Creatinine Kinase (CK, CPK) is an enzyme found primarily in the heart
and skeletal muscles, and to a lesser extent in the brain. Significant
injury to any of these structures will lead to a measurable increase in CK
Elevations found in:
- Myocardial infarction
- Crushing muscular trauma
- Any cardiac or muscle disease, but not myesthenia gravis or multiple
- Brain injury
- Once elevated, CK remains elevated for several days, if the
injury is acute.
- If there is on-going injury, the CK will remain elevated
- In acute MI, CK usually rises faster than SGOT and returns to normal
faster than the SGOT.
There are three Isoenzymes. Measuring them is of value in the presence of
elevated levels of CK or CKP to determine the source of the elevation.
- Normal levels of CK/CPK are almost entirely MM, from skeletal muscle.
- Elevated levels of CK/CPK resulting from acute myocardial infarction
are about half MM and half MB
Normal Values for CK, CPK*
Normal Values for CK or CPK Isoenzymes*
*These are general values taken from a variety of
sources. The actual normal values may vary from lab to lab and from one
type of testing protocol to another.