Measures of hypothalamic-pituitary-adrenal function in patients with asthma treated with inhaled glucocorticoids: clinical and research implications

Paediatric reference range for overnight urinary cortisol corrected for creatinine

OBJECTIVES

Systemic activity of inhaled corticosteroids (ICS) may be assessed via urinary cortisol measurement. Overnight urinary free cortisol corrected for creatinine (OUFCC) has been extensively reported in adult studies. However, a paediatric mass spectrometric (MS) reference range for OUFCC is not established. MS methods for OUFCC avoid cross-reactivity with other steroid hormones and are thus preferable to immunoassays. The aim of the present study was to define an MS OUFCC normative range in children.

METHODS

This was a cross-sectional study of healthy pre-pubertal children from 5 to 11 years. Children collected urine from 10 pm or bedtime, whichever was earlier, until 8 am. Urinary free cortisol was measured via a liquid chromatography tandem mass spectrometry (LC-MS/MS) assay (Acquity UPLC with Xevo TQ-S Mass Spectrometer [Waters]) with in-house reagents. Urinary creatinine was measured using a commercial assay (Roche).

RESULTS

Complete urine collections were obtained from 72 males and 70 females, mean age (SD) 8.6 (1.9) (range 5.0-11.8) years. The OUFCC 95% prediction interval was 1.7-19.8 nmol/mmol. Geometric mean OUFCC was 5.7; range 1.1-24.8 nmol/mmol.

CONCLUSIONS

The obtained normative LC-MS/MS OUFCC reference data facilitate the use of mass spectrometry OUFCC assays in assessment of systemic activity of endogenous and exogenous corticosteroids in children.

Insight into the interaction of inhaled corticosteroids with human serum albumin: A spectroscopic-based study

It is well known that the safety and efficacy profile of an inhaled cortocosteroid (ICS) is influenced by the pharmacokinetic properties and associated pharmacodynamic effects of the drug. Freely circulating, protein unbound, and active ICS can cause systemic adverse effects. Therefore, a detailed investigation of drug-protein interaction could be of great interest to understand the pharmacokinetic behaviour of corticosteroids and for the design of new analogues with effective pharmacological properties. In the present work, the interaction between some corticosteroids and human serum albumin (HSA) has been studied by spectroscopic approaches. UV–Vis spectroscopy confirmed that all the investigated corticosteroids can bind to HSA forming a protein-drug complex. The intrinsic fluorescence of HSA was quenched by all the investigated drugs, which was rationalized in terms of a static quenching mechanism. The thermodynamic parameters determined by the Van’t Hoff analysis of the binding constants (negative ΔH and ΔS values) clearly indicate thathydrogen bonds and van der Waals forces play a major role in the binding process between albumin and betamethasone, flunisolide and prednisolone, while hydrophobic forces may play a major role in stabilizing albumin-triamcinolone complexes.

Ciclesonide: A Pro-Soft Drug Approach for Mitigation of Side Effects of Inhaled Corticosteroids

Inhaled corticosteroids are used as one of the first-line drug therapy in patients with asthma. However, their long-term use is associated with various oropharyngeal and systemic side and adverse effects. Design of pro-soft drug is one of the strategies, which was adopted in the design of ciclesonide for mitigation of side effects usually observed with the use of inhaled corticosteroids. Ciclesonide, a pro-soft drug, is converted to an active metabolite desisobutyryl-ciclesonide in the lungs. The anti-inflammatory effect of desisobutyryl-ciclesonide is much higher than ciclesonide, and therefore, the local effect of the metabolite is higher with lower systemic side effects. Ciclesonide has favorable pharmacokinetic and pharmacodynamic properties as inhaled corticosteroid including low oral bioavailability, high plasma protein binding and rapid systemic clearance, high pulmonary deposition and distribution and long pulmonary residence duration. These advantageous properties make ciclesonide a very effective treatment option with low side effects. Various clinical studies support safety and efficacy of ciclesonide use in mild, moderate, and severe asthma patients.

