Plasma aldosterone response to ACTH stimulation test for diagnosis of primary aldosteronism: a cross-sectional study.

BACKGROUND: The diagnosis of primary aldosteronism (PA) requires screening and confirmation testing. The present study examined whether the 1 µg ACTH stimulation test for plasma aldosterone concentration (PAC) can accurately diagnose PA by bypassing the regular confirmatory steps of PA diagnosis. METHODS: A cross-sectional study with a total of 36 patients with an aldosterone-renin ratio (ARR) > 20 ng/dL per ng/m/hr were included. The confirmation test for PA was performed by saline infusion and the patients were categorized into PA and non-PA. PAC was collected at 20 and 40 min after 1 µg ACTH stimulation test. Multivariable logistic regression analysis was performed, and the associations are presented as odds ratios (OR) and 95% confidence intervals (CI). Diagnostic accuracy is presented as AuROC. RESULTS: Multivariable analysis found only PAC at 20 min after ACTH stimulation showed significant association with a diagnosis of PA (OR 1.18, 95%CI (0.99, 1.31), p = 0.040). AuROC for this value was 0.95 and the proposed cut-off was 52 ng/dL with a sensitivity of 71.4% and a specificity of 96.6%. CONCLUSIONS: Diagnosing PA may be aided by PAC at 20 min following 1 µg ACTH stimulation. This value may be used with patients for whom the confirmation test for PA cannot be conducted.

[Comparison of Different Doses of ACTH Used in ACTH Stimulation Test to Determine the Subtypes of Primary Aldosteronism]. / ä¸åŒå‰‚é‡ä¿ƒè‚¾ä¸Šè ºçš®è´¨æ¿€ç´ å ´å¥‹è¯•éªŒåœ¨åŽŸå‘æ€§é†›å›ºé ®å¢žå¤šç—‡åˆ†åž‹è¯Šæ–­ä¸­çš„æ¯”è¾ƒ.

Objective: To compare the diagnostic value of adrenocorticotropic hormone (ACTH) stimulation test (AST) with different doses of ACTH combined with midnight administration of 1 mg dexamethasone for the determination of the subtypes of primary hyperaldosteronism (PA). Methods: This is a prospective observational study. Patients diagnosed with PA in the Department of Endocrinology, the First Medical Center of of Chinese PLA General Hospital from January 1, 2020 to September 30, 2022 underwent AST with different doses of ACTH. All patients received 1 mg dexamethasone at midnight for inhibition. Then, the patients were randomly assigned to 25-unit and 50-unit ACTH treatment groups by a ratio of 1:2. Subtype classification and diagnosis of aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) was made on the basis of adrenal venous blood samples and/or postoperative pathology and clinical follow-up findings. Receiver operating characteristics (ROC) curves were plotted to examine the diagnostic efficacy and the difference of AST by varying doses of ACTH in distinguishing APA and IHA. Results: A total of 82 patients, including 49 patients with APA (59.8%) and 33 patients with IHA (40.2%), were enrolled. There were 29 patients in the 25-unit ACTH group (35.4%) and 53 patients in the 50-unit ACTH group (64.6%). There were no significant differences in age, sex, blood pressure, minimum serum potassium, and biochemical parameters between the 25-unit and 50-unit groups. After ACTH stimulation, plasma aldosterone concentration (PAC), cortisol (F), and PAC/F at different points of time showed no statistical difference between the two groups (P>0.05). The area under the curve (AUC) of PAC in the 25-unit group was higher than that of PAC/F. The AUC of PAC reached the maximum at 90 minutes (0.948, 95% confidence interval [CI]: 0870-1.000) and the optimal cutoff was 38.0 ng/dL, which had a sensitivity of 92.9% and a specificity of 86.7% for differentiating APA and IHA. Similar to the 25-unit group, the maximum AUC of PAC in the 50-unit group was greater than that of PAC/F. The AUC of PAC reached the maximum 90 minutes (0.930, 95% CI: 0.840-0.994) and the optimal cutoff was 39.6 ng/dL, which had a sensitivity of 91.2% and a specificity of 83.3%. The AUC of PAC at different points of time in the 25-unit ACTH group (0.862-0.948) was greater than that of 50-unit ACTH group (0.823-0.930), but the difference was not statistical significance. Conclusion: AST with 25-unit or 50-unit ACTH combined with small-dose dexamethasone can be used in PA subtype determination, ie, differentiation between APA and IHA. The optimal PAC cut-off values for 25-unit or 50-unit ACTH are similar, being 38.0 ng/dL and 39.6 ng/dL, respectively, and both cutoff values show higher sensitivity and specificity at 90 min. The AST with 25-unit ACTH has the smaller dose and the better safety. Therefore, it is recommended for the diagnosis of PA subtypes.

