Effects of posttraumatic stress disorder on cardiovascular stress responses in Gulf War veterans with fatiguing illness

Abnormal cardiovascular stress responses have been reported in Gulf War veterans with chronic fatigue. However, many of these veterans also suffer from posttraumatic stress disorder (PTSD), which could potentially explain the reported abnormalities. To test this hypothesis, 55 Gulf veterans (GVs) with chronic fatigue syndrome (CFS) or idiopathic chronic fatigue (ICF) were stratified into groups with (N=16) and without (N=39) comorbid PTSD, and were compared to healthy Gulf veterans (N=47) on cardiovascular responses to a series of stressors. The CFS/ICF with PTSD group had lower blood pressure responses to speech and arithmetic tasks, and more precipitous declines and slower recoveries in blood pressure after standing up than the controls. Similar trends in the CF/ICF group without PTSD were not significant, however. Both CFS/ICF groups had blunted increases in peripheral vascular resistance during mental tasks. However, only the veterans with comorbid PTSD had diminished cardiac output responses to the mental stressors and excessive vasodilatory responses to standing. Symptoms of posttraumatic stress were significant predictors of hypotensive postural responses, but only in veterans reporting a significant exposure to wartime stress. We conclude that comorbid PTSD contributes to dysregulation of cardiovascular responses to mental and postural stressors in Gulf veterans with medically unexplained fatiguing illness, and may provide a physiological basis for increased somatic complaints in Gulf veterans with symptoms of posttraumatic stress.