title: Growth hormone deficiency after mild combat-related traumatic brain injury.
abstract: OBJECTIVE
  Traumatic brain injury (TBI) has been recognized as a cause of growth hormone deficiency (GHD) in civilians. However, comparable data are sparse in veterans who incurred TBI during combat. Our objective was to determine the prevalence of GHD in veterans with a history of combat-related TBI, and its association with cognitive and psychosocial dysfunction.
  
  
  METHODS
  Single center prospective study.
  
  
  METHODS
  Twenty male veterans with mild TBI incurred during combat 8-72 months prior to enrollment.
  
  
  METHODS
  GHD was defined by a GH peak <3 μg/L during glucagon stimulation test. Differences in neuropsychological, emotional, and quality of life of the GHD Veterans were described using Cohen's d. Large effect sizes were considered meaningful.
  
  
  RESULTS
  Mean age was 33.7 years (SD 7.8) and all subjects had normal thyroid hormone and cortisol levels. Five (25%) exhibited a subnormal response to glucagon. Sixteen participants (80%) provided sufficient effort for valid neuropsychological assessment (12 GH-sufficient, 4 GHD). There were large effect size differences in self-monitoring during memory testing (d = 1.46) and inhibitory control (d = 0.92), with worse performances in the GHD group. While fatigue and post-traumatic stress disorder were comparable, the GHD group reported more depression (d = 0.80) and lower quality of life (d = 0.64).
  
  
  CONCLUSIONS
  Our study found a 25% prevalence of GHD in veterans with mild TBI as shown by glucagon stimulation. The neuropsychological findings raise the possibility that GHD has adverse effects on executive abilities and mood. Further studies are needed to determine whether GH replacement is an effective treatment in these patients.
authors.affiliation: Atlanta Veteran Affairs Medical Center, The Emory Clinic, Emory University, 1365 B Clifton Rd, Atlanta, GA, 30322, USA, aioachi@emory.edu.
authors.forename: Adriana G
authors.initials: AG
authors.lastname: Ioachimescu
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Hampstead
authors.forename: Anna
authors.initials: A
authors.lastname: Moore
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Burgess
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Phillips
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000453:epidemiology / Q000378:metabolism* / Q000523:psychology; D016022:Case-Control Studies; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology / Q000378:metabolism* / Q000523:psychology; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D007018:Hypopituitarism / Q000453:epidemiology / Q000378:metabolism* / Q000523:psychology; D007266:Inhibition, Psychological; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D015995:Prevalence; D011446:Prospective Studies; D012720:Severity of Illness Index; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology / Q000378:metabolism* / Q000523:psychology; D014728:Veterans / Q000523:psychology / Q000706:statistics & numerical data; D014857:Warfare
chemical_list: D019382:Human Growth Hormone