Diagnosis of ACTH deficiency. Comparison of overnight metyrapone test to either low-dose or high-dose ACTH test.
Test sensitivity and accuracy of 250 microg/m(2) ACTH test, 1 microg/m(2) ACTH test, and overnight metyrapone test were evaluated in 158 children at risk for ACTH deficiency. Of 38 given high-dose ACTH, 20 had normal responses to metyrapone and to high-dose ACTH. 14 had low response to metyrapone; of these only 2 had low cortisol response (<550 nmol/l) to high-dose ACTH. Of 120 given low-dose ACTH, 64 had normal responses to metyrapone and to low-dose ACTH. All 24 with low metyrapone response had low or borderline response to low-dose ACTH. The remaining children had an inconclusive metyrapone response. In conclusion, high-dose ACTH misses most diagnoses of ACTH deficiency (21% sensitivity, 100% specificity, 63% accuracy). In contrast, the low dose ACTH test accurately diagnoses 90% of patients with ACTH deficiency (100% sensitivity, 68% specificity). The low-dose ACTH test can serve as an accurate and practical screening test for adequacy of ACTH reserve.
Rose
S R
SR
Department of Pediatrics, University of Tennessee, Memphis and Methodist LeBonheur Children's Medical Center, Memphis, TN, USA. srose@utmem1.utmem.edu
Lustig
R H
RH
Burstein
S
S
Pitukcheewanont
P
P
Broome
D C
DC
Burghen
G A
GA
D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000032:analysis / Q000172:deficiency*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D007223:Infant; D008297:Male; D008797:Metyrapone / Q000009:adverse effects; D010913:Pituitary-Adrenal System / Q000378:metabolism; D011786:Quality Control; D014839:Vomiting / Q000209:etiology
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D008797:Metyrapone