ACTH stimulation test

Indication

  • Fertility disorders in women
  • Hirsutism: Exclusion diagnostics of AGS-associated hydroxylase deficiency
  • Checking the adrenal hormone reserve

Contraindications
Primary adrenal insufficiency; if necessary for preventing an acute adrenal crisis
oral doses of 1-2 mg of dexamethasone in the morning before the start of the test

Test material
Venous blood (serum Monovette)

Measuring parameters
17-OH progesterone and cortisol

Test procedure

  • Implementation for women in the 1st half of their cycle
  • 3 days before the test, the patient should not be given ACTH or glucocorticoids
  • The patient should not undertake any unusual physical exertion or undergo diagnostic or therapeutic interventions, dental treatment, etc.
  • 8:00 a.m. blood sampling for basal values (sample 1)
  • 0.25 mg of corticotropin (e.g. Synacten®) i.v.
  • Second blood sampling 60 minutes after stimulation (sample 2)
  • Third blood sampling 120 minutes after stimulation (sample 3)

  • Routine transport of all samples to the laboratory.

Reference ranges
A difference of less than 2.5 ng/ml between the basal value and the highest of the stimulated values for 17-OH progesterone suggests that there is no hydroxylase deficiency.
A cortisol increase of more than 20 µg/dl (550 nmol/l) 60 minutes after ACTH injection rules out adrenal insufficiency with sufficient probability.

Glossary

ACTH: adrenocorticotropic hormone, corticotropin
AGS: adrenogenital syndrome
hydroxylase deficiency: 21-hydroxylase, 11β-hydroxylase or 3β-hydroxysteroid dehydrogenase [3beta-HSD]
AC: adrenal cortex


Literature

Lothar Thomas (eds.), Labor und Diagnose, 5th ed. p. 1083, 1115

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