Assessment of central adrenal insufficiency in children and adolescents with Prader–Willi syndrome


Andrea Corrias, MD, Department of Pediatrics, Division of Pediatric Endocrinology, University of Torino, Regina Margherita Children’s Hospital, Piazza Polonia 94, 10126, Torino, Italy. Tel.: +39 011 313 5853; Fax: +39 011 313 5217; E-mail:


Objective  A recent study evidenced by metyrapone test a central adrenal insufficiency (CAI) in 60% of Prader–Willi syndrome (PWS) children. These results were not confirmed in investigations with low [Low-Dose Tetracosactrin Stimulation Test (LDTST), 1 μg] or standard-dose tetracosactrin stimulation tests. We extended the research by LDTST in paediatric patients with PWS.

Design  Cross-sectional evaluation of adrenal stress response to LDTST in a PWS cohort of a tertiary care referral centre.

Patients  Eighty-four children with PWS.

Measurements  Assessment of adrenal response by morning cortisol and ACTH dosage, and 1-μg tetracosactrin test. Response was considered appropriate when cortisol reached 500 nm; below this threshold, patients were submitted to a second test. Responses were correlated with the patients’ clinical and molecular characteristics to assess genotype–phenotype correlation.

Results  Pathological cortisol peak responses to the LDTST were registered in 12 patients (14·3%) who had reduced basal (169·4 ± 83·3 nm) and stimulated (428·1 ± 69·6 nm) cortisol levels compared to patients with normal responses (367·1 ± 170·6 and 775·9 ± 191·3 nm, < 0·001). Body mass index standard deviation score was negatively correlated with basal and peak cortisol levels (both P < 0·001), and the patients’ ages (< 0·001). In patients with deletion on chromosome 15, the cortisol peak was significantly lower than that in uniparental disomy (UPD) cases (= 0·030). At multiple regression analysis, the predictors of peak response were basal cortisol, age, and UPD subclass (r= 0·353, < 0·001). Standard-dose (250 μg) tetracosactrin test confirmed CAI in 4/12 patients (4·8% of the cohort).

Conclusions  Our results support the hypothesis that, albeit rare, CAI may be part of the PWS in childhood.