Elevated Liver Enzymes
On this page:
An initial step in detecting liver damage is a simple blood test to determine the presence of certain liver enzymes in the blood. Under normal circumstances, these enzymes reside within the cells of the liver. But when the liver is injured, these enzymes are spilled into the blood stream, raising the enzyme levels in the blood and signaling liver damage. Among the most sensitive and widely used of these liver enzymes are the aminotransferases. They include aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT).
Another name for aminotransferase is transaminase. The enzyme aspartate aminotransferase (AST) is also known as serum glutamic oxaloacetic transaminase (SGOT); and alanine aminotransferase (ALT) is also known as serum glutamic pyruvic transaminase (SGPT). To put matters briefly, AST = SGOT and ALT = SGPT.
The normal range of values for AST (SGOT) is from 5 to 40 units per liter of serum (the liquid part of the blood). The normal range of values for ALT (SGPT) is from 7 to 56 units per liter of serum.
AST (SGOT) and ALT (SGPT) are sensitive indicators of liver damage from different types of disease. In rare cases, higher-than-normal levels of these liver enzymes may have causes other than liver problems. The interpretation of elevated AST and ALT levels depends upon the whole clinical picture. The precise levels of these enzymes do not correlate well with the extent of liver damage or the prognosis. Thus, the exact levels of AST (SGOT) and ALT (SGPT) cannot be used to determine the degree of liver disease or predict the future. For example, patients with acute viral hepatitis may develop very high AST and ALT levels (sometimes in the thousands of units/liter range). But most patients with acute viral hepatitis A recover fully without residual liver disease.
What liver diseases cause high liver enzyme levels?
The highest levels of AST and ALT are found with disorders that cause the death of numerous liver cells (extensive hepatic necrosis). This occurs in such conditions as acute viral hepatitis A or B, pronounced liver damage inflicted by toxins as from an overdose of acetaminophen (Tylenol), and prolonged collapse of the circulatory system when the liver is deprived of fresh blood bringing oxygen and nutrients. AST and ALT serum levels in these situations can range anywhere from ten times the upper limits of normal to thousands of units/liter.
The most common cause of mild to moderate elevations of these liver enzymes is fatty liver. In the United States, the most frequent cause of fatty liver is alcohol abuse. Other causes of fatty liver include diabetes mellitus and obesity. Chronic hepatitis C is also becoming an important cause of mild to moderate liver enzyme elevations.
What medications cause abnormal liver enzyme levels?
A host of medications can cause abnormal liver enzymes levels. Examples include:
-- Pain relief medications such as aspirin, acetaminophen (Tylenol), ibuprofen (Advil, Motrin), neproxen (Narosyn), diclofenac (Voltaren), and phenybutazone (Butazolidine)
-- Anti-seizure medications such as phenytoin (Dilantin), valproic acid, carbamazepine (Tegretol), and phenobarbital
-- Antibiotics such as the tetracyclines, sulfonamides, isoniazid (INH), sulfamethoxazole, trimethoprim, nitrofurantoin
-- Cholesterol lowering drugs such as the "statins" (Mevacor, Pravachol, Lipitor, etc.) and niacin
-- Cardiovascular drugs such as amiodarone (Cordarone), hydralazine, quinidine, etc.
-- Anti-depressant drugs of the tricyclic type
What are the treatment options for high liver enzymes?
Evaluation of healthy patients with abnormal liver enzymes needs to be individualized. If alcohol or prescription drugs are responsible for the abnormal liver enzyme levels, stopping alcohol or the medication (under a doctor's supervision) should help. If obesity is suspected as the cause of fatty liver, weight reduction of 5% to 10% should also bring the liver enzyme levels to normal or near normal levels. If abnormal liver enzymes persist despite abstinence from alcohol, weight reduction and stopping certain suspected drugs, blood tests can be performed to help diagnose treatable liver diseases. The blood can be tested for the presence of hepatitis B and C virus and their related antibodies.
No comments:
Post a Comment