Distinct Late-Night Salivary Cortisol Cut-Off Values for the Diagnosis of Hypercortisolism.

Due to high morbidity and mortality of untreated hypercortisolism, a prompt diagnosis is essential. Measurement of late-night salivary cortisol provides a simple and non-invasive method. However, thresholds and reference ranges differ among studies. The goal of this study was to define a threshold of late-night salivary cortisol for the diagnosis of hypercortisolism based on the used assay. Moreover, the influence of different aetiologies of hypercortisolism and individual comorbidities were investigated. Prospective analyses of 217 patients, including 36 patients with proven hypercortisolism were carried out. A sum of 149 patients with suspicion of hypercortisolism but negative endocrine testing and 32 patients with hypercortisolism in remission served as control group. Late-night salivary cortisol was measured using an automated chemiluminescence immunoassay. Cut-off values were calculated by ROC analysis. The calculated cut-off value for the diagnosis of hypercortisolism was 10.1 nmol/l (sensitivity 94%; specificity 84%). Only slightly lower thresholds were obtained in patients with suspected hypercortisolism due to weight gain/obesity (9.1 nmol/l), hypertension or adrenal tumours (both 9.8 nmol/l) or pituitary adenomas (9.5 nmol/l). The late-night salivary cortisol threshold to distinguish between Cushing's disease and Cushing's disease in remission was 9.2 nmol/l. The cut-off value for the diagnosis of ectopic ACTH-production was 109.0 nmol/l (sensitivity 50%, specificity 92%). Late-night salivary cortisol is a convenient and reliable parameter for the diagnosis of hypercortisolism. Except for ectopic ACTH-production, thresholds considering different indications for evaluation of hypercortisolism were only slightly different. Therefore, they might only be useful if late-night salivary cortisol results near the established cut-off value are present.

Evaluation of Adrenal Vein Sampling Use and Outcomes in Patients With Primary Aldosteronism.

BACKGROUND: Primary aldosteronism (PA) occurs in 10%-20% of patients with resistant hypertension. Guidelines recommend adrenal vein sampling (AVS) to identify patients for surgical management. We evaluate the use of AVS in managing PA to better understand the selection and outcomes of medical versus surgical treatment. METHODS: A retrospective review was performed, and patients were divided into those who did (AVS) and did not have AVS (non-AVS). Demographics, aldosterone and renin levels, blood pressure, comorbidities, and antihypertensive medications were recorded. Reasons to defer AVS and medical versus surgical decision-making were examined and groups were compared. RESULTS: We included 113 patients; 39.8% (45/113) had AVS, whereas 60.2% (68/113) did not. Groups were similar in age, body mass index, and initial systolic blood pressure (SBP). In patients who underwent AVS, 31 of 45 (68.9%) had unilateral secretion and were referred for surgery, whereas 13 of 45 (28.9%) had bilateral secretion. Of the 31 referred for surgery, 26 underwent laparoscopic adrenalectomy, all cured; four refused surgery; and one counseled toward medical management by their physician. In 68 non-AVS patients, 6 (8.8%) underwent adrenalectomy without sampling and 2 with no clinical improvement. The remaining deferrals were because of normal or bilateral adrenal nodules on imaging (8/68, 11.8%); medical management due to poor surgical candidacy (12/68, 17.6%); patient refusal of intervention (13/68, 19.1%); or reasons not stated (28/68, 41.1%). At the follow-up, patients who underwent AVS had lower median SBP (135.4 mmHg versus 144.7 mmHg, P = 0.0241) and shorter follow-up (17.7 mo versus 54.0 mo, P < 0.0001). Surgically managed patients had biochemical resolution of PA with normalization of potassium levels (3.6 to 4.7mEq/L, P < 0.00001). CONCLUSIONS: AVS correctly selects patients for surgical management avoiding unnecessary surgery. However, despite guidelines, AVS is not always pursued as part of PA treatment, potentially excluding surgical candidates.

Consensus-driven in-hospital cortisol assessment after ACTH-secreting pituitary adenoma resection.

