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Intramuscular administration of ACTH1-24 vs. 24-hour blood sampling in the assessment of adrenocortical function

Salvatore Alesci1, Ioannis Ilias, Emmanuil Souvatzoglou

  • 1Clinical Neuroendocrinology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1284, USA.

Hormones (Athens, Greece)
|April 15, 2006
PubMed

Insights

Intramuscular ACTH1-24 injection, with a single 60-minute cortisol measurement, is a reliable alternative to intravenous testing for adrenal insufficiency. This convenient method accurately screens adrenal function in healthy men.

Area of Science:

  • Endocrinology
  • Clinical Diagnostics
  • Hormone Testing

Background:

  • The standard intravenous short Synacthen test (SSST) is a reliable diagnostic for adrenocortical insufficiency.
  • Intramuscular (i.m.) ACTH administration offers a simpler alternative, avoiding venous cannulation.
  • Data correlating i.m. ACTH1-24 response with 24-hour cortisol levels are limited.

Purpose of the Study:

  • To investigate the relationship between cortisol response to i.m. ACTH1-24 and 24-hour average cortisol concentration.
  • To evaluate the efficacy of i.m. ACTH1-24 as a convenient screening test for adrenal function.

Main Methods:

  • 64 healthy men underwent hourly blood sampling for 24-hour cortisol measurements.
  • The following day, participants received 250 microg i.m. ACTH1-24, with blood samples collected at baseline, 30, and 60 minutes.
  • Cortisol levels were analyzed, correlating i.m. ACTH response with 24-hour cortisol metrics (Cmax, AUC0-24).

Main Results:

  • All participants exhibited peak cortisol levels (Cmax) between 0600h and 1000h.
  • Cortisol levels significantly increased at 30 (C30ACTH) and 60 (C60ACTH) minutes post-i.m. ACTH1-24.
  • Both C30ACTH and C60ACTH showed significant correlations with Cmax and 24-hour integrated cortisol concentration (AUC0-24).
  • Morning mean cortisol (C(av)6-10) correlated strongly with AUC0-24.

Conclusions:

  • Intramuscular ACTH1-24 administration followed by a single 60-minute cortisol measurement is a valid screening test for adrenal function.
  • This method is convenient and cost-effective compared to traditional intravenous testing.
  • The study confirms the utility of i.m. ACTH1-24 for assessing adrenal function.

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