Alanine transaminase or ALT is a liver enzyme alongside AST, or aspartate aminotransferase. ALT helps in catalyzing the two parts of alanine cycle. This enzyme is also known as serum glutamic-pyruvic transaminase (SGPT). The enzyme is also referred to as alanine aminotransferase (ALAT). ALT is mainly associated with the liver but it can be found in various tissues of the body including the plasma. The liver is a very essential organ, which performs different functions such as storing fuel from food, making proteins, and removing toxins from body, and synthesis of the bile.
Bile is a fluid, which helps in digestion and absorption of fats in body. Liver enzymes are proteins that help the organ to build as well as break down proteins. The ALT is largely found in liver though it can be found in other tissues. It is an important enzyme for metabolism and the process of converting food into energy.
In normal circumstances, ALT is found inside the liver cells however, when the liver is injured or damaged, this enzyme may be released into the blood. Doctors can measure the levels of ALT to establish the wellness of the liver. These levels may also help establish if liver organ is being affected by a drug, disease, or other conditions.
ALT SGPT High – Causes
When there is a higher amount of ALT (SGPT) in blood, it may suggest the presence of a medical problem in body such as diabetes, congestive heart failure, hepatitis and problems with the bile duct. Elevated levels of the enzyme in blood may also indicate the presence of infectious mononucleosis or myopathy.
ALT is mostly used to screen for liver complications. Higher levels of ALT in blood can also be caused by other factors like dietary choline deficiency. It is important to know that elevated levels may not necessarily mean that there is a health complication in body. There are times when the levels can fluctuate and deviate from the normal. The levels can also change in response to physical exercises that are strenuous.
Higher levels of ALT may occur due to lead poisoning, liver damage such as cirrhosis and hepatitis, exposure to carbon tetrachloride, use of medicines like antibiotics, narcotics, and statins. The level of this liver enzyme may also rise due to growth spurts particularly in young children. The rapid growth witnessed in young children such as during onset of adolescence may spark elevated levels of this enzyme.
When tests show an elevated level of ALT in blood, the exact cause of the increased amount of the enzyme may be narrowed down by testing other enzymes. For example, if the increased levels of ALT are caused by myopathy problem, creatine kinase enzymes may be measured to rule out the cause. Various drugs such as anti-inflammatory drugs, cholesterol medications, and antibiotics may elevate the levels of this liver enzyme.
ALT Blood Test
Although low levels of alanine aminotransferase (ALT) are usually found in blood stream, when there is increased amount of this enzyme, it may signify some problems in the health of your body. An alanine aminotransferase (ALT) may be done to help identify liver disease such as hepatitis and cirrhosis or other liver conditions caused by virus, drugs, and alcohol.
The test results can help check if there is liver damage. In addition, the test may help determine the cause of jaundice such as a liver disease or blood disorder. If a patient is using cholesterol medication, the health of the liver may be checked by testing for the ALT enzyme in blood.
The normal readings for alanine aminotransferase (ALT) test in males may range from 10 to 40 units per liter (U/L) and in women they may range from 7- 35 U/L.
The results of the tests may be influenced by other factors and your doctor will determine if the levels signify health complications in body. The levels can be affected by strenuous exercise, recent surgery, taking certain herbal products such as valerian and use of other medications. Therefore, it is important when you are being tested of ALT levels to mention to your doctor any medication you may be using. The doctor may recommend that you stop taking the medication several days prior to the test.
It is essential to mention that both ALT and AST concentrations in serum or blood may not reflect the function of liver. This is because, you may have elevated levels of these enzymes but still have a normal functioning liver. In addition, increased levels of these enzymes in blood may only be used to detect inflammation that occurs on the liver due to injury or damage from other sources.
Therefore, elevated levels of both ALT and AST may not automatically be equated with liver disease. They can indicate either a liver disease or a condition arising from other parts of the body, but which affects the liver. For example, muscle damage can cause the level of these two enzymes to shoot up. A thorough clinical evaluation is needed to determine and interpret the results of the levels of these enzymes in blood.