Hair cortisol as a novel biomarker of HPA suppression by inhaled corticosteroids in children

Psychological and Physiological Stress and Stressors in Early Childhood Educators: An Observational Pilot Study

While early childhood educators' mental health is important, it may also affect the well-being and education of their students. Yet, little research has described the stress and stressors of early childhood educators (ECEs), particularly as the pandemic wanes. This pilot study aimed to (1) describe ECEs' psychological and physiological stress and (2) examine the association between ECEs' psychological and physiological stress levels with stressors. A convenience sample of 67 ECEs, serving children 0-5 years old from 13 early educational centers completed surveys on psychological stress (perceived stress, anxiety, and depression), stressors (economic hardship, food insecurity, adverse childhood experiences), and demographics in Fall 2021. A subsample of ECEs provided hair samples, analyzed for cortisol, to estimate physiologic stress. Regarding stress, 63% met the criteria for major depressive disorder and 41% for generalized anxiety disorder. Only 26% were taking medications to manage mental health. About 25% experienced the stressors of food insecurity and economic hardship; 80% experienced at least one adverse childhood experience. Only education level significantly predicted perceived stress and depression - above and beyond stressors, household income, race, and age. The results have policy and practice implications for implementing evidence-based solutions to buffer stress and stressors in early childhood educators.

Hair growth predicts a depression-like phenotype in rats as a mirror of stress traceability

As a subjective mood-related disorder with an unclear mechanism, depression has many problems in its diagnosis, which offers great space and value for research. At present, the methods commonly used to judge whether an animal model of depression has been established are mainly by biochemical index detection and behavioral tests, both of which inevitably cause stress in animals. Stress-induced hair growth inhibition has been widely reported in humans and animals. The simplicity of collecting hair samples and the observable state of hair growth has significant advantages; we tried to explore whether the parameters related to hair growth could be used as auxiliary indicators to evaluate a depression model in animals. The length and weight of the hair were calculated. Correlation analysis was conducted between the depressive behavioral results and the glucocorticoid levels in hair and serum. Learned helplessness combined with chronic restraint stress, and chronic unpredictable stress in the animal were detectable by superficial observation, weight ratio, and length of hair, and follicular development scores were significantly reduced compared to the control. The hair growth parameters of rats with depression, the rise in corticosterone, and the corresponding changes in behavioral parameters were significantly correlated. The neurotrophic factors, glucocorticoid-receptor (GR), brain-derived neurotrophic factor (BDNF), fibroblast growth factor 2 (FGF2), and fibroblast growth factor 5 (FGF5), are associated with depression and hair growth. Significant differences were detected between the stress and control groups, suggesting that the mechanism underlying the stress-phenomenon inhibition of hair growth may be related to growth factor mediation.

Associations of saliva cortisol and hair cortisol with generalized anxiety, social anxiety, and major depressive disorder: An epidemiological cohort study in adolescents and young adults

OBJECTIVES

Most of the observed associations of generalized anxiety disorder (GAD), social anxiety disorder (SAD) and major depressive disorder (MDD) with cortisol concentrations came from clinical and adult study samples, with inconsistent findings, partly due to method variance. We examined cross-sectional and longitudinal associations between GAD, SAD and MDD with saliva and hair cortisol as well as hair cortisol change in a population-based sample of adolescents and young adults, considering relevant co-factors.

DESIGN

Epidemiological cohort study in Dresden, Germany. Data of 1050 individuals (mean age: 17.2 years) assessed at baseline (11/2015-12/2016) and of 605 individuals assessed at 1-year follow-up (FU1) are used.

METHODS

Multivariable regression models were implemented to assess cross-sectional and longitudinal associations of DSM-5 defined 12-month diagnoses of GAD, SAD, and MDD, with short-term (saliva cortisol: cortisol awakening response (CAR) and area under the curve (AUC) as total cortisol) and long-term (hair cortisol) cortisol indices. Multivariable models were adjusted for age or "tanner" stage, waist circumference, tobacco and alcohol consumption, physical inactivity, and hair cortisol dependent confounder. Sex-specific analyses were additionally conducted.