Hypothalamic-pituitary-adrenal axis recovery after intermediate-acting glucocorticoid treatment in client-owned dogs.

BACKGROUND: In dogs, duration of hypothalamic-pituitary-adrenal (HPA) axis suppression after systemic glucocorticoid treatment is reported to vary from a few days to up to 7 weeks after glucocorticoid discontinuation. These data are derived mainly from experimental studies in healthy dogs and not from animals with spontaneous disease. HYPOTHESIS AND OBJECTIVE: To determine the timeline for recovery of the HPA axis in a group of ill dogs treated with intermediate-acting glucocorticoids (IAGCs). ANIMALS: Twenty client-owned dogs that received IAGC for at least 1 week. METHODS: Single-center prospective observational study. An ACTH stimulation test, endogenous ACTH concentration, serum biochemistry profile, and urinalysis were performed at T0 (2-6 days after IAGC discontinuation) and then every 2 weeks (eg, T1, T2, T3) until HPA axis recovery was documented (post-ACTH cortisol concentration > 6 µg/dL). RESULTS: The median time of HPA axis recovery was 3 days (range, 2-133 days). Eleven of 20 dogs showed recovery of the HPA axis at T0, 6/20 at T1, and 1 dog each at T2, T5, and T9. Dose and duration of treatment were not correlated with timing of HPA axis recovery. Activities of ALT and ALP were significantly correlated with the post-ACTH cortisol concentration (rs = -0.34, P = .03; rs = -0.31, P = .05). Endogenous ACTH concentration was significantly correlated with pre (r = 0.72; P < .0001) and post-ACTH cortisol concentrations (r = 0.35; P = .02). The timing of HPA axis recovery of the dogs undergoing an alternate-day tapering dose was not different compared to dogs that did not (3.5 vs 3 days, P = .89). CONCLUSION AND CLINICAL IMPORTANCE: Most dogs experienced HPA axis recovery within a few days after IAGC discontinuation. However, 2/20 dogs required >8 weeks.

Characterizing the alternative feedback mechanisms in the hypothalamic-pituitary-adrenal (HPA) axis and determining a stressed state in the African wild dog (Lycaon pictus).

Glucocorticoids are regulated by the hypothalamic-pituitary-adrenal (HPA) axis and are important in responding to various psychological and physiological stressors. For the African wild dog (Lycaon pictus) only one aspect of the HPA axis has been investigated with no information present on cortisol insufficiency. Here, a pilot study involving both HPA feedback mechanisms is characterized by dynamic function tests (i.e., stimulation and suppression) and a cutoff value for a stressed state is established. Results showed a mean plasma cortisol increase of 40.7% after the administration of Synacthen from initial values, with females recording higher concentrations than males. Using Youden's index, this adaptive response was able to determine a cutoff value of 80.72 ng/ml that infers a stress state. The observed response in the suppression test was similar to that reported in domestic dogs. These results expand the basic knowledge of adrenal function in this endangered species and provide a means in which to determine whether animals are stressed or not. The method used also has application to other species in gauging the degree of stress they are experiencing, which can assist in improving welfare outcomes for captive animals.

Salivary Cortisol Response to ACTH Stimulation Is a Reliable Alternative to Serum Cortisol in Evaluating Hypoadrenalism.

