High-dose and low-dose cosyntropin stimulation tests for diagnosis of adrenal insufficiency

Comparison of total, salivary and calculated free cortisol levels in patients with severe sepsis

Background

The purposes of the study were to compare serum total cortisol (STC), salivary cortisol (SaC) and calculated free cortisol (cFC) levels at baseline and after the adrenocorticotrophic hormone (ACTH) stimulation test in patients with severe sepsis (SS) and determine the suitability of use of SaC and cFC levels instead of STC for the diagnosis of adrenal insufficiency (AI) in patients with SS. And secondary aims of this study were to compare these parameters in patients with SS with healthy controls and check their effects on survival status of the patients.

Methods

Thirty patients with SS (15 men and 15 women) were compared with 16 healthy controls. Low-dose (1 μg) ACTH stimulation test was performed to the patients on the first, seventh and 28th days of diagnosis of SS, but in control group, 1 μg ACTH stimulation test was performed only once. STC, SaC and cFC levels were measured during ACTH stimulation test.

Results

Patients were categorized as having low or high baseline STC according to a cut-off level of 10 μg/dL. In high STC group, baseline and peak SaC levels were found to be 2.3 (0.2–9.0) and 3.4 (0.5–17.8) μg/dL on D1 and 1.1 (0.8–4.6) and 2.6 (1.3–2.9) μg/dL on D7, respectively. In the control group, baseline and peak SaC levels were 0.4 (0.1–1.4) and 1.1 (0.4–2.5) μg/dL, respectively. Baseline and peak SaC levels after ACTH stimulation were found to be higher in high STC group than in controls, but they were found to be similar in low STC and control groups. In high STC group, cFC levels were 0.3 (0.1–0.3) and 0.4 (0.3–0.7) μg/dL on D1 and 0.2 (0.1–0.3) and 0.4 (0.1–0.7) μg/dL on D7, respectively. In the control group, baseline and peak cFC levels were 1.7 (0.4–1.9) and 1.8 (1.0–6.6) μg/dL, respectively. cFC levels were found to be lower in patients with SS subgroups than in the control group. Baseline and stimulated STC, SaC and cFC levels did not differ according to the survival status. SaC, cFC and STC levels were found to be correlated with each other.

Conclusions

SS is associated with increased SaC, but decreased cFC levels when baseline STC is assumed to be sufficient. When STC level is assumed to be insufficient, SaC levels remain unchanged, but cFC levels are decreased. Lower STC levels is not associated with increased mortality in patients with SS. More data are needed in order to suggest the use of SaC and cFC instead of STC.

Trial registration

ClinicalTrials.gov No: NCT02589431

A Comparative Effectiveness Analysis of Alternative Strategies to Assess Hypothalamic-Pituitary-Adrenal Axis Function After Microsurgical Resection of Pituitary Tumors

BACKGROUND:

Observational methods can be used in conjunction with the comparative effectiveness research (CER) paradigm to inform decisions between alternative patient management strategies in real-world clinical settings.

OBJECTIVE:

To present a brief review of current observational research regarding 3 strategies for predicting normal hypothalamic-pituitary-adrenal (HPA) axis function after surgical resection of pituitary tumors and to apply the CER model to compare these management alternatives.

METHODS:

We designed and conducted 2 prospective observational studies involving 183 patients undergoing microsurgical resection for pituitary tumors. These investigations yielded a comprehensive database comprising longitudinal data from multiple clinical domains. We investigated 3 potential strategies to predict normal postoperative HPA axis function in this cohort, including preoperative adrenocorticotrophic hormone stimulation testing and measurement of serum cortisol levels immediately after surgery or on the first postoperative day. We performed a focused comparative effectiveness review to help inform the decision between the 3 potential clinical management strategies.

RESULTS:

This investigation illustrates the use of observational research methods in conjunction with CER methodology as one means of informing clinical management decisions. Of the 3 strategies for assessing postoperative HPA axis function studied, preoperative and immediate postoperative adrenocorticotrophic hormone stimulation testing had the highest sensitivity, accuracy, and positive predictive value for normal HPA axis function postoperatively. The preoperative strategy was also the most cost-effective approach (12% reduction vs benchmark).

CONCLUSION:

The decision to use any of the 3 strategies outlined requires attention to a specific patient's clinical situation, but this decision may be aided by the results of this CER analysis.

Assessment of the hypothalamic-pituitary-adrenal axis in critical illness

Cortisol is the main corticosteroid secreted from the human adrenal cortex, and it has a crucial role for survival in stressful conditions. An adequate increase in levels of cortisol helps patients to cope with the severity of the disease in the acute phase of critical illness. Either higher or lower than expected cortisol levels were found to be related to increased mortality. Prolonged activation of the hypothalamic-pituitary-adrenal (HPA) axis can result in hypercortisolemia or hypocortisolemia; both can be detrimental to recovery from critical illness. Primary and secondary adrenal insufficiency, relative adrenal insufficiency, tissue resistance to glucocorticoids, adrenocorticotrophic hormone deficiency and immune-mediated inhibition of the HPA axis can be the cause of the impairment of the secretion or action of cortisol in critically ill patients. Recently, some authors offered the term 'critical illness-related corticosteroid insufficiency' to better point out the relative adrenal insufficiency that is seen during critical illness. Patients with critical illness-related corticosteroid insufficiency not only have insufficient circulating cortisol but also have impaired cellular utilization of cortisol. In this article, how adrenal dysfunction presents in critical illness and how appropriate diagnosis and management can be achieved in the critical care setting will be discussed.

