Low-dose adrenocorticotropin test reveals impaired adrenal function in patients taking inhaled corticosteroids

Glucocorticoid-induced adrenal insufficiency after therapy with intravenous methylprednisolone in patients with moderate-to-severe and active Graves' orbitopathy: assessment with a low-dose corticotropin test

PURPOSE

We aimed to assess adrenal function following treatment of moderate-to-severe and active Graves' orbitopathy (GO) with intravenous methylprednisolone (IVMP) in weekly pulses in a cumulative dose of 4.5 or 7.5 g. We evaluated the impact of IVMP pulses on adrenal reserve using a low-dose (1 μg) ACTH stimulation test (LDT) for the first time.

METHODS

In this prospective study we evaluated adrenal function in 21 patients with moderate-to-severe and active GO treated with 12 weekly IVMP pulses according to the European Group on Graves' Orbitopathy (EUGOGO) recommendations. We assessed serum cortisol, plasma adrenocorticotropic hormone (ACTH), and dehydroepiandrosterone sulfate (DHEA-S) levels before the 1st and 12th IVMP pulse. We performed dynamic testing using LDT before the 12th IVMP pulse in all patients. In those who failed LDT, adrenal function was reassessed with LDT and the overnight metyrapone test after 4-7 weeks.

RESULTS

Two patients failed to achieve serum cortisol levels ≥ 18.1 μg/dL at 30 and 60 min in LDT and were diagnosed with glucocorticoid-induced adrenal insufficiency (GC-induced AI). They were recommended to take hydrocortisone in situations of acute stress. Both patients were reassessed within 4-7 weeks after treatment cessation and showed an adequate response in LDT and overnight metyrapone test. We observed a statistically significant decrease in DHEA-S levels (p = 0.004) before the 12th IVMP pulse compared to baseline in all patients.

CONCLUSION

For the first time, our research shows that administering IVMP in 12 weekly pulses can result in GC-induced AI. We suggest that patients should undergo careful evaluation for GC-induced AI, including LDT, after therapy with IVMP according to EUGOGO guidelines. Screening for altered adrenal reserve could prevent life-threatening complications, particularly during acute stress situations.

Should Pediatric Endocrinologists Consider More Carefully When to Perform a Stimulation Test?

INTRODUCTION

Pediatric endocrinology rely greatly on hormone stimulation tests which demand time, money and effort. The knowledge of the pattern of pediatric endocrinology stimulation tests is therefore crucial to optimize resources and guide public health interventions. Aim of the study was to investigate the distribution of endocrine stimulation tests and the prevalence of pathological findings over a year and to explore whether single basal hormone concentrations could have saved unnecessary stimulation tests.

METHODS

Retrospective study with data collection for pediatric endocrine stimulation tests performed in 2019 in a tertiary center.

RESULTS

Overall, 278 tests were performed on 206 patients. The most performed test was arginine tolerance test (34%), followed by LHRH test (24%) and standard dose Synachthen test (19%), while the higher rate of pathological response was found in insulin tolerance test to detect growth hormone deficiency (81%), LHRH test to detect central precocious puberty (50%) and arginine tolerance test (41%). No cases of non-classical-congenital adrenal hyperplasia were diagnosed. While 29% of growth hormone deficient children who performed an insulin tolerance test had a pathological peak cortisol, none of them had central adrenal insufficiency confirmed at low dose Synacthen test. The use of basal hormone determinations could save up to 88% of standard dose Synachthen tests, 82% of arginine tolerance + GHRH test, 61% of LHRH test, 12% of tests for adrenal secretion.

CONCLUSION

The use of single basal hormone concentrations could spare up to half of the tests, saving from 32,000 to 79,000 euros in 1 year. Apart from basal cortisol level <108 nmol/L to detect adrenal insufficiency and IGF-1 <-1.5 SDS to detect growth hormone deficiency, all the other cut-off for basal hormone determinations were found valid in order to spare unnecessary stimulation tests.

Defining Nonfunctioning Adrenal Adenomas on the Basis of the Occurrence of Hypocortisolism after Adrenalectomy

Background

In patients with adrenal incidentalomas (AIs), there is uncertainty on how to rule out hypercortisolism. The occurrence of postsurgical (unilateral adrenalectomy) hypocortisolism (PSH) has been proposed as a proof of the presence of presurgical hypercortisolism in AI patients. The aim of this study was to define the thresholds of cortisol level after the 1 mg overnight dexamethasone suppression test (F-1mgDST), urinary free cortisol (UFC), midnight serum cortisol (MSC), and adrenocorticotropin (ACTH) to predict the absence of PSH in AI patients undergoing surgery.

Methods

In 60 patients who underwent AI excision, cortisol secretion was assessed by a low-dose corticotropin stimulation test or insulin tolerance test when needed. We searched for the lowest presurgical value of F-1mgDST, UFC, and MSC and the highest value for ACTH in AI patients with PSH as indexes of normal cortisol secretion.

Results

The lowest values of F-1mgDST, UFC, and MSC and the highest value for ACTH in PSH patients were 1.2 µg/dL (33 nmol/L), 10.4 µg/24 hours (29 nmol/24 hours), 1.2 µg/dL (33 nmol/L), and 26.9 pg/mL (6 pmol/L), respectively, but only F-1mgDST <1.2 µg/dL (33 nmol/L) was able to predict the absence of PSH. Among AI patients with F-1mgDST <1.2 µg/dL (33 nmol/L) no subjects had diabetes mellitus and/or metabolic syndrome, and these subjects tended to have a better metabolic profile than those with F-1mgDST ≥1.2 µg/dL (33 nmol/L).

