WEDNESDAY, Nov. 7, 2007 (HealthDay News) -- Lowering your cholesterol could interrupt your slumber.
A new report found that the statin Zocor disrupts sleep patterns in some users.
"The study suggests that simvastatin [Zocor] is more likely to have sleep disruption," said Dr. Sidney Smith, past president of the American Heart Association and director of the Center for Cardiovascular Science and Medicine at the University of North Carolina School of Medicine. "The extent to which this would be a significant problem for patients is uncertain, but this should raise awareness that symptoms could be related to therapy."
The findings were presented Wednesday at the American Heart Association's annual meeting, in Orlando, Fla.
A growing number of Americans now take statins to reduce their cholesterol levels, as a way to prevent heart attack or stroke.
"There had long been concerns about statins adversely affecting sleep in case reports and case series dating back to at least 1990, just after the release of statins," said study author Dr. Beatrice Golomb, of the University of California, San Diego, School of Medicine's Department of Medicine. "The rub is that they used sample sizes that were tiny and follow-ups of only four to six weeks. The sample sizes were less than 20 or 30 -- not enough typically to show an effect unless the effect was huge," Golomb noted.
The new study, funded by the U.S. National Institutes of Health, is the largest of its kind and involved 1,106 healthy adult men and women who were randomly chosen to receive 20 milligrams of Zocor (simvastatin), 40 milligrams of Pravachol (pravastatin), or a placebo for six months. The two dosages of the two statins are considered approximately equivalent.
"We were looking at the impact of the most hydrophilic [Pravachol] and most lipophilic [Zocor] statins on a range of non-cardiac endpoints with sleep as a pre-specified secondary outcome," Golomb explained.
Lipophilic means the drug is soluble in fat, while hydrophilic means it is soluble in water. Previous research had implicated lipophilic statins in sleep disturbances.
"Simvastatin is fat-soluble, and can penetrate and cross into the brain," Smith explained.
Golomb said: "We did show significant worsening in both sleep quality outcome and sleep problem categories in patients taking simvastatin. Less sleep quality and more sleep problems."
Those participants who had worse sleep also showed a worsening in their aggression scores, compared to people in the other two study groups.
This doesn't mean that patients experiencing sleep problems should take themselves off Zocor or another statin, Smith said. "The broader benefit of decreasing heart attack and stroke must be taken into account," he said.
And patients who find themselves truly sleep-deprived can also talk to their doctor about finding an alternate statin, he said.
Visit the National Sleep Foundation for more on sleep disorders.