Dexamethasone suppression test predicts later development of an impaired adrenal function after a 14-day course of prednisone in healthy volunteers

BACKGROUND

Suppression of the adrenal function after glucocorticoid treatment is common, potentially dangerous, and unpredictable. Identification of patients at risk is of clinical importance. We hypothesized that the dexamethasone suppression test predicts the development of corticosteroid-induced impaired adrenal function.

METHODS

We included 39 healthy male volunteers. After a 1-microg ACTH test, all participants underwent an overnight 0.5-mg dexamethasone suppression test. Participants then took prednisone, 0.5 mg/kg body weight, for 14-day. After the withdrawal of prednisone, a 1-microg ACTH test was performed and a clinical score was assessed on days 1, 3, 7, and 21.

RESULTS

On days 1, 3, 7, and 21, 100, 50, 26.5 and 32.4% of the participants had a suppressed adrenal function. The risk of developing suppressed adrenal function decreased from 44 to 0% in patients with cortisol levels after the administration of dexamethasone in the lowest and highest quartiles respectively. Receiver operating curve (ROC) analysis performed to predict a suppressed adrenal function on day 7 after the withdrawal of prednisone showed an area under the curve (AUC) of 0.76 (95% confidence interval (CI) 0.58-0.89) for cortisol after the administration of dexamethasone, which was in the range of the AUC of 0.78 (95% CI 0.6-0.9) for pre-intervention cortisol after the administration of ACTH. Basal cortisol before intake of prednisone (AUC 0.62 (95% CI 0.44-0.78)) and the clinical score (AUC 0.64 (95% CI 0.45-0.79)) had significantly lower AUCs.

CONCLUSION

Circulating cortisol levels after a dexamethasone suppression test and a pre-intervention-stimulated cortisol level are predictive of later development of a suppressed adrenal function after a 14-day course of prednisone, and are superior to a clinical score or basal cortisol levels. This may allow a more targeted concept for the need of stress prophylaxis after cessation of steroid therapy.

Use of morning serum cortisol level after transsphenoidal resection of pituitary adenoma to predict the need for long-term glucocorticoid supplementation

Object

Accurate assessment of the hypothalamic-pituitary-adrenal (HPA) axis is critical for appropriate management of the disease in patients with pituitary adenoma after transsphenoidal resection. The authors examine the role of the morning total serum cortisol level in the early postoperative period as a predictor of long-term HPA function.

Methods

Morning total serum cortisol was measured in 83 patients on postoperative Day 1 (or Day 2 if the patient received glucocorticoids during surgery) after transsphenoidal surgery for pituitary adenoma. These results were compared with those of definitive assays of HPA function performed at 1–3 months postoperatively, including cortrosyn/synacthen stimulation test (CST), insulin tolerance test (ITT), and metyrapone test (MTT). The ability of the early-postoperative morning cortisol level to predict HPA function was determined using standard confusion matrix calculations and receiver-operator control curve analysis.

Results

The authors found that an early postoperative morning total cortisol level ≥ 15 μg/dl is a sensitive and accurate predictor of normal HPA function in the postoperative period (sensitivity 80.5%, specificity 66.7%, positive predictive value 96.9%).

Conclusions

A morning total cortisol level ≥ 15 μg/dl in the early postoperative period after transsphenoidal surgery for pituitary adenomas is a good predictor of normal HPA function. This test has good sensitivity and accuracy and correlates well with the results of additional, definitive assays of HPA function (CST, ITT, and MTT) performed at 1–3 months postoperatively. Accordingly, it is the authors' practice to avoid exogenous perioperative glucocorticoid supplementation in patients with normal preoperative HPA function and postoperative morning total cortisol levels ≥ 15 μg/dl 1–2 days after transsphenoidal pituitary adenomectomy.

Low-dose and high-dose adrenocorticotropin testing: indications and shortcomings

PURPOSE OF REVIEW

The 250 microg adrenocorticotropin test (high-dose test) is the most commonly used adrenal stimulation test, though the use of physiologic doses (1.0 microg or 0.5 microg/1.73 m) (low-dose test) has recently gained wider acceptance. These variants and the use of adrenocorticotropin test in the ICU, however, remain controversial. The validity of the low-dose test and the parameters for evaluation of high- and low-dose tests in different situations need reevaluation.