Conclusion

In AI patients a F-1mgDST <1.2 µg/dL (33 nmol/L) rules out PSH and could be used to exclude hypercortisolism in AI patients.

Accuracy of the Low-Dose ACTH Stimulation Test for Adrenal Insufficiency Diagnosis: A Re-Assessment of the Cut-Off Value

Background: The clinical practice shows that many low-dose ACTH-stimulation tests have a false positive result. The aim of the study was to determine the diagnostic accuracy of a low-dose ACTH-stimulation test in the diagnosis of adrenal insufficiency and to define its optimal cut-off. Methods: We analyzed data from 103 patients undergoing 1 µg ACTH-stimulation test. Four patients had adrenal insufficiency (AI) upon follow up: Two primary, and two secondary AI. Cortisol serum levels were evaluated at time 0, 20’, and 30’ after the injection of 1 µg i.v. of ACTH. The sensitivity, specificity, accuracy, and positive and negative predictive values of the test were calculated for both 20’ and 30’ sampling. The receiver operating characteristic (ROC) curve was obtained to assess the sensitivity and specificity of low-dose ACTH-stimulation test in the diagnosis of adrenal insufficiency at different cut-off values. Results: Considering 500 nmol/L as the standard cut-off value, low-dose ACTH stimulation test showed a 100% sensitivity and a 67.3% specificity, with a high rate of false positive results. ROC curve analysis showed that the cut-off of 401.5 nmol/L is the best compromise between sensitivity (100%) and specificity (93.9%). Conclusions: By using a cut-off value of 401.5 nmol/L for the low-dose ACTH stimulation test, the number of false positive patients decreased significantly, but the sensitivity remained high.

Low-protein diet decreased the adrenal function and spontaneous activity of mice during chronic heat stress

Protein restriction is a well-known risk factor that induces the deterioration of various biological functions. However, little is known about the effects of protein restriction on behavioral markers and the adrenal function of mice exposed to chronic stress. Here we evaluated the effects of a low-protein diet on the spontaneous activity and adrenal function of chronic heat-stressed mice. ICR mice were fed a control diet (20% protein) or a low-protein diet (10% protein) for 14 consecutive days. From the 10th day of the diet period, the mice were repeatedly exposed to a temperature condition of 35 ± 1 °C for 2 hr/day for four consecutive days. The spontaneous activities of the mice were estimated for the behavioral analysis. On the last day, we performed a blood collection test and an ACTH stimulation test for adrenal function analysis. For the blood collection test, mice were exposed to heat stress again for 2 hr, and blood was collected immediately after this heat stress. We measured the plasma levels of corticotropin releasing hormone, adrenocorticotropin (ACTH), and corticosterone. For the ACTH stimulation test, cosyntropin was intraperitoneally administered, and the plasma corticosterone levels were measured. The spontaneous activity of the low-protein mice was significantly lower than that of the control mice during the dark period of heat stress. The plasma corticosterone levels were greatly increased by heat stress, with no significant difference between the control and low-protein groups. The ACTH stimulation test revealed that the plasma corticosterone concentration of the heat-stressed low-protein mice was significantly lower than that of the heat-stressed controls. In conclusion, the low-protein diet decreased the spontaneous activity and the adrenal function of mice during heat stress, which implies that protein restriction during chronic heat stress induces fatigue by reducing the adrenal function.

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.

Evidence of hypothalamic-pituitary-adrenal axis suppression during moderate-to-high-dose inhaled corticosteroid use

The possible risk of adverse effects due to regular use of inhaled corticosteroids (ICS) is a real concern. Our aim was to describe the factors that have an impact on hypothalamic-pituitary-adrenal axis suppression (HPA-AS) in children and adolescents taking ICS regularly. The HPA axis status of patients who were on moderate-to-high-dose ICS [>176 and >264 μg/day fluticasone propionate-hydrofluoroalkane (FP-HFA) for patients 0-11 and ≥12 years, respectively] was investigated. Various types of ICS were converted to FP-HFA equivalent according to National Asthma Education and Prevention Program (NAEPP) guidelines. Participants with a baseline (8 a.m.) serum cortisol <15 μg/dL underwent a low-dose ACTH stimulation test (LDAT) to diagnose HPA-AS. Among 91 patients, 60 (75.9 %) participants underwent LDAT, and seven (7.7, 95 % CI 3.5-15.3 %) were diagnosed with HPA-AS. Ciclesonide was more frequently used by the participants with HPA-AS compared to patients with a normal HPA axis (42.9 vs. 4.8 %, p = 0.009). Use of ICS at moderate-to-high doses for at least 7 months distinguished participants with HPA-AS from those with a normal HPA axis. Among the duration, type, and dose of ICS, solely the use of ICS with a body mass index (BMI)-adjusted daily dose of ≥22 μg FP was found to increase the risk for HPA-AS (odds ratio (OR) 7.22, 95 % confidence interval (CI) 1.23-42.26, p = 0.028). The receiver operating characteristics (ROC) curve analysis revealed a cutoff value of 291 μg/day FP (area under the curve (AUC) = 0.840, p = 0.003) for predicting HPA-AS Conclusion: The prevalence of HPA-AS was found to be 7.7 % in children taking not only high-dose ICS but also moderate-dose ICS. Dose alone was found to be an actual risk factor for HPA-AS.

Cortisol response to low dose versus standard dose (back-to-back) adrenocorticotrophic stimulation tests in children and young adults with thalassemia major

BACKGROUND

Thalassemia major patients with repeated blood transfusion have high prevalence of endocrinopathies due to iron overload.