RESULTS

Cross-sectional analyses revealed positive associations between SAD and baseline saliva cortisol in multivariable models (CAR: β-coefficient: 0.12; 95% CI: 0.01; 0.23) but could not be confirmed after adjusting for "tanner" stage or comorbid depression. Cross-sectional analyses concerning GAD and MDD in the full baseline sample yielded no significant associations. Sex-specific linear models revealed a significant inverse cross-sectional association between MDD (β-coefficient: - 2.21; 95% CI: - 3.64; - 0.79) as well as SAD (β-coefficient: - 2.21; 95% CI: - 4.03; - 0.38) with baseline hair cortisol in males, but not in females. In longitudinal analyses, no significant associations were found in the fully adjusted model, except for a positive association between hair cortisol change between baseline and FU1 and FU1-SAD (OR: 1.07; 95% CI: 1.02; 1.12).

CONCLUSIONS

Results confirmed sex-specificity and the role of pubertal development in the association between cortisol with SAD and MDD, while no association emerged regarding cortisol and GAD. Future research in adolescents focusing on the role of cortisol in the pathogenesis of anxiety and depressive disorders would benefit from considering factors like sex-specificity and puberty development as well as comorbidity.

The social ecology of childhood and early life adversity

An increasing prevalence of early childhood adversity has reached epidemic proportions, creating a public health crisis. Rather than focusing only on adverse childhood experiences (ACEs) as the main lens for understanding early childhood experiences, detailed assessments of a child's social ecology are required to assess "early life adversity." These should also include the role of positive experiences, social relationships, and resilience-promoting factors. Comprehensive assessments of a child's physical and social ecology not only require parent/caregiver surveys and clinical observations, but also include measurements of the child's physiology using biomarkers. We identify cortisol as a stress biomarker and posit that hair cortisol concentrations represent a summative and chronological record of children's exposure to adverse experiences and other contextual stressors. Future research should use a social-ecological approach to investigate the robust interactions among adverse conditions, protective factors, genetic and epigenetic influences, environmental exposures, and social policy, within the context of a child's developmental stages. These contribute to their physical health, psychiatric conditions, cognitive/executive, social, and psychological functions, lifestyle choices, and socioeconomic outcomes. Such studies must inform preventive measures, therapeutic interventions, advocacy efforts, social policy changes, and public awareness campaigns to address early life adversities and their enduring effects on human potential. IMPACT: Current research does not support the practice of using ACEs as the main lens for understanding early childhood experiences. The social ecology of early childhood provides a contextual framework for evaluating the long-term health consequences of early life adversity. Comprehensive assessments reinforced with physiological measures and/or selected biomarkers, such as hair cortisol concentrations to assess early life stress, may provide critical insights into the relationships between early adversity, stress axis regulation, and subsequent health outcomes.

Assessment of adherence to corticosteroids in asthma by drug monitoring or fractional exhaled nitric oxide: A literature review

Background

Although the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear.

Objective

To perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide.

Design

We searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist.

Results

From 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non‐adherent patients, but no absolute cut‐off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence.

Conclusions and Clinical Relevance

Despite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.

Hair sampling for cortisol analysis with mother-toddler dyads living in low-income homes

BACKGROUND

A first step to advance stress science research in young children is understanding the relationship between chronic stress in a mother and chronic stress in her child. One non-invasive measure of chronic stress is hair cortisol. However, little is known about strategies for hair sampling in mother-toddler dyads living in low-income homes in the U.S. To address prior limitations, the purpose of this study was to understand the feasibility of sampling hair for cortisol analysis in mother-toddler dyads living in low-income homes in the U.S. We examined feasibility related to participation, eligibility, and gathering an adequate hair sample weight.

METHODS

We approached 142 low-income, racially diverse, urban-dwelling mothers who were participating in an ongoing longitudinal birth cohort study for informed consent to cut approximately 150 hairs from the posterior vertex of their scalp and their toddlers' (20-24 months) scalp. We demonstrated the process of sampling hair with a hairstyling doll during home visits to the mother and toddler using rounded-end thinning shears.

RESULTS

Overall, 94 of 142 mother-toddler dyads (66 %) participated in hair sampling. The most common reason for participation refusal was related to hairstyle. All but three hair samples were of adequate weight for cortisol extraction.

DISCUSSION

The findings from this study can help researchers address sampling feasibility concerns in hair for cortisol analysis research in mother-toddler dyads living in low-income homes in the U.S.

Hair Cortisol Concentration and Mental Disorder in Children With Chronic Physical Illness

Background

To examine changes in hair cortisol concentrations (HCC) in children with chronic physical illness and identify patterns of association between HCC and mental comorbidity.

Methods

A sample of 50 children aged 6 to 16 years were recruited within six months of being diagnosed with a chronic physical illness. Data were collected via hair samples, structured interviews, and behavioral checklists.

