Introduction: A CPK test or CPK Total is a blood test that measures the creatine kinase in the blood. CPK full form stands for Creatine Phosphokinase, which is a type of enzyme that is found mostly in your skeletal muscles and heart,brain .
It is responsible for converting creatine and adenosine triphosphate (ATP) to phosphocreatine and adenosine diphosphate (ADP). This reaction is reversible, and it helps to provide cells with energy.
CPK is released into the bloodstream when muscle tissue is damaged. This can happen due to a number of factors, including:
- Myocardial infarction(Heart attack)
- Stroke
- Rhabdomyolysis (muscle breakdown)
- Strenuous exercise
- electric shock
- Hereditary muscular disorders
- Medications
A blood test can be used to measure the levels of CPK in the bloodstream. High levels of CPK can indicate damage to muscle tissue. However, it is important to note that CPK levels can also be high for other reasons, such as strenuous exercise.
How To Prepare For Cpk Test?
- Avoid strenuous exercise for 24 hours before the test. Strenuous exercise can raise CPK levels, so it is best to avoid it before the test.
- Tell your doctor about any medications you are taking. Some medications can affect CPK level such as steroids, cholesterol-lowering medications, antifungal medications like Amphotericin B, alcohol, intramuscular injections
- There is no need to fast for the CPK test.
- The CPK test is usually performed as a blood test. The blood is drawn from a vein in your arm.
- The results of the CPK test are usually available within a day or 2.
- The CPK test is a relatively painless procedure. You may feel a slight prick when the needle is inserted, but this is usually brief and not painful.
The different types of CPK
- CPK-MB: This is the most specific marker for a heart attack. It is found in the heart muscle, but not in other tissues.
- CPK-MM: This is the most common type of CPK. It is found in skeletal muscle, but it can also be found in the heart muscle.
- CPK-BB: This type of CPK is found in the brain.
| CPK Type | Location | Function | Increased Levels |
|---|---|---|---|
| CPK-MB | Heart muscle | Converts creatine and ATP to phosphocreatine and ADP | Heart attack, rhabdomyolysis, brain injury |
| CPK-MM | Skeletal muscle | Converts creatine and ATP to phosphocreatine and ADP | Strenuous exercise, muscle injury, rhabdomyolysis |
| CPK-BB | Brain | Converts creatine and ATP to phosphocreatine and ADP | Brain injury |
| Condition | CPK Levels |
|---|---|
| Necrosis or inflammation of cardiac muscle | Very high |
| Thermal and electrical burns | Very high (usually higher than in Acute MI) |
| Rhabdomyolysis | Very high |
| Malignant hyperthermia | Very high |
| Striated muscle | High |
| Muscular dystrophy | High |
| Myotonic dystrophy | High |
| Amyotrophic lateral sclerosis (ALS) | High |
| Polymyositis | High |
| Severe or prolonged exercise | High |
| Status epilepticus | High |
| Parturition | High (frequently in the last few weeks of pregnancy) |
| Hypothermia | High |
| Familial hypokalemic periodic paralysis | High |
| Drugs | May be high |
Reflex Tests: Troponin I and CK-MB
Limitations of the test
Following Myocardial Infarction , CpK activity increases in 4-8 hours after acute onset, activities peak at 12-36 hours, and usually returns to normal level in 3-4 days. Although total CK has been used as a diagnostic tool for MI detection, along with CK-MB, it has been predominantly replaced with troponin I or T due to lack of myocardial specificity.
Exercise and muscle trauma (contact sports, traffic accidents, IM injections, surgery, convulsions, wasp or bee stings, and burns) can elevate serum CpK values.
To distinguish myoglobinuria from hemoglobinuria, serum CpK and LD(lactate dehydrogenase) may be helpful. CK is normal with uncomplicated hemolysis, but LD and LD-1 usually are increased.
- What is CPK?
CPK stands for creatine phosphokinase. It is an enzyme that is found in the heart, brain, and skeletal muscle. It is responsible for converting creatine and adenosine triphosphate (ATP) to phosphocreatine and adenosine diphosphate (ADP). This reaction is reversible, and it helps to provide cells with energy.
- What is the normal range for CPK?
The normal range for CPK varies depending on the laboratory that performs the test. However, a general guideline is that the total CPK level should be less than 120 micrograms per liter (mcg/L). The CPK-MB level should be less than 20 mcg/L, and the CPK-MM level should be less than 195 mcg/L.
- What does it mean if my CPK levels are high?
High levels of CPK can indicate damage to muscle tissue. This can happen due to a number of factors, including
- Myocardial infarction(Heart attack)
- Stroke
- Rhabdomyolysis (muscle breakdown)
- Strenuous exercise
- Muscular disorders
- Medications
- What does it mean if my CPK-MB levels are high?
A high CPK total level is not as specific as a high CPK-MB level for a heart attack. However, it can be indicative of other conditions, such as muscle injury or rhabdomyolysis.
- What is the treatment for high CPK levels?
The treatment for high CPK levels depends on the underlying cause. If the high levels are due to a heart attack, you may need medication or surgery to open up the blocked artery. If the high levels are due to rhabdomyolysis, you may need fluids and medication to help your kidneys clear the damaged muscle tissue from your bloodstream.
- What are the risks of high CPK levels?
The risks of high CPK levels depend on the underlying cause. However, in general, high CPK levels can increase your risk of developing complications, such as kidney damage or heart failure.