Statins are wonderful drugs for decreasing levels of low-density lipoprotein, or “bad” cholesterol, and thus reducing the risk of atherosclerosis and heart disease. However, although usually mild, statins do have side effects, and new research shows that some of them may prompt some men just starting out on statins to exercise less. The new report appears this week in the Journal of the American Medical Association (JAMA) Internal Medicine.

A team of researchers in Portland, Oregon determined that the statin users they studied exercised approximately 40 minutes less each week than those who were not taking any statin drugs, including Lipitor, Zocor, Crestor, Lescol, Pravachol, and Vytorin. The results confirm previous observations by others, although the authors of the report stress that statin use should not be discontinued. The side effects of statin drugs sometimes include muscle ache, weakness, and fatigue.

“Statins are extremely helpful for people who need them,” stressed study lead author David Lee, an assistant professor in the Department of Pharmacy Practice at Oregon State University/Oregon Health and Science University’s College of Pharmacy in Portland. “They’ve really changed the landscape of cardiovascular health over the last 20 years.”

“But the thing I want people to be aware of is that they can have some adverse effects on muscles that might lead to a decrease in exercise,” Lee continued. “Because by being aware of that problem perhaps we can encourage patients to actually make an effort to push themselves to maintain their exercise habits. Because exercise is really very important, both for maintaining general health and for maintaining the ability to carry on independently as we age.”

This was a large study involving 3,000 male subjects of ages 65 years and older with an average age of 73. All men in the study were followed from 2000 to 2002, lived independently, and could walk without assistance during this period. About 25 percent of the men were already taking statins at the time of enrollment, and about another 25 percent began using statins during the study period, leaving about 1,500 men not taking statins at any time during the study.

All of the men reported their exercise habits and wore activity monitors for one-week periods near the end of the study. Activity levels for all men declined slightly over the study period, but men who began statin use during the study exhibited faster rates of activity decline compared with the men who did not take statins.

“Now, we didn’t look at the underlying cause or reason for decreased exercise,” Lee acknowledged. “But the main hypothesis is that people who take a statin do experience an increase in muscle pain. It’s actually the most common side effect. And observational studies have shown that as many as 20 percent of people taking statins will have muscle pain.”