Results

There was no change in HCC over six months. Baseline HCC was associated with internalizing—odds ratio (OR) = 1.29 (90% confidence interval (CI): 1.01–1.66)—and externalizing disorders—OR = 1.32 (90% CI: 1.07–1.64). Externalizing disorder at six months was associated with elevated baseline—OR = 1.25 (90% CI: 1.02–1.53)—and six-month HCC—OR = 1.25 (90% CI: 1.02–1.54). Associations between HCC and mental disorder weakened over time, and for internalizing disorders, changed direction (i.e., inverse association), albeit not significantly.

Conclusion

Results provide preliminary evidence that physiological stress, measured using HCC, may be implicated in the relationship between physical and mental illness, and these associations align with attenuated stress responses over time.

Hair cortisol and inhaled corticosteroid use in asthmatic children

BACKGROUND

Adrenal suppression is a side effect of long-term use of inhaled corticosteroids (ICS). Hair cortisol concentration (HCC) measurement is a noninvasive tool for measuring adrenal function that may be useful for asthmatic patients who are on long-term ICS treatment. The aim of this study was to compare HCC between children with and without asthma and to explore the association between HCC and ICS dose in asthmatic children.

METHODS

A cross-sectional observational study in subjects with or without asthma (n = 72 and 226, respectively, age 6-21 years). Hair samples were obtained from the posterior vertex for each subject and data on medication use were collected using questionnaires. HCC was analyzed by liquid chromatography-mass spectrometry in the most proximal 3 cm of hair.

RESULTS

Median HCC was significantly lower in subjects with asthma than in subjects without asthma: 1.83 pg/mg and 2.39 pg/mg, respectively (P value after adjustment for age, sex, and body mass index: .036). Median HCC was 1.98 pg/mg in asthmatics using no ICS, 1.84 pg/mg in those using a low dose, 1.75 pg/mg in those on a medium dose, and 1.46 in those using a high ICS dose (P = .54).

CONCLUSION

We observed a significantly lower HCC in asthmatics than in healthy controls and a nonsignificant trend of lower HCC with increasing ICS dose. Whether HCC measurement may be used to detect individuals at risk for hypocortisolism and may be useful to monitor adrenal function in asthmatic children using ICS needs to be further investigated.

Headliner in Physiology and Management of Childhood Asthma: Hypothalamic-Pituitary-Adrenal Axis

Asthma is the most common chronic inflammatory disease of children. Inhaled corticosteroids (ICS) are the cornerstone of asthma therapy which are the most effective, commonly used treatment of persistent asthma. Mostly, studies on the relationship between asthma and cortisol have focused on side effects of treatment. Recently, asthmatic patients not treated with ICS have been reported to have an attenuated activity and/or responsiveness of their Hypothalamic-Pituitary- Adrenal (HPA) axis. Moreover, it has been proposed that asthma worsening with stress may be due to a dysfunctional HPA axis, or cortisol insensitivity due to chronic psychological stress through impaired glucocorticoid receptor expression or function. Although long-term ICS treatment might produce adrenal suppression or iatrogenic Cushing syndrome, improvement of adrenal function has also been detected in some of asthmatic cases. Thus, the response scheme of HPA axis still contains undiscovered features in asthma. The management of asthma can be improved by increasing knowledge on the role of HPA axis in asthma pathophysiology. The risk for side effects of ICS can be minimized through increased awareness, early recognition of at-risk patients and regular patient follow-up. This review was written to draw attention to the role of HPA axis in both asthma and its treatment and to illustrate a follow up algorithm of HPA axis in the management of asthma.

Multimorbidity in Children and Youth Across the Life-course (MY LIFE): protocol of a Canadian prospective study

INTRODUCTION

Multimorbidity, the co-occurrence of a chronic physical condition and mental disorder, affects a substantial number of children and youth and can lead to compromised quality of life, hardship for families, and an increased burden on the healthcare system. We are conducting a study to document the course of mental disorder in children and youth diagnosed with a chronic physical condition; identify predictors of child and youth multimorbidity; examine whether the effects of these predictors are moderated by relevant psychosocial and biological factors; explore potential inflammatory and stress biomarkers that mediate the onset of child and youth multimorbidity; and, assess whether multimorbidity in children and youth alters patterns of mental health service use.

