title: Changes in muscle strength in individuals with statin-induced myopathy: A summary of 3 investigations.
abstract: BACKGROUND
  There are inconsistent findings regarding muscular weakness in individuals with statin-induced myalgia.
  
  
  OBJECTIVE
  We used rigorous muscle testing to compare findings from 3 investigations in 3 different study populations to determine if statin myalgia is associated with measurable weakness.
  
  
  METHODS
  In all 3 studies, we measured maximal isometric handgrip strength, resting respiratory exchange ratio (RER), and knee extensor isometric and isokinetic force. In 2 of the 3 studies, elbow flexor isometric and isokinetic force and knee endurance fatigue index were also assessed. Knee extensor and elbow flexor measurements were obtained using an isokinetic dynamometer. Resting RER was measured using a metabolic breath-by-breath collection method. Measurement outcomes were compared on vs off drug.
  
  
  RESULTS
  In study 1, 18 participants fit the criteria for statin myalgia. Participants taking atorvastatin 80 mg daily had significantly lower muscle strength in 5 (P < .05) of 14 measured variables. Participants on placebo (N = 10) with myalgia had significantly lower muscle strength in 4 (P < .05) of 14 measured variables. In study 2, 18 participants tested positive for statin-induced myalgia when receiving simvastatin 20 mg daily and displayed no significant muscle strength changes (all P > .05). In study 3, 11 patients with statin-induced myalgia completed the study and had a significant decrease in 2 (P < .05) of 10 leg muscle strength variables. In all 3 studies, no significant changes were shown for handgrip strength or RER (all P > .05).
  
  
  CONCLUSIONS
  Our results indicate that after a short-term treatment with statin therapy, a rigorous muscle strength protocol does not show decrements of muscle strength in subjects with statin myalgia. Short-term treatment with statin therapy is not common in clinical practice. Thus, future studies should examine the effects of prolonged statin therapy on muscle strength.
authors.affiliation: Department of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA. Electronic address: Gregory.Panza@hhchealth.org.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Panza
authors.affiliation: Department of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA; Department of Health Sciences, University of Hartford, West Hartford, CT, USA.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Taylor
authors.affiliation: Department of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA.
authors.forename: Marcin R
authors.initials: MR
authors.lastname: Dada
authors.affiliation: Department of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT, USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Thompson
mesh_terms: D000328:Adult; D000368:Aged; D000069059:Atorvastatin / Q000008:administration & dosage / Q000009:adverse effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D063806:Myalgia / Q000139:chemically induced / Q000503:physiopathology
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000069059:Atorvastatin
keywords: Isokinetic dynamometer; Muscle strength; Myopathy; Statins; Strength testing