title: Traumatic brain injury and adrenal insufficiency: morning cortisol and cosyntropin stimulation tests.
abstract: BACKGROUND
  Adrenal insufficiency (AI) has a great impact on the prognosis of patients with traumatic brain injury. There is a lack of consensus regarding the diagnostic criteria of AI. In these patients with acute stress we compared fasting cortisol, low and high dose cosyntropin stimulation tests to assess adrenal function in patients with moderate to severe traumatic brain injury.
  
  
  METHODS
  This multicenter, cross-sectional study recruited 50 consecutive patients (aged between 15 and 70 years old) with moderate to severe traumatic brain injury who survived more than 5 days after the event. The patients' adrenal function was assessed using the fasting cortisol, 1 and 250-µg ACTH stimulation tests.
  
  
  RESULTS
  More cases of AI were detected by the 1-µg ACTH stimulation test compared to those detected by the basal serum cortisol level and 250-µg ACTH stimulation test. The κ test showed no agreement between these tests. The incidence of AI in the first 10 days after traumatic brain injury varied from 34% to 82% according to the various definitions of AI. The incidence of hypotension and need for vasopressors was higher in the patients diagnosed by the 250-µg ACTH stimulation test (p < 0.0001).
  
  
  CONCLUSIONS
  The incidence of secondary AI in moderate to severe traumatic brain injury seems to be high. A combination of stimulation test (either 250 or 1 µg) and basal cortisol level may improve diagnostic ability compared to either test alone. Hence performing both tests for the assessment of adrenal function in patients with traumatic brain injury is recommended.
authors.affiliation: Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Bita
authors.initials: B
authors.lastname: Mirzaie
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Mohajeri-Tehrani
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Annabestani
authors.forename: Mohammad Karim
authors.initials: MK
authors.lastname: Shahrzad
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Mohseni
authors.forename: Ramin
authors.initials: R
authors.lastname: Heshmat
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Afshani
authors.forename: Hamid Reza Aghaei
authors.initials: HR
authors.lastname: Meybodi
authors.forename: Bagher
authors.initials: B
authors.lastname: Larijani
keywords: adrenal insufficiency; cosyntropin test; traumatic brain injury