasis when it is threatened, or perceived as threatened. These steroid hormones have pleiotropic actions through binding to their cognate receptor, the human glucocorticoid receptor, which functions as a ligand-bound transcription factor inducing or repressing the expression of a large number of target genes. To achieve homeostasis, glucocorticoid signaling should have an optimal effect on all tissues. Indeed, any inappropriate glucocorticoid effect in terms of quantity or quality has been associated with pathologic conditions, which are characterized by short-term or long-lasting detrimental effects. Two such conditions, the primary generalized glucocorticoid resistance and hypersensitivity syndromes, are discussed in this review article. Undoubtedly, the tremendous progress of structural, molecular, and cellular biology, in association with the continued progress of biotechnology, has led to a better and more in-depth understanding of these rare endocrinologic conditions, as well as more effective therapeutic management.

The Psychoneuroimmunology of Stress Regulation in Pediatric Cancer Patients

Stress is a ubiquitous experience that can be adaptive or maladaptive. Physiological stress regulation, or allostasis, can be disrupted at any point along the regulatory pathway resulting in adverse effects for the individual. Children with cancer exhibit significant changes to these pathways in line with stress dysregulation and long-term effects similar to those observed in other early-life stress populations, which are thought to be, in part, a result of cytotoxic cancer treatments. Children with cancer may have disruption to several steps in the stress-regulatory pathway including cognitive-affective function, neurological disruption to stress regulatory brain regions, altered adrenal and endocrine function, and disrupted tissue integrity, as well as lower engagement in positive coping behaviours such as physical activity and pro-social habits. To date, there has been minimal study of stress reactivity patterns in childhood illness populations. Nor has the role of stress regulation in long-term health and function been elucidated. We conclude that consideration of stress regulation in childhood cancer may be crucial in understanding and treating the disease.

Increased Incidence of Stress-related Tic Habit Cough in Children During the Recent Greek Financial Crisis

BACKGROUND/AIM

Tic habit cough (THC) is not easily recognized and requires a high index of suspicion. Since there is evidence for stress-related etiology, the study presents our experience during the eight-year period of the recent Greek financial crisis.

PATIENTS AND METHODS

This is a descriptive prospective cross-sectional clinical study using a consistent approach to diagnosis, possible triggers and treatment options.

RESULTS

Fifty-one children (26 girls, age 9.5±3.1y) from a total of 3,793 new referrals for chronic cough fulfilled the criteria of THC (1.34%). Incidence rates per 1,000 person-years were 1.34 (95%CI=0.34-5.40), 3.91 (95%CI=1.86-8.19), 4.03 (95%CI=2.01-8.06) and 14.60 (95%CI=10.43-20.44) for every two years. Poisson analysis showed an increased trend during the four time periods with an incidence rate ratio equal to 2.21 (95%CI=1.58-3.09, p<0.001). THC was mainly attributed to learning difficulties, as well as stress-related impact of peer or family bullying, family financial problems and child anxiety disorders.

CONCLUSION

The incidence of THC is associated with the negative aspects of stressors during a period of financial crisis. The potential underlining psycho-physiological mechanisms are discussed as well as the fact that prompt diagnosis may result in successful interventions.

Prenatal exposure to isolated amniotic fluid disorders and the risk for long-term endocrine morbidity of the offspring

BACKGROUND

Amniotic fluid abnormalities may be associated with adverse perinatal outcomes, some of which are endocrine related.

OBJECTIVE

To evaluate whether in utero exposure to amniotic fluid abnormalities is associated with long-term endocrine morbidity in the offspring.

STUDY DESIGN

In this cohort study, the incidence of long-term endocrine disorders was compared between singletons exposed and non-exposed to oligohydramnios or polyhydramnios.

RESULTS

During the study period, 195 943 newborns were included in the study, of them 2.0% (n = 4072) and 2.9% (n = 5684) were exposed to oligohydramnios and polyhydramnios, respectively. Long-term endocrine morbidity was higher among children exposed to isolated amniotic fluid disorders, as was also noted in the Kaplan-Meier survival curve (log-rank test p < 0.001). Abnormal amniotic fluid volume was found to be independently associated with long-term endocrine morbidity of the offspring according to a Cox regression model controlled for clinically related confounders.

