title: Differences in the insulin tolerance test in patients with brain damage depending on posture.
abstract: OBJECTIVE
  The insulin tolerance test (ITT) is the gold standard for the diagnosis of GH deficiency (GHD) and hypocortisolism. As hypopituitarism is a common disorder after traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH), the test is increasingly used in patients with pre-existing brain damage.
  
  
  METHODS
  A cross-sectional, observational study.
  
  
  METHODS
  Fifty-six patients (41 TBI and 15 SAH) were tested with the ITT (0.15 IE/kg body weight, mean glucose 33 mg/dl). In 38 patients, the test was performed in a supine position; the other 18 patients were in a sitting position during the ITT.
  
  
  RESULTS
  Hypocortisolism and GHD were more often diagnosed in a supine than in a sitting position (hypocortisolism: 55.3% supine versus 0% sitting, P<0.0001; GHD: 42.1% supine versus 11.1% sitting, P=0.03). Patients in a sitting position suffered more often from symptoms such as tachycardia (61.1% sitting versus 15.8% supine, P=0.001), trembling (22.2 vs 7.9%, NS), and sweating (66.7 vs 28.9%, P=0.007). There were no significant differences between the groups in drowsiness (72.2% sitting versus 65.8% supine, NS), dizziness (44.4 vs 44.7%, NS), and fatigue (33.3 vs 15.8%, NS). Because of somnolence, the hypoglycemic state could only be stopped with i.v. administration of glucose in 25 supine patients (66%). In contrast, none of the 18 patients (0%) tested in a sitting position got somnolent or was in need of i.v. application of glucose (P<0.001).
  
  
  CONCLUSIONS
  In patients with brain injury, posture might affect rates of diagnosing GHD and hypocortisolism and sympathetic symptoms in the ITT. These findings are exploratory and need replication in a standardized setting.
authors.affiliation: Schön Klinik Bad Aibling, Kolbermoorer Straße 72, 83043 Bad Aibling, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kopczak
authors.forename: F
authors.initials: F
authors.lastname: von Rosen
authors.forename: C
authors.initials: C
authors.lastname: Krewer
authors.forename: H J
authors.initials: HJ
authors.lastname: Schneider
authors.forename: G K
authors.initials: GK
authors.lastname: Stalla
authors.forename: M
authors.initials: M
authors.lastname: Schneider
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001930:Brain Injuries / Q000097:blood*; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007004:Hypoglycemic Agents / Q000097:blood*; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D011187:Posture; D013345:Subarachnoid Hemorrhage / Q000097:blood*; D016683:Supine Position
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D006854:Hydrocortisone