A blinded, controlled trial found that high-dose statins increase muscle complaints, and high-dose atorvastatin increased average creatine kinase, suggesting that statins produce mild muscle injury even among asymptomatic subjects even though they don't decrease average muscle strength or exercise performance in healthy, previously untreated subjects.
Many clinicians believe that statins cause muscle pain, so researchers conducted the Effect of STatins On Skeletal Muscle Function and Performance (STOMP) study to assess symptoms and measure creatine kinase, exercise capacity, and muscle strength before and after atorvastatin 80 mg or placebo were administered for 6 months to 420 healthy, statin-naive subjects.
Results appeared online Nov. 26 in Circulation.
Researcher randomized 203 patients to atorvastatin and 214 to placebo. No individual creatine kinase value exceeded 10 times normal, but ALT exceeded 3 times UNL on two measurements performed within one week of the first elevated value in nine atorvastatin and one placebo subjects.
Creatine kinase levels increased an average of 20.8 +/- 141.1 U/L (P less than 0.0001) with atorvastatin. Atorvastatin increased average ALT values 15.7 +/- 27.4 U/L (P less than 0.0001).
There were no significant changes measures of muscle strength or exercise capacity with atorvastatin, but more atorvastatin than placebo subjects developed myalgia (19 vs. 10; P=0.05), predominantly leg symptoms. Myalgic subjects on atorvastatin decreased muscle strength in 5 of 14 variable compared to 4 of 14 on placebo (P=0.69).
"The observation that some placebo patients satisfied the myalgia definition documents the importance of using a double-blind trial to examine the incidence and characteristics of statin-associated myalgia and not relying solely on clinical characteristics," researcher wrote. "STOMP also demonstrated, we believe again for the first time, that high-dose statin treatment increases average CK [creatine kinase] levels, suggesting that statins produce low level muscle injury in healthy subjects that occurs independent of muscle symptoms."