Catecholaminergic stress responses during physical exercise in chronic fatigue syndrome

Completed Research Project

Title / Titel: Catecholaminergic stress responses during physical exercise in chronic fatigue syndrome

Summary / Zusammenfassung: In chronic fatigue syndrome (CFS), consistent evidence for dysregulations of the hypothalamus-pituitary-adrenal (HPA) axis exists. In general, the activity of HPA axis parameters exert a positive influence on the sympathetic nervous system (SNS) and vice versa. However, little is known about the responsiveness of the SNS under stress in CFS. We therefore repeatedly assessed catecholaminergic stress responses to a standardized exercise test until exhaustion in 21 CFS patients and 20 age and gender matched controls. Outcome variables were heart rate, ACTH, plasma and salivary cortisol, norepinephrine (NE), epinephrine (E), maximal work load, perceived exertion and exercise duration.
Groups differed significantly in the ACTH, but not in any cortisol parameter. Statistical control for workload, perceived exertion, and exercise duration did not influence these results. Groups did not differ in their heart rate response over time. Catecholaminergic responses to the exercise test differed significantly between the groups (time x group interaction effect: NE: F (1.09/42.42) = 4.30; P = 0.041; E: F (1.11/43.10) = 4.00; P = 0.048). However, these differences were not seen after the control for maximal workload in the exercise test.
Results indicate that CFS show lower absolute but normal relative catecholamine stress responses to physical exercise. Regarding the neuroendocrine stress response, CFS patients exhibit a lower ACTH response level, indicating a central dysregulations of the HAP axis. The discrepant findings for HPA axis and SNS speak against a generalized hyporeactivity of central stress systems in CFS.

Publications / Publikationen: Gaab, J., Engert, V., Schad, T., Heitz, V., Schürmeyer, T., Ehlert, U. (2003): Catecholaminergic responses to physical exercise in chronic fatigue syndrome. Conference proceeding, Psychosomatic Medicine, 65/1, A26.

Keywords / Suchbegriffe: Chronic fatigue syndrome, catecholamines, psychobiology

Project Leadership and Contacts / Projektleitung und Kontakte

Dr. phil. Jens Gaab (Project Leader)	jgaab@klipsy.uzh.ch
Prof. Ulrike Ehlert	ehlertu@klipsy.uzh.ch

Funding Source(s) / Unterstützt durch: Foundation, Others
Deutsche Studienstiftung (Scholarship to Jens Gaab)

Duration of Project / Projektdauer: May 1998 to Dec 2003