METHODS AND ANALYSIS

Multimorbidity in Children and Youth Across the Life-course (MY LIFE) is a prospective study. Two hundred and fifty children and youth aged 2-16 years diagnosed with a chronic physical condition along with one parent will be recruited from the outpatient clinics at a paediatric tertiary care centre. Data will be collected using a multi-informant, multimethod design at four time-points (at recruitment, and at 6, 12 and 24 months postrecruitment). Parents will provide reports for all children/youth. In addition, youth ≥10 years will self-report. Mental disorder will be assessed using structured interviews. On completion of data collection, participant-reported data will be linked to provincial health records to identify mental health services use. Multilevel analyses (survival, proportional hazard, structural equation modelling) will be used to address MY LIFE objectives.

ETHICS AND DISSEMINATION

This study has been approved by the University of Waterloo Human Research Ethics Board and the Hamilton Integrated Research Ethics Board. Findings will be disseminated to key stakeholders using a number of outlets (peer-reviewed publications and conferences, lay informational pamphlets, social media).

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

PROBLEM

Incorporating biomarkers of chronic stress into pediatric research studies may help to explicate the links between exposure to adversity and lifelong health, but there are currently very few parameters to guide nurse researchers in choosing appropriate biomarkers of chronic stress for use in research with children and adolescents.

METHODS

Biomarkers of chronic stress are described, including primary mediators (glucocorticoids, catecholamines, and cytokines) and secondary outcomes (neurologic, immune, metabolic, cardiovascular, respiratory, and anthropometric) of the chronic stress response.

RESULTS

Evidence of the use of each biomarker in pediatric research studies is reviewed. Recommendations for pediatric researchers, including selection of appropriate biomarkers, measurement considerations, potential moderators, and future directions for research, are presented.

DISCUSSION

A wide range of biomarkers is available for use in research studies with children. While primary mediators of chronic stress have been frequently measured in studies of children, measurement of secondary outcomes, particularly immune and metabolic biomarkers, has been limited. With thoughtful and theoretically based approaches to selection and measurement, these biomarkers present an important opportunity to further explore the physiologic pathways linking exposure to chronic stress with later health and disease.

CONCLUSION

The incorporation of chronic stress biomarkers into pediatric research studies may provide valuable insight into the mechanisms through which stressful environments "get under the skin" and ultimately inform efforts to promote health and reduce inequities among children exposed to adversity.

Hair cortisol concentration (HCC) as a measure for prenatal psychological distress - A systematic review

Prenatal environment reportedly affects the programming of developmental trajectories in offspring and the modification of risks for later morbidity. Among the increasingly studied prenatal exposures are maternal psychological distress (PD) and altered maternal hypothalamus-pituitary-adrenal (HPA) axis functioning. Both prenatal PD and maternal short-term cortisol concentrations as markers for HPA axis activity have been linked to adverse child outcomes and it has been assumed that maternal PD affects the offspring partially via altered cortisol secretion patterns. Yet, the existing literature on the interrelations between these two measures is conflicting. The assessment of cortisol levels by using hair cortisol concentration (HCC) has gained interest, as it offers a way to assess long-term cortisol levels with a single non-invasive sampling. According to our review, 6 studies assessing the associations between maternal HCC during pregnancy and various types of maternal PD have been published so far. Measures of prenatal PD range from maternal symptoms of depression or anxiety to stress related to person's life situation or pregnancy. The aim of this systematic review is to critically evaluate the potential of HCC as a biomarker for maternal PD during pregnancy. We conclude that HCC appears to be inconsistently associated with self-reported symptoms of prenatal PD, especially in the range of mild to moderate symptom levels. Self-reports on PD usually cover short time periods and they seem to depict partly different phenomena than HCC. Thus, methodological aspects are in a key role in future studies evaluating the interconnections across different types of prenatal PD and maternal HPA axis functioning. Further, studies including repetitive measurements of both HCC and PD during the prenatal period are needed, as timing of the assessments is one important source of variation among current studies. The significance of prenatal HCC in the context of offspring outcomes needs to be further investigated.

Assessment of hair cortisol as a potential biomarker for possible adrenal suppression due to inhaled corticosteroid use in children with asthma: A retrospective observational study

BACKGROUND

Inhaled corticosteroids (ICS) are the recommended long-term control therapy for asthma in children. However, concern exists regarding potential adrenal suppression with chronic ICS use. Our pilot study reported that hair cortisol in children was 50% lower during ICS therapy than prior to therapy, suggestive of adrenal suppression.

