Impaired recovery of hypothalamic-pituitary-adrenal axis function and hypoglycemic seizures after high-dose inhaled corticosteroid therapy in a toddler

Recovery of hypothalamo-pituitary-adrenal axis suppression during treatment with inhaled corticosteroids for childhood asthma

Objective

To describe recovery of adrenal insufficiency in asthmatic children treated with inhaled corticosteroids (ICS) and cortisol replacement therapy.

Design

Retrospective, observational study.

Patients

A total of 113 patients, 74 male; age 10.4 (3.3–16.5) years; beclomethasone-equivalent ICS dose, 800 μg, (100–1,000), tested by low dose short Synacthen (tetracosactide) test (LDSST), were studied. Test results were classified by basal and peak cortisol concentration: “normal” (basal >100 nmol/L, peak >500 nmol/L), “suboptimal” (basal >100 nmol/L, peak 350–499 nmol/L), “abnormal” (basal <100 nmol/L and/or peak <350 nmol/L). Patients with suboptimal results received hydrocortisone during periods of stress only, and those with abnormal responses received daily hydrocortisone, increased during periods of stress. A total of 73 patients (68%) had ≥2 LDSSTs over 2.2 years (0.2–7.7).

Measurements

Change in cortisol response to repeat LDSST (movement between diagnostic groups, difference in basal and peak cortisol >15% [2× the inter-assay coefficient of variation]), change in BMI and height standard deviation score (SDS).

Results

Baseline test results were abnormal in 17 patients (15%) and all of them had repeat tests. In 13 patients (76%), test results improved (normal in six, suboptimal in seven) and four (24%) remained abnormal. Baseline tests results were suboptimal in 54 patients (48%), of whom 50 (93%) were retested. Repeat tests were normal in 36 patients (72%), remained suboptimal in 11 (22%), and were abnormal in three (6%). Baseline tests results were normal in 42 patients, of whom six patients (14%) were retested. Results remained normal in three (50%), were suboptimal in two (33%), and abnormal in one (17%). Basal and peak cortisol levels increased by >15% in 33/73 (45%) and 42/73 (57%) patients, respectively, and decreased by >15% in 14/73 (19%) and 7/73 (10%), respectively. There was no significant change in height or BMI SDS.

Conclusion

Recovery of adrenal function is common and occurs during continued ICS and cortisol replacement therapy.

Global and Targeted Metabolomics Evidence of the Protective Effect of Chinese Patent Medicine Jinkui Shenqi Pill on Adrenal Insufficiency after Acute Glucocorticoid Withdrawal in Rats

Glucocorticoids are commonly used in anti-inflammatory and immunomodulatory therapies, but glucocorticoid withdrawal can result in life-threatening risk of adrenal insufficiency. Chinese patented pharmaceutical product Jinkui Shenqi pill (JKSQ) has potent efficacy on clinical adrenal insufficiency resulting from glucocorticoid withdrawal. However, the underlying molecular mechanism remains unclear. We used an animal model to study JKSQ-induced metabolic changes under adrenal insufficiency and healthy conditions. Sprague-Dawley rats were treated with hydrocortisone for 7 days with or without 15 days of JKSQ pretreatment. Sera were collected after 72 h hydrocortisone withdrawal and used for global and free fatty acids (FFAs)-targeted metabolomics analyses using gas chromatography/time-of-flight mass spectrometry and ultraperformance liquid chromatography/quadruple time-of-flight mass spectrometry. Rats without hydrocortisone treatment were used as controls. JKSQ pretreatment normalized the significant changes of 13 serum metabolites in hydrocortisone-withdrawal rats, involving carbohydrates, lipids, and amino acids. The most prominent effect of JKSQ was on the changes of FFAs and some [product FFA]/[precursor FFA] ratios, which represent estimated desaturase and elongase activities. The opposite metabolic responses of JKSQ in adrenal insufficiency rats and normal rats highlighted the "Bian Zheng Lun Zhi" (treatment based on ZHENG differentiation) guideline of TCM and suggested that altered fatty acid metabolism was associated with adrenal insufficiency after glucocorticoid withdrawal and the protective effects of JKSQ.

