Objective: The diagnosis of central hypoadrenalism (HPAI) is a major clinical challenge. The gold standard procedure remains insuline tolerance test (ITT). Liquid chromatography tandem mass spectrometry (LC-MS/MS) is considered the best procedure for the evaluation of cortisol levels. This study aimed to evaluate cut-offs of serum (TM-SeC) and salivary cortisol (SaC) by LC-MS/MS and serum cortisol by ECLIA assay (E-SeC) after Standard dose ACTH test (SDCT) in diagnosing HPAI.
Design: In this study we performed SDCT in 52 consecutive patients (F/M, 33/19, age 42.9±13 yrs) referred to our Center to evaluate at specific time points E-SeC, TM-SeC and SaC. In the same group of patients we also evaluated E-SeC after ITT, to diagnose HPAI (using a cut off<500 nmol/l).
Results: HPAI was diagnosed in 8 out of 52 patients (five patients operated on for a pituitary macroadenoma, and 3 with a pituitary microadenoma). Using the diagnosis of HPAI made by ITT as reference test, we found that after SDCT an E-SeC>348 nmol/l at 0-min, >671 nmol/l at 30-min or >756 nmol/l at 60-min excluded HPAI, whereas an E-SeC <155 nmol/l at 0-min, <436 nmol/l at 30-min or <527 nmol/l at 60-min confirmed HPAI. By using LC-MS/MS we found that after SDCT a TM-SeC >378 nmol/l at 0-min, >1012 nmol/l at 30-min or >1021 nmol/l at 60-min excluded HPAI, whereas a TM-SeC <149 nmol/l at 0-min, <334 nmol/l at 30-min or <351 nmol/l at 60-min confirmed HPAI. Similarly by LC-MS/MS we found that after SDCT a SaC >7.4 nmol/l at 0-min, >15.8 nmol/l at 30-min or >23.3 nmol/l at 60 min excluded HPAI, whereas a SaC<1.7 nmol/l at 0-min, < 4.7;nmol/l at 30-min or <7.3 nmol/l at 60-min confirmed HPAI.
Conclusions: We can conclude that even evaluating TM-SeC and SaC, after SDCT there is large gray area of indeterminate results.
20 - 23 May 2017
European Society of Endocrinology