Myoglobin

Myoglobin is a protein found in skeletal and cardiac muscle, where it is used to store and transport oxygen.

When there is muscle damage, myoglobin is released into the blood. Myoglobin is one of the first biomarkers to increase in the blood after cardiac injury, with levels beginning to rise within 2 to 3 hours of a myocardial infarction. Because of its low cardiac specificity (as it is also released by skeletal muscle), myoglobin is often used in combination with other more specific cardiac markers, such as troponin I or T, to improve the accuracy of the diagnosis of myocardial infarction.

Myoglobin is a key marker of rhabdomyolysis, a condition characterised by the rapid destruction of skeletal muscle, releasing muscle components into the bloodstream.

Rhabdomyolysis can be caused by trauma, intense physical effort, infection, toxins or medication. High levels of myoglobin in the blood (and in the urine, where it can cause myoglobinuria) are indicative of this condition. In patients with rhabdomyolysis, myoglobin measurement can be used to monitor the course of the disease and the effectiveness of treatment, in particular, to prevent renal complications (acute renal failure due to myoglobinuria).