CONTEXT: The serum total cortisol response to the ACTH stimulation test is widely used to assess adrenocortical function but is affected by changes in cortisol-binding globulin (CBG) concentration. Salivary cortisol reflects free cortisol concentrations and may offer a reliable alternative. OBJECTIVES: (1) To establish the salivary cortisol response to ACTH stimulation in healthy volunteers and patients with altered CBG concentrations; (2) to evaluate the performance of a lower reference limit (LRL) determined in healthy volunteers in patients with suspected hypoadrenalism (SH-patients). DESIGN: A 250 µg ACTH stimulation test was undertaken in 139 healthy volunteers, 24 women taking an estradiol-containing oral contraceptive pill (OCP-females), 10 patients with low serum protein concentration (LP-patients), and 30 SH-patients. Salivary cortisol was measured by liquid chromatography-tandem mass spectrometry. Mean and LRL of the 30-minute salivary cortisol response (mean-1.96 standard deviation) were derived from log-transformed concentrations. The LRL was applied as a diagnostic cut-off in SH-patients, with comparison to the serum response. RESULTS: Mean CBG concentrations (range) were 58 (42-81) mg/L, 64 (43-95) mg/L, 41 (28-60) mg/L, and 116 (84-159) mg/L in males, females, LP-patients, and OCP-females, respectively. The mean 30-minute salivary cortisol concentration was 19.3 (2.5th-97.5th percentile 10.3-36.2) nmol/L in healthy volunteers. Corresponding values were not different in OCP-females [19.7 (9.5-41.2) nmol/L; P = .59] or LP-patients [19.0 (7.7-46.9) nmol/L; P = .97]. Overall diagnostic agreement between salivary and serum responses in SH-patients was 79%. CONCLUSION: Salivary cortisol response to ACTH stimulation offers a reliable alternative to serum and may be especially useful in conditions of altered CBG concentration.

A Comparison of Lower Doses of Porcine Sequence Corticotropin with Standard Dose in Testing the Hypothalamic Pituitary Adrenal Axis in Healthy Individuals.

Context: Porcine sequence corticotropin (PSC) stimulation test (PSCST) is a reliable, cost-effective alternative to the short Synacthen test. Long-acting PSC is widely available as a 300 IU multidose vial (60 IU per 1 ml). Aims: To compare the efficacy of lower doses of PSC that can be given directly from the multidose vial without reconstitution, with standard dose in assessing the hypothalamic pituitary adrenal (HPA) axis in healthy individuals. Settings and Design: Prospective study comparing different doses of PSC. Methods and Material: In 13 healthy volunteers, serum Cortisol was estimated at 30 and 60 minutes after intramuscular administration of 24IU/250 µg standard dose (0.4 ml) and lower doses of PSC (18 IU/0.3 ml/;12 IU/0.2 ml; and 6 IU/0.1 ml), with a gap of 4 weeks between each dose. Statistical Analysis Used: Mean ± SD was used to express quantitative variables. ANOVA and paired T-test were used for statistical analysis. Results: The mean ± SD of peak Cortisol levels after PSCST with all doses of PSC were >18 ug/dl. The means of peak Cortisol responses to different doses of PSC among subjects were comparable. In a subject, there was no significant dose effect and interaction (dose x time) effect indicating that the different doses were comparable (both at 30 and 60 minutes) (p = 0.735). Conclusions: All tested lower doses of PSC obtained from the multidose vial without reconstitution, including the lowest dose (6 IU/62.5 µg) tested, were comparable in efficacy to the standard dose (24IU/250 µg) in assessing the adequacy of HPA axis in healthy individuals.

Real world evidence supports waking salivary cortisone as a screening test for adrenal insufficiency.

OBJECTIVE: Worldwide, adults and children are at risk of adrenal insufficiency largely due to infectious diseases and adrenal suppression from use of anti-inflammatory glucocorticoids. Home waking salivary cortisone is an accurate screening test for adrenal insufficiency, it has potential to reduce costs, and patients prefer it to the adrenocorticotropin (ACTH) (synacthen) stimulation test. We carried out a service evaluation of home waking salivary cortisone in clinical care to identify implementation barriers. DESIGN, PATIENTS AND MEASUREMENTS: Service evaluation in a centre where 212 patients referred for adrenal insufficiency had a waking salivary cortisone. Problems encountered during testing were recorded and patient feedback, via focus groups, collected. RESULTS: From all patients providing a waking salivary cortisone 55% had a normal test, 23% adrenal suppression, and 22% an equivocal result requiring a clinical centre ACTH stimulation test. The median (interquartile range [IQR]) for the time of the saliva sample was 07:40 (07:00-08:40). The median (IQR) days between collection and (i) delivery to local laboratory was 1 (0.25-2) day; (ii) reporting by local laboratory was 13 (11-18) days. Patients considered the test is "easy to do" and preferred it to the inpatient ACTH stimulation test. The principal challenge to clinical implementation was results reporting to clinicians due to delays at the local laboratory. CONCLUSIONS: This service evaluation provides real-world evidence that home waking salivary cortisone is an effective, practical screening test for adrenal insufficiency. It identified key barriers to testing implementation that need to be addressed when introducing the test to a health service.