The actual role of sodium cromoglycate in the treatment of asthma--a critical review

INTRODUCTION

Despite international consensus and clearly written guidelines urging wider use of corticosteroids or combinations of inhaled short- and long-acting β-agonists (SABA and LABA) and corticosteroids in persistent asthma, prescribing patterns and compliance rates fall far short of recommendations.

OBJECTIVES

The failure to use steroids more aggressively is due, in part, to their side effects, even with inhaled forms of the drug. There is a role for expanded use of sodium cromolyn in asthma. Its potent anti-inflammatory effects, lack of side effects, and acceptable dosing and method of delivery, as well as its special role in exercise-induced asthma, make it a very suitable choice in the initial therapy for control of asthma.

CONCLUSION

Compared to SABA and LABA, cromoglycates alone are unsuspicious of being used to enhance physical performance.

Short-term lower leg growth in 5- to 11-year-old asthmatic children using beclomethasone dipropionate inhalers with chlorofluorocarbon or hydrofluoroalkane propellants: a 9-week, open-label, randomized, crossover, noninferiority study

BACKGROUND

Beclomethasone dipropionate-hydrofluoroalkane (BDP-HFA) is a non-chlorofluorocarbon (CFC)-propelled metered dose inhaler. Data is needed to support the registration of BDP-HFA in pediatric populations for countries in the European Union.

OBJECTIVE

The aim of the study was to assess short-term lower leg growth in children with asthma during treatment with BDP-HFA 100 μg BID compared with BDP-CFC 200 μg BID.

METHODS

Children with asthma were included in this open-label, randomized, crossover study with 2-week run-in, active treatment, and washout periods. Lower leg length was measured every second week. As a secondary outcome parameter, 24-hour urine was collected for assessment of free cortisol. Interventions were inhaled BDP-HFA 100 μg BID with AeroChamber Plus spacer and BDP-CFC 200 μg BID with Volumatic spacer.

RESULTS

In 63 patients with asthma aged 5 to 11 years, BDP-HFA 100 μg BID was noninferior to BDP-CFC 200 μg BID, as the lower margin of CI (-0.03 to 0.10 mm/wk) of the estimated difference (0.03 mm/wk) was greater than the prespecified lower limit for noninferiority of -0.12 mm/wk. Mean (SD) lower leg growth rate during run-in, BDP-HFA 100 μg BID, and BDP-CFC 200 μg BID was 0.36 (0.17), 0.27 (0.21), and 0.23 (0.18) mm/wk, respectively (BDP-HFA estimate of difference, -0.09 [95% CI, -0.16 to -0.03 mm/wk; P < 0.01]; BDP-CFC estimate of difference, -0.13 [95% CI, -0.19 to -0.06 mm/wk; P < 0.001]). No statistically significant differences were seen in urinary free cortisol assessments. Eight and 6 mild to moderate adverse events in 10 children were reported during treatment with BDP-HFA and BDP-CFC, respectively. One event in each group was judged to be probably related to the study medication; no others were judged to be related.

CONCLUSIONS

No statistically significant differences were found in lower leg growth between BDP-HFA 100 μg BID with AeroChamber Plus spacer and BDP-CFC 200 μg BID with Volumatic spacer during 2-week treatment. Evidence of differences in systemic activity between the treatments was not found. EudraCT registration: 2007-007455-14.