MATERIALS AND METHODS

We examined the adrenocortical function in 23 thalassemic patients (10 children and 13 young adults) aged 8-26 years. Serum cortisol and dehydroepiandrosterone sulfate (DHEA-S) concentrations were determined in each subject before blood transfusion both in basal condition and after low dose (LD) (1 μg), followed by standard dose (SD) (250 μg, respectively) with synthetic corticotrophin beta 1-24 ACTH (Synacthen, Ciba). Normal controls were a group of 13 age- and sex-matched normal subjects.

RESULTS

Using a peak total cortisol cutoff level of 550 nmol/L and increments of 200 μg above basal cortisol, adrenal insufficiency (AI) was demonstrated in 8 patients (34.7%) after the LD ACTH and in 2 patients (8.7%) after SD cosyntropin (ACTH) test, but none of the controls. Using a peak total cortisol cutoff level of 420 nmol/L and increments of 200 μg above basal cortisol, AI was demonstrated in 5 patients (21.7%) after the LD ACTH and in 2 patients after SD ACTH test (8.7%), but none of controls. All patients with biochemical AI were asymptomatic with normal serum sodium and potassium concentrations and had no history suggestive of adrenal pathology. The peak cortisol concentrations in thalassemic patients with impaired adrenal function both after 1 μg and 250 μg cosyntropin (294 ± 51 nmol/L and 307 ± 58.6) were significantly lower than those with patients with normal (454 ± 79.7 nmol/L and 546.1 ± 92.2 nmol/L, respectively) and controls (460.2 ± 133.4 nmol/L and 554.3 ± 165.8 nmol/L, respectively). Adolescents and young adults, but not children with thalassaemia, had significantly lower peak cortisol concentration after SD ACTH versus controls. Peak cortisol response to LD ACTH was correlated significantly with peak cortisol response to SD in all patients (r = 0.83, P < 0.0001). In adolescents and young adults with thalassemia, DHEA-S levels before and after LD ACTH stimulation were significantly lower and the cortisol/DHEA-S ratios were significantly higher than the controls.

CONCLUSION

The use of LD ACTH test diagnoses more adrenal abnormalities versus SD ACTH in thalassemic patients. The relatively high prevalence of AI in thalassemic adolescents and young adults necessitates that these patients have to be investigated for AI before major surgery and those with impaired cortisol secretion should receive stress doses of corticosteroids during the stressful event.

Altered systemic hemodynamic and baroreflex response to angiotensin II in postural tachycardia syndrome

BACKGROUND

Postural tachycardia syndrome (POTS) is characterized by excessive orthostatic tachycardia and significant functional disability. We have previously found that patients with POTS have increases in plasma angiotensin II (Ang II) that are twice as high as healthy subjects despite normal blood pressures (BPs). In this study, we assess systemic and renal hemodynamic and functional responses to Ang II infusion in patients with POTS compared with healthy controls.

METHODS AND RESULTS

Following a 3-day sodium-controlled diet, we infused Ang II (3 ng/kg per minute) for 1 hour in patients with POTS (n=15) and healthy controls (n=13) in the supine position. All study subjects were women with normal BP. Ages were similar for patients with POTS and controls (mean±SEM, 30±2 versus 26±1 years; P=0.11). We measured the changes from baseline mean arterial pressure, renal plasma flow, plasma renin activity, aldosterone, urine sodium, and baroreflex sensitivity in both groups. In response to Ang II infusion, patients with POTS had a blunted increase compared with controls in mean arterial pressure (10±1 versus 14±1 mm Hg, P=0.01) and diastolic BP (9±1 versus 13±1 mm Hg, P=0.01) but not systolic BP (13±2 versus 15±2 mm Hg, P=0.40). Renal plasma flow decreased similarly with Ang II infusion in patients with POTS versus controls (-166±20 versus -181±17 mL/min per 1.73 kg/m(2), P=0.58). Postinfusion, the decrease in plasma renin activity (-0.9±0.2 versus -0.6±0.2 ng/mL per hour, P=0.43) and the increase in aldosterone (17±1 versus 15±2 pg/mL, P=0.34) were similar in both groups. The decrease in urine sodium excretion was similar in patients with POTS and controls (-49±12 versus -60±16 mEq/g creatinine, P=0.55). The spontaneous baroreflex sensitivity at baseline was significantly lower in patients with POTS compared with controls (10.1±1.2 versus 16.8±1.5 ms/mm Hg, P=0.003), and it was further reduced with Ang II infusion.

CONCLUSIONS

Patients with POTS have blunted vasopressor response to Ang II and impaired baroreflex function. This impaired vasoconstrictive response might be exaggerated with upright posture and may contribute to the subsequent orthostatic tachycardia that is the hallmark of this disorder. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00962949.

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

Prevalence of occult adrenal insufficiency and the prognostic value of a short corticotropin stimulation test in patients with septic shock

Background:

Corticosteroid insufficiency in acute illness can be difficult to discern clinically. Occult adrenal insufficiency (i.e., Δmax ≤9 μg/dL) after corticotropin may be associated with a high mortality rate.

Objective:

To assess the prevalence of occult adrenal insufficiency and the prognostic value of short corticotropin stimulation test in patients with septic shock.

Materials and Methods:

A total of 30 consecutive patients admitted in the adult intensive care unit of the Sheri Kashmir Institute of Medical Sciences who met the clinical criteria for septic shock were prospectively enrolled in the study. A low dose (1 μg) short corticotropin stimulation test was performed; blood samples were taken before the injection (T0) and 30 (T30) and 60 (T60) minutes afterward.