Early morning salivary cortisol and cortisone, and adrenal responses to a simplified low-dose short Synacthen test in children with asthma

OBJECTIVE

To examine serum cortisol responses to a simplified low-dose short Synacthen test (LDSST) in children treated with inhaled corticosteroids (ICS) for asthma and to compare these to early morning salivary cortisol (EMSC) and cortisone (EMSCn) levels.

DESIGN

Early morning salivary cortisol and EMSCn samples were collected for three consecutive days. On day three, Synacthen 500 ng/1·73 m(2) was administered intravenously. Samples were collected at 0, 15, 25, 35 min.

RESULTS

A total of 269 subjects (160 M: 109 F), median (range) age 10·0 (5·1-15·2) years were studied. Peak cortisol in the LDSST was <500 nmol/l in 101 subjects (37·5%) and <350 nmol/l in 12 subjects (4·5%). Basal cortisol correlated with peak cortisol: r = 0·55, (95% CI: 0·46, 0·63, P < 0·0001). Time at which peak cortisol concentration was achieved was significantly related to the value of peak cortisol (P < 0·0001), with higher cortisol peaks occurring later in the test and lower cortisol peaks occurring earlier. EMSC and EMSCn had no predictive value for the identification of patients with a peak cortisol <500 nmol/l. EMSCn was superior to EMSC in identifying patients with a peak cortisol <350 nmol/l: a minimum EMSCn cut-off value of 12·5 nmol/l gave a negative predictive value of 99·2% and positive predictive value of 30·1%.

CONCLUSION

Our data illustrate that basal measures of cortisol are likely to be of value in screening populations for patients at greatest risk of adrenal crisis. EMSCn shows promise as a screening tool for the identification of patients with severe adrenal insufficiency.

Why glucocorticoid withdrawal may sometimes be as dangerous as the treatment itself

Glucocorticoid therapy is widely used, but withdrawal from glucocorticoids comes with a potential life-threatening risk of adrenal insufficiency. Recent case reports document that adrenal crisis after glucocorticoid withdrawal remains a serious problem in clinical practice. Partly due to difficulties in inter-study comparison the true prevalence of glucocorticoid-induced adrenal insufficiency is unknown, but it might be somewhere between 46 and 100% 24h after glucocorticoid withdrawal, 26-49% after approximately one week, and some patients show prolonged suppression lasting months to years. Adrenal insufficiency might therefore be underdiagnosed in clinical practice. Clinical data do not permit accurate estimates of a lower limit of glucocorticoid dose and duration of treatment, where adrenal insufficiency will not occur. Due to individual variation, neither the glucocorticoid dose nor the duration of treatment can be used reliably to predict adrenal function after glucocorticoid withdrawal. Also the recovery rate of the adrenal glands shows individual variation, which may be why there is currently insufficient evidence to prove the efficacy and safety of different withdrawal regimens. Whether a patient with an insufficient response to an adrenal stimulating test develops clinically significant adrenal insufficiency depends on the presence of stress and resulting glucocorticoid demand and it is thus totally unpredictable and can change relative fast. Adrenal insufficiency should therefore always be taken seriously. Individual variation in hypothalamic-pituitary-adrenal axis function might be due to differences in glucocorticoid sensitivity and might be genetic. Further awareness of the potential side effect of withdrawal of glucocorticoid and further research are urgently needed.

Update on cystic fibrosis-related diabetes

Diabetes mellitus has emerged as a common comorbidity in cystic fibrosis and is considered a clinical entity (cystic fibrosis-related diabetes, CFRD) distinct from that of type 1 diabetes (T1DM) and type 2 diabetes (T2DM). The relevance of this diagnosis extends not only from its imposition of additional medical burden but its association with worse health outcomes in individuals with CF. This paper will review the 2010 U.S. and other international guidelines for screening and treating CFRD. It will highlight newer data regarding early glucose and insulin secretion defects, mechanisms linking CFRD to worse outcomes, and recent advances in T2DM that may provide insights for CFRD; insulin secretion will be reviewed as background for these recent developments.