RECENT FINDINGS

In the last few years, numerous studies have used the low-dose test as a single test following previous findings that it is more sensitive and accurate than the high-dose test. It is used mainly in secondary adrenal insufficiency and after treatment with therapeutic glucocorticosteroids to define hypothalamo-pituitary-adrenal suppression. Unless there is a very recent onset of disease, the results are interpreted by most researchers as diagnostic. The treatment of relative adrenal insufficiency, based on delta cortisol, has not yielded proof of correlation between this diagnosis and better prognosis with glucocorticoid treatment.

SUMMARY

For interpretation of an adrenocorticotropin test, only peak - and not delta - cortisol should be used. The use of 240-300 mg of hydrocortisone daily in ICU patients, including septic shock, should be considered as pharmacologic, rather than as a replacement dose. Using the low-dose test for this purpose will lead to further misdiagnosis.

Evaluation of adrenal function using the human corticotrophin-releasing hormone test, low dose Synacthen test and 9am cortisol level in children and adolescents with central adrenal insufficiency

BACKGROUND

The insulin tolerance test (ITT) has become less popular in paediatrics because of the risks associated with hypoglycaemia. Human corticotrophin-releasing hormone (hCRH) test results correlate with the ITT and may be an acceptable method to test for central adrenal insufficiency (CAI). Simpler tests, such as the low dose Synacthen test (LDST) and 9am cortisol, have also been proposed.

OBJECTIVE

To compare the ability of the hCRH test, LDST, 9am cortisol level and 24-h cortisol profiles to diagnose CAI in a paediatric population.

DESIGN AND SETTING

A cross-sectional study in a tertiary paediatric endocrine clinic.

PARTICIPANTS

Thirty-one children and adolescents (aged 2.3-18.3 years) with CAI risk factors had an hCRH test, LDST, 9am cortisol and 24-h cortisol profile performed.

RESULTS

Of 23 patients with confirmed CAI (hCRH peak cortisol < 400 nmol/), 19 failed the LDST (peak cortisol < 267 nmol/l, i.e. 10th percentile for controls). Nineteen would have failed based on the 10th percentile cut point for 9am cortisol (< 140 nmol/l). Using receiver operating characteristic (ROC) curve coordinates, a 9am cortisol < 108 nmol/l was sensitive (83%) and specific (99%) for CAI. The 9am cortisol levels measured on two occasions were repeatable (94%) and correlated (r = 0.83, P = 0.01). All eight adrenally sufficient patients (hCRH peak cortisol > or = 400 nmol/l) passed the LDST. Seven had normal 9am cortisol (> or = 140 nmol/l). The 24-h cortisol area under the curve (AUC) for these patients was within the 10th-90th percentiles for control subjects' AUC. The peak cortisol to hCRH and LDST were correlated (r = 0.88, P = 0.01), with no difference between the peaks (mean difference -5.3 nmol/l, P = 0.69).

CONCLUSIONS

In children with CAI risk factors, the diagnosis can be made if unstressed 9am cortisol is < 108 nmol/l. As cortisol levels > 381 nmol/l are highly suggestive of normal hypothalamic-pituitary-adrenal (HPA) function, stimulation testing need only be performed if 9am cortisol is 108-381 nmol/l. The LDST should be interpreted cautiously because mild CAI may be missed. When stimulation results are marginal, 24-h cortisol profiles can provide reassurance of normal cortisol status.

Plasma aldosterone response to the low-dose adrenocorticotrophin (ACTH 1-24) stimulation test

BACKGROUND

Endocrine tests for adrenal insufficiency use pharmacological doses of stimulant such as ACTH. More physiological tests have often used high-dose protocols for sampling frequency.

AIMS

To evaluate the response of plasma aldosterone concentration to low doses (125, 250 and 500 ng/m(2) body surface area) of synthetic ACTH.

DESIGN

A randomised trial in six normal adult males aged 18-27 years.

MATERIALS AND METHODS

Aldosterone concentration was measured by radioimmunoassay in serum from blood samples taken at 10 min intervals for 90 min.

RESULTS

All three doses produced a significant rise in plasma aldosterone concentration (125 ng/m(2), P = 0.003; 250 ng/m(2), P < 0.001; 500 ng/m(2), P < 0.001) but there was no effect of dose on either the peak or incremental plasma aldosterone concentration. Mean time to peak was similar between the doses and the two higher doses were associated with a longer secretory profile (125 ng/m(2) 56 (26 SD) mins, 250 ng/m(2) 74 (19) mins, 500 ng/m(2) 77 (21) mins; F = 3.39; P = 0.04). Peaks of 100% were detected within 30 min of drug administration and peak response was associated with the prestimulation plasma aldosterone concentration (r = 0.45; P = 0.003). The between- and within-individual coefficients of variation for prestimulation concentrations were 37.0% and 32.8%, and for the peak response were 27.2% and 27.2%, respectively.

CONCLUSIONS

The response of plasma aldosterone concentrations to low-dose ACTH administration requires a blood sampling protocol of 0, 10, 20 and 30 min to capture concentrations near the peak response. The high-dose protocol would have missed the response. Over the dose range studied no dose-response was observed so the selection of dose should be based on the dose effective to release steroids in the glucocorticoid pathway if this study is to be used in conjunction with such evaluation.