Acton-Prolongatum Stimulated Blood Steroid Profile in Apparently Healthy Asian Indian Women of Reproductive-Age Group.

Blood steroid profile is a recently introduced test in India that is commercially available through a few diagnostic laboratories. In adult women, ACTH-stimulated steroid panel helps to differentiate polycystic ovary syndrome (PCOS) from nonclassical forms of CAH. However, the interpretation of ACTH-stimulated steroid panels is often impeded by the limited availability of reference ranges. Here, we report the adrenal steroid levels after stimulation with Acton Prolongatum in Asian Indian women of reproductive age. This prospective study was conducted at a tertiary health care center in the Southern part of India. Apparently healthy women in the reproductive age group with regular menstrual cycles (21-35 days) at least over the last 6 months were included. All participants received intramuscular Acton Prolongatum® (Pfizer) in the morning hours during the follicular phase and the steroid profile was analyzed by liquid chromatography-tandem mass spectrometry in a blood sample collected 60-min later. The study included 32 apparently healthy women. The mean age of the study population was 22.19 ± 4.36 years. None of the participants experienced any adverse events during the procedure. The median (range) serum cortisol, 17α-hydroxyprogesterone, 11-deoxycortisol, and corticosterone were 22.65 (14.3-37.21) µg/dl, 99.72 (47.21-344.71) ng/dl, 287.2 (74.41-530.61) ng/dl and 728.04 (118.74-1708.2) respectively. In conclusion, this is the first report of the response of adrenal steroids measured by LC-MS/MS at 60 min after Acton Prolongatum in Asian Indian women of the reproductive age group. However, further larger studies are warranted to establish more robust ACTH-stimulated reference ranges for steroid profile in Indian women.

Hypothalamic-Pituitary Axis Function and Adrenal Insufficiency in COVID-19 Patients.

The outbreak of COVID-19 has affected more than half a billion people worldwide and caused more than 6 million deaths since 2019. The responsible virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily affects the lungs, but it has multisystemic effects. It is well known that dysfunction of multiple endocrine organs may occur during or after COVID-19. Impairment of the hypothalamic-pituitary-adrenal (HPA) axis is of utmost importance as it may lead to death if went undiagnosed. SARS-CoV-2 may cause both primary and secondary adrenal insufficiencies (AIs). The clinical manifestations of AI are generally non-specific and might be attributed to the complications caused by the infection itself. The underlying pathogenetic mechanisms were explained by the immunogenic, vascular effects of the infection or the direct effects of the virus. The diagnosis of AI in critically ill patients with COVID-19 is not straightforward. There is lack of consensus on the cut-off values of basal serum cortisol levels and stimulation tests during the disease. Here we review the literature with a special regard on the evaluation of the HPA axis in patients with COVID-19. We conclude that the possibility of AI should always be kept in mind when dealing with patients with COVID-19, and repeated basal cortisol measurements and the ACTH stimulation test results could guide the clinician during the diagnostic process.

Risk factors that are associated with adrenal insufficiency among patients with fever of unknown origin.

BACKGROUND: Adrenal insufficiency is one of the causes of fever of unknown origin (FUO). The purpose of this study is to find out risk factors that are associated with adrenal insufficiency in FUO patients. METHODS: This study was conducted retrospectively in a tertiary hospital with 846 beds in South Korea. All adult inpatients (age ≥19 years) who have requested a consult with the department of infectious disease for FUO between 1 July 20191 July 2019 and 30 June 202030 June 2020 were included in the study. Among them, those who underwent an adrenocorticotropic hormone (ACTH) stimulation test and had a fever of 37.8°C or higher within 48 hours of the ACTH stimulation test were finally included in the study subjects. RESULTS: A total of 202 FUO patients were enrolled and 61 (30.1%) were finally diagnosed with adrenal insufficiency. In a multivariate analysis, use of immunosuppressant within 3 months (OR 6.06, 95% CI 1.82-20.13, P = 0.003), use of corticosteroid within 3 months (OR 8.23, 95% CI 1.35-50.17, P = 0.022), sodium ≥ 136.7 (OR 3.43, 95% CI 1.49-7.88, P = 0.004), and calcium ≥ 8.4 (OR 0.31, 95% CI 0.14-0.71, P = 0.005) were proven to be factors associated with adrenal insufficiency in FUO patients. CONCLUSION: In conclusion, 30.1% of FUO patients were diagnosed with adrenal insufficiency. The risk factors that are associated with adrenal insufficiency in FUO patients were immunosuppressive prescription or systemic steroid prescription within 3 months, or with sodium ≥ 136.7 or calcium < 8.4.

