Comparison of salivary and calculated free cortisol levels during low and standard dose of ACTH stimulation tests in healthy volunteers

Can Salivary Cortisol be Used in Diagnosing Adrenal Insufficiency During the Acute and Subacute Phases of Traumatic Brain Injury?

INTRODUCTION

The diagnosis of adrenal insufficiency (AI) related to traumatic brain injury (TBI) remains a challenge. We investigated the basal and low-dose adrenocorticotropic hormone (ACTH)-stimulated serum cortisol and salivary cortisol (SaC) levels and the diagnostic utility of SaC levels during 28 days following TBI.

MATERIALS AND METHODS

Blood samples were collected for basal levels [sequentially from day 1 (D1) to D7 and on D28)] and for peak serum cortisol and SaC responses to the low-dose ACTH stimulation test (on D1, D7, and D28). After the patient enrollment period was completed, patients were retrospectively categorized as AI or AS (adrenal sufficiency) for each day separately, based on a basal serum cortisol cut-off level of 11 µg/dL, and data analysis was performed between the groups.

RESULTS

Thirty-seven patients and 40 healthy controls were included. Median basal serum cortisol levels were higher in patients on D1 but were similar on other days. Median basal SaC levels were higher in patients on D1 and D2 but were similar on other days. Median peak serum cortisol and SaC levels were similar on D1 but were lower in patients on D7 and D28. Median basal SaC levels were higher in the AS group than in the AI group on all days.

DISCUSSION AND CONCLUSIONS

When evaluating AI during the course of TBI, the cut-off for basal SaC levels is 0.5-0.6 µg/dL throughout the first week, except for 1.38 µg/dL on D2. SaC levels may serve as a surrogate marker for accurately reflecting circulating glucocorticoid activity.

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.

Stress levels of a group of dentists while providing dental care under clinical, deep sedation, and general anesthesia

OBJECTIVES

Professionals in the health sector have higher stress than others. The aim of this study was to evaluate the stress levels of dentists while treating with children under clinical, deep sedation, and general anesthesia.

MATERIALS AND METHODS

Blood pressure (systolic, diastolic), pulse value, and O₂ saturations were measured. Saliva samples were taken by the dentists 10 min before the treatment, at the 25th min of the treatment, and 30 min after the treatment under clinical, deep sedation, and general anesthesia. Salivary cortisol was measured by the electrochemiluminescence method. All data were analyzed statistically.

RESULTS

Cortisol values under the sedation were higher than clinical and general anesthesia (P < 0.05). As a result of the applied Dentist Job Stress Questionnaire, the stress level of dentists under sedation was higher than the clinical and general anesthesia (P < 0.05). Under sedation, systolic and diastolic blood pressures measured during the procedure were found to be high (P < 0.05).

CONCLUSIONS

Dentists who care for pediatric patients are more stressed when applying treatment under deep sedation. The results suggest the need for more training and practice to strengthen the education given on general anesthesia/sedation in pediatric dentistry training.

CLINICAL REVELANCE

To increase the health and treatment quality of the dentists, who spend most of the day with the dental treatment of children, should be taken precautions.

Investigation of the Hypothalamo-pituitary-adrenal (HPA) axis: a contemporary synthesis

The hypothalamo-pituitary-adrenal (HPA) axis is one of the main components of the stress system. Maintenance of normal physiological events, which include stress responses to internal or external stimuli in the body, depends on appropriate HPA axis function. In the case of severe cortisol deficiency, especially when there is a triggering factor, the patient may develop a life-threatening adrenal crisis which may result in death unless early diagnosis and adequate treatment are carried out. The maintenance of normal physiology and survival depend upon a sufficient level of cortisol in the circulation. Life-long glucocorticoid replacement therapy, in most cases meeting but not exceeding the need of the patient, is essential for normal life expectancy and maintenance of the quality of life. To enable this, the initial step should be the correct diagnosis of adrenal insufficiency (AI) which requires careful evaluation of the HPA axis, a highly dynamic endocrine system. The diagnosis of AI in patients with frank manifestations is not challenging. These patients do not need dynamic tests, and basal cortisol is usually enough to give a correct diagnosis. However, most cases of secondary adrenal insufficiency (SAI) take place in a gray zone when clinical manifestations are mild. In this situation, more complicated methods that can simulate the response of the HPA axis to a major stress are required. Numerous studies in the assessment of HPA axis have been published in the world literature. In this review, the tests used in the diagnosis of secondary AI or in the investigation of suspected HPA axis insufficiency are discussed in detail, and in the light of this, various recommendations are made.