Impact of inhaled and intranasal corticosteroids on the growth of children

Since inhaled and intranasal corticosteroids may be systemically bioavailable, risk of growth suppression cannot be ruled out in children treated with these compounds. The mechanisms by which exogenous corticosteroids can cause growth suppression may be multifactorial, involving influences on growth hormone secretory profiles and insulin-like growth factor-I activity, direct effects on the epiphyseal growth plate, and effects on bone and collagen turnover. When studies on growth in children treated with inhaled and intranasal corticosteroids are interpreted, it is important to discriminate between data on the final outcome of growth (adult height) and data on growth rate. No firm conclusions can be drawn on adult height from the available data. While the data on children treated with inhaled corticosteroids appear reassuring, there are no peer-reviewed studies on the final height of children treated with intranasal corticosteroids. The possibility of additive effects on the final height or growth rate of children receiving intranasal plus inhaled corticosteroids has also not been studied. When assessing the risk of growth rate suppression, specific corticosteroids, doses and inhaler systems must be evaluated separately. Standard paediatric doses of inhaled corticosteroids (budesonide 200 to 400 microg/day delivered from a metered dose inhaler with a spacer, dry powder budesonide 200 microg/day, or dry powder fluticasone propionate 200 microg/day) do not affect growth rate when a twice daily administration regimen is used. The risk of growth rate suppression in children treated with inhaled budesonide depends on the dosage and may become significant with 800 microg/day administered with a spacer, or with 400 microg/day administered with a dry powder device. When high doses of inhaled corticosteroids are used, the risk of adverse effects on growth rate can be reduced by once daily dosage in the morning. In fact, intranasal mometasone furoate 100 and 200microg from an aqueous pump spray and dry powder budesonide 200 and 400microg once daily in the morning have been found not to affect growth rate. Sensitivity to adverse effects on growth rate may vary between individuals. If growth suppression is detected, 'catch-up growth' may be expected when the dose of the inhaled or intranasal corticosteroid is reduced or other treatment modalities are introduced. Inhaled or intranasal corticosteroids should not be withheld from children with asthma or rhinitis. Topical corticosteroids should be given in doses that control disease symptoms; however, height measurements should be performed regularly in children receiving corticosteroids.

Clinical pharmacokinetic and pharmacodynamic profile of inhaled ciclesonide

Asthma is a chronic inflammatory disease of the airways, and inhaled corticosteroids (ICSs) are recommended as first-line therapy for persistent asthma of all severities. Ciclesonide is a novel ICS, which is administered as an aerosol solution in a metered-dose inhaler, using hydrofluoroalkane-134a as a propellant. Because of the high respirable particle fraction, high pulmonary deposition is obtained in patients, which constitutes the basis of effective therapeutic action. The parent compound, ciclesonide, is pharmacologically inactive and is activated in the target organ, the lung, to form its only pharmacologically active metabolite, desisobutyryl-ciclesonide (des-CIC). Low oral deposition combined with minimal formation of des-CIC in the oropharynx may minimize the typical oropharyngeal adverse events associated with ICSs. Low oral bioavailability, rapid clearance and high protein binding reduce pharmacologically relevant systemic exposure. The unique pharmacokinetic and pharmacodynamic profile of ciclesonide offers a rationale that supports the favourable risk-benefit profile observed in clinical trials in patients with persistent asthma.

Changes in human placental 5alpha-reductase isoenzyme expression with advancing gestation: effects of fetal sex and glucocorticoid exposure

5alpha-reduced steroids, including allopregnanolone, suppress neuronal activity and can have neuroprotective effects in the fetus. 5alpha-reductases in the placenta may contribute precursors to brain allopregnanolone synthesis. Preterm birth and glucocorticoids, administered for fetal lung maturation or for maternal asthma, may influence reductase expression. The aims of the present study were to evaluate placental 5alpha-reductase isoform expression during late gestation and to examine fetal sex differences and the effects of glucocorticoid therapies on the expression of these enzymes. Expression of the two 5alpha-reductase isoenzymes was measured in placental samples, whereas cortisol concentrations were measured in cord blood, from two cohorts. The first cohort consisted of women who delivered preterm and received betamethasone treatment (n=41); the second cohort consisted of women who delivered at term and were either healthy controls (n=30) or asthmatics who had used glucocorticoids (n=24). Placental expression of both isoenzymes increased with advancing gestation and there were marked sex differences in levels of 5alpha-reductase I (P<0.05), but not of 5alpha-reductase II. The expression of both enzymes was positively correlated with cortisol levels (P<0.05), but there was no effect of recent glucocorticoid exposure. These findings suggest that the preterm neonate may have lower developmental exposure to 5alpha-reduced steroids and may lack steroid-mediated neuroprotection depending on fetal sex.

