Rhabdomyolysis during heat stress can release which substances that increase the risk of kidney injury?

• A. Creatine kinase and myoglobin.
• B. Lactate and ammonia.
• C. Troponin and potassium.
• D. Glucose and insulin.

Answer: (A)

When muscle tissue breaks down during heat stress, it spills its contents into the blood. The substances most linked to kidney injury in this situation are myoglobin and creatine kinase. Myoglobin is a heme-containing protein that is filtered by the kidneys; in large amounts it can precipitate in the renal tubules and, through oxidative damage, cause tubular obstruction and acute kidney injury. Creatine kinase is released from damaged muscle cells and serves as a marker of the extent of rhabdomyolysis; higher CK levels indicate more muscle breakdown and a greater load of myoglobin to the kidneys. The other options don’t represent the nephrotoxic factors typically driving kidney injury in rhabdomyolysis.