An enzyme test measures certain proteins in the body responsible for regulating chemical activity. Different enzymes serve different functions, depending on which organ secretes them. Enzyme tests might reveal illness in the pancreas, heart, pituitary or thyroid glands, or in the digestive tract. A blood sample is drawn to test enzyme levels to help doctors diagnose disease.
Physicians might determine if a patient suffered a heart attack through a creatine phosphokinase (CPK) enzyme test. This enzyme also appears in the brain and muscles, but a specific evaluation of CPK levels might rule out or confirm a heart attack. A CPK enzyme test typically occurs in tandem with an electrocardiogram in an emergency room.
Levels of CPK rise within three to six hours after a heart attack. The concentration of the enzyme typically peaks within 12 to 24 hours and returns to normal about 48 hours later. Even when an electrocardiogram registers in the normal range, high CPK levels could indicate a heart attack occurred.
Some doctors also perform a troponin enzyme test when heart attack is suspected. This protein can remain elevated up to three weeks after a heart attack and indicates the amount of damage to the organ. Troponin levels increase when a heart attack occurs, and this enzyme test can be used to predict future heart attacks. Doctors also evaluate troponin levels to gauge whether medical treatments are working.
An amylase enzyme test might indicate pancreatic disease when levels rise. Amylase is also produced in the salivary glands, which help break down carbohydrates via the mouth, intestines, and stomach. A test might be performed when a patient complains of stomach pain, in order to reveal injury or malfunction of the pancreas.
These blood tests might indicate a blocked pancreatic or bile duct, perforated ulcer, salivary gland disease, or pancreatic cancer. Low levels of amylase might be present when chronic cirrhosis, hepatitis, or long-term pancreatic disease exists. Alcohol and certain drugs, including aspirin and birth control pills, might skew the amylase enzyme test.
A protease enzyme test measures how the body digests protein. Abnormal levels might indicate osteoporosis or arthritis. This enzyme also regulates some immune system functions and the levels of antibodies released. Too much protease could hinder immune system functioning and indicate an autoimmune system disorder. One sign this might be present occurs when sores or injuries heal slowly.
Peroxidase is released by the thyroid gland to produce hormones. It regulates blood pressure and the body’s metabolism. The adrenal glands and pituitary glands also release enzymes that can be tested for disease.