LACK OF ASSOCIATION BETWEEN FIBROMYALGIA SYNDROME AND ABNORMALITIES IN MUSCLE ENERGY-METABOLISM

Objective. To compare parameters of muscle energy metabolism in patien ts with fibromyalgia syndrome (FMS) and sedentary controls. Methods. T hirteen female FMS patients and 13 female sedentary controls underwent a standardized clinical assessment (including dolorimeter measurement s of the upper trapezius and tibialis anterior muscles) and a standard ized aerobic fitness test including measurement of maximum oxygen upta ke (VO2max). Phosphorus (P-31) magnetic resonance spectroscopy studies of the upper trapezius and tibialis anterior muscles were then perfor med in FMS patients and controls, at rest and during and following a m uscle-fatiguing exercise protocol. Results. FMS patients and controls had similar levels of VO2max and of maximum voluntary contraction (MVC ) of the upper trapezius and tibialis anterior muscles. After controll ing for VO2max and MVC, measurements of phosphocreatine (PCr), inorgan ic phosphate (P-i), and intracellular pH in these muscles were not sig nificantly different in FMS patients versus sedentary controls either at rest, during exercise, or during recovery. In the patients with FMS , no correlation was found between overall or local pain severity and the principal muscle metabolic parameter, PCr/P-i. Inverse correlation s between dolorimeter scores at 2 muscle sites and tibialis anterior P Cr/P-i were found both in patients and in controls. Conclusion. This s tudy demonstrates that under the conditions studied, muscle energy met abolism in FMS is no different than that in sedentary controls. These findings do not support the hypothesis that detectable defects in musc le energy metabolism occur in FMS.