Results:

The prevalence of occult adrenal insufficiency was 57%. The 28-day mortality rate was 60% and the median time to death was 12 days. The following seven variables remained independently associated with death: organ system failure scores, simplified acute physiology score II score, mean arterial pressure, low platelet count, PaO₂:FIO₂, random baseline cortisol (T0) >34 μg/dL, and maximum variation after test (Δmax) of ≤9 μg/dL. Three different mortality patterns were observed: (I) low (T0 ≤34 μg/dL and Δmax >9 μg/dL; a 28-day mortality rate of 33%),(II) intermediate (T0 >34 μg/dL and Δmax >9 μg/dL or T0 ≤34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 71%), and (III) high (T0 >34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 82%).

Conclusion:

A short corticotropin test using low-dose corticotropin (1 μg) has a good prognostic value. High basal cortisol and a low increase in cortisol on corticotropin stimulation test are predictors of a poor outcome in patients with septic shock.

In polycystic ovary syndrome, adrenal steroids are regulated differently in the morning versus in response to nutrient intake

OBJECTIVE

To investigate adrenal steroid regulation in polycystic ovary syndrome.

DESIGN

Five-hour oral glucose tolerance test (OGTT) and frequently sampled-intravenous gluclose tolerance test.

SETTING

University research center.

PATIENT(S)

Thirty patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Anthropometrics, leptin, cortisol, DHEAS, glucose, insulin.

RESULT(S)

Morning cortisol correlated with sensitivity index (SI, r = .540), DHEAS correlated inversely with age (r = -.6359), body mass index (BMI, r = -.6199), fat mass (r = -0.630), and leptin (r = -0.5676). Between the second and fourth hour of OGTT, cortisol changes (Delta) exhibited three patterns: I, responders (n = 9, Delta: 10.7 +/- 1.0 microg/dL); II, nonresponders (n = 10, Delta: -3.5 +/- 0.6 microg/dL); III, intermediates (n = 11, Delta: 4.3 +/- 1.0 microg/dL). Compared with nonresponders, responders were more obese (BMI: 37.0 +/- 1.6 vs. 31.7 +/- 1.8 kg/m(2)); had higher leptin (28.9 +/- 1.7 vs. 24.1 +/- 1.1 ng/mL), and lower DHEAS (133 +/- 12 vs. 236 +/- 32 ng/mL), higher glucose at 1 h of OGTT (195 +/- 13 vs. 131 +/- 12 mg/dL), higher area under the curve (AUC)(Glucose) (332 +/- 20 vs. 265 +/- 17 mg/dL), higher AUC(Insulin) (244 +/- 50 vs. 125 +/- 30 muU/mL), and lower nadir glucose (61 +/- 2 vs. 70 +/- 2 mg/dL).

CONCLUSION(S)

Obesity and insulin resistance are associated with lower morning cortisol and DHEAS but increased cortisol and DHEA responses after glucose ingestion. Morning steroid levels may not reflect the day-long exposure.

Adrenal response in children with septic shock

OBJECTIVE

To describe the serum cortisol profile and evaluate the adrenal response in children with septic shock, and determine the influence of these factors on the outcome and mortality in this group.

METHODS

Between May and November 2003, 22 children with septic shock admitted to two pediatric intensive care units in southern Brazil were followed. Adrenal function was evaluated based on the levels of cortisol measured on the occasion of the diagnosis of septic shock and on the response of serum cortisol 30 min after the administration of intravenous corticotrophin (0.5 microg/1.73m(2)). Adrenal insufficiency was defined as a baseline serum cortisol below 690 nmol/l and/or a cortisol response to corticotrophin less than 250 nmol/l.

RESULTS

Adrenal insufficiency was detected in 17 patients (77.3%). All patients who died had baseline cortisol higher than 690 nmol/l. A cortisol response to corticotrophin less than 250 nmol/l was associated with a 60% mortality (RR = 7.2, 1.03-50.28). Regression analysis showed that the combination of baseline cortisol higher than 690 nmol/l and a cortisol response to corticotrophin less than 250 nmol/l were associated with mortality after correction for gender and PRISM.

CONCLUSIONS

Adrenal insufficiency is a frequent finding in children with septic shock. The low-dose corticotrophin stimulation test seems to be an important tool to distinguish between a normal cortisol response to stress and evidence of adrenal failure. Mortality was significantly higher in children that failed to respond to a corticotrophin stimulation test.

Adrenal responses to low dose synthetic ACTH (Synacthen) in children receiving high dose inhaled fluticasone

BACKGROUND AND AIMS

Clinical adrenal insufficiency has been reported with doses of inhaled fluticasone proprionate (FP) > 400 microg/day, the maximum dose licensed for use in children with asthma. Following two cases of serious adrenal insufficiency (one fatal) attributed to FP, adrenal function was evaluated in children receiving FP outwith the licensed dose.

METHODS

Children recorded as prescribed FP > or = 500 microg/day were invited to attend for assessment. Adrenal function was measured using the low dose Synacthen test (500 ng/1.73 m2 intravenously) and was categorised as: biochemically normal (peak cortisol response > 500 nmol/l); impaired (peak cortisol < or = 500 nmol/l); or flat (peak cortisol < or = 500 nmol/l with increment of < 200 nmol/l and basal morning cortisol < 200 nmol/l).

