Screening for hypothalamic-pituitary-adrenal axis suppression in asthmatic children remains problematic: a cross-sectional study

Hypothalamic-pituitary-adrenal axis suppression in asthma: A glucocorticoid receptor polymorphism may protect

BACKGROUND

Asthmatic children on corticosteroids can develop hypothalamic-pituitary-adrenal axis suppression (HPAS). Single nucleotide polymorphisms (SNPs) rs242941 and rs1876828 of the corticotrophin-releasing hormone receptor 1 (CRHR1) gene were associated with lower stimulated cortisol (F) levels, whereas rs41423247 of the glucocorticoid receptor (NR3C1) gene was associated with higher basal F levels. The objective of the current study was to confirm whether these three SNPs are associated with HPAS in asthmatic children.

METHODS

DNA was extracted from saliva obtained from 95 asthmatic children, who had previously undergone basal F and metyrapone testing. Thirty-six children were classified as suppressed. Non-suppressed children were subclassified according to their post-metyrapone adrenocorticotropin (PMTP ACTH) level into a middle (106-319 pg/mL) and a high (>319 pg/mL) ACTH response group. TaqMan^® polymerase chain reaction assays were utilized.

RESULTS

Only rs41423247 was inversely associated with HPAS (OR = 0.27 [95% CI 0.06-0.90]). Its GC genotype was inversely associated with HPAS (log odds = -1.28, P = .021). √PMTP ACTH was associated with CC (effect size = 10.85, P = .005) and GC genotypes (effect size = 4.06, P = .023). The C allele is inherited as a dominant trait (effect size = -1.31 (95% CI -2.39--0.33; P = .012). In the high ACTH response group, both genotypes affected the PMTP ACTH (effect sizes 1.41 and 15.46; P-values .023 and <2 × 10^-26 for GC and CC, respectively).

CONCLUSIONS

The C allele of rs41423247 was found to be protective against HPAS. CC genotype is associated with the highest PMTP ACTH response.

Inhaled Corticosteroids and Endocrine Effects in Childhood

Asthma is the most common chronic inflammatory disease of children, and inhaled corticosteroids (ICSs) are the most effective and commonly used treatment of persistent asthma. ICSs currently approved for and commonly used by children with asthma include beclomethasone dipropionate, budesonide, fluticasone propionate, mometasone furoate, ciclesonide, and triamcinolone acetonide. This article reviews 4 areas critical to understanding potential adverse endocrine outcomes of ICSs and placing them in proper perspective: (1) influence of drug/delivery device properties on systemic steroid burden; (2) adrenal insufficiency during ICS treatment; (3) growth effects of ICS and asthma itself; and (4) bone mineral accretion during ICS therapy.

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.

Screening practices for paediatric asymptomatic adrenal suppression in Canada: Are we addressing this important risk?

Background

Children with adrenal suppression (AS), a potential side effect of glucocorticoids (GCs) may be asymptomatic, present with nonspecific signs and symptoms or with adrenal crisis. Asymptomatic AS (AAS) can only be diagnosed through screening. Identifying and treating asymptomatic patients before symptoms develop may reduce morbidity. Screening guidelines for AS are lacking. Consequently, screening practices are highly variable.

Objective

To assess (1) the screening practices for and recognition of paediatric AAS among clinicians in Canada and (2) the educational impact of a 2-year surveillance program of symptomatic AS cases.

Methods

Before and after a 2-year Canadian Paediatric Surveillance Program (CPSP) study of symptomatic AS, participants were surveyed through the CPSP. The prestudy survey was sent to 2,548 participants in March 2010 and the poststudy survey was sent to 2,465 participants in April 2013.

Results

Response rates were 32% for the prestudy survey and 21% for the poststudy survey. Between the pre- and poststudy surveys, the percentage of physicians who reported routinely screening patients on GCs for AS increased from 10% to 21% and the percentage who reported having a screening policy in their office/centre increased from 6% to 11%. There was no significant change in the percentage of physicians who had diagnosed a child/youth with AAS in the preceding year.

Conclusion

Frequency of screening for AAS increased following the 2-year study but remains low. Development of a clinical practice guideline should increase both awareness of asymptomatic AS among Canadian paediatricians and the identification of AAS, before symptoms develop.

Benefits and Risks of Long-Term Asthma Management in Children: Where Are We Heading?

International guidelines provide recommendations for a stepwise approach to the management of asthma in children 0-4 years old, 5-11 years old, and adolescents who are treated as adults. Therapy is aimed at two domains of control: current impairment and future risk. The long-term controller medications, inhaled corticosteroids (ICSs), ICSs in combination with long-acting β₂ agonists, leukotriene receptor antagonists, and immunomodulators, exhibit different efficacies for these domains. The risk:benefit ratios of the available medications need to be carefully assessed. This review briefly presents the benefits and the potential risks of available asthma medications in children to assist the practitioner in the optimal use of asthma medications. Specifically, the systemic activity of the ICSs and how to minimize their effects on growth and adrenal activity are reviewed as well as other potential adverse effects. Dosing strategies such as intermittent therapy are also assessed.

