Oct. 14 (HealthDay News) -- U.S. researchers have identified a common gene mutation linked to side effects in people taking cholesterol-lowering statin drugs.

Statins can reduce high cholesterol and lower the risk of heart attack or stroke. But 25 percent to 50 percent of people prescribed the potentially lifesaving drugs stop taking them after a year because of side effects, in particular muscle aches.

The study included 509 people taking one of three types of statins: atorvastatin (Lipitor), simvastatin (Zocor) or pravastatin (Pravachol). The patients took the drugs for an initial period of eight weeks and then had their doses increased for an additional eight weeks.

The Duke University Medical Center researchers found that people with the common mutation in the SLCO1B1 gene were more likely to have muscle aches. The more copies of the mutation, the greater their risk.

The study also found that the muscle side effects differed depending on the type of statin. People taking simvastatin reported the most side effects while those taking pravastatin had the least muscle aches.

The findings, published online Oct. 12 in the Journal of the American College of Cardiology, may help doctors increase the number of patients who keep taking the drugs.

"If a genetic test can be developed to determine who will experience side effects that will likely make patients go off their medication, we can target these individuals for counseling about common side effects, monitor them more closely or tailor their medication accordingly," lead author and cardiologist Dr. Deepak Voora said in a Duke news release.

SOURCE: Duke Medicine, news release, Oct. 12, 2009