OBJECTIVE

To evaluate hair cortisol concentration (HCC) as a potential biomarker for possible adrenal suppression from ICS use in children with asthma.

METHODS

A retrospective observational study was performed at asthma clinics in Vancouver, Winnipeg, and Toronto, Canada. Children (n = 586) were recruited from July 2012 to December 2014 inclusive of those without asthma, with asthma not using ICS, and with asthma using ICS. The most recent three-month HCC was measured by enzyme immunoassay and compared among the groups. Quantile regression analysis was performed to identify factors potentially affecting HCC.

RESULTS

The median HCC was not significantly different among the children: No ICS (n = 47, 6.7 ng/g, interquartile range (IQR) 3.7-9.8 ng/g), ICS Treated (n = 360, 6.5 ng/g, IQR 3.8-14.3 ng/g), and Controls (n = 53, 5.8 ng/g, IQR 4.6-16.7 ng/g). 5.6% of the children using ICS had hair cortisol <2.0 ng/g compared to none in the control groups (P < .05, comparing ICS Treated (20/360) to all Controls combined (0/100)) and only half had been exposed to systemic corticosteroids. Age, sex, BMI, and intranasal corticosteroid use were significantly associated with HCC.

CONCLUSIONS

Results suggest HCC may be a potential biomarker for adrenal suppression as a population of children using ICS with HCC < 2.0 ng/g was identified compared to none in the control groups. Further research is needed to determine if those children have or are at risk of adrenal suppression or insufficiency.

Determinants of hair cortisol concentration in children: A systematic review

BACKGROUND

Several factors are known contribute to hair cortisol concentration (HCC) in adults. However, there is less research on determinants of HCC in children and adolescents. HCC is a valuable tool for medical research pertaining to the hypothalamic-pituitary-adrenal (HPA) axis. This review aims to assess the extent to which established determinants of HCC in adults have been consistently reported in children (birth - 18 years) and to identify determinants of HCC specific to this age group.

METHODS

Eligible studies were identified, selected and appraised as per PRISMA-P guidelines and as detailed in our systematic review protocol, registered on PROSPERO (registration number CRD42017056220). In view of contrasting methods and measures, a meta-analysis could not be done but a qualitative synthesis was performed.

RESULTS

Thirty-six studies were included in the analysis. Higher HCC is associated with male sex and anthropometry, particularly increased body mass index and waist circumference. There is preliminary evidence to suggest that socio-economic status is inversely related to child HCC, particularly with reference to caregiver education and income. Of note, most of the studies analysing socio-economic variables were performed in relatively equal societies. Hair wash frequency and use of hair products and treatments do not affect HCC when proximal segments of hair are used. There is conflicting evidence regarding the relationship between HCC and age in children and adolescents. Further investigation is required to better delineate if and how the following are associated with HCC in children: hair colour, hair type, exposure to trauma and stressors, psychiatric illness, atopic illness, steroid use (including topical and inhaled steroids) and perinatal variables.

CONCLUSIONS

Sex and anthropometry are potential confounders and should be considered for adjustment in hair cortisol research. Hair wash frequency and use of hair products and treatments are not important confounders when proximal hair segments are used. A better understanding of HCC in children in relation to exposure to trauma and stressors is required before it can be used as a biomarker, particularly in terms of vulnerable developmental stages, definition and measurement of stress, and temporal relationship to stressors. Age, SES and other correlates also warrant further investigation.

Long-Term Cortisol Concentration in Scalp Hair of Asthmatic Children Using Inhaled Corticosteroids: A Case-Control Study

INTRODUCTION

Inhaled corticosteroids (ICS) can interfere with the hypothalamic-pituitary-adrenal (HPA) axis and may lead to adrenal insufficiency, resulting in a decrease of cortisol production. Cortisol levels measured in scalp hair provide a marker for long-term cortisol exposure. Data regarding hair cortisol concentration (HCC) in asthmatic children with ICS therapy are scarce. The aim of this study is to compare HCC in asthmatic children under ICS treatment with a healthy control group.

METHODS

We set up a case-control study measuring the cortisol concentration in scalp hair in asthmatic children (N = 80) treated with ICS and healthy controls (N = 252) aged 4-18 years. Anthropometric characteristics and hair samples from the posterior vertex were obtained. At least 5 mg of the most proximal 3 cm of hair was used for each hair sample. HCC was analyzed by liquid chromatography-tandem mass spectrometry.