Salivary cortisol levels by tandem mass spectrometry during high dose ACTH stimulation test for adrenal insufficiency in children

PURPOSE

Serum cortisol measurements after ACTH stimulation are currently used to evaluate for adrenal insufficiency in children. We aim to determine if salivary cortisol measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) can confirm or replace serum cortisol during high dose ACTH stimulation test to improve test compliance and interpretation. We also aim to gain preliminary understanding of normal ranges of salivary cortisol in normal children at am, bedtime, and midnight.

METHODS

Children aged 6-17 years meeting study criteria and tested for adrenal insufficiency were recruited to concomitantly collect saliva and serum samples during high dose ACTH stimulation test. Normal children aged 3-18 years were recruited to collect morning, bedtime, and midnight saliva samples. Salivary cortisol was measured using LC-MS/MS while serum cortisol was determined by an immunoassay.

RESULTS

Salivary cortisol in normal children were higher at am and lower at bedtime and midnight (p value <0.0002 and <0.007, respectively). The midnight and bedtime levels were not sufficiently different (p value 0.36). Salivary cortisol during ACTH stimulation test positively and closely correlated with serum cortisol with 100% specificity and sensitivity when 18 µg/dL for serum and 500 ng/dL for salivary cortisol were used as cutoff values respectively for adrenal sufficiency.

CONCLUSIONS

Measurement of salivary cortisol by LC-MS/MS is less invasive, more convenient and better time controlled in busy pediatric clinic, therefore is better suited for young children to be used during high dose ACTH stimulation test to evaluate for adrenal insufficiency and to assist interpretation of test results by serum cortisol.

The Low-Dose ACTH Test: Usefulness of Combined Analysis of Serum and Salivary Maximum Cortisol Response in Pediatrics

CONTEXT

The low-dose (1 µg) ACTH test (LDT) is widely used to assess central adrenal insufficiency (CAI); however, the serum cortisol cutoff value is controversial. Salivary cortisol (SC) may be a more accurate measurement for CAI.

OBJECTIVE

To assess a new maximum cutoff value of serum cortisol after LDT in pediatric patients, taking into account serum and SC measurements.

DESIGN AND SETTING

Prospective study in a pediatric tertiary referral center.

WORKING HYPOTHESIS

The combined analysis of serum and SC response to LDT might improve LDT for CAI diagnosis.

PARTICIPANT AND OUTCOME MEASUREMENT

A total of 145 pediatric patients underwent LDT. Serum and SC levels were measured. A central adrenal sufficient (CAS) response was established according to the reference serum cortisol cutoff value of ≥497 nmol/L.

RESULTS

The LDT study showed central adrenal sufficiency in 72 patients and CAI in 73 patients. Considering the lower quartile of maximum SC value (21 nmol/L) in the CAS group, an intermediate CAI (InCAI) group and a real CAI (RCAI) group were defined. Regarding the median maximum value of serum cortisol levels in the InCAI group, a new serum cortisol cutoff value of 450 nmol/L was established. Furthermore, 91% of the patients in the RCAI group were below this cutoff value.

CONCLUSION

The combined evaluation of maximum serum and SC levels to LDT might be useful to define an InCAI group and to avoid unnecessary hormone replacement therapy. However, rigorous patient follow-up is required.

Characterization of the serum and salivary cortisol response to the intravenous 250 µg ACTH1-24 stimulation test

PURPOSE

The ACTH_1-24 stimulation test is commonly used to assess the hypothalamic-pituitary-adrenal (HPA) axis. Given variations in CBG concentration and binding affinity, serum total cortisol may misclassify some patients. Salivary cortisol correlates well with serum free cortisol but is easier to measure and widely available in commercial laboratories. The aim of this study was to investigate the utility of measuring salivary cortisol during the ACTH_1-24 stimulation test.

DESIGN AND METHODS

Case-control study in a clinical research facility. Eighty-seven patients with suspected cortisol deficiency, twenty-four healthy controls, and ten healthy women on the oral contraceptive (OC) underwent an intravenous 250 µg ACTH_1-24 stimulation test. Concordance of ACTH_1-24 stimulated serum and salivary cortisol was evaluated.

RESULTS

There was a significant difference in serum cortisol between the healthy volunteers and the women on the OC (P < 0.001) but no difference in salivary cortisol. The lower limit of the reference interval for salivary cortisol at 60 min was 26 nmol/L. 27/89 (30%) of tests with suspected HPA axis disorder failed the 60 min serum cortisol cut-off of 500 nmol/L. Of these, 24/27 (89%) had a salivary cortisol of <26 nmol/L. In contrast, 12/19 (63%) tests and 5/43 (12%) tests where the 60 min serum cortisol was 500-599 and ≥600 nmol/L, respectively had a salivary cortisol of <26 nmol/L.

