From the Guidelines
Creatine kinase (CK) elevation is primarily caused by damage or stress to muscle, heart, and brain tissues, with common causes including strenuous exercise, muscle trauma, rhabdomyolysis, myocardial infarction, and muscular dystrophies, as well as medications like statins and certain antipsychotics. The causes of CK elevation can be categorized into several groups, including:
- Muscle-related causes, such as strenuous exercise, muscle trauma, rhabdomyolysis, and muscular dystrophies
- Cardiovascular causes, such as myocardial infarction
- Medication-related causes, such as statins (e.g., atorvastatin, simvastatin), certain antipsychotics, and colchicine
- Inflammatory and infectious causes, such as polymyositis and viral myositis
- Endocrine disorders, such as hypothyroidism
- Other causes, including seizures, surgery, and electrolyte abnormalities The degree of CK elevation often correlates with the extent of tissue damage, with mild elevations (2-5 times normal) occurring with exercise and severe elevations (>10,000 U/L) suggesting rhabdomyolysis 1. When evaluating CK elevation, it is essential to consider recent physical activity, medication history, and accompanying symptoms like muscle pain or weakness, as CK levels can rise within 2-12 hours of muscle injury, peak at 24-72 hours, and typically normalize within 3-5 days if the injury resolves 1. Persistent elevation warrants further investigation for underlying muscle disorders. It is also important to note that ethnicity, body composition, and individual exercise intensity can affect CK levels, making interpretation of results challenging 1. In clinical practice, CK levels greater than 3000 U·L−1 are considered abnormal or pathological, possibly associated with an increased risk of acute kidney injury 1. Overall, a comprehensive approach to evaluating CK elevation is necessary to determine the underlying cause and provide appropriate management.
From the Research
Causes of Creatine Kinase (CK) Elevation
The causes of creatine kinase (CK) elevation are varied and can be attributed to several factors. Some of the main causes include:
- Acute myocardial infarction, which is a common cause of CK elevation, as seen in 2 where it was found to be the most frequent cause in 32% of patients.
- Neuromuscular disorders, although this is a rare cause, as found in 2 where it was only present in 2% of patients.
- Drug intake, which was found to be a frequent cause of CK elevation in 32% of patients in 2.
- Physical exercise, which can cause muscle damage and lead to CK elevation, as discussed in 3.
- Trauma, such as falls or haematoma, which can also cause CK elevation, as seen in 2 where fall was a cause in 24% of patients and haematoma in 17% of patients.
- Malignancy, which was found to be a cause of CK elevation in 11% of patients in 2.
- Intramuscular injection, which was also found to be a cause of CK elevation in 16% of patients in 2.
Clinical Implications
CK elevation can have significant clinical implications, particularly in the diagnosis and management of acute myocardial infarction. As seen in 4, elevated CK levels can be used to diagnose myocardial infarction, but the sensitivity and specificity of this test can be limited. In addition, CK elevation can also be a predictor of mortality and myocardial recovery after primary percutaneous coronary intervention, as found in 5.
Muscle Damage and Exercise
CK elevation can also occur due to muscle damage caused by exercise, as discussed in 3. This can be a concern for athletes and individuals who engage in strenuous physical activity. However, the clinical significance of CK elevation in this context is still a topic of debate, and more research is needed to fully understand its implications.
Other Causes
Other causes of CK elevation, such as directional coronary atherectomy and stenting, can also occur, as seen in 6. However, the clinical significance of CK elevation in these contexts is generally limited, and it is not considered a major complication.