Pharmacokinetic and pharmacodynamic properties of inhaled ciclesonide

Inhaled corticosteroids are recommended first-line therapy for persistent asthma of all severities; however, oropharyngeal and systemic adverse events can be a concern. Inhaled corticosteroids exert their therapeutic and adverse effects by interacting with glucocorticoid receptors within and outside the lungs, respectively. Ciclesonide is a novel inhaled corticosteroid that possesses a unique pharmacokinetic and pharmacodynamic profile. Ciclesonide is inactive itself and converted to its pharmacologically active metabolite, desisobutyryl-ciclesonide, in the target organ, the lungs. Pulmonary activation combined with low oral deposition may minimize oropharyngeal adverse events, and low oral bioavailability, rapid clearance, and high protein binding may reduce systemic exposure. In addition, high pulmonary deposition due to the highly respirable particles, combined with the potential for prolonged lung retention via lipid conjugation, provides for effective therapeutic action.

Evaluation of tests of hypothalamic-pituitary-adrenal axis function used to measure effects of inhaled corticosteroids

OBJECTIVES

To review the evidence supporting the evaluation of hypothalamic-pituitary-adrenal (HPA) axis function as a measure of systemic exposure and clinical adverse events, discuss factors that affect systemic exposure to inhaled corticosteroids (ICSs), and review the effects of various ICSs that are currently available or under development on HPA axis function from a therapeutic perspective.

DATA SOURCES

Randomized published clinical trials and review articles on the topic of HPA axis suppression were retrieved in MEDLINE. Searches dating back to 1988 were restricted to human studies published in English.

STUDY SELECTION

Studies that evaluated HPA axis function and the methods used to measure its activities and the effects of ICSs (fluticasone propionate, budesonide, beclomethasone dipropionate, mometasone furoate, and ciclesonide) were selected.

RESULTS

Factors that influence adverse events caused by ICSs include pharmacokinetic and pharmacodynamic properties, delivery devices, and therapeutic dose and duration. Basal measurements of blood and urinary cortisol levels, reflecting basal HPA axis function, are the most sensitive markers for assessing systemic ICS bioavailability but, compared with dynamic stimulation tests, are poor clinical predictors of adrenal dysfunction.

CONCLUSIONS

Basal serologic and urinary cortisol tests provide the best measures of assessing and comparing systemic ICS exposure. Long-term clinical studies are needed to determine whether such tests are predictive of ICS toxicity.

Short-term growth and adrenal function in children with asthma treated with inhaled beclomethasone dipropionate hydrofluoroalkane-134a

Inhaled beclomethasone dipropionate (BDP) with the propellant hydrofluoroalkane-134a (HFA) has been designed to be equivalent in terms of safety to chlorofluorocarbon (CFC)-formulated metered dose inhalers (MDI). The aim was to assess whether BDP HFA MDI 100 microg twice daily was equivalent to BDP CFC MDI 100 microg twice daily in terms of effects on short-term lower leg growth rate (LLGR) and measures of hypothalamic-pituitary-adrenal (HPA) function. The study consisted of a randomized double-blind cross-over trial with three active, a run-in and two wash-out periods each consisting of 2 wk. The place of study was a secondary referral outpatient clinic. The subjects involved were 14 boys and 10 girls with asthma, aged 7-12 yr. They were all administered BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily. The outcome measures included LLGR and 24-h urine-free cortisol (UFC) and total cortisol metabolites (TCM). Mean (SD) LLGR during run-in and BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily periods were 0.43 (0.23), 0.09 (0.29), 0.10 (0.45) and 0.08 (0.27) mm/wk. The one-sided 97.5% confidence interval for the difference in LLGR between BDP HFA 100 microg and BDP CFC 100 microg was 0.24, thus, below the predefined criterion of 0.20 mm/week. Inter-period comparisons of active treatments showed no differences between means of LLGR, UFC or TCM. Though non-inferiority between BDP HFA and CFC 100 microg twice daily in terms of effects on LLGR was not found, equivalence was suggested by comparisons of LLGR during run-in and active treatments and by HPA function measures.

Pharmacologic characteristics and adrenal suppression with newer inhaled corticosteroids: A comparison of ciclesonide and fluticasone propionate

BACKGROUND

Inhaled corticosteroids (ICSs) are the most potent anti-inflammatory choice for patients with asthma. Selecting the most appropriate ICS for a patient requires a thorough understanding of the pharmacologic properties of each drug.