RESULTS

A total of 422 children had been receiving FP alone or in combination with salmeterol; 202 were not investigated (137 FP within license; 24 FP discontinued); 220 attended and 217 (age 2.6-19.3 years) were successfully tested. Of 194 receiving FP > or = 500 microg/day, six had flat responses, 82 impaired responses, 104 were normal, and in 2 the LDST was unsuccessful. Apart from the index child, the other five with flat responses were asymptomatic; a further child with impairment (peak cortisol 296 nmol/l) had encephalopathic symptoms with borderline hypoglycaemia during an intercurrent illness. The six with flat responses and the symptomatic child were all receiving FP doses of > or = 1000 microg/day.

CONCLUSION

Overall, flat adrenal responses in association with FP occurred in 2.8% of children tested, all receiving > or = 1000 microg/day, while impaired responses were seen in 39.6%. Children on above licence FP doses should have adrenal function monitoring as well as a written plan for emergency steroid replacement.

Decreased cortisol response to insulin induced hypoglycaemia in asthmatics treated with inhaled fluticasone propionate

AIMS

To assess adrenal function in asthmatic children treated with inhaled fluticasone propionate for up to 16 weeks.

METHODS

Children with asthma and bronchial hyperresponsiveness to inhaled methacholine were treated with inhaled fluticasone 250-750 microg/day via Volumatic spacer. The insulin tolerance test (ITT) was performed to assess adrenal function.

RESULTS

Eighteen asthmatic patients (10 boys, 8 girls), aged 7-17 years received inhaled fluticasone therapy at a median dose of 477 microg/m2 per day for 5-16 weeks. Adrenal suppression, defined as 60 minute serum cortisol less than 500 nmol/l, was found in 9 of 18 children. Following the ITT, the median basal and 60 minute serum cortisol concentrations of the suppressed group were 135.0 and 350.0 nmol/l, respectively; the corresponding values for the unsuppressed group were 242.2 and 564.7 nmol/l. Repeat ITT in the suppressed group 2-3 months after discontinuation of fluticasone revealed that all patients had a 60 minute serum cortisol greater than 500 nmol/l.

CONCLUSION

After therapy for asthma with inhaled fluticasone at approximately 500 microg daily for up to 16 weeks, half the children had evidence of adrenal suppression.

Inhaled corticosteroids in childhood asthma: long-term effects on growth and adrenocortical function

Inhaled corticosteroids (ICS) are the most potent of all the available inhaled treatments, and are effective medications for long-term control of asthma. However, their use in children is limited by the risk of systemic adverse effects. Although results reported in the literature on the adverse effects of ICS are conflicting and often restricted to a small number of cases with a limited follow-up, most of them show an early decrease in growth velocity without significant influence on final adult height. Partial adrenal suppression has also been demonstrated in children treated with ICS for more than 2 months. Only children with mild persistent, moderate, or severe asthma not controlled by non-corticosteroid drugs should be treated with ICS for long periods. The dose of ICS must be individually adjusted to minimize the possible adverse effects on growth, and all children with asthma receiving long-term treatment with ICS must be regularly evaluated for growth impairment, which may necessitate dose reduction or drug replacement.

Systemic activity of inhaled corticosteroid treatment in asthmatic children: corticotrophin releasing hormone test

BACKGROUND

A study was undertaken to assess the function of the hypothalamic-pituitary-adrenal axis (HPA) in a group of asthmatic children before and after treatment with inhaled corticosteroids.

METHODS

Thirty prepubertal patients of mean (SD) age 6.7 (1.8) years were treated with inhaled corticosteroids. All children underwent a corticotrophin releasing hormone (CRH) test with evaluation of serum cortisol and adrenocorticotrophin hormone (ACTH) levels before and after 3 months of treatment. Twenty four hour urine samples were also collected to measure free cortisol (UFC) excretion.

RESULTS

Subjects showed no difference between basal serum cortisol levels (mean change -18; 95% CI -41 to 5; p=0.118) and delta (peak minus basal) levels (mean change -13; 95% CI -38 to 12; p=0.308) before and after treatment, whereas the peak cortisol level (mean change -31; 95% CI -55 to -7; p=0.013) and area under the curve (AUC) (mean change -175; 95% CI -288 to -63; p=0.003) after CRH were significantly lower following treatment. Basal, peak and AUC ACTH were significantly lower after treatment (p<0.05, p=0.004 and p=0.003, respectively), while delta ACTH was similar before and after treatment ((mean change -12; 95% CI - 31 to -7; p=0.199). No significant reduction in 24 hour UFC was observed after the treatment period (before 14.9 (7.1), after 15.0 (11.6); mean change 0.1, 95% CI -5.2 to 5.4; p=0.967). No correlation was found between UFC and any of the parameters of cortisol excretion following the CRH test, either before or after treatment.

CONCLUSIONS

These data suggest that, at the dosage and for the treatment period used, inhaled steroids do not seem to suppress the HPA axis in the majority of patients. The CRH test may be more sensitive than 24 hour UFC and morning plasma cortisol levels in evaluating systemic activity of inhaled corticosteroid treatment.

Survey of adrenal crisis associated with inhaled corticosteroids in the United Kingdom

BACKGROUND

Until recently, only two cases of acute adrenal crisis associated with inhaled corticosteroids (ICS) had been reported worldwide. We identified four additional cases and sought to survey the frequency of this side effect in the United Kingdom.

METHODS

Questionnaires were sent to all consultant paediatricians and adult endocrinologists registered in a UK medical directory, asking whether they had encountered asthmatic patients with acute adrenal crisis associated with ICS. Those responding positively completed a more detailed questionnaire. Diagnosis was confirmed by symptoms/signs and abnormal hypothalamic-pituitary-adrenal axis function test results.

