Objective: The aim of this study was to evaluate the effects of acupuncture treatment on serum levels of serotonin and substance P (SP) as well as on clinical parameters in patients with fibromyalgia (FM).
Methods: This is a randomized controlled clinical trial. Seventy-five women with FM were randomized into one of three kinds of acupuncture treatment: real acupuncture group (AcG), sham acupuncture group (ShG), and simulated acupuncture group (SiG). Treatments were applied semiweekly for four weeks. The serum levels of serotonin and SP were evaluated before and after the eight sessions. Patients were clinically assessed by visual analog scale (VAS), the number of tender points (NTP), Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory (BDI), and Nottingham Health Profile (NHP) at baseline, after the last treatment, and one and three months after completion of all treatments.
Results: Serum serotonin values increased significantly after treatment in AcG and ShG (P < 0.001 and P < 0.01, respectively). The increase in the AcG was also different from both of the other groups (P < 0.01). While SP levels decreased in the AcG, they increased in the SiG (P = 0.001). In the AcG, significant improvements were found in almost all clinical outcomes after treatment. These usually continued for three months. In the ShG, there were also significant changes on the NTP, VAS, FIQ, and BDI scores after treatment. Improvements on the NTP and FIQ scores lasted for three months. In the SiG, significant improvements were found only in the NTP, VAS, and BDI scores after treatment.
Conclusions: Acupuncture, rather than sham or placebo acupuncture, may lead to long-term improvements on clinical outcomes and pain neuromediator values. Changes in serum serotonin and SP levels may be a valuable explanation for acupuncture mechanisms in FM treatment.