Use of P-31 magnetic resonance spectroscopy to detect metabolic abnormalities in muscles of patients with fibromyalgia

Abstract

Objective. To investigate the metabolic and functional status of muscles of fibromyalgia (FM) patients, using P-31 magnetic resonance spectroscopy (MRS). Methods. Twelve patients with FM and 11 healthy subjects were studied. Clinical status was assessed by questionnaire. Biochemical status of muscle was evaluated with P-31 MRS by determining concentrations of inorganic phosphate (Pi), phosphocreatine (PCr), ATP, and phosphodiesters during rest and exercise. Functional status was evaluated from the PCr/Pi ratio, phosphorylation potential (PP), and total oxidative ca-Results. Patients with FM reported greater difficulty in performing activities of daily living as well as increased pain, fatigue, and weakness compared with controls. MRS measurements showed that patients had significantly lower than normal PCr and ATP levels (P < 0.004) and PCr/Pi ratios (P < 0.04) in the quadriceps muscles during rest. Values for PP and V, , , also were significantly reduced during rest and exercise. Conclusion. P-31 MRS provides objective evidence for metabolic abnormalities consistent with weakness and fatigue in patients with FM. Noninvasive P-31 MRS may be useful in assessing clinical status and evaluating the effectiveness of treatment regimens in FM. pacity (VInaJ. Fibromyalgia (FM) is a syndrome of unknown cause and poorly understood pathophysiology, with an estimated prevalence as high as 10% in one population study (1). Although levels of serum muscle enzymes and electromyography findings are normal in FM patients, histologic studies indicate the presence of abnormalities in the morphology of muscle fibers (2 3). These abnormalities include the presence of ragged red fibers (4) and swelling of capillary endothelial cells (5-7). Abnormal distribution of oxygenation in the trapezius muscle of FM patients as measured with an oxygen-sensitive electrode has been reported (S), and this finding is consistent with other observations reported by Bennett et al, who found that the blood flow in the exercising muscles of FM patients was significantly lower than in age-and sex-matched controls (9). Decreased levels of the high-energy phosphate compounds ATP and phos-phocreatine (PCr) have been observed in muscle biopsy samples from patients with FM (4). The technique of P-31 magnetic resonance ypec-troscopy (MRS) has been shown to be useful in the evaluation of a number of muscle diseases, including glycogen phosphorylase deficiency (lo), mitochondria1 myopathies (11,12) and dermatomyositis (DM) (13,14), Recent P-31 MRS studies in FM investigated both resting and exercising muscles by evaluation of PCr/ inorganic phosphate (PCr/Pi) ratios (15-19), but no defect was found. However, it is critical to determine the absolute levels of Pi, PCr, and ATP, since ratios of these compounds can be normal while the actual concentrations of compounds are reduced (20). In the present study, we used P-31 MRS to quantitate levels of Pi, PCr, and ATP and their relevant ratios in the muscles of clinically characterized FM patients (21). The metabolic ab...

Evidence for metabolic abnormalities in the muscles of patients with fibromyalgia

“…This value for the muscles of the patients with FM was 60% lower than normal values (P<0.01) ( Table 3). The explanation for the reduced work performance (V) during exercise may be explained in part by this low PP, as well as by the decreased work/ energy-cost ratio (pounds lifted/[Pi/PCr]) and low total oxidative capacity (V max ), which were approximately 55% below normal values (P<0.001) [25]. These low values indicate that oxidative phosphorylation was significantly impaired in the patients with FM.…”

Muscle abnormalities in juvenile dermatomyositis patients: P-31 magnetic resonance spectroscopy studies

“…Two control subjects who were tested frequently over 10 months had stable metabolite levels at rest, with a variation of Ϯ6%. Two patients (patients 8 and 9) and the controls were examined on a Siemens SP magnet, which was previously shown in extensive comparative experiments to yield results equivalent to those of the Siemens GBSII magnet (29).…”

Altered Inflammatory Mediators in Fibromyalgia

“…So, it was found a lower intracellular concentration of ATP in muscle cells [46, [72][73][74][75] and in neuronal cells [46] and peripheral blood mononuclear cells [76,77] of FM patients. We only found a study which evaluated plasma levels of ATP in patients with FM [78] this study reported lower ATP levels in the plasma of FM patients with respect to the healthy people group.…”