The Reliability of Salivary Cortisol Compared to Serum Cortisol for Diagnosing Adrenal Insufficiency with the Gold Standard ACTH Stimulation Test in Children.

The ACTH (adrenocorticotropic hormone) stimulation test is the gold standard for the diagnosis of adrenal insufficiency (AI), performed with ACTH high dose (HDT) or low dose (LDT). As salivary cortisol has been proposed as an alternative to serum cortisol, our aim was to evaluate the reliability of salivary cortisol compared to serum cortisol for diagnosing AI in children. Data were collected retrospectively. Salivary and serum cortisol values derived by 80 ACTH stimulation tests were obtained (39 F, 36 M; median age 11.5 years, IQR 6.9). Sampling was performed at baseline and after 30 and 60 min from ACTH administration during the HDT, and at baseline and 10, 20, 30, 40 and 60 min after the stimulation for the LDT. A serum cortisol level > 420 nmol/L ruled out AI. The correlation coefficients between serum and salivary cortisol for the HDT (n = 24) were 0.80 at t0, 0.48 at t30 and 0.75 at t60. All patients were adrenal sufficient. In 41% of the LDT, peak serum cortisol indicated insufficient adrenal function. The correlation coefficients between serum and salivary cortisol were 0.59 at t0 and 0.33 at the peak. For a cut-off of salivary cortisol < 15 nmol/L, sensitivity was 73.9% and specificity 69.6%. Our data do not support salivary cortisol as a valid alternative to serum cortisol during LDT. Regarding the HDT, results are more encouraging, however, further studies are needed.

Effect of Long-term Inhaled Corticosteroids on the Hypothalamic-Pituitary-Adrenal Axis in Children with Asthma.

OBJECTIVES: To assess the effect of the long-term use of inhaled corticosteroids (ICS) on the hypothalamic-pituitary-adrenal (HPA) axis. METHODS: Children (5-18 y) diagnosed with asthma and on ICS therapy for ≥6 mo were included. In the first step, screening with fasting at 8 AM, cortisol level was measured; a value <15 mcg/dl was considered low. Children with low fasting cortisol levels were subjected to adreno-corticotropic hormone (ACTH) stimulation test in the second step. Post-ACTH stimulation, cortisol level <18 mcg/dl was considered to have HPA axis suppression. RESULTS: A total of 78 children (males 55, 70.5%) diagnosed with asthma, with a median age of 11.5 (8, 14) y, were enrolled. The median duration of ICS use was 12 (12-24) mo. The median value of post-ACTH stimulation cortisol level was 22.5 (20.6, 25.5) mcg/dl, and a value <18 mcg/dl was observed in 4 (5.1%; 95% CI 0.2-10%) children. There was statistically no significant correlation between low post-ACTH stimulation cortisol level with ICS dose (p = 0.23) and asthma control (p = 0.67). None of the children had clinical features of adrenal insufficiency. CONCLUSIONS: In this study, a few children had low post-ACTH stimulation cortisol values; however, none had clinical evidence of HPA axis suppression. Therefore, ICS is a safe drug in children for treating asthma, even for long-term use.

Expanding the use of salivary cortisol as a non-invasive outpatient test in the dynamic evaluation of suspected adrenal insufficiency.

Background: Adrenal insufficiency (AI) is potentially life-threatening, and accurate diagnosis is crucial. The first-line diagnostic test, the adrenocorticotrophic hormone (ACTH) stimulation test, measures serum total cortisol. However, this is affected in states of altered albumin or cortisol-binding globulin levels, limiting reliability. Salivary cortisol reflects free bioactive cortisol levels and is a promising alternative. However, few studies are available, and heterogenous methodologies limit applicability. Methods: This study prospectively recruited 42 outpatients undergoing evaluation for AI, excluding participants with altered cortisol-binding states. Serum (immunoassay) and salivary (liquid chromatography tandem mass spectrometry) cortisol levels were sampled at baseline, 30 min, and 60 min following 250 µg synacthen administration. AI was defined as a peak serum cortisol level <500 nmol/L in accordance with guidelines. Results: The study recruited 21 (50%) participants with AI and 21 without AI. There were no significant differences in baseline characteristics, blood pressure, or sodium levels between groups. Following synacthen stimulation, serum and salivary cortisol levels showed good correlation at all timepoints (R2 = 0.74, P < 0.001), at peak levels (R2 = 0.72, P < 0.001), and at 60 min (R2 = 0.72, P < 0.001). A salivary cortisol cut-off of 16.0 nmol/L had a sensitivity of 90.5% and a specificity of 76.2% for the diagnosis of AI. Conclusion: This study demonstrates a good correlation between serum and salivary cortisol levels during the 250 µg synacthen test. A peak salivary cortisol cut-off of 16.0 nmol/L can be used for the diagnosis of AI. It is a less invasive alternative to evaluate patients with suspected AI. Its potential utility in the diagnosis of AI in patients with altered cortisol-binding states should be further studied.