PURPOSE: Remission from Cushing disease (CD) after pituitary adenoma resection may be predicted by a postoperative reduction in serum cortisol level. A 2008 consensus statement recommends assessing morning cortisol levels during the first postoperative week, and replacing glucocorticoid (GC) if cortisol nadir of < 2 or < 5 µg/dL is achieved. We sought to evaluate adherence to consensus recommendations following adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma resection at our tertiary medical center, and assess time to cortisol nadir to better define the window for assessment and intervention. METHODS: We retrospectively analyzed data extracted from in-hospital electronic medical records for CD surgeries between January 1991 and September 2015. We compared cortisol levels and collection times, ACTH measurement, and postoperative and discharge GC treatment before and after consensus statement publication in July 2008. RESULTS: 107 surgeries were performed in 92 patients with CD. After 2008, more surgeries had at least one cortisol value assessed (67.9% before vs. 91.3% after, p = 0.033), with median initial cortisol measurement at 14 h post-surgery. However, ACTH measurement remained unchanged (42.9% vs. 43.5%; p > 0.99). Cortisol collection during GC treatment tended to increase (32.7% vs. 57.1%; p = 0.068). Of surgeries performed without prior GC treatment, 31.7 and 55.0% had a cortisol nadir of < 2 and < 5 µg/dL, respectively, within 72 h postoperative. CONCLUSIONS: Our physicians were more diligent in measuring in-hospital postoperative cortisol levels consistent with 2008 consensus recommendations. Better management of cortisol measurements and their timing is an opportunity for improvement.

Adrenal venous sampling for primary aldosteronism: laboratory medicine best practice.

Primary aldosteronism (PA) is the most common form of secondary hypertension and is critical to identify because when caused by an aldosterone-producing adenoma (APA) or another unilateral form, it is potentially curable, and even when caused by bilateral disease, antihypertensives more specific to PA treatment can be employed (ie, aldosterone antagonists). Identification of unilateral forms is not generally accomplished with imaging because APAs may be small and elude detection, and coincidental identification of a non-functioning incidentaloma contralateral to an APA may lead to removal of an incorrect gland. For this reason, the method of choice for identifying unilateral forms of PA is selective adrenal venous sampling (AVS) followed by aldosterone and cortisol analysis on collected samples. This procedure is technically difficult from a radiological standpoint and, from the laboratory perspective, is fraught with opportunities for preanalytical, analytical and postanalytical error. We review the process of AVS collection, analysis and reporting. Suggestions are made for patient preparation, specimen labelling practices and nomenclature, analytical dilution protocols, which numerical results to report, and the necessary subsequent calculations. We also identify and explain frequent sources of confusion in the aldosterone and cortisol results and provide an example of tabular reporting to facilitate interpretation and communication between laboratorian, radiologist and clinician.

Clinical Utility of the Adrenocorticotropin Stimulation Test with/without Dexamethasone Suppression for Definitive and Subtype Diagnosis of Primary Aldosteronism.

The adrenocorticotropin (ACTH) stimulation test (AST) has been reported to be useful for diagnosing primary aldosteronism (PA), particularly for differentiating PA subtypes under 1-mg dexamethasone suppression (DS). The aim of our study was to clarify the effect of 1-mg DS on AST results. A retrospective cohort study was conducted using data for 48 patients (PA: 30/48). We estimated the difference in plasma aldosterone concentration (PAC) responsiveness to ACTH stimulation with single (AST alone) and combined (AST under 1-mg DS) tests within the same patient. We compared the diagnostic accuracy of these two tests for PA and the laterality of hyperaldosteronism. We found no differences in PAC responsiveness to ACTH stimulation between single and combined tests, and observed a significant positive linear relationship (30 min, R² = 0.75, p-value < 0.01). Both tests showed the highest diagnostic accuracy for PA following 30 min of ACTH stimulation. The ability to detect the laterality of hyperaldosteronism was inconsistent and differed according to the two definitions: lateralization ratio and the absolute aldosterone levels in adrenal venous sampling. PAC responsiveness to ACTH stimulation was similar for AST with and without 1-mg DS. AST can be performed under both conditions with similar accuracy to detect PA.

Enhanced cosyntropin stimulation test performance enabled by electronic medical record.

PURPOSE: To improve performance of the cosyntropin stimulation test (CST) used for diagnosis of adrenal-cortisol insufficiency by implementing an electronic medical record (EMR) system protocol. METHODS: We implemented a SmartForm protocol of the validated CST in our EMR system (CS-Link™, EPIC) system and compared medical staff test performance before and after protocol implementation. RESULTS: Correct performance of the CST improved significantly after EMR implementation. The number of correctly performed CSTs increased from 16.1 % before to 53.5 % after implementation (p < 0.0001) while those performed incorrectly and were uninterpretable decreased from 36.2 to 7.1 % (p < 0.0001). This performance improvement result in a calculated cost savings of $50,414 for every 100 tests performed. CONCLUSIONS: The EMR system is useful for guiding medical staff to accurately perform the CST, reduce the number of wasted tests, and maximize staff time and resources.

Serum inhibin pro-αC is a tumor marker for adrenocortical carcinomas.

