Park, Julie and Titman, Andrew and Lancaster, Gillian and Selvarajah, Bhavana and Collingwood, Catherine and Powell, Darren and Das, Urmi and Dharmaraj, Poonam and Didi, Mohammed and Senniappan, Senthil and Blair, Joanne (2022) Baseline and peak cortisol response to the low dose short Synacthen test relates to indication for testing, age and sex. Journal of the Endocrine Society, 6 (6). ISSN 2472-1972
Full text not available from this repository.Abstract
Objective To review the outcomes of a simplified low dose Synacthen test (LDSST) performed in a tertiary endocrine service over seven years, and to examine for relationships between cortisol measurements and indication for testing, age and sex. Design Retrospective, observational study of LDSST performed in 2008 – 2014 (N=335) and 2016-2020 (N=160). Methods LDSST were performed by endocrine nurses. Synacthen 500ng/1.73m 2 administered as IV bolus, sampling at 0, 15, 25 and 35 minutes. Results Mean (± 1SD) baseline cortisol was 221 ± 120 nmol/L, peak 510 ± 166nmol/L and increment 210 ± 116 nmol/L. 336 (70%) of patients had a normal response (baseline cortisol >100nmol/L, peak >450nmol/L), 78 (16%) a suboptimal response (peak cortisol 350-450nmol/L) and were prescribed hydrocortisone to during periods of stress only, 67 (14%) an abnormal response (baseline <100nmol/L or peak <350nmol/L) and were prescribed daily hydrocortisone. Basal, peak and incremental increases in cortisol were higher in females (p=0.03, p<0.001, p=0.03 respectively). Abnormal results occurred most frequently in patients treated previously with pharmacological doses of glucocorticoids or structural brain abnormalities (p<0.0001). Discussion There are concerns that the specificity of the LDSST is poor. The low prevalence and strong association of abnormal results with indication for testing, suggests that over diagnosis occurred infrequently in this clinical setting.