Association of Fibromyalgia to serum levels of C-reactive protein in a large Appalachian population

Background: Fibromyalgia (FM) is a disease of poor etiology characterized by chronic widespread pain.  To date there is no consensus on effective treatment.  Limited research has suggested a link between FM and inflammation.  However, these studies have been small, and findings have been inconsistent.  In this study, the authors investigated the association between inflammatory marker serum C-reactive protein (CRP) levels and FM in a large Appalachian population.

Methods: Study participants were 51,689 adults drawn from 6 Perfluorooctanoic Acid contaminated water districts in the mid-Ohio valley (N= 1,001 cases of FM, 50,688 adults free of FM). Participants completed a comprehensive health survey; serum levels of CRP and other blood markers were also measured. Medical history, including physician diagnosis of FM, was ascertained via self-report. We used logistic regression to assess the independent association of FM diagnosis to serum CRP.  Analyses were adjusted for demographic and lifestyle factors, comorbid conditions, and sleep impairment. 

Results: CRP showed a modest, significant, positive association with FM after adjustment for potential confounders.  FM was also significantly and positively associated with age, female gender, and number of comorbidities.  In addition, adults reporting a diagnosis of autoimmune disease, cardiovascular disease, kidney disease, or certain other chronic conditions were significantly more likely to have FM. 

Conclusions: Findings of this large, cross-sectional study indicate a significant positive association of FM to serum CRP, suggesting that inflammation may play a role in this still poorly understood pain syndrome.  Prospective studies are needed to confirm these findings and elucidate potential causal relationships.