Precocious pubarche: distinguishing late-onset congenital adrenal hyperplasia from premature adrenarche.
BACKGROUND
Because precocious pubarche (PP) reveals late-onset congenital adrenal hyperplasia (LO-CAH) in 5 to 20% of cases, an adrenal stimulation test is recommended in all patients presenting with it. This test is stressful and expensive, and results are normal in more than 80% of cases.


OBJECTIVE
Our objective was to identify clinical and plasma predictors of LO-CAH among patients presenting with PP.


METHODS
We conducted a retrospective cohort study that included all patients seen for PP at our hospital between 1999 and 2006 (n = 238). All had undergone an ACTH test.


METHODS
LO-CAH was defined by a post-ACTH 17-hydroxyprogesterone (17-OHP) plasma level greater than 10 ng/ml and confirmed by mutational analysis of the CYP21 gene. The association of standard clinical and laboratory indicators with LO-CAH was assessed.


RESULTS
Ten (4%) of 238 patients had LO-CAH. Basal 17-OHP, Delta4-androstenedione, and testosterone plasma levels were significantly higher in these patients. A 2-ng/ml threshold for basal 17-OHP plasma levels offered 100% (95% CI, 69-100) sensitivity for the diagnosis of LO-CAH and 99% (95% CI, 96-100) specificity.


CONCLUSIONS
We identified three plasma predictors of LO-CAH in patients presenting with PP. A selective strategy based on a 2-ng/ml basal 17-OHP plasma level threshold would have safely avoided 99% of the unnecessary ACTH tests among our patients.
Armengaud
Jean-Baptiste
JB
Université Paris Descartes, Paris, France.
Charkaluk
Marie-Laure
ML
Trivin
Christine
C
Tardy
Véronique
V
Bréart
Gérard
G
Brauner
Raja
R
Chalumeau
Martin
M
D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood* / Q000175:diagnosis; D050499:Adrenarche / Q000097:blood*; D000324:Adrenocorticotropic Hormone; D000735:Androstenedione / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011629:Puberty, Precocious / Q000097:blood*; D012189:Retrospective Studies; D013739:Testosterone / Q000097:blood
D013739:Testosterone; D000735:Androstenedione; D019326:17-alpha-Hydroxyprogesterone; D000324:Adrenocorticotropic Hormone