Some cholesterol drugs linked to sleep disruptions

The popular cholesterol-lowering drug simvastatin appears to disrupt sleep patterns of some patients, researchers reported at the American Heart Association’s Scientific Sessions 2007.

The findings are significant because sleep problems can affect quality of life and may have adverse health consequences, such as promoting weight gain and insulin resistance.

In the largest study of its kind, researchers compared two types of cholesterol-lowering drugs called statins – simvastatin, which is soluble in fats, and pravastatin, which is soluble in water.

Because simvastatin is fat-soluble it can more readily penetrate cell membranes and cross the blood brain barrier into the brain. The brain controls sleep, and many of the brain’s nerve cells are wrapped in a fatty insulating sheath called myelin.

The results showed that simvastatin use was associated with significantly worse sleep quality. A significantly greater number of individuals taking simvastatin reported sleep problems than those taking either pravastatin or the placebo. On average, the water-soluble statin had a greater adverse effect on sleep quality.

Patients taking simvastatin who are having sleep problems should consult with their doctor as sleep deprivation is a major problem in a minor number of people.