What Is ALT?
Alanine transaminase (ALT) is an enzyme that mainly exists in your liver and that helps the liver convert food into energy.
High enzyme levels can be a sign that the liver is injured or irritated, and the enzymes are leaking out of the liver cells.
ALT other names:
ALT used to be called serum glutamic-pyruvic transaminase, or SGPT, this is sometimes called an SGPT test.
Why did I get an ALT blood test:
An ALT blood test is often included in a liver panel and comprehensive metabolic panel, and healthcare providers use it to help assess your liver health. The alanine aminotransferase (ALT) test is a blood test that checks for liver damage.
What are some of the functions of your liver?
Your liver does a lot of important things for you, for example:
→ It makes a fluid called bile that helps your body digest food.
→ It removes waste products and other toxins from your blood.
→ It produces proteins and cholesterol.
Diseases such as hepatitis and cirrhosis can damage your liver and prevent it from doing its many jobs.
Why Is ALT important to measure?
Your body uses ALT to break down food into energy. Normally, ALT levels in the blood are low. If your liver is damaged, it will release more ALT into your blood and levels will rise.
The ALT test can be done as part of a blood panel during a regular exam. If you've already been diagnosed with liver disease, your doctor can use the ALT test to see how well your treatment is working.
Here are some reasons you might get this test:
→ You've been exposed to the hepatitis virus.
→ You drink a lot of alcohol.
→ You have a family history of liver disease.
→ You take medicine that's known to cause liver damage.
What are symptoms of liver disease?
Your doctor might recommend ALT if you have symptoms of liver disease or damage, such as:
→ Stomach pain or swelling
→ Yellow skin or eyes (a condition called jaundice)
→ Extreme tiredness (fatigue)
→ Dark-colored urine
→ Light-colored poop
→ Itchy skin
What are normal ALT results?
A normal ALT test result can range from 7 to 55 units per liter (U/L), but it varies depending on the laboratory used. Levels are normally higher in men.
What other tests can be done that are related to ALT?
Since many types of liver problems can cause ALT levels to increase, healthcare providers do not use the test alone to diagnose conditions. An ALT blood test is most often included in a blood test panel, such as a liver enzyme panel or a comprehensive metabolic panel (CMP). A blood panel measures several aspects of your blood with one sample and can provide more detailed information about your overall health.
To find out what type of liver disease you have, your doctor might also test the levels of other enzymes and proteins found in your liver, including:
→ Alkaline phosphatase
→ Lactate dehydrogenase (LDH)
→ Total protein
How is alanine transferase (ALT) different from aspartate transferase (AST)?
Aspartate transferase (AST) is another enzyme that’s commonly measured along with AST in a liver function panel or comprehensive metabolic panel. Both of these enzymes can leak into your bloodstream when certain cells in your body are damaged.
AST and ALT are both commonly considered liver enzymes, but there are greater amounts of AST in other parts of your body, such as your heart, skeletal muscles and pancreas. Because of this, ALT is considered to be more directly tied to your liver health, but healthcare providers use both measurements to assess the health of your liver.
Should I be worried if I have high or low alanine transaminase (ALT) test results?
Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
If your ALT test result is high or low, it doesn't necessarily mean that you have a medical condition that needs treatment. Other factors can affect your levels, including:
→ Exercise: Intense or extreme exercise can cause a temporary increase in ALT levels.
→ Medications: Several medications and supplements can affect ALT levels, including over-the-counter pain medications such as acetaminophen.
→ Sex: Scientists believe hormonal differences contribute to sex differences in ALT levels.
→ Menstruation: ALT levels can increase or decrease during your menstrual cycle.
→ Age: ALT levels tend to decrease with older age.
→ Heritage: Research shows that people who have Mexican-American heritage are more likely to have elevated levels of ALT.
→ Body mass index: Several studies have revealed an association between ALT levels and body mass index (BMI), which may change the interpretation of test results in people who have obesity.
In addition to the above factors, when analyzing your ALT results, your healthcare provider will take into consideration many aspects of your health and situation, including:
→ Your medical history.
→ How high or low your ALT results are.
→ Previous ALT results.
→ The results of other tests usually taken alongside ALT.
→ If you’re experiencing symptoms.
Do I need follow-up tests if my ALT results are abnormal?
It’s common for healthcare providers to recommend follow-up tests if you have an abnormal ALT level.
Follow-up testing may include:
→ Repeat ALT blood tests.
→ Other blood tests.
→ Imaging tests.
→ A biopsy.
Additional testing may be immediate if you have significantly elevated ALT levels and/or are experiencing symptoms of a liver condition.
Every person and situation is unique, so there’s no single follow-up testing plan that works for everyone. Together, you and your provider will determine the best plan.
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Having a lower than normal ALT result is uncommon and usually isn’t a cause for concern. However, a lower than normal ALT level could indicate a vitamin B6 deficiency or chronic kidney disease. If your ALT result is lower than what's considered normal, your healthcare provider will likely have you retake the test or undergo further testing to make sure nothing is causing your low level.
