OBJECTIVE: The objective of this study was to examine whether inappropriate cardiovascular responses to stressors may underlie symptoms in Gulf War veterans with chronic fatigue. METHODS: Psychophysiological stress testing was performed on 51 Gulf War veterans with chronic fatigue (using the 1994 case definition of the Centers for Disease Control and Prevention) and 42 healthy veterans. Hemodynamic responses to cold pressor, speech, and arithmetic stressors were evaluated using impedance cardiography. RESULTS: Veterans with chronic fatigue had diminished blood pressure responses during cognitive (speech and arithmetic) stress tests due to unusually small increases in total peripheral resistance. The cold pressor test, however, evoked similar blood pressure responses in the chronic fatigue and control groups. Low reactivity to cognitive stressors was associated with greater fatigue ratings among ill veterans, whereas an opposite relation was observed among healthy veterans. Self-reported neurocognitive decline was associated with low reactivity to the arithmetic task. CONCLUSIONS: These results suggest a physiological basis for some Gulf War veterans' reports of severe chronic fatigue. A greater deficit with responses processed through cerebral centers, as compared with a sensory stimulus (cold pressor), suggests a defect in cortical control of cardiovascular function. More research is needed to determine the specific mechanisms through which the dissociation between behavioral and cardiovascular activities identified in this study may be contributing to symptoms in Gulf War veterans.
OBJECTIVE: The objective of this study was to examine whether inappropriate cardiovascular responses to stressors may underlie symptoms in Gulf War veterans with chronic fatigue. METHODS: Psychophysiological stress testing was performed on 51 Gulf War veterans with chronic fatigue (using the 1994 case definition of the Centers for Disease Control and Prevention) and 42 healthy veterans. Hemodynamic responses to cold pressor, speech, and arithmetic stressors were evaluated using impedance cardiography. RESULTS: Veterans with chronic fatigue had diminished blood pressure responses during cognitive (speech and arithmetic) stress tests due to unusually small increases in total peripheral resistance. The cold pressor test, however, evoked similar blood pressure responses in the chronic fatigue and control groups. Low reactivity to cognitive stressors was associated with greater fatigue ratings among ill veterans, whereas an opposite relation was observed among healthy veterans. Self-reported neurocognitive decline was associated with low reactivity to the arithmetic task. CONCLUSIONS: These results suggest a physiological basis for some Gulf War veterans' reports of severe chronic fatigue. A greater deficit with responses processed through cerebral centers, as compared with a sensory stimulus (cold pressor), suggests a defect in cortical control of cardiovascular function. More research is needed to determine the specific mechanisms through which the dissociation between behavioral and cardiovascular activities identified in this study may be contributing to symptoms in Gulf War veterans.
Authors: Dane B Cook; Aaron J Stegner; Paul R Nagelkirk; Jacob D Meyer; Fumiharu Togo; Benjamin H Natelson Journal: Med Sci Sports Exerc Date: 2012-06 Impact factor: 5.411
Authors: Kristen Salomon; Lauren M Bylsma; Kristi E White; Vanessa Panaite; Jonathan Rottenberg Journal: Int J Psychophysiol Date: 2013-06-10 Impact factor: 2.997
Authors: Roberta F White; Lea Steele; James P O'Callaghan; Kimberly Sullivan; James H Binns; Beatrice A Golomb; Floyd E Bloom; James A Bunker; Fiona Crawford; Joel C Graves; Anthony Hardie; Nancy Klimas; Marguerite Knox; William J Meggs; Jack Melling; Martin A Philbert; Rachel Grashow Journal: Cortex Date: 2015-09-25 Impact factor: 4.027