title: Neurally mediated hypotension in fatigued Gulf War veterans: a preliminary report.
abstract: BACKGROUND
  Many patients with chronic fatigue syndrome (CFS) have neurally mediated hypotension when subjected to head-up tilt, suggesting autonomic nervous system dysfunction. Some Gulf War veterans have symptoms similar to CFS. Whether they also tend to have neurally mediated hypotension is unknown.
  
  
  METHODS
  We performed 3-stage tilt-table testing on 14 Gulf War veterans with chronic fatigue, 13 unfatigued control Gulf War veterans, and 14 unfatigued control subjects who did not serve in the Gulf War. Isoproterenol was used in stages 2 and 3 of the tilt protocol.
  
  
  RESULTS
  More fatigued Gulf War veterans than unfatigued control subjects had hypotensive responses to tilt (P < 0.036). A positive response to the drug-free stage 1 of the tilt was observed in 4 of 14 fatigued Gulf War veterans versus 1 of 27 unfatigued control subjects (P < 0.012). Heart rate and heart rate variation during stage 1 was significantly greater in the fatigued group (P < 0.05).
  
  
  CONCLUSIONS
  We conclude that more fatigued Gulf War veterans have neurally mediated hypotension than unfatigued control subjects, similar to observations in CFS. Autonomic nervous system dysfunction may be present in some fatigued Gulf War veterans.
authors.affiliation: Preventive Medicine, Evans US Army Community Hospital, Fort Carson, Colorado, USA. shirley.davis@med.va.gov
authors.forename: S D
authors.initials: SD
authors.lastname: Davis
authors.forename: S F
authors.initials: SF
authors.lastname: Kator
authors.forename: J A
authors.initials: JA
authors.lastname: Wonnett
authors.forename: B L
authors.initials: BL
authors.lastname: Pappas
authors.forename: J L
authors.initials: JL
authors.lastname: Sall
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005221:Fatigue / Q000150:complications* / Q000503:physiopathology*; D015673:Fatigue Syndrome, Chronic / Q000150:complications / Q000503:physiopathology; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008877:Middle East; D018667:Tilt-Table Test; D014728:Veterans; D014857:Warfare