CONCLUSIONS

Salivary cortisol provides additional diagnostic value during the 250 µg ACTH_1-24 stimulation test in patients with proven or suspected alterations in CBG and potentially those with a borderline 60 min serum cortisol 500-599 nmol/L.

Prolonged hypothalamic-pituitary-adrenal axis activation after acute coronary syndrome in the GENESIS-PRAXY cohort

Background

Glucocorticoid excess has been linked with cardiovascular disease. Little is known about the long-term cortisol response in patients after acute coronary syndrome.

Design

The objective of this study was to describe the distribution of salivary cortisol in the post-acute phase of acute coronary syndrome and to describe the association of late-night salivary cortisol with cardiovascular risk factors.

Methods

We used late-night salivary cortisol measurements post-discharge to estimate hypothalamic-pituitary-adrenal axis activity in 309 patients aged 18–55 years enrolled in the GENESIS-PRAXY study from January 2009–April 2013. We evaluated hypothalamic-pituitary-adrenal axis activity and its association with hypertension, dyslipidemia, diabetes, smoking, family history, prior acute coronary syndrome, psychiatric diseases, acute coronary syndrome severity, as well as mortality and rate of rehospitalization at 12 months.

Results

Persistently elevated late-night salivary cortisol>2.92 nmol/l was seen in 99 (32.0%) patients: within the range of what may be seen in Cushing’s disease. Elevated late-night salivary cortisol was associated with previous acute coronary syndrome (13.3% vs 24.2%, p = 0.02), peripheral vascular disease (3.8% vs 13.1%, p = 0.002), and smoking (32.9% vs 46.5% p = 0.02). Elevated late-night salivary cortisol was associated with higher hemoglobin A1c values (5.6 ± 3.0 vs 6.1 ± 2.9, p = 0.008) and lower high density lipoprotein values (0.94 ± 0.53 vs 0.86 ± 0.50, p = 0.01). There were no differences in psychiatric symptom scores, acute coronary syndrome severity or mortality, and rate of rehospitalization at 12 months.

Conclusions

Many patients post-acute coronary syndrome have prolonged, marked activation of the hypothalamic-pituitary-adrenal axis. Late-night salivary cortisol co-associates with several cardiovascular risk factors. Further studies are needed to confirm the exact role of hypothalamic-pituitary-adrenal axis activity in the pathophysiology of cardiovascular disease.

GENDER DETERMINES SERUM FREE CORTISOL: HIGHER LEVELS IN MEN

OBJECTIVE

Because only the free fraction of serum cortisol can readily access glucocorticoid receptors, we investigated whether or not a gender-related difference in serum free cortisol (FC) exists in the basal and adrenocorticotropic hormone (ACTH)-stimulated state.

METHODS

Serum total cortisol (TC) and FC were measured in 323 subjects (175 men; 148 women). Additionally, the low-dose 1-μg ACTH test was performed in 56 subjects (30 women, 26 men). Subjects were healthy volunteers, recruited in a preventive medicine screening program and an outpatient clinic.

RESULTS

Overall, basal serum TC and FC level were ~18 and ~33%, respectively, higher in men than in women (TC, 14.5 ± 0.33 μg/dL vs. 12.3 ± 0.33 μg/dL; P<.0001; FC, 0.68 ± 0.02 μg/dL vs. 0.51 ± 0.02 μg/dL; P<.0001). The higher FC in men relative to women was apparent across a wide age range (17 to 86 years) and persisted after adjustment for age and body mass index. The FC fraction (%FC, out of TC) was concordantly higher in men (5.4 ± 0.09% vs. 4.8 ± 0.3%; P = .046). FC was not related to the estimated menopausal status (women age below and above 47, 50, or 53 years). ACTH-stimulated FC levels were significantly higher in men compared to women, as reflected by the area under the response curve (49.4 ± 3.4 μg × min vs. 39.6 ± 2.2 μg × min; P = .0014).

CONCLUSION

Gender is an unrecognized determinant of serum FC in humans. The possibility of lifelong exposure to the higher bioactive fraction of cortisol under basal conditions or daily stress involving ACTH stimulation should be further investigated in the context of gender-related phenotypic features such as "android" (visceral) fat deposition and longevity.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone BMI = body mass index CBG = cortisol-binding globulin FC = free cortisol HPA = hypothalamic-pituitary-adrenal TC = total cortisol.