OBJECTIVE: The insufficient diagnostic accuracy for differentiation between benign and malignant adrenocortical disease and lack of sensitive markers reflecting tumor load emphasize the need for novel biomarkers for diagnosis and follow-up of adrenocortical carcinoma (ACC). DESIGN: Since the inhibin α-subunit is expressed within the adrenal cortex, the role of serum inhibin pro-αC as a tumor marker for ACC was studied in patients. METHODS: Regulation of adrenal pro-αC secretion was investigated by adrenocortical function tests. Serum inhibin pro-αC levels were measured in controls (n=181) and patients with adrenocortical hyperplasia (n=45), adrenocortical adenoma (ADA, n=32), ACC (n=32), or non-cortical tumors (n=12). Steroid hormone, ACTH, and inhibin A and B levels were also estimated in patient subsets. RESULTS: Serum inhibin pro-αC levels increased by 16% after stimulation with ACTH (P=0.043). ACC patients had higher serum inhibin pro-αC levels than controls (medians 733 vs 307 ng/l, P<0.0001) and patients with adrenocortical hyperplasia, ADA, or non-adrenocortical adrenal tumors (148, 208, and 131 ng/l, respectively, P=0.0003). Inhibin pro-αC measurement in ACC patients had a sensitivity of 59% and specificity of 84% for differentiation from ADA patients. Receiver operating characteristic analysis displayed areas under the curve of 0.87 for ACC vs controls and 0.81 for ACC vs ADA (P<0.0001). Surgery or mitotane therapy was followed by a decrease of inhibin pro-αC levels in 10/10 ACC patients tested during follow-up (P=0.0065). CONCLUSIONS: Inhibin pro-αC is produced by the adrenal gland. Differentiation between ADA and ACC by serum inhibin pro-αC is limited, but its levels may constitute a novel tumor marker for ACC.

Faecal glucocorticoid metabolites: how to express yourself - comparison of absolute amounts versus concentrations in samples from a study in laboratory rats.

During the last two decades, measurement of faecal cortisol or corticosterone metabolites (FCM) has become one of the most important tools to non-invasively monitor stress in animals. However, to reliably assess an animal's adrenocortical activity, a careful validation of this technique for each species and sex investigated is obligatory. Usually results in these validation studies and in subsequent applications are expressed as concentration (FCM(conc)). Nevertheless, some authors express their results as absolute amounts (FCM(abs)) and claim this to be more accurate. A physiological validation to prove this assumption, however, is still missing as well as information about the influence of the intervals set for faecal sampling, although the chosen intervals might play an important role. Since FCM(conc) and FCM(abs) may differ and therefore lead to different conclusions, our study aimed to gain fundamental and scientifically valid information about these parameters by re-analysing a set of data obtained in a study on laboratory rats. The data basis used was derived from four validation experiments performed in male and female rats: an adrenocorticotrophic hormone challenge test, a dexamethasone (Dex) suppression test, an investigation of the diurnal variation (DV) of glucocorticoids and the stress response in reaction to the injection procedure itself (for details see Lepschy et al. Non-invasive measurement of adrenocortical activity in male and female rats. Lab Anim 2007;41:372-87). Faecal samples were collected in short time intervals and the exact amount of faeces voided during each sampling interval was documented. Throughout all performed tests strong positive correlations between FCM(conc) and FCM(abs) were found (median of r(s) > 0.72). In males, for all calculated sampling intervals (4, 8 and 12 h) pharmacological stimulation, suppression and the DV of adrenocortical activity were reflected accurately using both FCM(conc) and FCM(abs). In females, suppression of FCM by Dex was also clearly reflected in both systems. However, pharmacological stimulation was only reflected accurately by means of FCM(conc), which clearly limits the usability of FCM(abs). Thus, using the data of physiological validation experiments, we clearly demonstrate for the first time advantages and disadvantages of presenting results as FCM(conc) or FCM(abs). Based on our findings in laboratory animals such as rats, giving results as FCM(conc) seems to be more appropriate and FCM(abs) - if at all - might only be used as an addition.

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.

Profile, mean residence time of ACTH and cortisol responses after low and standard ACTH tests in healthy volunteers.

