What is the significance of elevated Creatine Kinase (CK) levels?

From the Guidelines

Elevated Creatine Kinase (CK) levels are a significant indicator of rhabdomyolysis and potential acute kidney injury, particularly when levels exceed 1000 IU/L, and are associated with increased morbidity and mortality 1. The significance of elevated CK levels can be understood through their correlation with muscle damage and the subsequent risk of acute kidney injury.

• In severe limb trauma patients, elevated CK levels above five times normal (approximately 1000 IU/L) are a sign of rhabdomyolysis, which can lead to acute kidney injury due to myoglobin-induced intraluminal kidney tubular obstruction 1.
• High CK levels, such as those above 75,000 IU/L, have been associated with a high incidence of newly formed acute kidney injury (>80%) in patients with crush syndrome following an earthquake 1.
• The measurement of plasma myoglobin may be more sensitive and specific than CK levels in identifying the risk of acute kidney injury, which is correlated with increased mortality 1.
• Assessing plasma potassium levels for hyperkalaemia and measuring kidney function through plasma creatinine tests can complement the evaluation of CK levels in determining the risk of acute kidney injury 1. The clinical significance of elevated CK levels highlights the importance of monitoring and managing patients with severe muscle damage to prevent complications such as acute kidney injury and reduce morbidity and mortality.

From the FDA Drug Label

Atorvastatin calcium may cause myopathy (muscle pain, tenderness, or weakness associated with elevated creatine kinase [CK]) and rhabdomyolysis. Discontinue atorvastatin calcium if markedly elevated CK levels occur or if myopathy is either diagnosed or suspected. IMNM is characterized by proximal muscle weakness and elevated serum creatine kinase that persists despite discontinuation of statin treatment;

Elevated Creatine Kinase (CK) levels are significant as they may indicate myopathy or rhabdomyolysis, which are potential side effects of statin use, including atorvastatin calcium.

• Myopathy is characterized by muscle pain, tenderness, or weakness associated with elevated CK levels.
• Rhabdomyolysis is a serious condition that can lead to acute kidney injury and rare fatalities.
• Immune-Mediated Necrotizing Myopathy (IMNM) is another condition associated with statin use, characterized by proximal muscle weakness and elevated serum CK that persists despite discontinuation of statin treatment. The presence of elevated CK levels may require discontinuation of atorvastatin calcium and further evaluation to determine the underlying cause 2.

From the Research

Significance of Elevated Creatine Kinase (CK) Levels

Elevated Creatine Kinase (CK) levels can be an indicator of various conditions, including:

• Muscle damage or injury, such as those caused by strenuous exercise or physical activity 3
• Rhabdomyolysis, a serious condition that can lead to acute kidney injury (AKI) if not promptly treated 4, 5
• Myopathy, a disease that affects the muscles, which can be asymptomatic in its early stages 3
• Huntington's disease, a rare genetic disorder that can cause muscle atrophy and elevated CK levels 4

Factors Influencing CK Levels

Several factors can influence CK levels, including:

• Age, gender, race, muscle mass, physical activity, and climatic conditions 3
• Level of training, muscle size, and fiber type 3
• Presence of underlying medical conditions, such as muscle diseases or genetic disorders 3, 4

Clinical Implications

Elevated CK levels can have significant clinical implications, including:

• Increased risk of AKI and renal failure if left untreated 4, 5
• Need for prompt recognition and management of rhabdomyolysis to preserve renal function 5
• Importance of monitoring CK levels and renal function in patients with suspected myopathy or rhabdomyolysis 3, 6, 5
• Potential link between elevated CK levels and underlying medical conditions, such as Huntington's disease 4

Diagnosis and Management

Diagnosis and management of elevated CK levels involve:

• Measuring CK levels and other markers of muscle damage, such as myoglobin and lactate dehydrogenase 3, 7
• Assessing renal function and monitoring for signs of AKI or renal failure 3, 6, 5
• Providing aggressive intravenous saline resuscitation and managing electrolyte abnormalities to prevent cardiac arrhythmias and arrest 5
• Considering the use of sodium bicarbonate and mannitol in patients with acidosis or inadequate urine output 5