CONCLUSION

In utero exposure to isolated amniotic fluid abnormalities is independently associated with long-term endocrine morbidity in the offspring.

Association between Salivary Alpha-Amylase and Executive Functioning in Healthy Children

The main aim of this study was to confirm the relationship between executive performance and salivary alpha-amylase (SAA) activity in a sample of 64 healthy children (39 boys), and compare it to the association of SAA output and salivary flow rate (SFR). Executive functioning was assessed via fluency, trail-making, rings and inhibition tasks from the Batería de Evaluación Neuropsicológica de la Función Ejecutiva en Niños [Battery of Neuropsychological Assessment for Executive Function in Children] (ENFEN), merged into an ENFEN total score. SAA activity, output, and SFR were measured at baseline, one minute before, and one minute after the end of a neuropsychological testing session. Our results confirmed a direct, linear and significant association between SAA activity and executive functioning, r(64) = .351, p < .05, and extended it to SAA output, r(64) =.431, p < .05. The mean level of SAA output was the best predictor of executive functioning (β = .431, p < .05) and explained 18.2 % of the variance in ENFEN total score. In sum, and compared to SAA activity, measuring SAA output may be a more precise and indirect marker to assess executive functioning in children.

Early maternal perceived stress and children's BMI: longitudinal impact and influencing factors

BACKGROUND

Maternal perceived stress has been discussed to contribute to the development of childhood overweight. Our aim was to investigate the longitudinal relationship of early maternal perceived stress and BMI z-scores in preschool children (≤ five years).

METHODS

A longitudinal analysis was conducted in 498 mother-child pairs of the German prospective birth cohort LINA with information on maternal perceived stress during pregnancy, one and two years after birth. BMI z-scores were based on annual measurements of children's weight/height and calculated based on WHO reference data. General estimation equations were applied to evaluate the impact of maternal stress on children's longitudinal BMI z-scores. Potential stressors contributing to the perceived stress of the mother were assessed by linear regression models. Using mediation analyses we evaluated the relationship between stressors, maternal perceived stress, and children's BMI z-score development.

RESULTS

Postnatal maternal stress during the first year after birth had a positive longitudinal relationship with children's BMI z-scores up to the age of five years. Gender-stratified analyses revealed that only girls showed this positive association while boy's BMI z-scores were unaffected by maternal stress. We identified three neighborhood strains and two socio-demographic factors, which contributed to the maternal perceived stress level. Stressors themselves did not directly affect girl's BMI z-scores but rather mediated their effect through the perceived stress level.

CONCLUSIONS

While different stressors contribute to maternal stress, the perceived stress level - rather than the stressors themselves - is strongly positively associated with BMI z-score development in girls.

Endocrine active metals, prenatal stress and enhanced neurobehavioral disruption

Metals, including lead (Pb), methylmercury (MeHg) and arsenic (As), are long-known developmental neurotoxicants. More recently, environmental context has been recognized to modulate metals toxicity, including nutritional state and stress exposure. Modulation of metal toxicity by stress exposure can occur through shared targeting of endocrine systems, such as the hypothalamic-pituitary-adrenal axis (HPA). Our previous rodent research has identified that prenatal stress (PS) modulates neurotoxicity of two endocrine active metals (EAMs), Pb and MeHg, by altering HPA and CNS systems disrupting behavior. Here, we review this research and further test the hypothesis that prenatal stress modulates metals neurotoxicity by expanding to test the effect of developmental As ± PS exposure. Serum corticosterone and behavior was assessed in offspring of dams exposed to As ± PS. PS increased female offspring serum corticosterone at birth, while developmental As exposure decreased adult serum corticosterone in both sexes. As + PS induced reductions in locomotor activity in females and reduced response rates on a Fixed Interval schedule of reinforcement in males, with the latter suggesting unique learning deficits only in the combined exposure. As-exposed males showed increased time in the open arms of an elevated plus maze and decreased novel object recognition whereas females did not. These data further confirm the hypothesis that combined exposure to chemical (EAMs) and non-chemical (PS) stressors results in enhanced neurobehavioral toxicity. Given that humans are exposed to multiple environmental risk factors that alter endocrine function in development, such models are critical for risk assessment and public health protection, particularly for children.

