• Heart Health Screen
Cholesterol, Triglycerides and Cardiac Risk Ratio:
Desirable ranges for the various cholesterol components and for triglycerides are:
Total Cholesterol: < 200 mg/dL
HDL Cholesterol: > 60 mg/dL highly desirable
< 40 mg/dL undesirable
LDL Cholesterol: < 100 mg/dL
Triglycerides: < 250 mg/dL
Cholesterol and triglycerides are measured as a way to determine the risk of developing diseases involving the arteries, especially the arteries of the heart. If these tests are elevated you may be at increased risk for a heart attack or a stroke. These tests include total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides. Increased levels of HDL cholesterol and decreased levels of LDL cholesterol are desirable.
The ratio of total cholesterol to HDL cholesterol defines a cardiac risk ratio. The desirable number for this is <4.5.
Accurate assessment of your triglycerides requires a fasting sample. The total cholesterol, HDL cholesterol, and LDL cholesterol are only minimally affected by recent ingestion of food, if at all.
Your overall risk factor for cardiac disease includes not only evaluation of cholesterol and triglycerides but many other factors including age, weight, family history, smoking, if you have diabetes, exercise history and your blood pressure. Additional laboratory tests that also contribute to your overall risk include high-sensitive C-reactive protein and homocysteine levels.
While an uncommon occurrence, decreased lipids are found with some cases of malabsorption, malnutrition, and advanced liver disease.
• Anemia Screen
Hemoglobin, Iron, Total Iron Binding Capacity and % Iron Saturation:
Hemoglobin is the oxygen carrying molecule found in your red blood cells. Decreased levels of hemoglobin are found in anemia. Anemia can be due to many factors and is not a diagnosis. Mechanisms leading to anemia include not having adequate building blocks to make hemoglobin (being deficient in iron, vitamin B12, or folate), destruction of red blood cells, having a chronic illness or bleeding. If you are found to be anemic your physician needs to do additional testing to determine why you are anemic.
Hemoglobin can be increased (polycythemia) in association with smoking, extensive lung disease and rarely in some cancers. With marked dehydration the hemoglobin can be relatively increased.
Iron is a necessary building block for hemoglobin, a major component of red blood cells. The hemoglobin molecule binds oxygen and delivers it to the tissues throughout the body. Iron is also used in other cells in the body, particularly muscle where it is part of myoglobin.
Decreased levels of body iron are associated with anemia due to iron deficiency. Iron circulates in the blood bound to a transport protein called transferrin. Blood levels of iron can be decreased in iron deficiency anemia and anemia of chronic disease. If it is determined that the anemia is due to iron deficiency, it is necessary to find out the cause of the iron deficiency as this can often be associated with occult blood loss in the stool secondary to bleeding ulcers or colon cancer.
In order to determine the cause of decreased blood iron levels it is helpful to look at other tests such as total iron binding capacity (TIBC) and % iron (or transferrin) saturation. TIBC is a measurement of the blood iron related to the % iron saturation. Less than half of the iron receptor sites on the transferrin molecule contain bound iron. If there is less iron available, a greater number of iron receptor sites are empty resulting in a decrease in the % iron saturation. The TIBC and % iron saturation are thus inversely related. The TIBC reflects how many more iron molecules could be bound to the transferrin protein. If the level of blood iron is decreased, then a greater number of iron molecules could potentially bind to the transferring protein and the TIBC is increased. An increased TIBC is typically associated with iron deficiency.
There are conditions when your body has too much iron. This most common condition associated with increased iron stores is hemochromatosis. In this inherited condition, too much iron is absorbed from the gut resulting in excess iron being deposited in various organs, most commonly the liver, heart, and the pancreas. The condition is not typically symptomatic until you are in your 30’s or 40’s, but the increased iron deposition has been occurring long before then. Individuals with this condition would have increased serum iron and decreased TIBC.
• Kidney Function
Sodium, Potassium, Chloride and Carbon Dioxide:
Sodium, potassium, chloride and carbon dioxide are components of the blood that are termed electrolytes. They are typically measured with other electrolytes. Electrolytes can be abnormal with disorders involving the heart, kidneys, brain, lungs or gastrointestinal tract. They reflect abnormalities of water balance and dehydration as well as acid-base disorders. Mild electrolyte abnormalities can occur without any symptoms. The sodium level in your blood is not an indication as to whether or not you have high blood pressure. Monitoring electrolytes like sodium and potassium when someone is taking a medication for high blood pressure is a common practice. An abnormal sodium, potassium, chloride or carbon dioxide level is an indicator of an underlying disorder - it is not a diagnosis. If any of your electrolytes are abnormal, a physician needs to determine why so that appropriate treatment can be started.
Blood Urea Nitrogen and Creatinine:
Blood urea nitrogen (BUN) and creatinine are products of protein and muscle metabolism. They are used to evaluate the flow of blood to the kidneys, the ability of the kidney to produce urine and the body’s overall hydration. Abnormalities of any of these functions are typically reflected by increased BUN or creatinine levels. The BUN and creatinine are typically evaluated with electrolytes and glucose. Occasionally a very high protein diet can result in increased BUN and creatinine levels. Excessive muscle break down may be associated with an increased creatinine level. Decreased BUN or creatinine levels are typically of no clinical significance. They can be found with marked inadequate dietary protein or muscle wasting.
