Adrenocorticotropic hormone stimulation test during high-dose glucocorticoid therapy.
OBJECTIVE
To define the effective time frame of adequate serum cortisol response to the short standard 250-microg adrenocorticotropic hormone stimulation test (ACTH-ST) after initiation of high-dose glucocorticoid therapy in order to assist in the diagnosis of adrenal insufficiency.


METHODS
We performed an ACTH-ST at 4 different times in hospitalized patients, who had a documented intact hypothalamic-pituitary-adrenal axis and were receiving high-dose dexamethasone therapy for nonendocrine diseases, to determine the time until the serum cortisol response is compromised. The ACTH-ST was performed at the following time intervals after initiation of dexamethasone therapy - 24, 48, 72, and 96 hours. The outcome measures were cortisol levels measured at 0, 30, and 60 minutes after administration of 250 microg of cosyntropin.


RESULTS
Of the overall group of 11 study patients, all those (n = 8) tested within the first 72 hours after initiation of dexamethasone therapy had an adequate response (serum cortisol level at 60 minutes, >or=18 microg/dL). Two of the 3 patients tested at 96 hours after initiation of dexamethasone therapy had a suppressed cortisol response at 60 minutes. At 30 minutes, all cortisol levels except 1 were inadequate (<18 micro/dL).


CONCLUSIONS
This study suggests indirectly that the ACTH-ST may be used for the diagnosis of suspected adrenal insufficiency within the first 3 days after initiation of empiric glucocorticoid therapy. An inadequate response of serum cortisol at 60 minutes to the ACTH-ST may be indicative of adrenal insufficiency in this setting. Additional studies with more patients in each therapy time point are needed to confirm these initial results.
Villabona
Carmen V
CV
Division of Endocrinology, Rush University Medical Center, Chicago, Illinois, USA.
Koh
Chung
C
Panergo
Jessel
J
Reddy
Arati
A
Fogelfeld
Leon
L
D000309:Adrenal Insufficiency / Q000175:diagnosis*; D000324:Adrenocorticotropic Hormone; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000188:drug therapy*; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013117:Spinal Cord Compression / Q000188:drug therapy; D013997:Time Factors
D005938:Glucocorticoids; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone