Injectable tetracosactide hexa-acetate, ACTH 1-24 (Synacthen), is not marketed in many countries including India, whereas Injectable long acting porcine sequence, ACTH 1-39 (Acton Prolongatum®) is easily available and much cheaper. This study aimed to find the diagnostic accuracy of ACTH stimulation test using i.m. Acton Prolongatum® (acton prolongatum stimulation test, APST) in comparison with Synacthen (short synacthen test, SST) for the diagnosis of glucocorticoid insufficiency.
Subjects with a suspicion of adrenal insufficiency based on clinical features underwent a SST with 250 µg Synacthen followed by APST using 30 units of Acton Prolongatum®. Serum cortisol levels were measured at 60 and 120 min following injection of Acton Prolongatum®. Stimulated peak cortisol of less than 18 µg/dL on SST was considered as adrenal insufficiency.
Forty seven patients with mean age of 36.7 ± 14.4 years were enrolled for the study. Based on SST, twenty (n = 20) persons were classified as having adrenal insufficiency, whereas twenty-seven (n = 27) were found to be normal. Area under the curve of APST (at 120 min) was 0.986 when compared to SST, thus proving its high accuracy. A serum cortisol cut off value of 19.5 µg/dL at 120-min following stimulation with Acton Prolongatum® showed a sensitivity of 100% and specificity of 88%.
ACTH stimulation test using Acton Prolongatum® is an economical and accurate alternative to the short Synacthen test.