|
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
levels.
Elevations found in:
- Myocardial infarction
- Crushing muscular trauma
- Any cardiac or muscle disease, but not myesthenia gravis or multiple
sclerosis
- Brain injury
- Hypothyroidism
- Hypokalemia
- Once elevated, CK remains elevated for several days, if the
injury is acute.
- If there is on-going injury, the CK will remain elevated
indefinitely.
Note:
- In acute MI, CK usually rises faster than SGOT and returns to normal
faster than the SGOT.
CK/CPK Isoenzymes
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.
| Isoenzyme |
MM |
BB |
MB |
| Synonym |
CK3 |
CK1 |
CK2 |
| Found in: |
Skeletal M.
Heart M. |
Brain
GI Tract
GU Tract |
Heart M. |
- 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*
| Men |
5-100 IU/L |
|
Women |
10-70 IU/L |
| Pregnancy |
5-40 IU/L |
Normal Values for CK or CPK Isoenzymes*
| MM |
97%-100% |
|
MB |
0%-3% |
| BB |
0% |
*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.
|