OBJECTIVE

This review details the pharmacologic properties of ciclesonide (CIC) and fluticasone propionate (FP) and reviews the available data on suppression of the hypothalamic-pituitary-adrenal axis as a measure of systemic exposure and safety profile.

METHODS

Clinical studies and case reports were identified through a MEDLINE and EMBASE search of English-language articles. The databases were searched for the years 1990 to April 2005 using the terms ciclesonide, fluticasone, ICS, and adrenal suppression. All studies were clinical trials of pharmacologic properties of the ICSs in humans.

RESULTS

A total of 1082 articles were identified. CIC and FP are 2 of the most potent ICSs. Both have high receptor-binding affinities (12 times and 18 times that of dexamethasone, respectively), and both may provide enhanced respiratory effects through a prolonged pulmonary residence time. The CIC metered dose inhaler dispenses smaller and more highly respirable particles than FP (1.1-2.1 pm vs 2.8-3.2 microm, respectively). Therefore, a greater percentage of administered CIC is topically deposited in the lungs (52% vs 12% to 13% for FP). CIC is delivered as an inactive parent compound, which is converted to its active metabolite, desisobutyryl-CIC (des-CIC), by esterases in the airways. More than 50% of a dose of CIC is deposited and distributed evenly throughout the lungs of healthy adults; lipid conjugation in the lung also may increase lung residence time. On entering the systemic circulation, both corticosteroids are rapidly cleared by the liver (elimination half-life of 3.5 hours for CIC vs 7.8 hours for FP). However, plasma protein binding is greater with CIC/des-CIC (99%/ approximately 99%) than FP (90%), resulting in reduced amounts of des-CIC (<I%) versus FP (10%) circulating free in the plasma. Although studies of low or medium doses of FP have produced conflicting results, high doses of FP (>660 pg/d) may result in adrenal suppression. CIC has not been reported to produce any significant adrenal suppression throughout its studied dose range (up to 1280 micro/d).

CONCLUSIONS

A review of the literature suggests that CIC, as compared with FP, achieves greater pulmonary deposition, causes fewer adverse oropharyngeal effects, deposits less biologically active drug in the systemic circulation, and has less potential for adrenal suppression.

Inhaled ciclesonide versus inhaled budesonide or inhaled beclomethasone or inhaled fluticasone for chronic asthma in adults: a systematic review

Background

Ciclesonide is a new inhaled corticosteroids licensed for the prophylactic treatment of persistent asthma in adults. Currently beclomethasone dipropionate, budesonide and fluticasone propionate are the most commonly prescribed inhaled corticosteroids for the treatment of asthma but there has been no systematic review comparing the effectiveness and safety ciclesonide to these agents. We therefore aimed to systematically review published randomised controlled trials of the effectiveness and safety of ciclesonide compared to alternative inhaled corticosteroids in people with asthma.

Methods

We performed literature searches on MEDLINE, EMBASE, PUBMED, the COCHRANE LIBRARY and various Internet evidence sources for randomised controlled trials or systematic reviews comparing ciclesonide to beclomethasone or budesonide or fluticasone in adult humans with persistent asthma. Data was extracted by one reviewer.

Results

Five studies met the inclusion criteria. Methodological quality was variable. There were no trials comparing ciclesonide to beclomethasone. There was no significant difference between ciclesonide and budesonide or fluticasone on the following outcomes: lung function, symptoms, quality of life, airway responsiveness to a provoking agent or inflammatory markers. However, the trials were very small in size, increasing the possibility of a type II error. One trial demonstrated that the combined deposition of ciclesonide (and its active metabolite) in the oropharynx was 47% of that of budesonide while another trial demonstrated that the combined deposition of ciclesonide (and its active metabolite) in the oropharynx was 53% of that of fluticasone. One trial demonstrated less suppression of cortisol in overnight urine collection after ciclesonide compared to fluticasone (geometric mean fold difference = 1.5, P < 0.05) but no significant difference in plasma cortisol response.

