Skip to content
My WebMD Sign In, Sign Up

Cholesterol & Triglycerides Health Center

Font Size
A
A
A

Muscle Damage From Statins May Evade Blood Test

Normal CPK Test Doesn't Rule Out Muscle Injury
By
WebMD Health News
Reviewed by Louise Chang, MD

statins_muscle_damage.jpg

July 6, 2009 - Statin users with prolonged statin-related muscle pain may also experience muscle damage, even when a blood test used to identify muscle injury is normal, new research shows.

Studies suggest that between 10% and 15% of patients who take cholesterol-lowering statin drugs like Crestor, Lipitor, Lescol, Mevacor, Zocor, and Pravachol experience muscle pain as a side effect of treatment.

Most do not end up with muscle damage, and a simple blood test is routinely performed to identify patients who do.

But the new study suggests the test for elevated levels of an enzyme associated with muscle injury, known as creatine phosphokinase or CPK, may be less accurate than widely believed.

“The patients in our study were unusual in that they had experienced weeks to months of persistent muscle problems,” Richard H. Karas, MD, PhD, tells WebMD. “We found that these patients can have evidence of microscopic damage to their muscles even with a normal CPK.”

Serious Statin Injury Is Rare

It is not clear what percentage of patients experience statin-related muscle injury, known as myopathy. About 1 in 10,000 develop a potentially deadly muscle condition known as rhabdomyolysis, Karas says.

Karas and colleagues from Boston’s Tuft’s University and Switzerland’s University of Bern examined biopsy samples from 83 patients, including 44 with statin-related muscle pain lasting from several weeks to several months.

They found microscopic evidence of muscle injury in 25 of the 44 patients diagnosed with treatment-related muscle pain, including several who had stopped taking statins before the biopsy samples were collected.

In general, CPK levels were highest in patients with muscle pain who were currently taking statins, but many patients with evidence of muscle injury had CPK levels in the normal range.

“Our findings call into question whether normal or mildly elevated levels of serum (CPK) can be used to exclude underlying and possibly ongoing muscle injury,” the researchers wrote in the July 7 issue of the Canadian Medical Association journal CMAJ.

Karas stresses that the vast majority of patients who take statins experience no muscle-related side effects. He adds that those who do notice unexplained muscle pain while taking a statin should discuss it with their doctor.

”Patients on statin therapy who are feeling fine should not worry about muscle damage, and no one should stop treatment without talking to their doctor,” he says.

The finding that CPK testing can confirm, but not rule out, statin-related muscle injury comes as no surprise to cardiologist Sidney C. Smith, Jr., MD, who is a past president of the American Heart Association. He tells WebMD that several smaller studies have shown the same thing.

Smith is a professor of medicine at the University of North Carolina at Chapel Hill.

“This is not a new, but it is important research,” he says. “And it is important to point out that we are talking about a minority of a minority of patients taking statins.”

Is This Normal? Get the Facts Fast!

Is Your Cholesterol Level Heart Healthy?
What is your LDL (low-density lipoprotein) level?

Get the latest Cholesterol Management newsletter delivered to your inbox!


or
Answer:
Desirable
0-199
Borderline
200-239
High
240+

Your level is currently

Congratulations! Your total cholesterol level is in the Desirable range, and your level of "bad" LDL cholesterol is optimal.

Congratulations! Your total cholesterol level is in the Desirable range, and your level of "bad" LDL cholesterol is near optimal.

Your total cholesterol level is in the Desirable range, but your level of "bad" LDL cholesterol is borderline high. If your LDL goes higher, your total cholesterol level could become Borderline High. Consider reducing the amount of foods you eat with saturated fats and increasing physical activity. If you get more exercise, your level of "good" HDL cholesterol may increase, which could also help to keep your levels of LDL and total cholesterol in check.

Your total cholesterol level is in the Desirable range, but your level of "bad" LDL cholesterol is High. This may mean that your level of high-density lipoprotein (HDL), or "good" cholesterol, is too low. It is best to have a high level of "good" HDL and a low level of "bad" LDL. The HDL helps keep your LDL level in check. Ask your doctor for your HDL level. If your HDL is low, increasing your physical activity can increase it, which may help reduce your LDL level.

