Statins Affect Skeletal Muscle Performance: Evidence for Disturbances in Energy Metabolism.
Level 4 - case-series / case-control
Cross-sectional comparative study
PubMed 29040646 · doi:10.1210/jc.2017-01561
What was done
In a cross-sectional study, researchers compared 10 long-term symptomatic statin users, 10 asymptomatic statin users, and 10 control subjects (total n = 30). Participants underwent maximal incremental cycling tests to measure exercise capacity and substrate use, involuntary electrically stimulated isometric quadriceps contractions to assess muscle fatigue and contraction kinetics, and vastus lateralis muscle biopsies to evaluate mitochondrial oxidative capacity and content.
What was found
Peak oxygen uptake, maximal workload, and ventilatory efficiency did not differ between groups. Both statin groups had a depressed anaerobic threshold compared to controls (P = 0.01). Muscle relaxation time was prolonged and the rate of maximal force rise was decreased in both statin groups compared to controls (Ptime×group < 0.001 for both). Symptomatic statin users had lower mitochondrial activity of complex II (P = 0.03) and complex IV (P = 0.04), and tended to have lower complex III activity (P = 0.05) compared to controls. Mitochondrial content tended to be lower in both statin groups than in controls.
Why it matters
This paper shows that statin use impairs muscle contractile dynamics and lowers anaerobic threshold even in patients without muscle complaints, indicating subclinical mitochondrial and energetic disturbances.
Limits
The sample size was very small (n = 10 per group, total n = 30). The cross-sectional design cannot prove causality, and details regarding statin types, doses, treatment duration, and baseline pre-statin fitness were not reported in the abstract.
Cited by
- supports Muscle biopsies of individuals taking statins show mitochondrial damage even in the absence of muscle pain or elevated muscle enzymes.