Normal Cortisol Response on Low-Dose Synacthen (1 μg) Test in Children with Prader Willi Syndrome

• Published in: The journal of clinical endocrinology and metabolism Vol. 95; no. 12; pp. E464 - E467
• Main Authors: Nyunt, Ohn, Cotterill, Andrew M, Archbold, Sinead M, Wu, Joyce Y, Leong, Gary M, Verge, Charles F, Crock, Patricia A, Ambler, Geoffrey R, Hofman, Paul, Harris, Mark
• Format: Journal Article
• Language: English
• Published: United States Endocrine Society 01.12.2010
• Subjects: Adrenocorticotropic Hormone - blood; Australasia; Body Mass Index; Child; Child, Preschool; Cosyntropin - therapeutic use; Female; Gonadal Steroid Hormones - therapeutic use; Hormones - therapeutic use; Humans; Hydrocortisone - blood; Male; Prader-Willi Syndrome - blood; Prader-Willi Syndrome - drug therapy; Reference Values; Thyroxine - therapeutic use; Australasia
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2010-0647

Introduction: It has been postulated that central adrenal insufficiency (CAI), resulting from hypothalamic dysfunction, may contribute to the increased unexplained death rates in Prader Willi syndrome (PWS). A study using the overnight metyrapone test reported a 60% prevalence of CAI in children with PWS. We used a low-dose Synacthen test to screen for CAI in children with PWS. Methods: We studied 41 children with genetic diagnosis of PWS [20 males; mean age, 7.68 (±5.23) yr] in five pediatric endocrinology centers in Australasia. All participants were randomly selected, and none had a history of Addisonian crisis. Ten of the cohort were receiving sex hormone therapy, 19 were receiving GH, and four were receiving T4. Their mean body mass index z-score was +1.48 (±1.68). Baseline morning ACTH and cortisol levels were measured, followed by iv administration of 1 μg Synacthen. Post-Synacthen cortisol levels were measured at 30 min, and a cortisol level above 500 nmol/liter was considered normal. Results: The mean baseline ACTH and cortisol were 15 (±14) ng/liter and 223 (±116) nmol/liter, respectively. The mean 30-min plasma cortisol was 690 (±114) nmol/liter, and the average increase from baseline was 201%. Conclusions: Our result suggests that CAI is rare in children with PWS. Prevalence of central adrenal insufficiency in children with Prader Willi syndrome is rare.