Healthcare professionals often order blood lab tests to diagnose and monitor NAFLD or NASH. Let's dive into some of the most commonly ordered blood lab tests and what they measure.
Liver Function Tests (LFTs)
Liver Function Tests are a group of blood tests that help measure the overall health and function of the liver. Commonly ordered LFTs for NAFLD and NASH include:
- Alanine Aminotransferase (ALT): ALT is an enzyme found mainly in the liver. This enzyme breaks down the amino acid alanine which helps the body produce glucose, a source of energy for the body. When there is damage or inflammation in the liver, this enzyme is released into the blood stream. For this reason, elevated ALT levels can indicate liver inflammation or damage.
- Aspartate Aminotransferase (AST): Similar to ALT, AST is an enzyme found in the liver. The enzyme can also be found with high concentrations in the heart. This enzyme breaks down the amino acid aspartate which helps the body produce glucose. When there is damage or injury to liver or heart, this enzyme is released into the blood stream. Therefore, elevated AST levels may suggest liver injury, but it is less specific for liver disease compared to ALT.
- Alkaline Phosphatase (ALP): ALP is an enzyme present in many body tissues, including the liver, bones, intestines, and kidneys. This enzyme helps break down compounds like proteins and nucleotides. This process helps in the digestion and recycling of these molecules within the body. Elevated ALP levels can indicate liver or bone disease.
- Gamma-Glutamyl Transferase (GGT): GGT is an enzyme found mainly in the liver and bile ducts. Its job is to help break down and transport molecules called gamma-glutamyl groups. Elevated GGT levels may indicate liver disease or excessive alcohol consumption.
A Lipid Profile measures the levels of different types of fats (lipids). A lipid profile usually measures:
- Low-Density Lipoprotein (LDL) Cholesterol: LDL cholesterol is considered the "bad" cholesterol. Elevated LDL cholesterol levels increase the risk of cardiovascular disease,
- High-Density Lipoprotein (HDL) Cholesterol: HDL cholesterol is considered the "good" cholesterol. Higher levels of HDL are generally beneficial and can help protect against cardiovascular disease.
- Total Cholesterol: This measures the total amount of cholesterol in the blood, including both LDL and HDL cholesterol.
- Triglycerides: Triglycerides are a type of fat. Their main function is to help store energy for your body to use later.
Fasting Blood Glucose
Fasting Blood Glucose measures the amount of glucose (sugar) in the blood after fasting for a specific period, usually overnight. Elevated fasting blood glucose levels can indicate impaired glucose metabolism.
Hemoglobin A1c (HbA1c)
HbA1c is a blood test that provides an average estimate of blood sugar levels over the past 2-3 months. It is commonly used to monitor long-term glucose control in individuals with diabetes. Since NAFLD or NASH patients are at a higher risk of developing diabetes, measuring HbA1c helps assess their overall glycemic control.
C-reactive Protein (CRP)
CRP is a protein produced by the liver that helps the body identify and respond to inflammation. Elevated CRP levels may indicate inflammation in the body, including the liver.