Slightly high ALT levels may be caused by:
→ Alcohol abuse
→ Cirrhosis (long-term damage and scarring of the liver)
→ Mononucleosis (Mono)
→ Drugs such as statins, aspirin, and some sleep aids
Moderately high ALT levels may be because of:
→ Chronic (ongoing) liver disease
→ Alcohol abuse
→ Blockage of the bile ducts
→ Heart attack or heart failure (when your heart can’t pump enough blood to your body)
→ Kidney damage
→ Muscle injury
→ Damage to red blood cells
→ Heat stroke
→ Too much vitamin A
Very high ALT levels can be caused by:
→ Acute viral hepatitis
→ An overdose of drugs such as acetaminophen (Tylenol)
→ Liver cancer
It’s important to know that having a high ALT test result doesn't necessarily mean you have a medical condition. Less than 5% of people with elevated ALT levels have severe liver conditions. Other factors can affect your ALT levels.
How to potentially lower ALT levels:
Regardless of what’s causing your elevated ALT levels, it’s important to work with your doctor to find and address the underlying cause. But in the meantime, there are a few things you can try that may help lower your ALT levels.
→ Reduce/limit/stop alcohol consumption. Subjects with elevated ALT levels should be advised complete abstinence from alcohol, as even a small amount of alcohol intake may be harmful for them.
→ Lose weight. ALT is often elevated in people who are obese. If you are overweight, losing weight may improve your liver health and help reduce ALT.
→ Quit smoking. It is important to quit smoking to strengthen the liver and improve ALT levels. It is equally essential to avoid second-hand smoke because a passive smoker can breathe in most of these harmful toxins, which can cause similar cell damage.
→ Get regular exercise. Overall health improvement is seen in a person who exercises regularly, which means doing regular cardiovascular or aerobic exercise can improve health and reduce ALT levels. Studies indicated that a minimum of 150 minutes of regular activity per week can improve liver enzymes, such as ALT, in an adult.
→ Consider taking probiotic supplements to improve your digestive health. The overall evidence indicates that supplementation with probiotics led to a reduced level of liver enzymes.
→ Drink coffee: Several studies have found that coffee may have a protective effect on the liver and that drinking it can lower liver enzymes. A recent study found that drinking anywhere from 1 to 4 cups of coffee per day can help lower ALT levels and reduce the risk of liver disease and cancer.
→ Consume more folate or take folic acid. Consuming more folate-rich foods and adding a folic acid supplement to your diet are both linked to lower ALT levels. While the terms “folate” and “folic acid” are often used interchangeably, they aren’t quite the same. They’re two different forms of vitamin B9. Folate is a naturally occurring form of B9 found in certain foods. Folic acid is a synthetic form of B9 used in supplements and added to some processed foods. Your body processes them in different ways, too. While they aren’t quite identical, both folate and folic acid have benefits when it comes to liver health and lowering ALT.
To help lower ALT levels, consider adding more folate-rich foods to your diet, such as:
→ leafy greens, including kale and spinach
→ Brussels sprouts
You can also try taking a folic acid supplement. Most folic acid supplements contain doses of either 400 or 800 micrograms. Aim for a daily dose of 800 micrograms, which is the equivalent of 0.8 milligrams.
Make changes to your diet. Adopting a healthier diet can help lower ALT levels and reduce your risk of liver disease. Reducing the amount of fat and carbohydrates can also help treat and prevent NAFLD, a common cause of high ALT. To improve liver health and help lower ALT, you don’t necessarily need to make drastic changes to your diet. Start by trying to eat at least five servings of fresh fruits and vegetables per day.
You can also try incorporating these tips into your weekly meal planning:
→ Limit fruits and vegetables served with high calorie sauces or added sugar and salt.
→ Replace saturated and trans fats with monounsaturated and polyunsaturated fats.
→ Choose fiber-rich whole grains.
→ Swap fried foods for baked or roasted ones.
→ Snack on nuts, which have various health benefits.
Medical treatment. There is no specific medical treatment for high ALT. Treatment, if any, depends on what’s causing the increase. For most causes of high ALT, treatment involves lifestyle changes, such as exercise, a modified diet, and reducing alcohol intake. Depending on the results of your liver panel and your medical history, your healthcare professional may recommend checking them again at a later date.
If they’re very high or if you have risk factors for liver disease or other symptoms, your doctor may recommend further testing or an appointment with a liver specialist to help diagnose the underlying cause of your high ALT.
Depending on what your healthcare professional suspects, they may recommend any of the following:
→ blood tests to check for other conditions, such as hepatitis B and C as well as diabetes
→ liver ultrasound
→ abdominal CT scan
→ thyroid stimulating hormone (TSH) test
→ creatine kinase (CK) test
→ lipid panel
→ iron studies to rule out hereditary hemochromatosis
High levels of ALT can be a result of damage or injury to cells. Because ALT is most concentrated in the liver, abnormal ALT test results are generally associated with conditions affecting the liver, such as inflammation (hepatitis) and scarring (cirrhosis).
At the same time, ALT can be elevated without any underlying health problem. Multiple factors can affect ALT; in most cases, high ALT is not a sign of severe liver disease.
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