Evaluation of Adrenal Reserve in Patients with Differentiated Thyroid Cancer Receiving Thyroid Hormone Suppression Therapy- case-control Comparative Study.

BACKGROUND: Patients with differentiated thyroid cancer (DTC) are exposed to subclinical exogenous hyperthyroidism for the suppression of thyroid-stimulating hormone (TSH). In this study, we aimed to evaluate the adrenal reserve in DTC patients receiving suppression therapy. MATERIALS AND METHODS: The study included 55 DTC patients on suppression therapy and 32 healthy volunteers. Basal serum cortisol of all participants and adrenocorticotropic hormone (ACTH) of the patient group were measured. A standard-dose ACTH test (0.25 mg) was performed in patients with a basal cortisol <14.5 mcg/dL. RESULTS: In the patient group, TSH was lower, free thyroxine (fT4) was higher, and free triiodothyronine (fT3) was similar to those of the control group (p < .01, p < .01, p = .140, respectively). The serum cortisol of the patient group was significantly lower than the control group (12.14 ± 5.12 mcg/dL vs 18.00 ± 5.56 mcg/dL, p < .001). A total of 34 (61.8%) patients with DTC had a basal cortisol <14.5 mcg/dL. Prolonged TSH suppression (≥5 years vs <5 years) was associated with lower basal cortisol (7.46 ± 2.63 mcg/dL vs 9.48 ± 2.65 mcg/dL, p = .022). The ACTH stimulation test showed that 2 (5.8%) patients had a cortisol response <18 mcg/dL. The rate of adrenal insufficiency was 3.6% in DTC patients. A moderate negative correlation was found between ACTH and fT3 of patients with low basal cortisol (r = -0.358, p = .038). CONCLUSION: Patients with DTC receiving TSH suppression therapy are at risk for adrenal insufficiency. The duration and severity of suppression might increase this possibility. Dynamic testing with synthetic ACTH can be used to reveal insufficient cortisol response in case of clinical suspicion.

Cortisol values during the standard-dose cosyntropin stimulation test: Personal experience with Elecsys cortisol II assay.

Purpose: There has been debate regarding the appropriate cortisol cutoff during the cosyntropin stimulation test (CST) when newer cortisol assays are used. We aimed to evaluate the proper cortisol values during the standard dose CST in patients with normal hypothalamic-pituitary-adrenal (HPA) axis when the Elecsys® Cortisol II assay from Roche Diagnostics is used. Methods: We retrospectively reviewed the medical records of patients evaluated for possible adrenal insufficiency using the standard-dose (250 mcg) CST from January 2018 to December 2020 and eventually judged to have a normal HPA axis. All the CSTs were done in the outpatient setting. Evaluation by an endocrinologist, restrictive exclusion criteria including prior glucocorticoid and opioid use, and lack of glucocorticoid treatment for at least 6 months after the CST was used to define normal HPA axis. The results are reported in the median (range). Results: We identified 63 patients who met the inclusion criteria and were considered to have a normal HPA axis. The median age was 54.7 (27.6-89.1) years; 32 (51%) were female, and 27 (43%) were white. The duration of follow-up after the CST without any glucocorticoid replacement was 13.9 (6.3-43.9) months. Cortisol levels were 21.7 (15.7-29.1) µg/dl and 24.4 (17.9-35.8) µg/dl at 30- and 60-minutes after cosyntropin administration, respectively. The lowest cortisol levels at 30 and 60 minutes for patients with either normal TSH or gonadal axis (n=47) or in whom both axes were normal (n=18) were similar to the ones of the entire cohort. Conclusion: Our study supports using a lower than previously recommended cortisol cutoff value at 30 minutes after Cosyntropin using the Roche Elecsys® Cortisol II assay. The lowest cortisol levels in our cohort were 15.7 and 17.9 µg/dL at 30 and 60 minutes after the CST, respectively. Therefore, it is essential to consider the time of cortisol draw after cosyntropin administration.