RESULTS

From an initial 2912 questionnaires, 33 patients met the diagnostic criteria (28 children, five adults). Twenty-three children had acute hypoglycaemia (13 with decreased levels of consciousness or coma; nine with coma and convulsions; one with coma, convulsions and death); five had insidious onset of symptoms. Four adults had insidious onset of symptoms; one had hypoglycaemia and convulsions. Of the 33 patients treated with 500-2000 micro g/day ICS, 30 (91%) had received fluticasone, one (3%) fluticasone and budesonide, and two (6%) beclomethasone.

CONCLUSIONS

The frequency of acute adrenal crisis was greater than expected as the majority of these patients were treated with ICS doses supported by British Guidelines on Asthma Management. Despite being the least prescribed and most recently introduced ICS, fluticasone was associated with 94% of the cases. We therefore advise that the licensed dosage of fluticasone for children, 400 micro g/day, should not be exceeded unless the patient is being supervised by a physician with experience in problematic asthma. We would also emphasise that until adrenal function has been assessed patients receiving high dose ICS should not have this therapy abruptly terminated as this could precipitate adrenal crisis.

Airway and systemic effects of hydrofluoroalkane fluticasone and beclomethasone in patients with asthma

BACKGROUND

With the transition to hydrofluoroalkane-134a propellants in metered dose inhalers, it is important to consider the efficacy and safety profiles of formulations containing inhaled corticosteroids. We examined the airway and systemic effects of hydrofluoroalkane-134a fluticasone propionate (FLU-HFA) and beclomethasone dipropionate (BEC-HFA) at recommended labelled doses.

METHODS

Twenty mild to moderate asthmatics were randomised in crossover fashion to receive 6 weeks of 500 micro g/day followed by 1000 micro g/day FLU-HFA and BEC-HFA. Measurements were made at baseline after placebo run in and washout, and after each randomised treatment. The primary airway outcome for benefit was the dose of methacholine provoking a fall in forced expiratory volume in 1 second (FEV(1)) of 20% or more (methacholine PD(20)) and for systemic adverse effects was overnight urinary cortisol/creatinine (OUCC).

RESULTS

For mean responses, both doses of BEC-HFA and FLU-HFA produced significant improvements in PD(20) compared with baseline. The improvement was not significantly greater with 1000 micro g/day FLU-HFA versus BEC-HFA, a 1.69 fold difference (95% CI 0.94 to 3.04). Both doses of BEC-HFA but not FLU-HFA caused significant suppression of OUCC compared with baseline, with significantly (p<0.05) lower values at 1000 micro g/day for BEC-HFA versus FLU-HFA (1.97 fold difference (95% CI 1.28 to 3.02)).

CONCLUSION

There was no difference in the airway and systemic effects in patients with mild to moderate asthma between FLU-HFA and BEC-HFA at a dose of 500 micro g/day. At 1000 micro g/day there was increased systemic bioactivity with BEC-HFA compared with FLU-HFA, without any gain in airway efficacy.

Growth, systemic safety, and efficacy during 1 year of asthma treatment with different beclomethasone dipropionate formulations: an open-label, randomized comparison of extrafine and conventional aerosols in children

OBJECTIVE

To assess the long-term safety of hydrofluoroalkane 134a (HFA)-beclomethasone dipropionate (BDP) extrafine aerosol administered by the Autohaler compared with chlorofluorocarbon (CFC)-BDP administered by a press-and-breathe metered-dose inhaler (pMDI) and spacer (+S) in the treatment of children with asthma.

METHODS

This 12-month, open-label, randomized, multicenter study enrolled 300 children who were aged 5 to 11 years and had well-controlled asthma on inhaled CFC-BDP or budesonide; 256 patients were using doses within the recommended range (200-400 microg) and were analyzed separately. Patients were randomized in a 1:3 ratio to continue on CFC-BDP+S at approximately the same dose as they were using before study entry or switch to HFA-BDP at half the daily dose.

RESULTS

Asthma control was well maintained in the HFA-BDP group as evidenced by lung function tests and asthma symptoms compared with CFC-BDP+S at approximately twice the dose. There were no significant differences between the HFA-BDP 100 to 200 microg and CFC-BDP+S 200 to 400 microg treatment groups in mean change from baseline in height (5.23 cm vs 5.66 cm at month 12, respectively) or mean growth velocity from day 1 to month 12 (5.27 cm/y vs 5.71 cm/y, respectively). There were no significant differences between groups in adrenal function tests or markers of bone metabolism.

CONCLUSIONS

In this long-term study in children with asthma, extrafine HFA-BDP provided long-term maintenance of asthma control at approximately half the dose compared with CFC-BDP+S. There were no clinically meaningful differences between HFA-BDP extrafine aerosol and conventional CFC-BDP+S with regard to growth or other systemic effects.

