Effects of non-pharmacological interventions on inflammatory biomarker expression in patients with fibromyalgia: a systematic review

Introduction Fibromyalgia (FM) is a prevalent disorder. However, few studies have evaluated the effect of treatment interventions on biomarker expression. The aim of this review was to explore the efficacy of non-pharmacological interventions on inflammatory biomarker expression, specifically cytokines, neuropeptides and C-reactive protein (CRP), in FM patients. Method A literature search using PubMed, EMBASE, PsycINFO and the Cochrane library was performed from January 1990 to March 2015. Randomized controlled trials (RCTs) and non-RCTs published in English, French or Spanish were eligible. Results Twelve articles with a total of 536 participants were included. After exercise, multidisciplinary, or dietary interventions in FM patients, interleukin (IL) expression appeared reduced, specifically serum IL-8 and IL-6 (spontaneous, lipopolysaccharide (LPS)-induced, or serum). Furthermore, the changes to insulin-like growth factor 1 (IGF-1) levels might indicate a beneficial role for fatigue in obese FM patients. In contrast, evidence of changes in neuropeptide and CRP levels seemed inconsistent. Conclusion Despite minimal evidence, our findings indicate that exercise interventions might act as an anti-inflammatory treatment in FM patients and ameliorate inflammatory status, especially for pro-inflammatory cytokines. Additional RCTs focused on the changes to inflammatory biomarker expression after non-pharmacological interventions in FM patients are needed.