New Diagnostic Cutoffs for Adrenal Insufficiency After Cosyntropin Stimulation Using Abbott Architect Cortisol Immunoassay.

INTRODUCTION: The accurate interpretation of the cosyntropin (adrenocorticotropic hormone [ACTH]) stimulation test requires method- and assay-specific cutoffs of the level of cortisol. Compared with a historical cutoff (18 µg/dL) for polyclonal antibody-based immunoassays, lower thresholds were proposed for the Roche Elecsys II assay, which uses a monoclonal antibody. However, cutoffs for other commonly adopted, monoclonal antibody-based cortisol assays were not yet available. Here, we established the thresholds for the level of cortisol specific to the Abbott Architect immunoassay by comparing the measurements of the level of cortisol using 3 immunoassays. METHODS: The ACTH stimulation test was performed in patients with suspected adrenal insufficiency (n = 50). The serum cortisol level was measured using the Abbott Architect, Roche Elecsys II, and Siemens Centaur assays. The results of the Abbott assay were also compared with those of liquid chromatography-tandem mass spectrometry. The receiver operating characteristic analysis was performed to derive new diagnostic thresholds for the Abbott assay using the polyclonal antibody-based Siemens assay as the reference method. RESULTS: The concentrations of cortisol measured using the Abbott assay were similar to those measured using liquid chromatography-tandem mass spectrometry and the Roche Elecsys II assay but significantly lower than those measured using the Siemens assay. The optimized threshold for cortisol using the Abbott assay was 14.6 µg/dL at 60 minutes after stimulation (sensitivity, 92%; specificity, 96%) and 13.2 µg/dL at 30 minutes after stimulation (sensitivity, 100%; specificity, 89%). CONCLUSION: We recommend a threshold of 14.6 µg/dL for the level of cortisol at 60 minutes after ACTH stimulation for the Abbott assay. In comparison with the historical threshold of 18 µg/dL, the application of the new cutoff may significantly decrease false-positive results due to ACTH stimulation testing. The use of assay-specific cutoffs will be essential for reducing misclassification and overtreatment in patients with suspected adrenal insufficiency.

Biochemical assessment of adrenal insufficiency after adrenalectomy for non-cortisol secreting tumors: clinical correlation and recommendations.

BACKGROUND: Data regarding changes in cortisol axis after adrenalectomy for non-cortisol secreting tumors and their correlation with adrenal insufficiency are limited. Our aim was to analyze these changes and their clinical correlations to guide management after adrenalectomy for non-Cushing's tumors. METHODS: Following IRB approval, postoperative cortisol axis changes were analyzed in patients who underwent unilateral adrenalectomy for non-Cushing's tumors. A morning serum cortisol of ≥ 10 µg/dl was accepted as a sufficient adrenal response. RESULTS: 223 adrenalectomies were analyzed. In 63% of patients, POD1 serum cortisol was ≥ 10 µg/dl and in 37% < 10 µg/dl. No patient with a POD1 cortisol ≥ 10 µg/dl developed AI symptoms, whereas symptoms of AI were observed in 4% of those with < 10 µg/dl. In patients with a POD1 cortisol of < 10 µg/dl, the rate of steroid replacement therapy initiation was 100%, 8%, and 25% when the decision was based on serum cortisol, clinical symptoms, and serum cortisol plus ACTH stimulation test results, respectively. In 90% of asymptomatic patients, hypocortisolemia resolved uneventfully within a week on repeat morning cortisol testing. 75% of patients with hypocortisolemia on POD1 demonstrated an adequate cortisol response to ACTH stimulation test. CONCLUSION: Although postoperative hypocortisolemia was observed in 37% of patients undergoing unilateral adrenalectomy for non-cortisol secreting tumors, majority did not develop symptoms of adrenal insufficiency. All three steroid initiation approaches appeared safe, with management based on clinical symptoms or selective ACTH stimulation testing sparing more patients from steroids compared to steroid initiation based on POD 1 cortisol levels alone.

Evaluation of resting cortisol concentration testing in dogs with chronic gastrointestinal signs.