Safety of inhaled and intranasal corticosteroids: lessons for the new millennium

Although inhaled and intranasal corticosteroids are first-line therapy for asthma and allergic rhinitis, there has recently been an increasing awareness of their propensity to produce systemic adverse effects. The availability of more potent and lipophilic corticosteroids and new chlorofluorocarbon (CFC)-free formulations has focused attention on these safety issues. The main determinant of systemic bioavailability of these drugs is direct absorption from the lung or nose, where there is no first-pass inactivation. Consequently, the systemic bioavailability of inhaled corticosteroids is greatly influenced by the efficiency of the inhaler device. Thus, when comparing different inhaled corticosteroids it is imperative to consider the unique drug/device interaction. The pharmacokinetic profile is important in determining the systemic bioactivity of inhaled and intranasal corticosteroids. For highly lipophilic drugs, such as fluticasone propionate or mometasone furoate, there is preferential partitioning into the systemic tissue compartment, and consequently a large volume of distribution at steady state. In contrast, drugs with lower lipophilicity, such as triamcinolone acetonide or budesonide, have a smaller volume of distribution. The systemic tissue compartment may act as a slow release reservoir, resulting in a long elimination half-life for the lipophilic drugs. For intranasal corticosteroids, a high degree of lipophilicity diminishes water solubility in mucosa and therefore increases the amount of drug swept away by mucociliary clearance before it can gain access to tissue receptor sites. This may reduce the anti-inflammatory efficacy in the nose, but might also reduce the propensity for direct systemic absorption from the nasal cavity. The hydrofluoroalkane (HFA) formulations of beclomethasone dipropionate are solutions and exhibit a much higher respirable fine particle dose than do the CFC formulations. Dose-response studies with one of the HFA formulations have shown therapeutic equivalence at half the dosage, with little evidence of adrenal suppression at dosages up to 800 microg/day. A lack of similar studies for another of the available HFA formulations has led to a discrepancy in the recommendations for equivalence. Although in vitro studies have pointed to a similar fine particle distribution for the HFA and CFC formulations of fluticasone propionate, this is not supported by in vivo data for lung bioavailability, suggesting that care will be required when switching these formulations. Prescribers of inhaled and intranasal corticosteroids should be aware of the potential for long term systemic effects. The safest way to use these drugs is to 'step-down' to achieve the lowest possible effective maintenance dosage.

Repetitive graded ACTH stimulation test for adrenal insufficiency

ACTH stimulation is useful in assessing the hypothalamo-pituitary-adrenal axis. However, there is still some debate about the proper dose and interpretation. We designed a new protocol using repetitive graded ACTH stimulation. Thirty-two patients with the diagnosis of adrenal insufficiency (Al) were studied. After taking samples for baseline ACTH and cortisol, 1 microg fresh-prepared ACTH (Synacthen (1-24)) was injected intravenously, then 5, 50 and 100 microg at hourly interval. Cortisol responses were measured at 30, 60, 120, 180 and 240 min. The secondary Al group (26 subjects) had cortisol responses in between those of the control group (8 subjects) and the primary Al group (6 subjects). The minimal overlap between the secondary Al group and the control group occurred at a 30-min cortisol response after 1 microg ACTH stimulation, using 20 microg/dl as the cut-off level. There was only one exception which showed an episodic release at 30 min. There were 5, 10 and 9 patients with secondary Al who responded normally to 5, 50 and 100 microg ACTH stimulation, respectively. Maximal cortisol increments of the primary Al group were all below 4 microg/dl. Although there were 11 cases of secondary Al whose cortisol responses overlapped with those of primary Al, only two of them had a cortisol increment less than 4 microg/dl. Our new protocol combines the advantage of the low dose ACTH stimulation test, a sensitive method for detecting mild Al, and the ACTH infusion test, a longer test to mimic surgical stress.

Short-term dose-response relationships for the relative systemic effects of oral prednisolone and inhaled fluticasone in asthmatic adults

AIMS

To determine the systemic dose-response relationships with oral prednisolone and inhaled fluticasone propionate administered in a putative 11:1 mg equivalent basis, in terms of effects on adrenal, bone and haematological markers.

METHODS

Twelve asthmatic patients mean (s.e.) age, 28.8 [3.3] years, FEV1 94.7 [3.6]% predicted, FEF(25-75) 65.5 [6.1]% predicted were studied in a double-blind, double dummy randomised crossover design comparing placebo, inhaled fluticasone propionate via volumatic spacer given twice a day (ex actuator dose 0.44 mg day-1, 0.88 mg day-1, 1.76 mg day-1 ) and oral prednisolone given once daily (5 mg day-1, 10 mg day-1, 20 mg day-1 ). All treatments were for 4 days at each dose level with a 7-day washout at crossover. Measurements were made at 08.00 h after the last dose of each dose level for plasma cortisol, serum osteocalcin and blood eosinophil count.

RESULTS

There were significant dose-related effects for suppression of all three endpoints with both prednisolone and fluticasone propionate. Parallel slope analysis revealed a calculated dose ratio for relative potency of 8. 5:1 mg (95% CI 5.7-11.2) comparing Pred with FP for morning cortisol. The magnitude of suppression with FP was less for osteocalcin and eosinophils than for cortisol.

CONCLUSIONS

Systemic tissues exhibit different dose-response relationships for the effects of inhaled and oral corticosteroids with suppression of cortisol being greater than osteocalcin or eosinophils. For cortisol suppression we observed an 8.5:1 mg relative potency ratio comparing prednisolone with fluticasone propionate. Patients taking high dose inhaled fluticasone propionate should therefore be screened for evidence of impaired adrenal reserve.

Tests of adrenal insufficiency

AIM

In suspected adrenal insufficiency, the ideal test for assessing the hypothalamo-pituitary-adrenal axis is controversial. Therefore, three tests were compared in patients presenting with symptoms suggestive of adrenal insufficiency.

METHOD

Responses to the standard short Synacthen test (SSST), the low dose Synacthen test (LDST), and the 08:00 hour serum cortisol concentration were measured in 32 patients. A normal response to the synacthen test was defined as a peak serum cortisol of >/= 500 nmol/l and/or incremental concentration of >/= 200 nmol/l. The sensitivity and specificity of the 08:00 hour serum cortisol concentration compared with other tests was calculated.

