Aspartate Aminotransferase: The Blood Marker & Genetic Influence

Disclaimer: This article is for informational purposes only and is not intended for diagnostic use. LifeDNA does not provide diagnostic reports on any traits discussed. Genetics is just one piece of the puzzle; please consult a healthcare professional for comprehensive guidance on any health condition.

Aspartate aminotransferase (AST) is also known as serum glutamic-oxaloacetic transaminase (SGOT). It is an enzyme found mainly in the liver and heart. It is also in smaller amounts in tissues such as muscles, kidneys, and the brain.

AST plays a vital role in the amino acid metabolism process. It speeds up a reaction where an amino group (-NH2) is moved from one molecule (aspartate) to another (alpha-ketoglutarate), creating two new molecules (oxaloacetate and glutamate). This reaction is part of a crucial metabolic reaction in the body called the citric acid cycle. This cycle is the main way by which cells produce energy.

AST is also one of the four liver enzymes. The others are alkaline phosphatase (ALP), alanine transaminase (ALT), and gamma-glutamyl transferase (GGT). Liver enzymes are proteins that facilitate specific chemical reactions in the liver.

AST concentration in the blood is commonly measured in liver function tests to diagnose and monitor liver health and to identify conditions such as hepatitis, cirrhosis, and liver fibrosis. AST levels also assess muscle damage, heart attacks, and other medical conditions that can lead to cellular injury.

The Four Liver Enzymes

The four liver enzymes include ALT, AST, ALP, and GGT. ALT and AST are involved in amino acid metabolism. They are released into the bloodstream whenever the liver cells are damaged. ALP is associated with bile duct function. It is elevated in conditions affecting bile flow, such as cholestasis. GGT often rises with alcohol consumption and liver damage thus helping diagnose liver disease and bile duct obstruction, Monitoring these enzymes aids in detecting and managing liver disorders.

Read in more detail: The Genetics of Liver Enzymes.

What Does AST Level Mean in Your Blood Report?

The level of AST in your blood report is a key indicator of the health of your liver and other tissues where we can find this enzyme. Elevated AST levels typically signal that there has been damage to the cells in these tissues. It causes AST to discharge into the bloodstream.

In the context of liver health, high AST levels can indicate liver inflammation or damage due to conditions such as hepatitis, cirrhosis, fatty liver disease, or liver fibrosis. It can also result from toxic injury to the liver, such as from excessive alcohol consumption or the use of certain medications. However, AST is not liver-specific and can be elevated due to muscle damage, myocardial infarction (heart attack), or other conditions that cause cellular injury, such as severe infections or physical trauma.

AST Levels

Normal AST levels in adults typically range from 10 to 40 units per liter (U/L) of blood. However, this can vary slightly depending on the laboratory and population norms. It’s necessary to consider AST levels with other tests, particularly alanine aminotransferase (ALT), which is more specific to the liver. The AST/ALT ratio can provide further insight into the underlying cause of elevated liver enzymes. A healthcare provider will interpret AST levels in the context of other clinical information to determine the cause of the elevation and the appropriate course of action.

Genetics of AST Levels

GOT1

The GOT1 gene encodes AST. Elevated levels of AST in the blood can indicate tissue damage or disease in these organs, making GOT1 a gene of interest in medical research and diagnostics.

A 2011 genome-wide association study (GWAS) conducted from the Heredity and Phenotype Intervention (HAPI) Heart Study on 866 Amish participants identified a significant association with a cluster of SNPs on chromosome 10q24.1, near the GOT1 gene, which encodes cytosolic AST (cAST). Sequencing revealed an in-frame deletion of three nucleotides (p.Asn389del) in GOT1. Carriers of this deletion had significantly lower AST levels compared to non-carriers. Researchers observed this deletion in 20 additional Amish individuals but not in 647 outbred Caucasians.

Other Highlighted Markers

A 2021 GWAS involving over 388,000 people of European ancestry from UKB and DiscovEHR analyzed 11 million genetic markers and identified 336 independent genetic associations with AST levels. Of these, 61 were reported new. Additionally, the study found 12 AST associations significantly influenced by body mass index (BMI) and potential liver disease risks, which could benefit therapeutic development. Among the identified AST-associated variants in this study, a missense SNP-rs3816873 in the MTTP gene has shown the most significant association with lipoproteins modulation, particularly in low-density lipoproteins (LDL) and hepatic steatosis. Research conveys that alteration in the MTTP function due to the intervention of this variant could increase the risk of developing liver diseases. Other loci from previous studies were also present, which include PNPLA3, HSD17B13, and MARC1. These findings also suggest that genetic variants associated with AST levels, especially those modified by BMI, play a significant role in liver disease outcomes.

Non-Genetic Factors Influencing AST Levels

Liver conditions like hepatitis, cirrhosis, and fatty liver disease

Heart ailments

Muscle injuries due to trauma or strenuous exercise and chronic muscle diseases

Certain medications, such as statins, analgesics, and antibiotics, can elevate AST.
Excessive alcohol consumption is a significant factor in raising AST levels.
Exposure to industrial chemicals and toxins can also increase AST.

Infections such as mononucleosis can cause elevated AST levels.
Severe infections, like sepsis, can increase AST.

Poorly managed diabetes can lead to liver damage and higher AST levels.
Excess weight leads to fatty liver disease, which can raise AST.

Severe malnutrition can impact liver function and AST levels.
Diets high in fat can contribute to fatty liver disease and elevated AST.

An underactive thyroid can affect liver function and AST levels.
Gluten intolerance can lead to liver inflammation and increased AST.

Optimize Your AST Levels Naturally

Diet

Start with a balanced diet rich in fruits, vegetables, whole grains, and lean proteins while avoiding excessive consumption of saturated and trans fats, refined sugars, and highly processed foods.
Incorporate liver-friendly foods such as leafy greens, garlic, and beets, which help detoxify and support liver function.
Regular hydration is essential, so drink plenty of water throughout the day.
Reducing or eliminating alcohol consumption can significantly lower AST levels, as alcohol is a common cause of liver damage like liver cirrhosis.
Maintaining a healthy weight through diet and regular exercise can prevent fatty liver disease. It is a condition that is often associated with elevated AST levels.

Other Lifestyle Changes

Aim for at least 150 minutes of moderate-intensity exercise weekly, such as brisk walking, cycling, or swimming. Exercise improves overall metabolism and reduces the risk of obesity-related liver issues.
It’s also essential to avoid unnecessary medications and to use over-the-counter drugs responsibly, as some can contribute to liver stress.
If you need to take medications, do so under the guidance of a healthcare professional.
Lastly, managing stress through meditation, yoga, or deep-breathing exercises can improve overall health and support liver function, contributing to optimal AST levels.