BACKGROUND: Resting cortisol concentrations are routinely measured in dogs with chronic gastrointestinal signs to rule out hypoadrenocorticism based on a concentration >2 µg/dL (>55 nmol/L). HYPOTHESIS/OBJECTIVES: To assess the cross-sectional prevalence of hypoadrenocorticism in a group of dogs with chronic gastrointestinal signs presented to a referral internal medicine service. ANIMALS: Two-hundred and eighty-two client-owned dogs with chronic gastrointestinal signs and with resting cortisol concentration testing performed. METHODS: Retrospective review of medical records (final diagnosis, resting cortisol concentration, and adenocorticotropic hormone [ACTH] stimulation test results) of a referral population of dogs between May 2013 and September 2017. RESULTS: Resting cortisol concentration was <2 µg/dL (<55 nmol/L) in 79 patients (28%). Repeated resting cortisol concentration measurements were performed in 28 dogs, and in 8, resting cortisol concentrations remained <2 µg/dL (<55 nmol/L). Post-ACTH cortisol concentration was <2 µg/dL (<55 nmol/L) in 1 dog, consistent with a diagnosis of hypoadrenocorticism and giving a prevalence estimate of hypoadrenocorticism in this population of dogs of 0.3% (95% confidence interval [95CI], 0.03-1.5%). In 19 dogs with an initial resting cortisol concentration <2 µg/dL (<55 nmol/L), hypoadrenocorticism was excluded based on a repeat resting cortisol concentration >2 µg/dL (>55 nmol/L). Overall, the most common diagnosis was chronic primary inflammatory enteropathy (176/282, 62.4%), followed by extragastrointestinal neoplasia (17/282, 6%), protein-losing enteropathy, pancreatitis and megaesophagus (10/282, 3.5% each). CONCLUSIONS AND CLINICAL IMPORTANCE: Although dogs with hypoadrenocorticism can present with chronic gastrointestinal signs, it was the final diagnosis in only 1 of 282 dogs presenting to a referral internal medicine service for signs of chronic enteropathy. Repeated resting cortisol concentration may be considered as a test to try and exclude hypoadrenocorticism.

Adrenal Vein Sampling in a Patient With Primary Hyperaldosteronism and Severe Contrast Allergy.

We report on a case of a 50-year-old female patient with primary hyperaldosteronism, in whom adrenal venous sampling was required to differentiate between unilateral and bilateral disease. Because of a history of severe allergy to iodinated contrast media, premedication with glucocorticoids was indicated. Exogenous glucocorticoids, however, can affect measurements of serum cortisol. To avoid this potential confounding effects on the cortisol assay, we decided to use dexamethasone instead of prednisolone or hydrocortisone. A high-dose adrenocorticotropin (ACTH) stimulation test with the simultaneous use of dexamethasone revealed an adequate adrenal cortisol response. ACTH-stimulated adrenal venous sampling showed reliable results, which provided a solid basis for further clinical decision-making.

A Predictive Risk Score to Diagnose Adrenal Insufficiency in Outpatients: A 7 Year Retrospective Cohort Study.

Background: The diagnosis of adrenal insufficiency (AI) requires dynamic tests which may not be available in some institutions. This study aimed to develop a predictive risk score to help diagnose AI in outpatients with indeterminate serum cortisol levels. Methods: Five hundred and seven patients with intermediate serum cortisol levels (3-17.9 µg/dL) who had undergone ACTH (adrenocorticotropin) stimulation tests were included in the study. A predictive risk score was created using significant predictive factors identified by multivariable analysis using Poisson regression clustered by ACTH dose. Results: The seven predictive factors used in the development of a predictive model with their assigned scores are as follows: chronic kidney disease (9.0), Cushingoid appearance in exogenous steroid use (12.0), nausea and/or vomiting (6.0), fatigue (2.0), basal cortisol <9 µg/dL (12.5), cholesterol <150 mg/dL (2.5) and sodium <135 mEq/L (1.0). Predictive risk scores range from 0-50.0. A high risk level (scores of 19.5-50.0) indicates a higher possibility of having AI (positive likelihood ratio (LR+) = 11.75), while a low risk level (scores of <19.0) indicates a lower chance of having AI (LR+ = 0.09). The predictive performance of the scoring system was 0.82 based on the area under the curve. Conclusions: This predictive risk score can help to determine the probability of AI and can be used as a guide to determine which patients need treatment for AI and which require dynamic tests to confirm AI.