Creatine phosphokinase (a.k.a., creatine kinase, CPK, or CK) is an enzyme (a protein that helps to elicit chemical changes in your body) found in your heart, brain, and skeletal muscles. When muscle tissue is damaged, CPK leaks into your blood. Therefore, high levels of CPK usually indicate some sort of stress or injury to your heart or other muscles. To test CPK, blood is drawn from a vein in your arm
In the hospital, a person’s CK-MB level is often checked when they exhibit signs of heart attack. However, in lupus treatment, an elevated CPK may suggest muscle inflammation due to disease activity or an overlapping condition. CPK levels can also be high after strenuous exercise, so your doctor may wish to recheck your CPK after several days of rest. If your CPK is high with no exercise or remains high with rest, your doctor may order additional tests to determine which type (isoenzyme) of CPK is elevated. This information will help her/him to determine the source of the damage (skeletal muscles, heart, or brain). Certain medications, such as statins, can cause increases in CPK, so be sure to tell your doctor about any medications you currently take.
- “CK.” Lab Tests Online. 8 April 2009. American Association for Clinical Chemistry. 12 July 2009 <http://labtestsonline.org/understanding/analytes/ck/test.html>.
- “Creatine phosphokinase test.” Medline Plus. 19 Feb 2009. US National Library of Medicine and National Institutes of Health. 12 July 2009 <http://www.nlm.nih.gov/medlineplus/ency/article/003503.htm>.