Part of patients presenting as premature pubarche shows bone age advancement (> 2SD) and or 17OHP peak above that expected for the normal population (3 ng/ml.), but under the expected for the diagnosis of late-onset 21OHase deficiency (15 ng/ml.) The aim of this study was to evaluate if the ACTH response after DDAVP stimulation could be useful to identify patients with partial enzymatic deficiency. We studied 18 girls with puharche between 4 0 and 4 7 years (mean=5 7) All patients received dexamethasone (10 mcg/kg) at 12.00 p.m overnight before the test. they presented basal cortisol suppressed and showed urine density above 1020 during DDAVP test (20mcg. nostril) The patients were divided in two groups according BA advancement and 17OHP peak 60 min after ACTH stimulus (25 UI. bolus IV) The group 1 had 8 pat with BA similar to CA and 17OHP < 3n/mL. The group 2 had 10 pat with BA > 2SD and or 17OHP peak > 3ng/mL. The results are summarized in Table Both groups presented similar CA and Pubarche age When we applied BA - CA and 17OHP peak as a critena to separate the groups. we observed that basal 17OHP showed a significant difference. probably related to significant correlation between basal and pot-stimulus 17OHP values (Pearson. r = 0.47, p=0.04) There was no significant correlation between 17OHP and ACTH values When we analyzed the ACTH secretion during DDAVP test. we just found a tendency to higher values on group 2 in relation to group 1 (p = 0.1).

Table 1
Full size table

We concluded that the pituitary stimulation with DDAVP would not be able to confirm that patients with BA advancement or increased 17OHP peak have over-production of ACTH.