Conclusion

There is very little evidence comparing CIC to other ICS, restricted to very small, phase II studies of low power. These demonstrate CIC has similar effectiveness and efficacy to FP and BUD (though equivalence is not certain) and findings regarding oral deposition and HPA suppression are inconclusive. There is no direct comparative evidence that CIC causes fewer side effects since none of the studies reported patient-based outcomes.

Effects of glucocorticoids on the hypothalamic-pituitary-adrenal axis in children and adults

Inhaled and intranasal corticosteroids are widely used as effective, first-line treatments for asthma and allergic rhinitis. Despite a good safety profile of these formulations, there is increasing concern about their propensity to produce systemic adverse effects. Suppression of the hypothalamic-pituitary-adrenal axis is one of the most important potential complications. This article reviews the effects of inhaled and intranasal corticosteroids on the hypothalamic-pituitary-adrenal axis function in adults and children.

Assessment of the relation between short and intermediate term growth in children with asthma treated with inhaled glucocorticoids

OBJECTIVE

To assess the relation between short-term growth and intermediate term growth in children with asthma treated with inhaled glucocorticoids.

DESIGN

An open 12 months parallel group trial with visits to the clinic on day 1, after 2, 4, 8, 12, 20, 28, 36, 44 and 52 weeks.

SETTING

Outpatient clinic in a secondary referral centre.

SUBJECTS

Sixteen children with asthma aged 9 (6-13) years; 16 matched healthy subjects.

METHODS

Knemometry and stadiometry.

INTERVENTIONS

Dry-powder inhaled budesonide 200 microg twice daily.

PRIMARY OUTCOME MEASURES

Intra-group comparisons of mean lower leg growth rates.

SECONDARY OUTCOME MEASURES

Inter-group comparisons of mean lower leg growth rates and intra-group comparisons of mean height-standard deviation scores.

RESULTS

One year mean lower leg growth rate (0.36 mm/week) did not differ from the rates during the 2 (0.27 mm/week; P = 0.23), 4 (0.33 mm/week; P = 0.54), 8 (0.36 mm/week; P = 0.79) or 12 (0.33 mm/week; P = 0.49) weeks intervals in the asthma group. Similarly, in the healthy children 2 (0.56 mm/week; P = 0.63), 4 (0.46 mm/week; P = 0.36), 8 (0.43 mm/week; P = 0.49) and 12 (0.43 mm/week; P = 0.66) weeks mean growth rates did not vary statistically significantly from the 1 year growth rate (0.42 mm/week). Mean lower leg growth rates, however, were consistently lower during all periods in the children with asthma (P = 0.02-0.03). At completion of the study mean height-standard deviation score in the asthma group (-0.19) was significantly suppressed as compared with the score at study entry (-0.03) (P = 0.02), whereas no statistically significant variation was detected in the control group.

CONCLUSIONS

Short-term lower leg growth rates are consistent with intermediate term growth rates in group studies in children with asthma treated with inhaled dry powder budesonide 400 microg/day. Short-term group knemometry should be an integral part of growth evaluations of new inhaled glucocorticoids, doses and inhalation devices in children with asthma.

Effect of intranasal fluticasone propionate and triamcinolone acetonide on basal and dynamic measures of hypothalamic-pituitary-adrenal-axis activity in healthy volunteers

BACKGROUND

Most published studies show that intranasal corticosteroids have no effect on the hypothalamic-pituitary-adrenal (HPA) axis, but there have been isolated reports to the contrary, contradicting accumulated knowledge on pharmacokinetics.

OBJECTIVE

To re-evaluate the effect of fluticasone propionate aqueous nasal spray (FPANS) and triamcinolone acetonide (TAA) aqueous nasal spray on the HPA axis using an improved study design.

