Intramuscular ACTH stimulation test for assessment of adrenal function

Area of Science:

• Endocrinology
• Diagnostic testing

Background:

• Adrenal insufficiency diagnosis typically relies on the short Synacthen test, but Synacthen is not officially marketed in India.
• This limitation necessitates an alternative method for assessing adrenal function in Indian patients.

Purpose of the Study:

• To validate and assess the efficacy of Acton Prolongatum, administered intramuscularly, as an adrenocorticotropic hormone (ACTH) stimulation test for evaluating adrenal function.
• To establish Acton Prolongatum as a viable diagnostic tool for adrenal insufficiency in India.

Main Methods:

• A two-group study design: a validation group and a study group.
• Intramuscular injection of 25 units of ACTH (Acton Prolongatum), with blood samples collected after 60 minutes for cortisol estimation.
• Adrenal insufficiency was diagnosed if post-ACTH cortisol levels were below 18.0 microg/dl.

Main Results:

• The study included 61 subjects in the validation group and 89 in the study group.
• In healthy individuals and those with diabetes mellitus or hypothyroidism, basal and post-ACTH cortisol levels were within normal ranges.
• Patients with known adrenal insufficiency showed significantly lower basal cortisol and all had post-ACTH cortisol levels below 18.0 microg/dl.
• In the study group, 41.6% were diagnosed with adrenal insufficiency; basal cortisol alone detected only 60% of these cases, demonstrating a sensitivity of 60% and specificity of 100% compared to ACTH-stimulated levels.

Conclusions:

• The intramuscular ACTH test using Acton Prolongatum is effective for evaluating adrenal function in suspected primary or secondary adrenal insufficiency.
• Basal cortisol measurements alone exhibit poor sensitivity for diagnosing adrenal insufficiency.