The Hypothalamic-Pituitary-Adrenal Axis in Fibromyalgia: Where Are We in 2001?

SUMMARY

Objectives: To summarize the current status of the hypo-thalamic pituitary adrenal [HPA] axis in the fibromyalgia syndrome [FMS].

Findings: Attention has been focused on the HPA axis in FMS because there is a perceived association of the onset of this disorder with physiologically stressful situations. The medical literature strongly supports some kind of dsyfunction in the HPA system in FMS, but when studies have compared FMS with healthy normal controls, the actual patterns of HPA axis abnormalities have been suprisingly variable. It is possible that some of this variability may relate to a variable balance between the two receptors for corticotropin-releasing hormone which exhibit opposite influences on the stress management system when activated.

Conclusions: The roles of the psychological stress response systems, including the HPA axis, remain uncertain in FMS because there has been so much variability of the findings from controlled studies. Part of the problem may be that pain is the defining symptom in the classification of FMS while the HPA axis may relate more to fatigue and psychological distress.

KEYWORDS:

• Hypthalamic pituitary adrenal axis
• fibromyalgia syndrome
• pain
• fatigue