Long-acting porcine ACTH stimulated salivary cortisol in the diagnosis of adrenal insufficiency

Long-acting porcine ACTH stimulated salivary cortisol reduces the overdiagnosis of adrenal insufficiency compared to serum cortisol in cirrhosis liver

BACKGROUND

There are no reliable methods in clinical practice to diagnose adrenal insufficiency (AI) in patients with cirrhosis owing to variable cortisol-binding protein levels. This leads to unreliable results in ACTH stimulated serum cortisol test. We aimed to estimate the long-acting porcine (LA)ACTH-stimulated serum and salivary cortisol levels of patients at different stages of cirrhosis using second generation electrochemiluminescence and to determine the prevalence of true adrenal insufficiency in these patients.

DESIGN, PATIENTS AND MEASUREMENTS

We included 135 noncritical patients with cirrhosis (45 each from CHILD A, B and C) and 45 healthy controls. Serum and salivary samples were collected at baseline in the morning and at 1 and 2 h after LA-ACTH injection.

RESULTS

In healthy subjects, the 2.5th centile of 2 h ACTH stimulated serum and salivary cortisol were 19.8 and 0.97 μg/dL, which were used as cut-offs for defining AI based on serum and saliva respectively. The median (interquartile-range) 2-h stimulated salivary cortisol in Child A, B, C categories and controls were 1.36(1.23-2.38), 1.46(1.18-2.22), 1.72(1.2-2.2) and 2.12(1.42-2.72) μg/dL respectively. Six subjects (4.4%) were diagnosed to have AI based on stimulated salivary cortisol cut-off, whereas 39 (28.9%) cirrhosis subjects had inadequately stimulated serum cortisol. Three patients (symptomatic) required steroid replacement therapy. Hypoalbuminemia was identified as a major risk factor for the misdiagnosis of adrenal insufficiency by serum cortisol-based testing.

CONCLUSIONS

Long-acting porcine ACTH stimulated salivary cortisol reduces the overdiagnosis of adrenal insufficiency compared to serum cortisol in cirrhosis liver. Stimulated salivary cortisol is a promising investigation for evaluation of adrenal function in cirrhosis and more studies are required for its further validation before clinical 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.

Frequently Asked Questions in Patients With Adrenal Insufficiency in the Time of COVID-19

Adrenal insufficiency (AI) is a life-threatening disorder, with increased morbidity and mortality, especially in case of an acute illness that can increase the requirement of cortisol. A novel infectious disease, termed Coronavirus Disease 2019 (COVID-19), appeared in 2020. Therefore, AI patients are experiencing a novel challenge: the risk of infection. In our experience, a prompt contact to the Endocrine center (with a telemedicine consultation) and a full awareness of diseases (cortisol deficiency, COVID-19 and the self-management of an adrenal crisis) are important to motivate patients. Vaccine is an effective treatment to prevent hospitalization and aggressive course of COVID-19. Some patients manifest challenges due to inequitable access and vaccine hesitancy, resulting in a delay in the acceptance of vaccines despite the availability of vaccination services. Therefore, an effort of all physicians must be conducted in order to advise patients with AI. In this short review, we try to answer some frequently asked questions regarding the management of patients with AI.

Glucocorticoid Withdrawal-An Overview on When and How to Diagnose Adrenal Insufficiency in Clinical Practice

Glucocorticoids (GCs) are widely used due to their anti-inflammatory and immunosuppressive effects. As many as 1-3% of the population are currently on GC treatment. Prolonged therapy with GCs is associated with an increased risk of GC-induced adrenal insufficiency (AI). AI is a rare and often underdiagnosed clinical condition characterized by deficient GC production by the adrenal cortex. AI can be life-threatening; therefore, it is essential to know how to diagnose and treat this disorder. Not only oral but also inhalation, topical, nasal, intra-articular and intravenous administration of GCs may lead to adrenal suppression. Moreover, recent studies have proven that short-term (<4 weeks), as well as low-dose (<5 mg prednisone equivalent per day) GC treatment can also suppress the hypothalamic-pituitary-adrenal axis. Chronic therapy with GCs is the most common cause of AI. GC-induced AI remains challenging for clinicians in everyday patient care. Properly conducted GC withdrawal is crucial in preventing GC-induced AI; however, adrenal suppression may occur despite following recommended GC tapering regimens. A suspicion of GC-induced AI requires careful diagnostic workup and prompt introduction of a GC replacement treatment. The present review provides a summary of current knowledge on the management of GC-induced AI, including diagnostic methods, treatment schedules, and GC withdrawal regimens in adults.