Skeletal muscles are those muscles attached to bones and whose contractions make those bones move. When the muscles are diseased or damaged, such as in muscular dystrophy, the cells deteriorate and break open. The contents of the cells, including aldolase, spill into the bloodstream. Measuring the amount of aldolase in the blood indicates the degree of muscle damage. As muscles continue to deteriorate, aldolase levels decrease and eventually fall below normal.
Less muscle means fewer cells and less aldolase.
Muscle weakness may be caused by neurologic as well as muscular problems. The measurement of aldolase levels can help pinpoint the cause. Aldolase levels will be normal where muscle weakness is caused by neurological disease, such as poliomyelitis or multiple sclerosis, but aldolase levels will be elevated in cases of muscular disease, such as muscular dystrophy. Aldolase is also found in the liver and cardiac muscle of the heart. Damage or disease to these organs, such as chronic hepatitis or a heart attack, will also increase aldolase levels in the blood, but to a lesser degree.