Creatine Kinase: Factbites

Creatine Kinase Factbites

Creatine Kinase (CK) is the most sensitive enzyme and in the presence of most diseases, levels can be elevated as much as 50 to 100 times the reference level.

CK is often determined routinely in emergency patients. In addition, it is determined specifically in patients with chest pain and acute renal failure. Normal values are usually between 25 and 200 U/L. This test is not specific for the type of CK that is elevated. In females, total Creatine Kinase should be 10-79 units per liter (U/L).

Elevation of CK is an indication of damage to muscle. It is therefore indicative of injury, rhabdomyolysis, myocardial infarction, myositis, myocarditis, malignant hyperthermia and neuroleptic malignant syndrome.

Creatine kinase (CK or CPK) is an enzyme or type of protein found in muscle and brain that leaks out and is released into the bloodstream when muscle is damaged. CK helps cells make the energy needed to move: may also be tested from the patient's medical record. The CK level usually parallels a disease activity.

In normal conditions, there is very little creatine kinase circulating in the blood of the average, healthy human being.

Muscle wasting is a hallmark of a number of diseases, including cancer, bacterial sepsis, AIDS, diabetes, and end-stage heart, kidney, and obstructive pulmonary disease. Progression of skeletal muscle atrophy is one of the characteristic features in cancer patients. Skeletal muscle atrophy is a common comorbidity of cancer. The progressive depletion of skeletal muscle is a hallmark of many types of advanced cancer. However, a clinical feature of demyelination is muscle weakness without muscle atrophy.

Guillain-Barré syndrome and similar disorders do not produce evidence of muscle inflammation, such as elevation of the CK. Hypokalaemic periodic paralysis has a predilection for thyrotoxicity in some patients. It is associated with a low potassium concentration but it too is associated with a normal creatine kinase level.

Persons with cancer typically have high CK levels.

Metastatic malignant neoplasms cause severe body wasting-cachexia. The hallmark of muscle damage or muscle wasting is elevation of CK concentration. The wasting away of fat and muscle (cachexia) is the most visible hallmark of metastatic cancer.

Elevation of CK may be seen in stroke, extreme shock, or brain tumor(s). A very high creatine kinase value indicates severe muscle fiber breakdown (necrosis). Even in paraneoplastic disorders the serum CK level is typically elevated 8-100 times normal. Persistent or ongoing muscle injury will maintain high CK concentrations.

The hallmark of muscle damage is elevation of creatine kinase ( CK ) concentration, which is also present in all patients with rhabdomyolysis. During episodes of acute muscle breakdown (rhabdomyolysis), CK levels can temporarily go off the scale, topping out at 50,000 to 200,000 U/L.

Other forms of muscle damage, such as from a fall, a car accident, surgery, or a shot, can also increase CK. CK levels usually rise significantly in about 2 to 3 hours or perhaps a little longer (can rise two-fold within six hours) and peak within 24 hours. High CPK levels may be seen in patients who have: Heart attack; Brain injury or stroke.

See also

• Reference ranges for common blood tests

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