Cancer risk seen with very low cholesterol levels

CHICAGO - Lowering bad, or LDL, cholesterol is one of the top strategies for preventing heart disease, but taking it too low may raise the risk of cancer, a study cautioned on Tuesday.

The red flag comes from a large-scale retrospective analysis of 23 studies involving statin drugs such as Lipitor, Pravachol and Zocor which lower cholesterol. More than 41,000 patients participated in the trials.

Researchers were looking at the data to evaluate the side effects of these drugs -- specifically whether they damage liver or muscle cells -- when they noticed that low LDL levels were associated with an increased cancer risk.

They found an extra case of cancer for every 1,000 patients with low LDL (low-density lipoprotein) levels compared to higher LDL levels.

The finding is preliminary and further studies will be needed to determine whether the malignancy is a side effect of the drugs or a function of low levels of this type of cholesterol, the researchers cautioned.

"This analysis doesn't implicate the statin in the increasing risk of cancer," said lead author Richard Karas, professor of medicine at Tufts University School of Medicine in Boston.

"The demonstrated benefits of statins in lowering the risk of heart disease remain clear; however certain aspects of lowering LDL with statins remain controversial and merit further research."

John LaRosa, an authority on statins at State University of New York said there was insufficient evidence to suggest that "there is any problem with LDL lowering that outweighs its significant benefits on vascular disease."

However, "we must continue to be vigilant in ensuring that its benefits clearly outweigh its risks," he wrote in an editorial that was printed with the study in the Journal of the American College of Cardiology.

As to the main question of the study, whether the drugs damage the liver and muscle cells, the investigators said they found no link between lowering LDL and liver or muscle irritation.

They did however find that liver toxicity levels increased with higher statin dosage. Those findings come from records on more than 75,000 patients.

source : www.channelnewsasia.com