Increases in creatine kinase with atorvastatin treatment are not associated with decreases in muscular performance

Abstract

Background: The present study examined if increases in creatine kinase (CK) levels during high-dose atorvastatin treatment are associated with changes in skeletal muscle function and symptoms.

Methods: The Effect of Statins on Muscle Performance study (STOMP) investigated the effects of atorvastatin 80 mg daily for 6 months on muscle performance, exercise capacity, and the incidence of statin-associated muscle complaints in healthy adults.

Results: CK levels increased with atorvastatin (n = 202) from 132.3 ± 120.9 U/L (mean ± SD) at baseline to 159.7 ± 170.4 and 153.1 ± 139.4 U/L at 3 and 6 months, respectively (P ≤ 0.002 for both). Changes in CK with atorvastatin treatment were not associated with changes in muscle function or the incidence of myalgia. More subjects on atorvastatin (n = 24) compared to placebo (n = 12 of 217) doubled their CK level at 6 months (P = 0.02). No differences in muscle function or physical activity were observed between atorvastatin-treated subjects who did or did not double their CK.

Conclusions: Results of the present investigation extend the findings of STOMP by demonstrating that greater increases in CK levels with high-dose atorvastatin treatment did not deleteriously impact skeletal muscle function or predict skeletal muscle complaints. This study was registered at ClinicalTrials.gov (NCT00609063).

Keywords: Exercise; Muscle; Myalgia; Statins.

© 2013 Elsevier Ireland Ltd. All rights reserved.

Figures

Figure 1

Individual changes in creatine kinase (CK) from baseline (Pre) in atorvastatin-treated subjects (Post) who doubled their CK value from baseline (n = 24). Mean CK levels (grey bars) increased significantly (P

Figure 2

Relationship between changes (Post - Pre) in creatine kinase (CK) and handgrip strength (A), isometric elbow extension (B), and isometric leg extension (C) in atorvastatin-treated subjects who exhibited a two-fold or greater increase in CK (n = 24). Linear regression was performed to evaluate relationships between variables. Data were log transformed for analyses but raw data are depicted in the figure. *The relationship between changes in CK and handgrip strength was no longer significant when sex and age were controlled (r2 = 0.30, P = 0.063).