Objectives: 

Fibromyalgia (FM) is a syndrome mainly characterized by the presence of chronic widespread pain and tenderness. Although its aetilogy remains still unclear, it has been proposed that alterations in the stress responses could be involved, so that it has been proposed as a stress-related disease. Furthermore, FM it has been related with alterations of the serotoninergic system and of the melatonin concentrations. Bearing this in mind, the purpose of this study was to evaluate the neuroendocrine/stress status of FM patients compared to an aged-matched control group of healthy women (HW).

Materials: 

Circulating concentration of CRH, ACTH, cortisol, NA, eHsp72 and serotonin were evaluated (by ELISA) in a group of 25 FM patients and compared to a group of 20 HW. Additionally, urine concentration of 6-sulfatoxymelatonin (a metabolite of melatonin which reflects the nocturne values of this hormone) was also evaluated (by ELISA) in a group of 13 FM patients compared to a group of 10 HW.

Results: 

FM patients presented higher circulating concentration of cortisol (p<0.05), NA (p<0.001), and eHsp72 (p<0.01), but lower concentrations of CRH, ACTH, and serotonin compared to HW. FM patients presented higher concentration of urine 6-sulfatoxymelatonin than HW.

Conclusions: 

The present study confirms that an altered neuroendocrine/stress status underlies FM, mainly reflected by elevated concentration of stress mediators such as cortisol, NA, and eHsp72, as well as by a disrupted feedback in the HPA axis, reflected by elevated circulating levels of cortisol and a diminished response of CRH and ACTH, all that compared to a control group of healthy women. The FM patients seem also denoted an altered circuit of serotonin-melatonin system.

This work has been supported by grants from MICINN-DEFER (DEP2009-10041)of Spain and Junta d Extremadura-FEDER (PRI09A003 and GR10020).