Low-dose dexamethasone suppression test in chronic fatigue syndrome and health.
OBJECTIVE
Subtle dysregulations of the hypothalamus-pituitary-adrenal axis in chronic fatigue syndrome have been described. The aim of this study was to examine the negative feedback regulations of the hypothalamus-pituitary-adrenal axis in chronic fatigue syndrome.


METHODS
In 21 patients with chronic fatigue syndrome and 21 healthy control subjects, awakening and circadian salivary free cortisol profiles were assessed over 2 consecutive days and compared with awakening and circadian salivary free cortisol profiles after administration of 0.5 mg of dexamethasone at 11:00 PM the previous day.


RESULTS
Patients with chronic fatigue syndrome had normal salivary free cortisol profiles but showed enhanced and prolonged suppression of salivary free cortisol after the administration of 0.5 mg of dexamethasone in comparison to the control subjects.


CONCLUSIONS
Enhanced negative feedback of the hypothalamus-pituitary-adrenal axis could be a plausible explanation for the previously described alterations in hypothalamus-pituitary-adrenal axis functioning in chronic fatigue syndrome. Because similar changes have been described in stress-related disorders, a putative role of stress in the pathogenesis of the enhanced feedback is possible.
Gaab
Jens
J
Center for Psychobiological and Psychosomatic Research, University of Trier, Trier, Germany. jgaab@klipsy.unizh.ch
Hüster
Dominik
D
Peisen
Renate
R
Engert
Veronika
V
Schad
Tanja
T
Schürmeyer
Thomas H
TH
Ehlert
Ulrike
U
D000328:Adult; D003907:Dexamethasone; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012016:Reference Values; D012463:Saliva / Q000378:metabolism
D003907:Dexamethasone; D006854:Hydrocortisone