Statin-Associated Myopathy in a Pediatric Preventive Cardiology Practice

Objectives To describe muscle-related statin adverse effects in real-world pediatric practice. Study design Using prospectively collected quality improvement data from a pediatric preventive cardiology practice, we compared serum creatine kinase (CK) levels among patients prescribed and not prescribed statins, and pre-/poststatin initiation. Multivariable mixed-effect models were constructed accounting for repeated measures, examining the effect of statins on log-transformed CK (lnCK) levels adjusted for age, sex, weight, season, insurance type, and race/ethnicity. Results Among 1501 patients seen over 3.5 years, 474 patients (14 ± 4 years, 47% female) had at least 1 serum CK measured. Median (IQR) CK levels of patients prescribed (n = 188 patients, 768 CK measurements) and not prescribed statins (n = 351 patients, 682 CK measurements) were 107 (83) IU/L and 113 (81) IU/L, respectively. In multivariable-adjusted models, lnCK levels did not differ based on statin use (β = 0.02 [SE 0.05], P  = .7). Among patients started on statins (n = 86, 130 prestatin and 292 poststatin CK measurements), median CK levels did not differ in adjusted models (β for statin use on lnCK = .08 [SE .07], P  = .2). There was a clinically insignificant increase in CK over time (β = .08 [SE .04], P  = .04 per year). No muscle symptoms or rhabdomyolysis were reported among patients with high CK levels. Conclusions In a real-world practice, pediatric patients using statins did not experience higher CK levels, nor was there a meaningful CK increase with statin initiation. These data suggest the limited utility to checking CK in the absence of symptoms, supporting current guidelines.