[News for adrenal insufficiency]

The congress of the Endocrine Society 2008 approached the diagnostic, etiologic, prognostic and therapeutic novelties of adrenal insufficiency (AI). Diagnosis of AI often requires serum cortisol measurement during dynamic tests. Salivary cortisol measurement was reported to have an equivalent diagnostic performance to serum cortisol and that is even better when CBG levels are altered. Iatrogenic AI is much more frequent than Addison's disease. Two studies have shown that patients with inhaled corticosteroid and opioid treatments should be tested for AI. A Norwegian study reported an increased mortality in the subgroup of young men that presented Addison's disease before the age of 40. Plasma cortisol concentration in patients with current glucocorticoid replacement therapy differs notably from those observed in physiological condition. This imperfect replacement may be responsible for adverse physical condition and impaired quality of life. Two formulations of delayed hydrocortisone tablets with different pharmacokinetics from usual hydrocortisone (DuoCort and Chronocort) are in development. The first study is promising and shows that these formulations better mimick the body's natural cortisol release. Its use in the treatment of AI in patients with congenital adrenal hyperplasia has also been tested.

A rationale for using steroids in the treatment of severe cases of H5N1 avian influenza

Acute hypercytokinaemia represents an imbalance of pro-inflammatory and anti-inflammatory cytokines, and is believed to be responsible for the development of acute respiratory distress syndrome and multiple organ failure in severe cases of avian (H5N1) influenza. Although neuraminidase inhibitors are effective in treating avian influenza, especially if given within 48 h of infection, it is harder to prevent the resultant hypercytokinaemia from developing if the patient does not seek timely medical assistance. Steroids have been used for many decades in a wide variety of inflammatory conditions in which hypercytokinaemia plays a role, such as sepsis and viral infections, including severe acquired respiratory syndromes and avian influenza. However, to date, the results have been mixed. Part of the reason for the discrepancies might be the lack of understanding that low doses are required to prevent mortality in cases of adrenal insufficiency. Adrenal insufficiency, as defined in the sepsis/shock literature, is a plasma cortisol rise of at least 9 μg dl−1 following a 250 μg dose of adrenocorticotropin hormone (ACTH), or reaching a plasma cortisol concentration of >25 μg dl−1 following a 1–2 μg dose of ACTH. In addition, in the case of hypercytokinaemia induced by potent viruses, such as H5N1, systemic inflammation-induced, acquired glucocorticoid resistance is likely to be present. Adrenal insufficiency can be overcome, however, with prolonged (7–10 or more days) supraphysiological steroid treatment at a sufficiently high dose to address the excess activation of NF-κB, but low enough to avoid immune suppression. This is a much lower dose than has been typically used to treat avian influenza patients. Although steroids cannot be used as a monotherapy in the treatment of avian influenza, there might be a potential role for their use as an adjunct treatment to antiviral therapy if appropriate dosages can be determined. In this paper, likely mechanisms of adrenal insufficiency are discussed, drawing from a broad background of literature sources.

Assessment of adrenal suppression in children with asthma treated with inhaled corticosteroids: use of dehydroepiandrosterone sulfate as a screening test

BACKGROUND

Inhaled corticosteroids (ICs) are considered first-line therapy for persistent asthma. At medium to high doses, ICs can suppress the hypothalamic-pituitary-adrenal (HPA) axis. Various provocative stimuli have been used to evaluate HPA axis function, but they are labor intensive and time-consuming. Dehydroepiandrosterone sulfate (DHEA-S) is a corticotropin-dependent adrenal androgen precursor that is suppressible in patients treated with ICs.

OBJECTIVES

To evaluate DHEA-S as a possible marker for HPA axis dysfunction in children treated with ICs.

