What Do My Blood Test Results Mean? - Part THREE - Complete Metabolic Panel - CMP
Continued from Part 2: Researched by awordlover
6 - LFT: Liver Function Tests
The test included in Liver function panel are "ALT" (Alanine Transaminase sometimes called SGPT), "AST" (Aspartate Aminotransferase sometimes called SGOT), "ALP" (Alkaline phosphatase), "GGT" (Gamma Glutamyl Transpeptidase), "LDH" (Lactic Acid Dehydrogenase), "PT and INR". "Albumin and "Total Bilirubin" are also part of this panel.
So what the heck does all that mean!? Well the Liver Function Test panel (LFT) is probably the most used panel of tests for diagnosing various disorders and diseases. So it is pretty important.
- ALT is a liver enzyme found in pancreas, liver, heart, muscles and kidney. The test measures the amount of the enzyme present in the blood. Usually a physician wants to see a low number here - it is normal for this level to be lower than normal range. When you have a higher ALT, it suggests acute liver damage (for example - due to alcoholism, toxic use of drugs, acetaminophen overdose/overuse or viral hepatitis). But when you have a high cholesterol level coupled with a low ALT, it suggests a congested liver, mononucleosis, alcoholism, kidney infection, liver damage, chemical pollution, or myocardial infarction (past, present, or upcoming). Normal range for males is 10 - 40 IU/L. Normal range for females is 7- 39 IU/L.
- AST is a liver enzyme found in the liver cells. The test measures the amount of the enzyme present in the blood. AST is normall found in the red blood cells, heart, muscle tissue, liver, pancreas and kidneys. Usually a physician wants to see a low number here - it is normal for this level to be lower than normal range. If the heart or liver is damaged or diseased, AST levels will rise and stay high for up to 4 days after incident. This test helps identify specific liver disease and is used in the ongoing monitoring of cholesterol medications to make sure they are not damaging the liver. Normal range for males is 14 - 20 U/L. Normal range for females is 10 - 36 U/L.
- ALP is a liver enzyme found in the biliary ducts of the liver. Elevated ALP is present in hepatitis, gallstones, liver cancer, heart failure, mononucleosis, pregnancy, bone injuries, rapid bone growth (puberty), and Vitamin D deficiency. This test is used as a tumor marker and also a consideration in gall bladder disease and bile duct blockages. A physician may order this test if he sees bone problems on X-rays or how well a treatment for Vitamin D deficiency is working for the patient. Normal range for adults is 25-100 U/L. Normal range for children is 300 U/L or less.
- GGT is a liver enzyme found in the bile ducts. Elevated GGT indicates a bile flow problem and is often present in chronic alcoholism and drug abuse. Other reasons for elevated GGT are: congestive heart failure, cirrhosis, toxic use of drugs, hepatitis, or liver tumor. Elevated GGT always indicates bile flow problems, not bone disease the way ALP test does. Normal range is 0 - 51 IU/L.
Take a breath - we are almost done! ::smile::
Liver Enzymes Tests Explained
LDH is an enzyme found in many body tissues, including the liver.
- Elevated levels of LDH may indicate liver damage. Along with other tests, this test is useful in confirming stroke, hepatitis, myocardial infarction or pulmonary infarction. It is also used in the staging of melanoma and to determine the performance of chemotherapy in regard to lymphoma. False readings come from the tubes of blood being stored in extreme temperatures or if the blood is hemolyzed (either when collected or from the use of NSAIDS or antibiotics).
- Low levels may indicate hypoglycemia, malnutrition, or organ damage. This test is done in conjunction with 5 other LDH tests, so you will often have more than one result. Normal range vary widely from lab to lab, but a good reference is 100 - 300 IU/L.
PT and INR -
- PT is also called Prothrombin time test and evaluates your blood's ability to clot. It helps diagnose bleeding disorders.
- The INR part is the international normalized ratio which means that no matter what lab did your test, your physician can understand the results.
- A PT is almost always done with a PTT test (Partial Prothrombin Time) which monitors anticoagulant drug therapy such as warfarin (coumadin), Lovenox, or heparin - these drugs slow down clotting. In addition, these tests are always performed before any surgical event. So if you are on anticoagulant drugs, a PT/INR will be routinely performed to make sure your drugs are working properly and that your PT/INR are appropriately prolonged.
- Normal PT Values: 10-12 seconds. A prolonged PT can be due to a vitamin K deficiency, hormones replacement or contraceptive drugs, liver disease, and overuse of the anti-coagulant drugs. The PT result can also be altered by a diet high in vitamin K, liver, green tea, dark green vegetables and soybeans.
- Normal PTT Values: 30 to 45 seconds. Prolonged PTT times can be due to liver problems, lupus and other diseases that result in poor clotting.
- Normal INR Values: 1 to 2. This is universal and standardized in all countries since the 1980s.