RESULTS

HCC did not significantly differ between asthmatic children using ICS and healthy controls (p = 0.950) after adjustment for age, gender, height, body mass index, and socioeconomic status. No correlation was found between budesonide dosage and HCC levels (r = -0.031, p = 0.78).

CONCLUSION

There was no evidence of suppression of basal cortisol production, as measured in scalp hair, in asthmatic children using ICS, compared to healthy controls. No conclusions can be drawn on the HPA-axis stress response in these children.

Measuring Stress in Young Children Using Hair Cortisol: The State of the Science

Extensive literature suggests that adverse experiences in early childhood may deleteriously impact later health. These effects are thought to be related to the impact of persistent or chronic stress on various biological processes, mediated by dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, and ultimately irregularities in cortisol levels. Ameliorating persistent stress in young children requires accurately measuring the chronicity of physiologic stress, which is difficult in young children because of unreliable self-report and the burden and inaccuracy associated with using invasive acute-stress biomeasures. A better way to approximate persistent stress in young children is measuring hair cortisol concentration (HCC), as it only requires one noninvasive collection to measure months of HPA-axis activity or experienced stress. However, few studies measure HCC in young children despite wide use in adult stress research. This article reviews and synthesizes research that uses HCC to approximate persistent stress in healthy children, 12-60 months of age. Reviewed studies indicate that HCC is elevated in young children who are experiencing forms of persistent stress such as low socioeconomic status and maternal distress. Hair cortisol is thus a promising measure of early childhood persistent stress, but due to the limited use of HCC in this population, much research is still needed. Specifically, nurse researchers may need to measure several factors associated with early childhood persistent stress and HCC to identify which children are at risk for stress-related disease.

The use of inhaled corticosteroids in pediatric asthma: update

Despite the availability of several formulations of inhaled corticosteroids (ICS) and delivery devices for treatment of childhood asthma and despite the development of evidence-based guidelines, childhood asthma control remains suboptimal. Improving uptake of asthma management plans, both by families and practitioners, is needed. Adherence to daily ICS therapy is a key determinant of asthma control and this mandates that asthma education follow a repetitive pattern and involve literal explanation and physical demonstration of the optimal use of inhaler devices. The potential adverse effects of ICS need to be weighed against the benefit of these drugs to control persistent asthma especially that its safety profile is markedly better than oral glucocorticoids. This article reviews the key mechanisms of inhaled corticosteroid action; recommendations on dosage and therapeutic regimens; potential optimization of effectiveness by addressing inhaler technique and adherence to therapy; and updated knowledge on the real magnitude of adverse events.

Hair cortisol as a hypothalamic-pituitary-adrenal axis biomarker in pregnant women with asthma: a retrospective observational study

Background

Cortisol is a hormone involved in many physiological functions including fetal maturation and epigenetic programming during pregnancy. This study aimed to use hair cortisol as a biomarker of chronic inhaled corticosteroid (ICS) exposure and assess the potential effects of asthma on the hypothalamic-pituitary-adrenal (HPA) axis in pregnant women. We hypothesized that pregnant women with asthma treated with ICS would exhibit lower hair cortisol concentrations, indicative of adrenal suppression, compared to women with asthma not using ICS and women who do not have asthma.

Methods

We performed an observational retrospective cohort study. Hair samples were analyzed from pregnant women with asthma, with (n = 56) and without (n = 31) ICS treatment, and pregnant women without asthma (n = 31). Hair samples were segmented based on the growth rate of 1 cm/month and analyzed by enzyme immunoassay to provide cortisol concentrations corresponding to preconception, trimesters 1–3, and postpartum. Hair cortisol concentrations were compared within and among the groups using non-parametric statistical tests.

Results

Hair cortisol concentrations increased across trimesters for all three groups, but this increase was dampened in women with asthma (P = 0.03 for Controls vs. ICS Treated and Controls vs. No ICS). ICS Treated women taking more than five doses per week had hair cortisol concentrations 47 % lower in third trimester than Controls. Linear regression of the third trimester hair cortisol results identified asthma as a significant factor when comparing consistent ICS use or asthma as the predictor (F_{(1, 25)} = 9.7, P = 0.005, R²_adj = 0.257).

Conclusions

Hair cortisol successfully showed the expected change in cortisol over the course of pregnancy and may be a useful biomarker of HPA axis function in pregnant women with asthma. The potential impact of decreased maternal cortisol in women with asthma on perinatal outcomes remains to be determined.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0962-4) contains supplementary material, which is available to authorized users.