Skeletal muscle ultrastructure and function in statin-tolerant individuals

Area of Science:

• Biochemistry
• Muscle Physiology
• Pharmacology

Background:

• Statins significantly reduce cardiovascular mortality but can cause side effects like myalgia and myopathy in up to 15% of patients.
• Projected increases in statin users may lead to a higher incidence of muscle-related adverse events.

Purpose of the Study:

• To investigate the molecular, cellular, and whole tissue effects of statins on skeletal muscle structure and function.
• To determine if chronic statin therapy induces deleterious adaptations in muscle myofilaments.

Main Methods:

• Evaluated skeletal muscle structure and contractile function in 12 statin-tolerant individuals and 12 controls.
• Assessed myosin isoform expression, fiber type distribution, single fiber tension, and whole muscle force.
• Analyzed myosin-actin cross-bridge kinetics in myosin heavy chain I and IIA fibers.

Main Results:

• No significant differences were observed in myosin isoform expression, fiber type distribution, or single fiber maximal tension between statin users and controls.
• Whole muscle contractile force and myosin-actin cross-bridge kinetics in specific fiber types remained similar between groups.
• No molecular, cellular, or whole tissue evidence of statin-induced muscle morphology changes was found.

Conclusions:

• Chronic statin therapy in healthy, asymptomatic individuals does not appear to cause detrimental structural or functional changes at the myofilament level.
• The study found no evidence of statin-induced alterations in skeletal muscle morphology or function.
• These findings suggest statins are safe for muscle tissue in statin-tolerant individuals.