title: Corticotropin and cortisol response to maximal exercise testing in central diabetes insipidus.
abstract: BACKGROUND
  It is known that arginine vasopressin (AVP) has a stimulatory effect on corticotropin (adrenocorticotropic hormone; ACTH) and cortisol secretion especially during stress. The present study was designed to investigate the effect of stress on ACTH and cortisol levels in patients with central diabetes insipidus (DI) with endogenous AVP deficiency receiving AVP therapy, and to determine whether these children need steroid replacement during stress.
  
  
  METHODS
  Seven patients with a median age of 12 years (range 7-13 years) with idiopathic central DI on appropriate Desmopressin (DDAVP) therapy (group 1) and seven healthy controls with a median age of 15 years (range 13-20 years; group 2) were included in the study. Acute stress was produced in all children by treadmill exercise, assessed by maximal oxygen consumption and heart rate. ACTH and cortisol levels were determined before and after exercise.
  
  
  RESULTS
  In group 1, median ACTH level after exercise (28.3 pg/mL) was not different from the median value (24.0 pg/mL) before exercise. However, median cortisol level (10.5 microg/dL) was significantly increased (14.9 microg/dL; P < 0.05) with exercise. In group 2, cortisol (median 9.3 microg/dL) and ACTH levels (median 6.3 pg/mL) were significantly increased after exercise (15 mug/dL and 13.6 pg/mL, respectively; P < 0.05). There was no significant difference between the groups with respect to cortisol levels before and after exercise, but the stimulated ACTH levels after exercise were higher in patients with DI than in the controls (P < 0.05). A positive correlation was observed between total daily DDAVP dose and cortisol level after exercise (r(s)= 0.786, P < 0.05).
  
  
  CONCLUSIONS
  Cortisol response during acute stress is normal in children with DI and these patients do not need extra steroid treatment during stress. In contrast, the normal cortisol response obtained by increased ACTH levels in these patients indicates an increased sensitivity of corticotroph cells.
authors.affiliation: Pediatric Endocrinology Unit, Faculty of Medicine, Istanbul University, Istanbul, Turkey. firdevbas@superonline.com
authors.forename: Firdevs
authors.initials: F
authors.lastname: Bas
authors.forename: Feyza
authors.initials: F
authors.lastname: Darendeliler
authors.forename: Burak
authors.initials: B
authors.lastname: Tatli
authors.forename: Mehmet
authors.initials: M
authors.lastname: Unal
authors.forename: Abidin
authors.initials: A
authors.lastname: Kayserilioglu
mesh_terms: D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D050034:Antidiuretic Agents / Q000008:administration & dosage; D002648:Child; D003894:Deamino Arginine Vasopressin / Q000008:administration & dosage; D020790:Diabetes Insipidus, Neurogenic / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male
chemical_list: D050034:Antidiuretic Agents; D000324:Adrenocorticotropic Hormone; D003894:Deamino Arginine Vasopressin; D006854:Hydrocortisone