Morning salivary cortisol versus short Synacthen test as a test of adrenal suppression

BACKGROUND: The short Synacthen test (SST) is the most commonly used test for the assessment of adrenal suppression. We investigated the potential of a simpler and more cost-effective procedure [morning salivary cortisol (MSC)] as an outpatient screening tool to detect adrenal suppression in patients using topical intranasal corticosteroids for rhinosinusitis. METHOD: Forty-eight patients who were using topical corticosteroids underwent adrenal function assessment by way of SST and MSC measurement. RESULTS: Sixteen of the 48 patients had impaired MSCs. Of these 16 patients, 15 had an impaired SST (sensitivity 100%) and one had a normal SST. All patients with normal MSCs also had normal SSTs (specificity 97%). CONCLUSION: The morning salivary cortisol measurement is a useful screening tool for adrenal suppression in this setting.