Myopathy during statin therapy in the daily practice of an outpatient cardiology clinic: prevalence, predictors and relation with vitamin D.

OBJECTIVE

The mechanism of statin-related myopathy is unknown, while its prevalence is probably underestimated. An association between statin-related myopathy and vitamin D deficiency has been reported. In this pilot study we assessed the prevalence of myopathy in statin users attending the outpatient clinic of the Department of Cardiology of a University Hospital from October 2009 to March 2010. We also searched for predictors of myopathy and investigated whether the myopathy was associated with vitamin D deficiency.

RESEARCH DESIGN AND METHODS

Statin-treated patients were asked to complete an assisted structured questionnaire. Serum creatine kinase (CK) and 25-hydroxyvitamin D (25(OH)D) were measured. Patients with rheumatic diseases, muscle diseases, (poly)neuropathy and peripheral arterial disease were excluded from predictor analysis.

MAIN OUTCOME MEASURES

Percentage of patients with myopathy in the daily clinical practice of an outpatient clinic, serum 25(OH)D, CK, and predictors of myopathy.

RESULTS

One hundred and four statin-treated patients completed the questionnaire. Serum 25(OH)D was measured in 93 patients. Twenty patients with confounding comorbidities were excluded from analysis. Of the remaining 84 patients, 33% reported myopathy, 24% had myalgia and 6% myositis. Rhabdomyolysis was not observed. Time spent outdoors during winter (≤6 h/week; OR: 10.61; 95% CI: 1.91-58.88), total number of prescribed drugs (1.39; 1.05-1.83), BMI (1.35; 1.07-1.69), CK (1.02; 1.00-1.03) and consumption of fish (≥1/week; 0.19; 0.04-0.89) were predictors of myopathy in multivariate analysis.

CONCLUSIONS

Considering the small patient group and a relatively narrow range of vitamin D levels, we arrive at the following statements: 1) one out of three patients reported myopathy; 2) BMI, CK, number of prescription drugs, time spent outdoors and fish consumption were myopathy predictors; and 3) myopathy and 25(OH)D were unrelated.