Reduced high-energy phosphate levels in the painful muscles of patients with primary fibromyalgia.

Muscle energy metabolism was studied by chemical analysis of biopsy samples from: 1) trigger points in the trapezius muscle from 15 patients with primary fibromyalgia (PF), 2) nonpainful, anterior tibial muscle from 6 patients with PF, and 3) the trapezius muscle from 8 healthy controls. We found a decrease in the levels of adenosine triphosphate, adenosine diphosphate, and phosphoryl creatine, and an increase in the levels of adenosine monophosphate and creatine, in the trapezius muscles from the patients. These findings support the notion that the pain in patients with PF is of muscular origin.