Your total cholesterol level is in the Desirable range, but your level of "bad" LDL cholesterol is Very High. This may mean that your level of high-density lipoprotein (HDL), or "good" cholesterol, is too low. It is best to have a high level of "good" HDL and a low level of "bad" LDL because the HDL helps keep your LDL level in check. Ask your doctor for your HDL level. If your HDL is low, increasing your physical activity can increase it, which may help reduce your LDL level.

Your total cholesterol level is Borderline High, but fortunately your level of "bad" LDL cholesterol is optimal. This could mean you have a high level of high-density lipoprotein, or "good" HDL cholesterol, which protects against heart disease. Or you could have other non-measured increases in LDL-like particles that can increase heart disease. Your LDL level also could be optimal if you are taking a statin medication. Please check with your doctor to get your complete lipid profile and see if you may need additional treatment. In the meantime, find more information on WebMD's Cholesterol Health Center.

Your total cholesterol level is Borderline High, but fortunately your level of "bad" LDL cholesterol is near optimal. This could mean you have a high level of high-density lipoprotein, or "good" HDL cholesterol, which protects against heart disease. Or you could have other non-measured increases in LDL-like particles that can increase heart disease. Your LDL level also could be optimal if you are taking a statin medication. Please check with your doctor to get your complete lipid profile and see if you may need additional treatment. In the meantime, find more information on WebMD's Cholesterol Health Center.

Your total cholesterol level is Borderline High. Your level of "bad" LDL cholesterol is Borderline High, too. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels!

Your total cholesterol level is Borderline High. Your level of "bad" LDL cholesterol is High. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels!

Your total cholesterol level is Borderline High. But your level of "bad" LDL cholesterol is Very High. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels!

Your total cholesterol is High, but your level of "bad" LDL cholesterol is optimal. This could mean you have a high level of high-density lipoprotein, or "good" HDL cholesterol, which protects against heart disease. Or you could have elevated secondary lipids, such as non-HDL particles that increase the risk of heart disease. Your LDL level also could be optimal if you are taking a statin medication. Please check with your doctor to get your complete lipid profile and see if you may need additional treatment. In the meantime, find more information on WebMD's Cholesterol Health Center.

Your total cholesterol is High, but your level of "bad" LDL cholesterol is near optimal. This could mean you have a high level of high-density lipoprotein, or "good" HDL cholesterol, which protects against heart disease. Or you could have elevated secondary lipids, such as non-HDL particles that increase the risk of heart disease. Your LDL level also could be optimal if you are taking a statin medication. Please check with your doctor to get your complete lipid profile and see if you may need additional treatment. In the meantime, find more information on WebMD's Cholesterol Health Center.

Your total cholesterol level is High. Your level of "bad" LDL cholesterol is Borderline High. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels!

Your total cholesterol level is High. Your level of "bad" LDL cholesterol is High, too. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels! If you are struggling to bring down your total cholesterol and LDL cholesterol levels, your doctor may prescribe medication, such as statins. Following medication, dietary, and exercise instructions should result in improvements.

Your total cholesterol level is High, and your level of "bad" LDL cholesterol is Very High. Working to bring down your total cholesterol decreases your LDL cholesterol level. You can do this by exercising more and eating less food with saturated fats. Check food labels! If you are struggling to bring down your total cholesterol and LDL cholesterol levels, your doctor may prescribe statins or other cholesterol-lowering medications.

Start Over

Step:  of 

Today on WebMD

cholesterol lab test report
Article
Compressed heart
Article
 
Compressed heart
Article
chocolate glazed donut and avocado
SLIDESHOW
 
Heart Foods Slideshow
Slideshow
Cholesterol Fact or Fiction
Quiz
 
Food & Fitness Planner
TOOL
Attractive salad
ARTICLE
 
Heart Disease Overview Slideshow
SLIDESHOW
worst sandwich slideshow
SLIDESHOW
 
Fat Foods Fit Foods
SLIDESHOW
Bad Cholesterol
VIDEO
 

WebMD Special Sections