Yes, elevated levels of Creatine Kinase (CK), specifically those associated with rhabdomyolysis, can damage kidneys.
Here's a breakdown of how this occurs:
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Creatine Kinase (CK) and Muscle Damage: CK is an enzyme found primarily in muscle tissue. When muscle tissue is damaged, CK is released into the bloodstream. Elevated CK levels indicate muscle injury.
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Rhabdomyolysis: Rhabdomyolysis is a severe condition characterized by the rapid breakdown of muscle tissue. It's diagnosed when CK levels are significantly elevated, typically five times the upper limit of normal (above 1000 U/L). The normal range is roughly 22-198 U/L.
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Myoglobin Release: Along with CK, damaged muscle releases myoglobin, a protein that carries oxygen within muscle cells.
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Kidney Damage from Myoglobin: Myoglobin is filtered by the kidneys. However, in high concentrations, myoglobin can overwhelm the kidneys' filtering capacity and cause:
- Oxidative Damage: Myoglobin can cause oxidative damage to the kidney tubules, the structures responsible for filtering waste.
- Tubular Obstruction: Myoglobin can precipitate and form casts that block the kidney tubules, impairing their function.
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Acute Kidney Injury (AKI): The combined effects of oxidative damage and tubular obstruction can lead to acute kidney injury (AKI), a sudden decline in kidney function.
In summary, while CK itself doesn't directly damage the kidneys, the muscle breakdown that causes elevated CK (especially in rhabdomyolysis) releases myoglobin, which does directly damage the kidneys and can result in AKI.
