Björn Gerdle, Kristina Söderberg, Laia Salvador Puigvert, Lars Rosendal, Britt Larsson
DOI: 10.2340/16501977-0581

Objective: The aim of this study was to compare the interstitial concentrations of pyruvate, lactate and glutamate in the trapezius muscle between patients with fibromyalgia syndrome and healthy controls.
Design: Comparative cross-sectional study.
Subjects: Patients with fibromyalgia (n = 19) and healthy controls (n = 19); all women.
Methods: Subjects answered a questionnaire about different aspects of pain. Pressure pain thresholds over the trapezius and tibialis anterior muscles were determined. The inter­stitial concentrations of pyruvate, lactate and glutamate were determined in the resting trapezius muscle by the microdialysis technique, with samples collected every hour for 5 consecutive hours. Pain intensity was also rated.
Results: Significantly higher interstitial concentrations of pyruvate and lactate were found in patients with fibromyalgia­ syndrome. The multivariate regression analyses of group membership and pressure pain thresholds of the trapezius confirmed the importance of pyruvate and lactate.
Conclusion: Different mechanisms that may increase pyruvate and lactate in patients with fibromyalgia syndrome are discussed. Improved understanding of peripheral muscle alterations in patients with fibromyalgia syndrome could lead to mechanism-based rehabilitation.