Cortisol response to adrenocorticotropin testing in non-classical congenital adrenal hyperplasia (NCCAH).

Background: The adequacy of cortisol response in non-classical congenital adrenal hyperplasia (NCCAH) has not been fully elucidated. The aim was to evaluate cortisol response to adrenocorticotropin (ACTH) stimulation test in children and adolescents with NCCAH and heterozygotes for CYP21A2 gene mutations. Methods: One hundred and forty-six children and adolescents, mean age 7.9 (0.7-17.5) years with clinical hyper-androgenism, were evaluated retrospectively. Thirty-one subjects had NCCAH, 30 were heterozygotes for CYP21A2 gene mutations, while 85 showed normal response to ACTH test. Results: Baseline cortisol levels did not differ among NCCAH, heterozygotes, and normal responders: 15.75 (5.83-59.6) mu g/dL vs. 14.67 (5.43-40.89) mu g/dL vs. 14.04 (2.97-34.8) mu g/dL, p = 0.721. However, NCCAH patients had lower peak cortisol compared to heterozygotes and control group: 28.34 (12.25-84.40) vs. 35.22 (17.47-52.37) mu g/dL vs. 34.92 (19.91-46.68) mu g/dL, respectively, p = 0.000. Peak cortisol was < 18 mu g/dL in 7/31 NCCAH patients and in one heterozygote. Conclusions: A percentage of 21.2% NCCAH patients showed inadequate cortisol response to ACTH stimulation. In these subjects, the discontinuation of treatment on completion of growth deserves consideration.