1. ¹Department of Emergency Medicine, University of Michigan Medical Center, Ann Arbor, MI, USA
2. ²Department of Medicine (Rheumatology), University of Michigan Medical Center, Ann Arbor, MI, USA
3. ³Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
4. ⁴Department of Medicine (Rheumatology), Georgetown University Medical Center, Washington, DC, USA
5. ⁵Michigan Pain Specialists, Ann Arbor, MI, USA
6. ⁶Department of Psychiatry, University of Michigan Medical Center, Ann Arbor, MI, USA
7. ⁷Center for Statistical Consulting and Research, University of Michigan Medical Center, Ann Arbor, MI, USA

Correspondence: Dr SA McLean, University of Michigan Chronic Pain and Fatigue Research Center, 24 Frank Lloyd Wright Drive, PO Box 385, Ann Arbor, MI 48106, USA. Tel: +1 734 615 2765; Fax: +1 734 998 6900, E-mail: samclean@umich.edu

Received 10 March 2006; Revised 7 June 2006; Accepted 25 July 2006; Published online 23 August 2006.

Abstract

Previous studies have identified stress system dysregulation in fibromyalgia (FM) patients; such dysregulation may be involved in the generation and/or maintenance of pain and other symptoms. Corticotropin-releasing factor (CRF) is the principal known central nervous system mediator of the stress response; however, to date no studies have examined cerebrospinal fluid (CSF) CRF levels in patients with FM. The relationship between CSF CRF level, heart rate variability (HRV), and pain, fatigue, and depressive symptoms was examined in patients with FM. Among participants (n=26), CSF CRF levels were associated with sensory pain symptoms (r=0.574, p=0.003) and affective pain symptoms (r=0.497, p=0.011), but not fatigue symptoms. Increased HRV was also strongly associated with increased CSF CRF and FM pain. In multivariate analyses adjusting for age, sex, and depressive symptoms, the association between CSF CRF and sensory pain symptoms (t=2.54, p=0.027) persisted. Women with FM who reported a history of physical or sexual abuse had lower CSF CRF levels than women who did not report such a history. CSF CRF levels are associated with both pain symptoms and variation in autonomic function in FM. Differences in CSF CRF levels among women with and without a self-reported history of physical or sexual abuse suggest that subgroups of FM patients may exist with different neurobiological characteristics. Further studies are needed to better understand the nature of the association between CSF CRF and pain symptoms in FM.