METHODS

Children with moderate-to-severe persistent asthma and a history of medium- to high-dose IC exposure for at least 6 months were evaluated using low-dose and standard high-dose cosyntropin stimulation testing to assess adrenal function, and DHEA-S levels were compared with the results.

RESULTS

Thirteen (59%) of 22 patients exhibited an abnormal cortisol response to cosyntropin. Age- and sex-specific mean DHEA-S z scores were significantly lower in cosyntropin abnormal responders (-1.2822) compared with normal responders (0.2964) (P = .008). The receiver operating characteristic curve for DHEA-S z scores had an area of 0.786 (95% confidence interval, 0.584-0.989), reaching 100% sensitivity with a DHEA-S z score of -1.5966 or less and 100% specificity with a DHEA-S z score greater than 0.0225.

CONCLUSIONS

Most children develop biochemical evidence of adrenal suppression after treatment with medium to high doses of ICs. The presence of low DHEA-S levels can be used as a screening test to identify the child who needs more formal testing of the HPA axis.

Pharmacogenomics and the future of drug therapy

With the completion of the human genome project, many investigators are striving to translate the resulting wealth of new information into new and improved clinical practices. Pharmacogenomics represents one of the most promising of these applications for adult- and pediatric-based therapies. This article provides a historical perspective, but most importantly, uses this background to illustrate important principles of the field. The application of pharmacogenomics to asthma therapy is presented as an example of the current status of pharmacogenomics as it is being applied to an important pediatric health problem. Finally, a discussion of future promises and challenges to the application of pharmacogenomics is presented, including economic and ethical issues.

Biotransformation of fluticasone: in vitro characterization

Fluticasone propionate (FTP) is a synthetic trifluorinated glucocorticoid with potent anti-inflammatory action that is commonly used in patients with asthma. After oral or intranasal administration, FTP undergoes rapid hepatic biotransformation; the principal metabolite formed is a 17beta-carboxylic acid derivative (M1). M1 formation has been attributed largely to cytochrome P450 3A4 (CYP3A4); however, there are no published data that confirm this assertion. Hence, in vitro studies were conducted to determine the role that human P450s play in the metabolism of FTP. Consistent with in vivo data, human liver microsomes catalyzed the formation of a single metabolite (M1) at substrate concentrations 0.95) with CYP3A4/5 activities in a panel of human liver microsomes (n = 14) and was markedly impaired by the CYP3A inhibitor ketoconazole (>94%) but not by inhibitors of other P450 enzymes ( Collapse

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MESH Headings

• Androstadienes/metabolism
• Anti-Inflammatory Agents/metabolism
• Biotransformation
• Cytochrome P-450 CYP3A
• Cytochrome P-450 Enzyme Inhibitors
• Cytochrome P-450 Enzyme System/genetics
• Cytochrome P-450 Enzyme System/metabolism
• Dose-Response Relationship, Drug
• Enzyme Inhibitors/pharmacology
• Fluticasone
• Humans
• In Vitro Techniques
• Ketoconazole/pharmacology
• Kinetics
• Lung/enzymology
• Lung/metabolism
• Microsomes, Liver/drug effects
• Microsomes, Liver/enzymology
• Microsomes, Liver/metabolism
• Mifepristone/pharmacology
• Recombinant Proteins/metabolism

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Grants

• 1 U01 HD044239-2 NICHD NIH HHS
• 2 U01 HD031313-12 NICHD NIH HHS

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Affiliation(s)

Robin E Pearce Division of Pediatric Clinical Pharmacology and Medical Toxicology, Department of Pediatrics, Children's Mercy Hospitals and Clinics, Kansas City, MO 64108, USA
J Steven Leeder
Gregory L Kearns

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Overview of the pharmacogenetics of asthma treatment

Asthma affects approximately 300 million individuals worldwide. Medications comprise a substantial portion of asthma expenditures. Despite the availability of three primary therapeutic classes of medications, there are a significant number of nonresponders to therapy. Available data, as well as previous pharmacogenetic studies, suggest that genetics may contribute as much as 60-80% to the interindividual variability in treatment response. In this methodologic review, after providing a broad overview of the asthma pharmacogenetics literature to date, we describe the application of a novel family-based screening algorithm to the analysis of pharmacogenetic data and highlight our approach to identifying and verifying loci influencing asthma treatment response. This approach seeks to address issues related to multiple comparisons, statistical power, population stratification, and failure to replicate from which previous population-based or case-control pharmacogenetic association studies may suffer. Identification of such replicable loci is the next step towards the goal of 'individualized therapy' for asthma.

