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 capacity (Vmax).
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 Vmax 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.