From the Guidelines
Normal creatine kinase (CK) levels are generally considered to be between 22 and 198 units per liter (U/L) for men and 10 to 170 U/L for women, though these ranges can vary slightly between laboratories 1. When evaluating CK levels, it's essential to consider various factors that can influence results, including:
- Sex: CK levels can differ between men and women, with men typically having higher levels 1
- Age: CK levels may vary across different age groups, although specific ranges are not well-defined in the provided evidence
- Race: Black individuals tend to have higher baseline CK levels compared to South Asian and white individuals 1
- Recent physical activity: Strenuous exercise, especially eccentric contractions, can lead to increased CK levels due to muscle damage 1 CK is an enzyme that plays a crucial role in energy production within muscle cells, and elevated levels often indicate muscle damage or injury. However, the relationship between CK levels and muscle damage is not always straightforward, and interpretation of results should be done on an individual basis, considering the clinical context and potential confounding factors 1. In clinical practice, CK levels above 3000-5000 U/L are often considered abnormal and may be associated with an increased risk of acute kidney injury or other pathological conditions 1. Nevertheless, it's crucial to interpret CK results in conjunction with other clinical findings and patient history to determine the underlying cause of elevated levels.
From the Research
Normal Creatine Kinase (CK) Levels
The normal range for creatine kinase (CK) levels can vary depending on the laboratory and the individual's muscle mass, but generally, it is considered to be between 60-400 U/L for males and 30-200 U/L for females 2.
Factors Affecting CK Levels
CK levels can be affected by various factors, including:
- Muscle damage or injury, such as rhabdomyolysis, which can cause elevated CK levels 3, 4, 2
- Statin use, which can cause muscle symptoms, including myalgia and elevated CK levels 4, 5
- Physical activity, which can cause temporary elevations in CK levels
Clinical Significance of CK Levels
Elevated CK levels can indicate muscle damage or injury, and can be used to diagnose conditions such as rhabdomyolysis 3, 4, 2. CK levels can also be used to monitor the effectiveness of treatment for muscle-related conditions.
Measurement of CK Levels
CK levels are typically measured using a blood test, and the results are usually available within a few hours. The test measures the amount of CK enzyme in the blood, which can indicate muscle damage or injury 2.