Intramuscular Short-term ACTH Test for the Determination of Adrenal Function in Children: Safe, Effective and Reliable

ABSTRACT

Objective: Standard short adrenocorticotropic hormone (ACTH) stimulation test (SST) has traditionally been used for assessing adrenal gland fuction by intravenous (iv) application. However the iv form is not readily available in all countries, including Turkey. The aim of this study was to evaluate the effectiveness of the intramuscular (im) SST. Methods: Patients underwent im SST with suspected adrenal insufficiency (AI) and hyperandrogenism. The SSTs were done with 250 mcg ACTH (Synacthen Depot ampul, concentration 1 mg/mL). The cases were divided into two groups suspected AI (group 1 n=87); and hyperandrogenism group (group 2 n=124). Definite AI was defined as peak cortisol <18 µg/dL, suspected AI as a peak cortisol of 18-21 µg/dL and normal result was defined as a peak cortisol ≥22 µg/dL. Results: The mean age of the patients was 11.7±5.2 years. In 164 patients (78%) all of the peak cortisol tests were normal (≥22 mcg/dL). The rates were 64% and 88% in group 1 and 2, respectively. Only 8.5% (n=18) of all cases had an inadequate peak cortisol response of <18 mcg/dL. On follow up, 15 patients whose peak cortisol was <18 mcg/dL needed cortisol therapy. Of all cases 3.3% (n=8) had 17-OHP ≥10 ng/dL. Clinical findings suggestive of non-classical congenital adrenal hyperplasia and/or mutation were found in six of these cases (75%). No local and systemic side effects or allergic reactions were observed in any patient. Conclusion: IM ACTH SST is a safe, effective and reliable test in children with suspected AI. There were no local or systemic side effects, supporting the reliability of the im ACTH test.