Exp Clin Endocrinol Diabetes 2002; 110(8): 381-385
DOI: 10.1055/s-2002-36422
Article

© Johann Ambrosius Barth

The Value of Low Dose (1 μg) ACTH Stimulation Test in the Investigation of Non-Classic Adrenal Hyperplasia due to 11β-Hydroxylase Deficiency

K. Ünlühızarcı, F. Keleştimur, M. Güven, F. Bayram, R. Çolak
  • Department of Endocrinology Erciyes University Medical School, Kayseri, Turkey
Further Information

Publication History

received 22 February 2002 first decision 28 March 2002

accepted 22 April 2002

Publication Date:
08 January 2003 (online)

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Summary

Non-classic congenital adrenal hyperplasia (NCAH) is a rare cause of hirsutism and it results from a defect in the biosynthetic pathway of cortisol and/or aldosterone. 250 μg ACTH test (SDT) is used in the diagnosis of this disease. Our aim was to investigate the responses of 11-deoxycortisol to 1μg ACTH (LDT) test in women with NCAH due to 11-beta hydroxylase (11-β OH) deficiency and to compare them with the values obtained after SDT in the patients and in the control subjects. Eleven patients with NCAH due to 11-β OH deficiency and 15 control subjects were involved in the study. The main complaint of the patients with NCAH was hirsutism and the diagnosis was made if the adrenal 11-deoxycortisol response to SDT exceed threefold the 95th percentile of controls. ACTH stimulation tests were carried out consecutively by using 250 μg and 1 μg intravenous ACTH as a bolus injection after an overnight fast, and blood samples were drawn at 0,30 and 60 min. Peak cortisol, 17-hydroxyprogesterone (17-OHP) and DHEAS responses were similar in LDT and SDT while 11-deoxycortisol responses to LDT (15.7 ± 1.8 nmol/L) were significantly (p < 0.005) lower than the results obtained after SDT (76.3 ± 21.4 nmol/L) in women with 11-β OH deficiency. Peak cortisol and 17-OHP responses to LDT in patients and control subjects were similar. Peak 11-deoxycortisol responses to LDT were significantly (p < 0.05) higher in NCAH patients (15.7 ± 1.8 nmol/L) than in the control subjects (6.5 ± 0.8 nmol/L). However, in LDT, all patients had peak 11-deoxycortisol level lower than threefold the 95th percentile (25.8 nmol/L) of controls. This study represents the first demonstration that LDT gives similar cortisol but not 11-deoxycortisol responses to SDT in patients with 11-β OH deficiency. This study also showed that LDT can not replace SDT in every clinical situation.