METHODS

Twenty-three healthy volunteers were randomized in a double-blind, three-way crossover study. The study comprised a 4-day placebo run-in phase followed by three 4-day treatment periods (placebo, FPANS (200 microg once daily) or TAA aqueous nasal spray (220 microg once daily)), separated by 7-14 days washout intervals. Before the first, and on the last day of each treatment period, 12-h overnight urine was collected to assess cortisol excretion and cortisol creatinine ratio. Approximately 26 h after the last administration of study medication, volunteers underwent stimulation with 0.5 microg adrenocorticotropic hormone (ACTH). Serum cortisol concentrations were measured before and 20 and 30 min after injection. Blood and urine samples were analysed for cortisol by liquid chromatography tandem mass spectrometry.

RESULTS

Compared with placebo, EP or TAA had no significant effect on mean overnight (12 h) urinary cortisol excretion, and did not significantly suppress the overnight geometric mean urinary cortisol/creatinine excretion ratio. Values for serum cortisol before and after ACTH simulation showed no significant suppression, although there was a slight blunting of the HPA-axis response following TAA treatment.

CONCLUSION

This study confirms that there are no detectable effects on the HPA axis following short-term intranasal FP or TAA at their recommended dosages.

Blunted cortisol responses to psychosocial stress in asthmatic children: a general feature of atopic disease?

OBJECTIVE

Atopy is defined by the individual predisposition to develop a group of inflammatory disorders in response to certain food or environmental substances that are otherwise innocuous for the host. In previous studies we could demonstrate a reduced responsiveness of the hypothalamus-pituitary-adrenal (HPA) axis to psychosocial stress in young and adult patients with atopic dermatitis (AD), a chronic atopic skin disorder. With respect to the important immunoregulatory role of the HPA axis, especially under stress, this observation could be of clinical relevance and may at least partly explain stress-induced exacerbation of AD. The present study was designed to investigate whether attenuated responsiveness of the HPA axis to stress represents a characteristic feature of AD or whether it can also be found in other chronic manifestations of atopy.

METHODS

Children (aged 7-12) with allergic asthma (AA; N = 17) and age- and sex-matched healthy controls (N = 18) were exposed to the "Trier Social Stress Test for Children"(TSST-C), which mainly consists of a free speech and mental arithmetic tasks in front of an audience. Salivary cortisol was measured in ten-minute intervals before and after the TSST-C, while heart rate was monitored continuously. In addition, early morning cortisol levels (after awakening, +10, +20, +30 minutes) were assessed on three consecutive days.

RESULTS

Data analysis yielded a significant increase of cortisol concentrations (F (9297)= 16.79; p <.001) and heart rates (F(32,992)= 9.16; p <.001) after the stressor with no between-group difference in heart rate responses. However, AA children showed a significantly blunted cortisol response to the TSST-C when compared with the control group (F(9297)= 2.95; p <.01). Awakening in the morning was accompanied by a significant rise of cortisol levels on all three experimental days in AA and control subjects (all p <.001) that was not different between the two groups.

CONCLUSIONS

These findings suggest that a blunted adrenocortical response to stress may represent a common feature of chronic allergic inflammatory processes that may be relevant in different forms of chronic manifestation of atopy.

Safety profile of frequent short courses of oral glucocorticoids in acute pediatric asthma: impact on bone metabolism, bone density, and adrenal function

OBJECTIVE

Our study was designed to establish in children with asthma the safety profile of repeated short courses of oral glucocorticoids on bone mineralization and metabolism and adrenal function.

METHODS

This cross-sectional study compared the bone density, bone metabolism, and adrenal function of children who were and were not exposed to bursts of oral glucocorticoids. Children were considered exposed when, in the preceding year, they received >or=2 courses of oral glucocorticoids and were prescribed the same therapy for the index exacerbation. Children were considered unexposed when they had no exposure to oral glucocorticoids and were not prescribed any for the index exacerbation. Indices of bone metabolism were measured during the subsequent month. Cortisol responses to adrenocorticotrophic hormone stimulation and bone density were assessed 30 days after the index exacerbation.