Bilirubin monitors and diagnoses red cell destruction, pancreatic diseases, blocked bile ducts, liver disease like hepatitis, cirrhosis, and gall stones, evaluates for sickle cell anemia, and jaundice in newborns. Normal range for "direct bilirubin" is 0 - 0.3 mg/dL.Normal range for "total bilirubin" (indirect) is 0.3-1.0 mg/dL.
- A false reading leading to a decreased bilirubin can be attained by having too much lipids in the blood - high cholesterol. If the blood becomes hemolyzed in the collection and/or transport or if the blood is exposed to light, it will also lead to a false reading.ALWAYS ask for this test to be repeated if you have abnormal results.
Jaundice is when the white part of the eye and the skin becomes yellow with a reading of 2.5 mg/dL or above.
- Increased or elevated total (indirect) bilirubin can indicate mononucleosis, Gilbert's Disease, hemolytic anemia, jaundice in newborns, hepatitis, sickle cell anemia, pernicious anemia, low exposure to the sun, toxic effects of some drugs or transfusion reaction. Decreased total (indirect) bilirubin levels are seen in people who eat excessive amount of fats and a diet low in nitrogen bearing foods. Increased direct bilirubin can indicate cirrhosis or hepatitis.
Did you know that certain foods and/or medications (as well as fasting or eating) can alter the outcome of your bloodwork?
What Can Alter Test Results?
As with any blood test, what you ingest can alter the outcome of the test results.
- Alcohol can affect the PT/INR test.
- Antibiotics can increase the PT/INR.
- Contraceptives and hormone replacement and Vitamin K an decrease PT.
- Foods like beef and pork liver, green tea, broccoli, kale, turnip greens, and many soybean foods have huge amounts of Vitamin K which affects clotting.
Your doctor should be made aware of any of these issues if they pertain to you.
It is best to fast on most blood tests unless the test is dependent on having food/nourishment beforehand. Your doctor should tell you how to prepare for such tests.
- For example, a cup of coffee will reduce iron absorption in the blood by almost 30 percent. However, a cup of tea will reduce iron absorption in the blood by nearly 75 percent. Orange juice will increase iron absorption by 100% or more. So, fasting IS important.
The order in which the tubes are drawn is important to prevent cross contamination in the tubes used. First blood draw is for blood culture (if ordered), then the coagulation tube, then the non-additive tubes, and lastly the additive tubes.
Don't be afraid to question the phlebotomist if you think the order of the draw is incorrect.
- They won't like it, but hey, it is your blood and how many times do you want to be stuck to have blood taken? I'd rather question and get a dirty look than have to be stuck again.
Here are general guidelines for avoiding food and beverages including caffeine for 8 to 12 hours before your blood test.
Amylase - Pancreatitis disorder and pancreatic disease. NO fasting.
ANA - (Antinuclear Antibody test) lupus, polymyosistis, autoimmune diseases. NO fasting.
aPTT - (Activated Partial Thromboplastin Time) evaluates risk of excessive bleeding prior to a surgical procedure. NO fasting.
AIC - (Hemoglobin A1C or Glycohemoglobin) diabetes and prediabetes. NO fasting.
BMP - (Basic Metabolic Panel) diabetes and kidney disease. You may be asked to fast for 10 to 12 hours prior to test.
CBC - (Complete Blood Count/Hemogram) general health, anemia or infections, toxic substance exposure. NO fasting.
CMP - (Comprehensive Metabolic Panel) kidneys, liver, electrolyte and acid/base balance, blood sugar and blood proteins and cholesterol. You may be asked to fast for 10 to 12 hours prior to test.
Electrolytes - (Electrolyte Panel) fluids and electrolyte balance. NO fasting.
Glucose - (Fasting Blood Sugar) blood glucose level, diabetes, pre-diabetes, and hypoglycemia. Fast 8-12 hours pre-test including avoidance of caffeine.
HIV Antibody - (Human Immunodeficiency Virus) HIV infection. NO fasting.
Lipid Profile - Coronary heart disease, stroke, blood vessel blockage, hardening of arteries. Avoid food and beverages, except water before your test.
Lyme Disease - (Lyme Antibodies Detection) exposure to Lyme disease. NO fasting.
Mono - (Mononucleosis) NO fasting.
Avoid beverages with caffeine including decaffeinated coffee. Most caramel colored sodas contain caffeine...root beer is the exception - it has no caffeine.
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Final word by awordlover
I hope this series of three hubs has brought you more understanding of your blood tests, the results, why they are done, and most importantly - to remind you that you are entitled to copies of your records when you ask for them. They will not automatically be given to you.
Published January 2012 Anne DiGeorge
Updated 2/2/2014 by Rachael O'Halloran to include copyscape information and update format issues
© 2012 awordlover