Identification of HLA-A2-restricted immunogenic peptides derived from Vitamin D-Binding Protein

T-cell-mediated destruction of pancreatic β cells leads to Type 1 diabetes (TID). Vitamin D-Binding Protein (VDBP) has been identified as an autoantigen and T cell reactivity against VDBP increases in the development of T1D. Autoreactive cytotoxic T lymphocytes (CTLs) recognize β-cell-derived peptides in the context of major histocompatibility complex class I molecules. However, little is known about the VDBP-derived immunogenic peptides that are presented in the context of human HLA molecules. Here, we predicted and identified VDBP derived immunogenic peptides that were presented in association with human HLA-A2 molecule. The VDBP derived peptides binding to HLA-A∗0201 were predicted by using a computer-assisted algorithm. The candidate peptides were synthesized, then affinity between peptides and HLA-A∗0201 were analyzed. In addition, the CTL activity of the peptides was detected by cytotoxicity assay and ELISPOT assay in vitro. Furthermore, HLA-A∗0201-transgenic mice were immunized with peptides to induce the CTL activity in vivo. The results demonstrated that peptides of VDBP containing residues 211-219 and 235-243 had high affinity with HLA-A∗0201. In addition, these peptides elicited potent CTL responses in vitro, and induced T1D in vivo. Therefore, this experiment identified immunogenic HLA-A∗0201-restricted epitopes derived from VDBP, and provided pathogenesis theory of T1D.

Chronic stress and body composition disorders: implications for health and disease

Recent studies have suggested that body composition is key to health and disease. First, fat tissue is a complex, essential, and highly active metabolic and endocrine organ that responds to afferent signals from traditional hormone systems and the central nervous system but also expresses and secretes factors with important endocrine, metabolic, and immune functions. Second, skeletal muscle mass is an important predictor of health in adult life, while severe mass loss has been associated with the frailty of old age. Studies have shown that skeletal muscle is also an important endocrine organ that secretes factors with autocrine, paracrine, or endocrine actions, which have been associated with inflammatory processes. Third, the bone is also a systemic endocrine regulator playing a pivotal role in health and disease. Finally, proper hydration in humans has been neglected as a health factor, especially in adults. Chronic stress and stress hormone hypersecretion alone or associated with distinct disorders, such as anxiety, depression, obesity, metabolic syndrome, autoimmune disorders, type 2 diabetes mellitus, and polycystic ovary syndrome (PCOS), have been associated with psychological and somatic manifestations, typically, increased fat mass, osteosarcopenia/frailty, cellular dehydration, and chronic systemic inflammation. This review aims to provide new insights into the newly developed concept of stress-related osteosarcopenic obesity and its prevention.

The importance of trait emotional intelligence and feelings in the prediction of perceived and biological stress in adolescents: hierarchical regressions and fsQCA models

The purpose of this study is to analyze the combined effects of trait emotional intelligence (EI) and feelings on healthy adolescents' stress. Identifying the extent to which adolescent stress varies with trait emotional differences and the feelings of adolescents is of considerable interest in the development of intervention programs for fostering youth well-being. To attain this goal, self-reported questionnaires (perceived stress, trait EI, and positive/negative feelings) and biological measures of stress (hair cortisol concentrations, HCC) were collected from 170 adolescents (12-14 years old). Two different methodologies were conducted, which included hierarchical regression models and a fuzzy-set qualitative comparative analysis (fsQCA). The results support trait EI as a protective factor against stress in healthy adolescents and suggest that feelings reinforce this relation. However, the debate continues regarding the possibility of optimal levels of trait EI for effective and adaptive emotional management, particularly in the emotional attention and clarity dimensions and for female adolescents.