SUN-308 Central Adrenal Insufficiency Is Rare in Adults with Prader-Willi Syndrome

Introduction: Prader-Willi syndrome (PWS) is associated with several hypothalamic-pituitary hormone deficiencies. There is no agreement on the prevalence of central adrenal insufficiency (CAI) in adults with PWS. This is partly due to the variable results of the synacthen test, compared with the more robust metyrapone test (MTP) and insulin tolerance test (ITT). In some countries, patients with PWS receive stress-dose corticosteroids during physical or psychological stress. Side effects of frequent corticosteroids use are weight gain, osteoporosis, diabetes mellitus and hypertension, already major problems in adults with PWS. However, undertreatment of CAI can cause significant morbidity or even mortality. To prevent over- and undertreatment with corticosteroids, we assessed the prevalence of CAI in a large international cohort of adults with this rare disorder. Methods: The hypothalamic-pituitary-adrenal axis was tested in 81 adult subjects (55 Dutch, 10 British, 10 French, 6 Swedish) with genetically confirmed PWS. For multiple-dose MTP, 11-deoxycortisol >230 nmol/L (7.6 g/dL) was considered sufficient. For Dutch, French and Swedish patients who underwent ITT, cortisol >500 nmol/L (18.1 μg/dL) was considered sufficient. For British patients cortisol >450 nmol/L (16.3 μg/dL) was considered sufficient, as this center used a different assay. Additionally, we reviewed medical files of 645 adults with PWS from Italy (240), France (110), the Netherlands (110), Australia (60), Spain (45), Sweden (38) and the United Kingdom (42) for symptoms of hypocortisolism/adrenal crisis during surgery. Results: Data on 81 adult subjects (46 males and 35 females), median age (range) 25.2 yr (18.0 – 55.5), median BMI (range) 29.1 kg/m2 (20.0 – 62.0), with genetically confirmed PWS were collected. 33 subjects (41%) were using GH treatment since childhood. Multiple-dose MTP was performed in 45 subjects and ITT in 36 subjects. Both tests were well tolerated by all individuals. CAI was excluded in 80 of 81 patients. One patient with a peak cortisol level of 494 nmol/L (just below cut-off level of 500 nmol/L) was prescribed hydrocortisone for use during physical stress. There was no relation between baseline cortisol and ITT/multiple-dose MTP results. Even patients with a low baseline cortisol level (lowest: 102.0 nmol/L) had normal responses. Among the 645 patients whose medical files were reviewed, 200 had undergone surgery without perioperative corticosteroids treatment. None of them displayed any features of hypocortisolism/adrenal crisis. Conclusions: CAI is rare (1.2%) in adults with PWS. Based on these results, we recommend against routinely prescribing corticosteroids stress-doses in adults with PWS. Funding: CZ foundation.