Differential Association Between Statin Exposure and Elevated Levels of Creatine Kinase

BACKGROUND:Although hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) are generally well tolerated, myopathy can be a serious adverse event. The association among different statins, doses, and related risk factors is not well understood.Objective:To determine the prevalence of elevated creatine kinase (CK) levels in patients taking statins, specific doses of these drugs, and other factors. Simvastatin and lovastatin were the drugs of primary interest.METHODS:In a modified prevalence (cross-sectional) study, prescriptions and laboratory data for 215 191 patients exposed to a statin in 2002 were reviewed. A log-linear Poisson regression model was used to determine the statistical relationship of an elevated CK level to other independent variables.RESULTS:Prevalence of high elevation of CK levels (ie, n of cases/1000 pts. exposed to statins) was 1.6; prevalence of mild to moderate elevation of CK levels was 6.4. For high elevations, the prevalence ratios were lower for low doses of lovastatin t...