Use of salivary cortisol and cortisone in the high‐ and low‐dose synacthen test. (29th November 2017)

• Record Type: Journal Article
• Authors: Elder, Charlotte J.; Harrison, Robert F.; Cross, Alexandra S.; Vilela, Ruben; Keevil, Brian G.; Wright, Neil P.; Ross, Richard J.
• Is Part Of: Clinical endocrinology. Volume 88:Number 6(2018)
• Page Start: 772
• Page End: 778
• Publication Date: 2017-11-29
• Subjects: ACTH stimulation test -- addisons -- adrenal insufficiency -- cortisol -- cortisone -- cosyntropin -- saliva -- synacthen; Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.13509
• Languages: English
• ISSNs: 0300-0664

Abstract

Summary: Context: Salivary cortisone reflects serum cortisol levels, is more sensitive than salivary cortisol at lower values of serum cortisol and is noninvasive. Objective: To investigate the relationship between serum cortisol and salivary cortisol and cortisone following low‐ and high‐dose synacthen. Design and setting: Prospective pharmacodynamic studies in clinical research facilities. Participants and intervention: Thirty‐five dexamethasone‐suppressed, healthy adult males underwent an intravenous synacthen test: N = 23 low‐dose (1 mcg), N = 12 high‐dose (250 mcg). Paired serum and salivary samples were taken at 15 sampling points over 120 minutes. Main outcome measure: Serum cortisol and salivary cortisol and cortisone were analysed for correlations and by a mixed‐effects model. Results: At baseline, the correlation between serum cortisol and salivary cortisol was weak with many samples undetectable ( r = .45, NS), but there was a strong correlation with salivary cortisone ( r = .94, P < .001). Up to 50 minutes following synacthen, the correlation coefficient between serum cortisol and salivary cortisol and cortisone was <0.8, but both had a stronger correlation at 60 minutes (salivary cortisol r = .89, P < .001, salivary cortisone r = .85, P < .001). The relationship was examined excluding samples in the dynamic phase (baseline to 60 minutes). Salivary cortisol and cortisone showed a close relationship to serum cortisol. Salivary cortisone showed the stronger correlation: salivary cortisol r = .82, P < .001, salivary cortisone r = .96, P < .001. Conclusion: Following synacthen, both salivary cortisol and cortisone reflect serum cortisol levels, but there is a lag in their rise up to 60 minutes. The results support further research for possible future use of a 60‐minute salivary cortisone measurement during the synacthen test.