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

Abstract

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.