Which disorder is not characterized by an elevated serum myoglobin?

Which disorder is not characterized by an elevated serum myoglobin?

• A. Renal failure
• B. Vigorous exercise
• C. Acute myocardial infarction
• D. Hepatitis

Answer: (D)

Serum myoglobin rises when muscle tissue is damaged, because myoglobin leaks from the muscle into the bloodstream. This happens with skeletal muscle injury or intense exercise, and it also appears early after a myocardial infarction due to heart muscle damage. In renal failure, clearance of myoglobin is reduced and it can accumulate, especially if there’s concurrent muscle injury like rhabdomyolysis. Hepatitis involves liver inflammation and does not involve muscle breakdown, so serum myoglobin is not expected to be elevated unless there’s a separate muscle injury. Therefore, hepatitis is not associated with elevated serum myoglobin.

Serum myoglobin rises when muscle tissue is damaged, because myoglobin leaks from the muscle into the bloodstream. This happens with skeletal muscle injury or intense exercise, and it also appears early after a myocardial infarction due to heart muscle damage. In renal failure, clearance of myoglobin is reduced and it can accumulate, especially if there’s concurrent muscle injury like rhabdomyolysis. Hepatitis involves liver inflammation and does not involve muscle breakdown, so serum myoglobin is not expected to be elevated unless there’s a separate muscle injury. Therefore, hepatitis is not associated with elevated serum myoglobin.