Safety of inhaled corticosteroids: room for improvement

Inhaled corticosteroids (ICS) are the standard of care in asthma and are widely used in the treatment of patients with chronic obstructive pulmonary disease. High-dose regimens and long-term use of ICS in predisposed individuals may be associated with a variety of side effects, similar to those observed with systemic corticosteroid therapy. Side effects associated with long-term ICS use include reduction in growth velocity, cataracts, glaucoma, osteoporosis, and fractures. Fear of unwanted complications may be of concern in all patients using ICS, particularly in age- and gender-specific populations that are more prone to develop side effects or to reduce treatment adherence because of physical, behavioral, or psychological problems. In addition to concerns about ICS safety, dosing regimens that are difficult to follow may further reduce a patient's ability to comply with treatment. Ciclesonide, a new-generation ICS with unique pharmacokinetic properties, was developed to provide effective anti-inflammatory control for asthma with once-daily administration to improve patient adherence and a high safety profile to reduce the occurrence of local and systemic side effects.

Exogenous Cushing's syndrome and glucocorticoid withdrawal

Glucocorticoid therapy in various forms is extremely common for a wide range of inflammatory, autoimmune, and neoplastic disorders. It is therefore important for the physician to be aware of the possibility of both iatrogenic and factitious Cushing's syndrome. Although most common with oral therapy, it is also important to be alert to the fact that all forms of glucocorticoid delivery have the potential to cause Cushing's syndrome. Withdrawal from chronic glucocorticoid therapy presents significant challenges. These include the possibility of adrenal insufficiency after discontinuation of steroid therapy, recurrence of underlying disease as the glucocorticoid is being withdrawn, and the possibility of steroid withdrawal symptoms. Nonetheless, with patience and persistence, a reasonable approach to withdrawal of glucocorticoid therapy can be achieved.

Monitoring growth in asthmatic children treated with high dose inhaled glucocorticoids does not predict adrenal suppression

AIMS

To determine whether routine outpatient monitoring of growth predicts adrenal suppression in prepubertal children treated with high dose inhaled glucocorticoid.

METHODS

Observational study of 35 prepubertal children (aged 4-10 years) treated with at least 1000 microg/day of inhaled budesonide or equivalent potency glucocorticoid for at least six months. Main outcome measures were: changes in HtSDS over 6 and 12 month periods preceding adrenal function testing, and increment and peak cortisol after stimulation by low dose tetracosactrin test. Adrenal suppression was defined as a peak cortisol < or =500 nmol/l.

RESULTS

The areas under the receiver operator characteristic curves for a decrease in HtSDS as a predictor of adrenal insufficiency 6 and 12 months prior to adrenal testing were 0.50 (SE 0.10) and 0.59 (SE 0.10). Prediction values of an HtSDS change of -0.5 for adrenal insufficiency at 12 months prior to testing were: sensitivity 13%, specificity 95%, and positive likelihood ratio of 2.4. Peak cortisol reached correlated poorly with change in HtSDS (rho = 0.23, p = 0.19 at 6 months; rho = 0.33, p = 0.06 at 12 months).

CONCLUSIONS

Monitoring growth does not enable prediction of which children treated with high dose inhaled glucocorticoids are at risk of potentially serious adrenal suppression. Both growth and adrenal function should be monitored in patients on high dose inhaled glucocorticoids. Further research is required to determine the optimal frequency of monitoring adrenal function.