RESULTS

Eighty-three children (48 exposed, 35 unexposed) aged 2 to 17 years were enrolled. The median exposure level was 4 courses (range: 3-11) in the preceding year. Among exposed children, a transient decrease in serum osteocalcin was observed at the end of the 5-day course with a return to baseline by 30 days; no change was observed in urine pyridinoline cross-links. Mean bone density z score was similar in the exposed (-0.61 +/- 1.0 [standard deviation]) and unexposed (-0.67 +/- 0.9) groups. No cases of abnormal response to adrenocorticotrophic hormone suggestive of adrenal insufficiency were documented in the exposed (95% confidence interval: 0%-7%) or unexposed (0%-10%) groups.

CONCLUSIONS

Repeated short courses of oral glucocorticoids in the treatment of asthma seem to be reasonably safe; this practice was not associated with any lasting perturbation in bone metabolism, bone mineralization, or adrenal function.

Diurnal leptin rhythms in children treated with prednisolone once daily in the morning or in the evening

Serum leptin levels exhibit a marked diurnal variation in children. The aim of the present study was to investigate whether the timing of administration of exogenous glucocorticoids, which have been found to increase serum leptin, affects the diurnal rhythm. Four girls and four boys aged 10.6 to 15.8 (mean 13.2) years with asthma were studied. The design was an open 2-period cross-over trial with a 1-day run in, two 4-day periods of prednisolone 5 mg in the morning or in the evening, with a 3-week washout in between treatment periods. During run in and on the last day of the prednisolone periods a fasting blood sample was drawn at 08.00 h, and thereafter samples were obtained every 2 h throughout the day until 08.00 h the next morning. Serum leptin was measured by a specific radioimmunoassay. During all periods, leptin levels were low during the day with a nadir at 10.00 h (run-in [mean +/- SEM]: 3.9+/-1.28; morning prednisolone: 5.2+/-1.58; evening prednisolone: 5.7+/-2.02 microg/l). Increases in leptin levels were detected from 20.00 h with zeniths at 24.00 h (run in: 7.2+/-1.86; evening prednisolone: 9.2+/-2.36 microg/l) and 02.00 h (morning prednisolone: 9.4+/-1.78 microg/l) (F = 115.5; p <0.01). As compared to run in, leptin levels were increased at all time points during prednisolone treatment in the morning (F = 16.0, p = 0.01) and in the evening (F = 12.6, p = 0.01). No statistically significant differences were found in leptin levels during prednisolone in the morning or in the evening (F = 0.44, p = 0.53). Therefore, the timing of administration of exogenous glucocorticoids does not affect diurnal leptin rhythms in children.

Decreased morning serum cortisol levels in children with asthma treated with inhaled fluticasone propionate

OBJECTIVE

In an observational long-term study, we followed 62 children (37 males, 25 females; mean age: 11.6 +/- 2.9 years) with moderate-to-severe asthma for 2 years and studied the effects of fluticasone propionate (176-1320 microg/day) on the function of the hypothalamic-pituitary-adrenal axis.

STUDY DESIGN

Morning cortisol levels were monitored after patients had been on fluticasone for a mean of 8.0 +/- 5.2 months. Patients who had abnormal low morning cortisol levels (<5.5 microg/dL) were then switched either to lower fluticasone dosage or to other inhaled steroid formulation. Exact methods based on the binomial distribution were used to construct a 95% confidence interval for the true proportion of abnormal readings among those treated, and the Wilcoxon signed rank test was used to test for a significant difference between cortisol levels taken before and after the switch.

RESULTS

Twenty-two patients (36%) had abnormal morning cortisol levels while on fluticasone. Of the patients on a low dose (176 microg/day), 17% had abnormal values, whereas 43% of patients on a high dose (> or =880 microg/day) were abnormal. Patients with abnormal results (17/22) had their morning cortisol levels repeated 3 months after the switch. Thirteen of these patients (77%) had normal levels. A stratified analysis of the difference in morning cortisol levels before and after the switch showed significant increase in morning cortisol levels in the group receiving 440 microg/day or less of fluticasone (median difference: 5.25; confidence interval: 3.60-8.15), as well as in the group receiving 440 microg/day or more (median difference: 3.85; confidence interval: 1.00-7.60).

CONCLUSION

Inhaled fluticasone, even at conventional doses, may have greater effects on the adrenal function than previously recognized, but the clinical significance of this suppression still remains to be established.