MUSCLE-FIBER CHARACTERISTICS, CAPILLARIES AND ENZYMES IN PATIENTS WITH FIBROMYALGIA AND CONTROLS

In II female patients with Fibromyalgia Syndrome (FS), biopsies from t he m. vastus lateralis were analyzed, in order to reveal any possible changes which might explain muscular weakness and fatigue. Nineteen he althy subjects served as a control group. Light microscopy did not sho w any gross histopathological findings. Fiber composition and fiber ar eas did not differ between the two groups, except for a greater coeffi cient of variation of the area of type II A fibers and of the mean fib er area in the FS group. The number of capillaries per square millimet er and also the fiber area in relation to the capillaries, was lower i n the FS patients. Analysts of enzymes showed decreased levels of 3-hy droxy-CoA-dehydrogenase and citrate synthase in the patient group. The reduced oxidative enzyme levels and capillarization indicate reduced physical activity, although this does not associate with muscle fiber hypotrophy.