RESULTS

Three patients had neither an adequate peak nor increment after the SSST and LDST. All had a serum 08:00 hour cortisol concentration of < 200 nmol/l. Eight patients had abnormal responses by both criteria to the LDST but had normal responses to the SSST. Three reported amelioration of their symptoms on hydrocortisone replacement. Twenty one patients had a normal response to both tests (of these, 14 achieved adequate peak and increment after both tests and seven did not have an adequate peak after the LDST but had a normal increment). The lowest 08:00 hour serum cortisol concentration above which patients achieved normal responses to both the LDST and SSST was 500 nmol/l. At this cut off value (compared with the LDST), the serum 08:00 hour cortisol concentration had a sensitivity of 100% but specificity was only 33%.

CONCLUSION

The LDST revealed mild degrees of adrenal insufficiency not detected by the SSST. The value of a single 08:00 hour serum cortisol concentration is limited.

24 hour and fractionated profiles of adrenocortical activity in asthmatic patients receiving inhaled and intranasal corticosteroids

BACKGROUND

As both rhinitis and asthma are allergic conditions, they frequently occur together. The objective of this study was to assess the diurnal adrenocortical activity in asthmatics receiving inhaled (inh) and intranasal (n) formulations of two different corticosteroids, fluticasone propionate (FP) and triamcinolone acetonide (TAA), both given at clinically recommended doses.

METHODS

Twelve stable moderately severe asthmatic subjects of mean age 23.9 years and mean forced expiratory volume in one second (FEV1) 84% predicted were recruited into a randomised placebo (PL) controlled two-way crossover study comparing nPL + inhPL, nPL + inhFP (880 micrograms bid), and nFP (200 micrograms once daily) + inhFP (880 micrograms bid) with nPL + inhPL, nPL + inhTAA (800 micrograms bid) and nTAA (220 micrograms once daily) + inhTAA (800 micrograms bid), each given for five days with a 10 day washout period. Twenty four hour integrated and fractionated (overnight, 08.00 hours, daytime) serum cortisol levels and urinary cortisol/creatinine excretion were measured.

RESULTS

For 24 hour and fractionated serum cortisol levels and corrected urinary cortisol/creatinine excretion there were significant (p < 0.05) differences between all active treatments and placebo. For 24 hour integrated serum cortisol levels the ratio between inhaled TAA and FP was 2.3 fold (95% CI 1.2 to 4.3), and for 24 hour urinary cortisol/creatinine excretion the ratio was two-fold (95% CI 1.2 to 3.4). For 24 hour urinary cortisol excretion, with all active treatments, individual abnormal low values of < 40 nmol (< 14.4 micrograms) occurred in 17/24 with FP compared with 4/24 with TAA (p < 0.0005). The 24 hour serum cortisol profile was flattened by FP but not with TAA. The addition of nasal corticosteroid did not produce further significant suppression of mean cortisol values, although with intranasal FP there were three more abnormal values for 24 hour urinary cortisol excretion than with inhaled FP alone.

CONCLUSIONS

Both inhaled FP and TAA caused significant suppression of adrenocortical activity which was twice as great with FP, the latter being associated with significantly more individual abnormal values and loss of the normal diurnal circadian rhythm. Fractionated serum cortisol levels and urinary cortisol/creatinine excretion were as sensitive as the respective integrated 24 hour measurements. Although the addition of intranasal formulations did not produce further significant suppression of mean values, there were more individual abnormal cortisol values associated with the addition of intranasal FP.

Fluticasone propionate 750 micrograms/day versus beclomethasone dipropionate 1500 micrograms/day: comparison of efficacy and adrenal function in paediatric asthma

BACKGROUND

Previous studies have suggested a 2:1 efficacy advantage of fluticasone propionate (FP) over beclomethasone dipropionate (BDP) in adults on high dose inhaled steroids and children on low dose inhaled steroids. The lower doses of FP required to provide equivalent efficacy to BDP also appear to have fewer systemic effects as measured by adrenal function.

METHODS

The efficacy and safety of FP 750 micrograms/day and BDP 1500 micrograms/day were compared in 30 children with persistent asthma (requiring 1000-2000 micrograms/day of inhaled corticosteroids) in a 12 week randomised double blind crossover study. Medication was delivered by a spacer device in two divided doses. Primary efficacy variables were peak expiratory flows (PEF). Adrenal function was assessed by 24 hour urinary free cortisol levels at eight and 12 weeks and ACTH and low dose synacthen tests (LDST) at 12 weeks. The results were adjusted for sequence and period differences.

RESULTS

There was no difference in the primary efficacy variables over the two 12 week treatment periods (difference in adjusted means for morning PEF 1.3 l/min (95% CI -6.1 to 8.8), p = 0.112) and symptom scores (cough, tachypnoea, wheeze, shortness of breath; difference in adjusted means of night time scores: -0.06 (95% CI -0.14 to 0.03); p = 0.136). Similar degrees of mild adrenal dysfunction were found during BDP and FP treatment phases. Identical height gain velocities were shown during the corresponding periods.

CONCLUSIONS

FP 750 micrograms/day is as effective as BDP 1500 micrograms/day in children with persistent asthma. At these very high doses we were unable to demonstrate a safety advantage of FP over BDP as assessed by adrenal function. However, measures of adrenal function may have been influenced by concurrent and previous systemic steroid usage, and possibly by effects of disease activity.