OBJECTIVE: No consensus exists until now about the suitable dose of tetracosactin in the ACTH stimulation test for detecting adrenal insufficiency. Our aim was to characterize both the ACTH(1-24) and the cortisol profiles after standard high-dose test (250 microg) (HDT) and low-dose test (1 microg) (LDT) in healthy subjects in order to provide a deeper knowledge about the relationship between stimulus and response. DESIGN AND PATIENTS: ACTH tests were performed in 10 healthy volunteers (five men, five women) with at least 1 week of difference. MEASUREMENTS: Plasma ACTH(1-24) and ACTH(1-39) and serum cortisol were measured before tetracosactin i.v. injection and at 5, 15, 30, 45, 60, 75 and 90 min after stimulus. Area under the curve (AUC) of ACTH(1-24) and cortisol, as well as mean residence time (MRT) for ACTH(1-24) were calculated in both tests. RESULTS: Elimination of ACTH(1-24) was faster in HDT than in LDT (MRTs of 0.14 vs 0.37, respectively, P = 0.008), but plasma concentrations were higher up to 60 min cortisol production in HDT reaching a higher maximum concentration (Cmax: 1144 vs 960 nmol/l) but delayed in time (75 vs 52.5 min). No significant relationship was observed between AUC or Cmax of ACTH(1-24) and AUC, Cmax and increment of cortisol in any of the tests. However, a negative correlation of basal cortisol values was observed with relative cortisol increment (HDT: r = 0.77 P = 0.009; LDT: r = 0.94 P < 0.0001), but not so with Cmax (HDT: r = 0.22 P = 0.55; LDT: r = 0.57 P = 0.09). CONCLUSIONS: The elimination rate of ACTH in healthy volunteers was significantly lower in LDT than in HDT, but cortisol production rate appears to be identical in both tests, so that a maximum adrenal stimulation seems to exist. The use of LDT may be more adequate, although data from patients need studying.

Adrenocortical insufficiency after pituitary surgery: an audit of the reliability of the conventional short synacthen test.

BACKGROUND: Assessment of the hypothalamic-pituitary-adrenal (HPA) axis after pituitary surgery is important for appropriate decision making regarding replacement therapy. The synacthen test is often used but is questioned, as time has to elapse for adrenal atrophy to develop. OBJECTIVE: To audit the use of the 250 microg synacthen test after transsphenoidal adenomectomy. METHODS: A retrospective study of 110 patients submitted to first-time transsphenoidal adenomectomy. Anterior pituitary testing was performed preoperatively, 1 week and 1, 3, 6 and 12 months postoperatively. The adrenocortical function was tested by a synacthen test (250 microg synacthen i.v.). RESULTS: Thirty-two out of 71 patients with normal HPA function before surgery developed insufficiency postoperatively, seven patients presenting an insufficient test response after 1 week, 16 after 1 month and nine after 3 months, whereas none became insufficient during the remaining follow-up. Three patients presented symptomatic adrenal insufficiency during the first postoperative week despite a normal test. All of these developed an insufficient test 1 month postoperatively. A 1-week basal plasma cortisol > 400 nmol/l indicated HPA sufficiency, whereas a basal cortisol < or = 100 nmol/l indicated insufficiency when related to the diagnosis based on the 3-month synacthen test. CONCLUSION: This study confirms that the synacthen test is of limited use in the early postoperative phase, because out of 62 patients with normal 1-week postoperative synacthen responses, 23 patients developed a test that was indicative of adrenal insufficiency over 1-3 months. Our results indicate that a large proportion of patients should be considered for hydrocortisone replacement therapy up to 3 months postoperatively followed by reassessment of the HPA axis.

Establishment of reference values for endocrine tests. Part IV: Adrenal insufficiency.

BACKGROUND: The short Synacthen test, the overnight metyrapone test and the insulin tolerance test are frequently used in the evaluation of patients suspected of adrenal insufficiency. in the present study, we established reference values for these diagnostic tests, as well as for baseline morning plasma cortisol and adrenocorticotrophic hormone (ACTH). METHODS: We studied 50 subjects recruited from the general population, equally distributed according to sex and age between 20 and 69 years. A short ACTH stimulation test (250 microg Synacthen iv), an overnight metyrapone test (2.0, 2.5, or 3.0 g given orally depending on body weight at 23.30 hours) and an insulin tolerance test (0.15 U/kg actrapid iv) were performed. Reference intervals are given as the means +/- 2SD of observed hormone concentrations after logarithmic transformation. RESULTS: The following reference values were established: 09.00 hr plasma cortisol 150 to 802 nmol/l, 09.00 hr plasma ACTH 8 to 93 ng/l, peak plasma cortisol after Synacthen 591 to 1,113 nmol/l, peak plasma cortisol after insulin-induced hypoglycaemia 557 to 1,015 nmol/l, and plasma 11-deoxycortisol after metyrapone 197 to 759 nmol/l. CONCLUSION: We established reference values for diagnostic tests that are useful in the evaluation of patients suspected of primary or secondary/tertiary adrenal insufficiency.