Myoglobin: qué es, función y qué means when it is high

The myoglobin test is carried out to determine the amount of this protein in the blood, with the aim of identifying muscle and heart injuries. This protein is present in the heart muscle and in the other muscles of the body, supplying the necessary oxygen for muscle contraction.

In this way, myoglobin is normally not present in the blood, being released only when there is a trauma to a muscle after a sports injury, for example, or during a heart attack, where the levels of this protein increase in the blood by 1 3 hours after the infarction, reach the peak between 6 and 7 hours and return to normality in 24 hours.

For this reason, in healthy people, the myoglobin test is negative, being positive only when there is a problem in some muscle of the body.

Myoglobin Functions

Myoglobin is present in the muscles and is responsible for binding to oxygen and storing it until it becomes necessary. Therefore, during physical activity, for example, the oxygen stored by myoglobin is released to generate energy. However, in the presence of any situation that compromises the muscles, there may be release of myoglobin and other proteins in the blood circulation.

Myoglobin is present in all the striated muscles of the body, including the heart muscle, and is therefore also used as a marker of cardiac injury. In this way, the measurement of myoglobin in the blood is requested when there is a suspicion of a muscle injury caused by the following factors:

• Muscular dystrophy;
• Strong blow to the muscles;
• Muscle inflammation;
• Rhabdomyolysis;
• Convulsions;
• heart attack

Although it can be used when there is a suspicion of infarction, the current selection procedure to confirm the diagnosis is the troponin test, which measures the presence of this protein that is only present in the heart; not being influenced by other muscle injuries. Find out more about the troponin test.

Similarly, in the event that the presence of myoglobin in the blood is confirmed and it has very high values, an urine test can even be performed to assess renal health, as very high levels of myoglobin can cause lesions in the kidneys, harming their functioning.

How is the exam performed?

The main way to perform the myoglobin test is by taking a blood sample; without embargo, in many cases, the doctor can also request a sample of urine, the myoglobin is filtered and eliminated by the kidneys.

For none of the exams it is necessary to carry out some type of preparation, such as the day, for example.

What does high myoglobin mean

The normal result of the myoglobin test is negative or less than 0.15 mcg/dL, since, in normal situations, myoglobin is not found in the blood, only in the muscles.

However, when certain values ​​are above 0.15 mcg/dL, it is reflected in the exam that the myoglobin is high, being normally indicative of some problem in the heart or in other muscles of the body; for this reason, the doctor may request more specific exams such as electrocardiogram or cardiac markers to arrive at a more specific diagnosis.

Elevated myoglobin levels can also be a sign of other problems related to the muscles, such as excessive alcohol consumption or kidney problems; for this reason, the result must always be evaluated by a physician, based on the clinical history of each person.