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.

Symptomatic adrenal suppression among children in Canada

BACKGROUND

Adrenal suppression (AS) is an under-recognised side effect of glucocorticoid (GC) use. AS may go undetected until a physiological stress precipitates an adrenal crisis. The incidence of AS has not been established. We sought to estimate the minimum national incidence and presenting features of paediatric symptomatic AS.

METHODS

Through the established methodology of the Canadian Paediatric Surveillance Program, over 2500 paediatricians were surveyed monthly for 2 years (April 2010-March 2012) to report new cases of symptomatic AS.

RESULTS

Forty-six cases of symptomatic AS were confirmed. The estimated annual incidence is 0.35/100 000 children aged 0-18 years (95% CI 0.26 to 0.47). The most common presentations were growth failure (35%), non-specific symptoms (28%) or both (13%). Adrenal crisis occurred in six cases (13%). Thirty-seven children (80%) had received inhaled corticosteroid (ICS) alone or in combination with other GC forms. Many children received high but commonly prescribed doses of ICS.

CONCLUSIONS

AS is responsible for significant morbidity in children, including susceptibility to adrenal crisis. The minimal estimated incidence reported is for the entire paediatric population and would be much higher in the at-risk group (ie, children treated with GCs). Close monitoring of growth and possible symptoms of AS, which may be non-specific, are important in children on all forms of GC therapy including ICS. To reduce the risk of AS, physicians must be aware of the risk of AS, revisit GC doses frequently and use the lowest effective dose.

Inhaled corticosteroid related adrenal suppression detected by poor growth and reversed with ciclesonide

INTRODUCTION

This case series intends to highlight the association between decreased linear growth velocity and adrenal suppression in patients receiving inhaled corticosteroids for asthma. A potential treatment option is also discussed. Adrenal suppression secondary to inhaled corticosteroids has previously been reported and is often underrecognized. A decrease in linear height velocity has also been associated with inhaled corticosteroids. However, a decrease in height velocity has not been shown to predict adrenal suppression.

CASE STUDY

This case series of 15 patients receiving inhaled corticosteroids for control of asthma were noted to have a decrease in linear growth velocity ultimately associated with adrenal suppression. A change in inhaled corticosteroid to ciclesonide led to recovery of adrenal function without impacting asthma control.

RESULTS

Chart review from a pediatric pulmonology clinic was performed. Growth parameters and laboratory studies were recorded and analyzed. A mean decrease in height standard deviation score in the year prior to diagnosis of adrenal suppression was -0.59, -0.11, and -0.18, in pre-puberty, peri-puberty, and post-puberty patients, respectively. After ciclesonide therapy was initiated, a mean change in height standard deviation score of +0.40, +0.13, and -0.13, was noted for pre-puberty, peri-puberty, and post-puberty patients, respectively. A change in growth velocity of +5.3 cm/yr, +2.1 cm/yr, and -1.9 cm/yr, was noted for pre-puberty, peri-puberty, and post-puberty patients, respectively, after starting ciclesonide.

CONCLUSIONS

Height velocity should be monitored closely during routine asthma visits to identify potential adrenal suppression associated with inhaled corticosteroids use. Ciclesonide is a good option for asthma treatment that allows for adrenal recovery.

Children with asthma have significantly lower long-term cortisol levels in their scalp hair than healthy children

AIM

Noninvasive measurement of long-term cortisol levels is a useful way of evaluating the effect of chronic disease on the hypothalamic-pituitary-adrenal axis in children. The aim of this pilot study was to compare hair cortisol levels in children using inhaled corticosteroids for asthma and healthy children and to determine the association with short-term salivary cortisol levels.

METHODS

Cortisol levels were measured in the scalp hair and saliva of prepubertal children with asthma (n = 10) and without asthma (n = 10). Asthma control was assessed using an asthma questionnaire and pulmonary function tests.

RESULTS

The median (95% CI) cortisol level in the scalp hair of the children with asthma (2.0 pg/mg; 1.4-4.1) was significantly lower than the healthy children (4.3 pg/mg; 1.8-5.9). Morning salivary cortisol levels were significantly lower for the children with asthma (5.9 nmol/L; 3.2-11.1) than the healthy children (9.0 nmol/L; 4.4-31.6). There was no significant association between cortisol levels in hair and saliva.

CONCLUSION

Long-term cortisol levels were significantly lower in children with asthma than healthy children. Measuring long-term cortisol levels in scalp hair is an attractive, noninvasive tool that can evaluate the effect of asthma and its treatment on the hypothalamic-pituitary-adrenal axis.