title: Evaluation of skeletal muscle during calf exercise by 31-phosphorus magnetic resonance spectroscopy in patients on statin medications.
abstract: Muscle pain is a common side effect of statin medications, but the cause is poorly understood. We characterized phosphocreatine (PCr) exercise recovery kinetics in 10 patients with hypercholesterolemia before and after a 4-week regimen of statin therapy using 31-phosphorus magnetic resonance spectroscopy ((31) P-MRS). (31) P spectra were obtained before, during, and after exercise on a calf flexion pedal ergometer. Creatine kinase (CK) serum levels were drawn before and after statin therapy. The mean metabolic recovery time constant in subjects increased from 28.1 s (SE = 6.5 s) to 55.4 s (SE = 7.4 s) after statin therapy. The unweighted mean of the pre/post-recovery time difference was -27.3 s (SE = 12.4 s; P = 0.02). Pre- and post-therapy CK levels were not significantly different (P = 0.50). Metabolic recovery time in the calf is prolonged in patients after statin use. This suggests that statins impair mitochondrial oxidative function, and (31) P MRS is a potential study model for statin-associated myopathy.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, Massachusetts 02215, USA. jswu@bidmc.harvard.edu
authors.forename: Jim S
authors.initials: JS
authors.lastname: Wu
authors.forename: Catherine
authors.initials: C
authors.lastname: Buettner
authors.forename: Howard
authors.initials: H
authors.lastname: Smithline
authors.forename: Long H
authors.initials: LH
authors.lastname: Ngo
authors.forename: Robert L
authors.initials: RL
authors.lastname: Greenman
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000503:physiopathology*; D009135:Muscular Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology*; D010759:Phosphorus Isotopes
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010759:Phosphorus Isotopes