Statins comprise a large class of drugs that lower blood cholesterol levels by blocking the production of an enzyme involved in cholesterol synthesis. Although statins are generally well tolerated, as many as 10 to 20 percent of people taking the drugs experience complications, including myopathy (muscle damage), liver damage, and cognitive problems. A recent study found that atorvastatin, a commonly prescribed statin, reduces muscle cells' energy production.

The study involved eight inactive but otherwise healthy adults with overweight who took a high dose of atorvastatin (80 milligrams) daily for 56 days. Researchers collected muscle samples from the participants before they took the statin and then again after 14, 28, and 56 days to assess their muscle cells' capacity for energy production.

They found that over the 56 days, the muscle cells' ability to produce energy via oxidative phosphorylation diminished by more than 30 percent. Additionally, the muscle’s capacity to use oxygen, a key indicator of cardiorespiratory fitness, dropped by as much as 45 percent. The study investigators attributed this decline to the statin’s inhibition of specific components (complexes III and IV) within the mitochondria that are vital for energy production.

The findings from this very small study shed light on how high-dose atorvastatin therapy can significantly reduce the energy production in muscle cells, driving a decrease in muscle and aerobic fitness. They also underscore the importance of further research in larger groups to balance the health benefits of statins with their potential effects on muscle function. Learn more about statins in this deep-dive discussion with Dr. Peter Attia.