The low-dose dexamethasone suppression test in fibromyalgia.
OBJECTIVE
Fibromyalgia syndrome (FMS) has been associated with decreased cortisol secretion. Patients with posttraumatic stress disorder (PTSD) exhibit similar hypocortisolism in the context of increased negative feedback sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis. Because trauma and PTSD have been associated with fibromyalgia, we evaluated whether patients with fibromyalgia demonstrate increased HPA feedback sensitivity.


METHODS
Baseline blood samples were obtained at 0800 h, and 0.5 mg of dexamethasone was administered to 15 female patients with FMS and 20 normal controls at 2300 h. Adrenocorticotropin (ACTH), cortisol, and dexamethasone levels were measured at 0800 h after dexamethasone intake.


RESULTS
There were no group differences in mean ACTH or cortisol levels or in ACTH/cortisol ratio at baseline. After dexamethasone intake, patients with FMS exhibited more pronounced suppression of cortisol but not of ACTH, as well as increased ACTH/cortisol ratios compared with controls. Percent cortisol suppression was associated with pain and fatigue, while ACTH/cortisol ratio and dexamethasone availability were associated with stress and anxiety measures.


CONCLUSIONS
Our results suggest increased sensitivity to glucocorticoid feedback, manifested at the adrenal level, in FMS.
Wingenfeld
Katja
K
Department of Psychobiology, University of Trier, Trier, Germany.
Wagner
Dieter
D
Schmidt
Iris
I
Meinlschmidt
Gunther
G
Hellhammer
Dirk H
DH
Heim
Christine
C
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D001007:Anxiety / Q000097:blood / Q000523:psychology; D001676:Biofeedback, Psychology / Q000502:physiology; D003863:Depression / Q000097:blood / Q000523:psychology; D003907:Dexamethasone / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005221:Fatigue / Q000097:blood / Q000523:psychology; D005260:Female; D005356:Fibromyalgia / Q000097:blood* / Q000523:psychology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008875:Middle Aged; D010146:Pain / Q000097:blood / Q000523:psychology; D010913:Pituitary-Adrenal System / Q000503:physiopathology
D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone