Objective: To measure inorganic phosphate (Pi), phosphocreatine (PCr), ATP and phosphodiesters (PDE) in fibromyalgic muscle tissue by (31)P magnetic resonance spectroscopy.
Methods: A 1.5 Tesla scanner with a P 100 surface coil was used to examine 15 patients (mean age 49.9+/-14.3 yr) with fibromyalgia, according to the American College of Rheumatology criteria, and 17 healthy controls (mean age 30.2+/-5.8 yr).
Results: Compared with the controls, there were increases in the levels of PDE (+22%, P = 0.032) and Pi (+19%, P = 0.019) in the spectra of fibromyalgia patients, but there was no difference in pH.
Conclusion: The metabolic differences we found may have been related to weakness and fatigue in the fibromyalgia patients, but they do not fully explain the fibromyalgia symptoms.