ESPE Abstracts

Background: Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation and Neural tumor (ROHHADNET) is a rare condition. The first symptom is the appearance of rapid onset obesity (2–4 years) followed by central hypoventilation, hypothalamic dysfunction, dysautonomic symptoms and neural tumors.

Objective and hypotheses: Aim of this study was to evaluate adrenal function in ROHHADNET patients from a single-center.

Patients and methods: Six patients with ROHHADNET underwent clinical (BMI SDS) and biochemical evaluation for baseline cortisol and for Insulin Tolerance Test (ITT) at the mean age of 10.1±5.9 (range 4.7–19.9 years); four were also tested with low-dose ACTH test (Synachten 1 mcg/m²) after an interval of 0–4 years. All subjects had a morning baseline cortisol evaluation at the time of ROHHADNET diagnosis. Pituitary defects were present (n=4) in one patient, (n=3) in one, (n=2) in two and (n=1) in two patients While hyperprolactinemia was documented in all of them; five had neural crest tumor.

Results: BMI SDS was of 3.4±1.2 at the time of ITT and 3.7±1.4 at the time of ACTH test. None of the patients displayed hypercortisolism. Baseline cortisol pre-ITT was 8.5±5.3 mcg/dl with a peak cortisol of 14.2±8.1 mcg/dl. Baseline cortisol pre-ACTH test in those whot underwent ACTH test was 4.4±4.4 mcg/dl with a peak cortisol of 11.1±8.8 mcg/dl. Five patients received the diagnosis of Central adrenal Insufficiency (CAI). Baseline cortisol was not related to BMI SDS at any time point and it was variably associated with age (r’s 0.02–0.94); correlations between baseline cortisol levels at three different time points were variable (r’s from 0.1 to 0.87). The association between baseline cortisol and peak response was strong after ACTH (r=0.95, P 0.07), and moderate after ITT (r=0.7, P 0.13). The relation between peak cortisol responses after the two tests was significant (r=0.97, P 0.04). Both baseline cortisol and peak cortisol after ITT negatively correlated with the number of pituitary hormone defects (r’s=−0.68 to −0.93).

Conclusion: Central Adrenal Insufficiency was documented in 83% of ROHHADNET patients after dynamic testing with ITT or ACTH-low testing. Baseline cortisol value is not reliable for the diagnosis of CAI. While the severity of hypothalamic dysfunction appears to be correlated with CAI, age and BMI SDS are not associated.