• Liver Function
Albumin:
Albumin is a protein found in the blood. It is made in the liver and lost through either the urine or the gastrointestinal tract. A variety of chronic illnesses are associated with decreased albumin levels. Because albumin is synthesized in the liver, decreased levels can also be seen with liver injury or cirrhosis. Similar to total protein levels, decreased levels of albumin may occur in starvation or malnutrition. Kidney diseases resulting in increased loss of protein in the urine may be associated with a decrease in the albumin in the blood. Inflammatory disorders of the gastrointestinal tract can result in decreased breakdown and absorption of protein by the gastrointestinal tract resulting in decreased albumin in the blood. Increased albumin levels are most often found in association with dehydration.
Direct and Total Bilirubin:
Bilirubin is a component of bile, a substance made in the liver and concentrated in the gallbladder. Bile helps you digest food. Bilirubin is also formed from the break down products of red blood cells. When bilirubin levels are increased the skin can take on a yellowish appearance termed jaundice. Bilirubin testing is often combined with tests called “liver enzymes” they are ALT, AST and alkaline phosphatase. Bilirubin is generally increased in 3 types of diseases: hepatitis (inflammation of the liver), hemolysis (red cell breakdown) and problems in the biliary tract. In acute inflammatory processes that affect the liver (hepatitis), ALT and AST are typically also increased. Dramatic elevations of bilirubin compared to ALT and AST is associated with abnormalities of the biliary tract or red cell hemolysis rather than liver cell damage. When there is obstruction of the biliary tract the alkaline phosphatase is also likely to be elevated.
When bilirubin is produced a portion is to albumin (direct bilirubin) and the remainder is free (indirect bilirubin). Typically the total and direct bilirubin levels are reported. The indirect bilirubin level can be calculated by subtracting the direct from the total. Elevation of direct bilirubin greater than indirect bilirubin is typically seen in association with liver disease. A proportionally greater elevation of indirect bilirubin is more commonly associated with red cell hemolysis.
Alkaline Phosphatase:
Alkaline phosphatase is an enzyme found in mainly in the bone and liver. It is released with bone formation or destruction and in liver disease. Alkaline phosphatase levels tend to be higher than other liver tests in disorders of the bile duct system rather than conditions characterized primary by liver cell damage. medications, particularly hormonal therapy can be associated with biliary obstruction (cholestasis) and elevated levels of alkaline phosphatase.
Total Protein:
Total protein is measured to evaluate overall nutritional status, liver disease, kidney disease and gastrointestinal disorders. Most of the proteins in your blood are made in the liver. If the total protein level is decreased it is necessary to determine which proteins are decreased. Protein in the blood is lost through either the urine or the gastrointestinal tract. A variety of chronic illnesses are associated with decreased total protein levels. As most blood proteins are synthesized in the liver, decreased levels can be found in liver injury because of decreased liver synthesis. Decreased levels may occur in starvation or malnutrition. Kidney diseases resulting in increased loss of protein in the urine would result in decreased blood levels of total protein. Inflammatory disorders of the gastrointestinal tract can result in decreased breakdown and absorption of protein by the gastrointestinal tract resulting in decreased total protein in the blood. Increased total protein levels may be found with dehydration. Occasionally total protein levels can be increased in inflammatory conditions where a large amount of reactive (polyclonal) immunoglobulins are produced or in neoplastic conditions such as multiple myeloma (a cancer of plasma cells) that produces increased amounts of a tumor (monoclonal) immunoglobulin.
AST and ALT:
AST can be found in a variety of tissues including the heart, liver, kidney and skeletal muscle. High values usually suggest inflammatory liver disease (hepatitis) or other disease processes that are associated with ischemic (oxygen deprived) or necrotic (dead) liver cells. AST and ALT are typically compared with other tests indicative of liver disease such as alkaline phosphatase, and bilirubin. ALT is more sensitive for the detection of liver cell injury than for biliary obstruction compared to alkaline phosphatase and bilirubin. Because ALT is found in greater proportion to AST in liver cells than other organs, it is more specific for liver injury than AST.
• Diabetic Screen
Glucose:
Glucose is a sugar that provides energy for all the cells in your body to function. Elevated levels may indicate diabetes. Glucose tests can be used to monitor diabetes, look for pre-diabetic states and evaluate the presence of low levels of glucose (hypoglycemia). A fasting glucose of >126mg/dL on more than one occasion is adequate for the diagnosis of diabetes mellitus.
• Thyroid Screen
TSH and Free T4:
Thyroid stimulating hormone (TSH) and free T4 (free thyroxine) are used to screen for thyroid disease. They can also be used for monitoring the effect of thyroid replacement therapy. Diseases associated with both increased activity of the thyroid gland (hyperthyroidism) and decreased activity of the thyroid gland (hypothyroidism) affect a variety of parameters related to the body’s homeostasis such as heart rate, body temperature and metabolism.
TSH is made and secreted by the pituitary, a gland located within your brain. The TSH reaches the thyroid gland and stimulates it to secrete thyroid hormones including thyroxine. Elevated levels of TSH are seen when the thyroid gland is under stimulated (hypothyroidism) and not producing enough T4. Depressed levels are seen when there is over stimulation of the thyroid gland (hyperthyroidism) and there is too much T4. If you are receiving thyroid replacement therapy, a low value may indicate that you are taking too much replacement and a high value may indicate that you are not taking enough. A normal result on a sensitive TSH assay is acceptable evidence of adequate thyroid replacement.
Free T4 is the main hormone secreted by the thyroid gland. Most of the T4 circulates in the blood bound to a protein, thyroid binding globulin. Only the free (non-bound) hormone is active. Increased free T4 is associated with hyperthyroidism and decreased levels are associated with hypothyroidism.
• Prostate Screen
PSA:
Prostate specific antigen (PSA) is a glycoprotein produced exclusively by cells present in the prostate. PSA is produced by both normal and cancerous prostatic tissue. Increased values can be seen not only with cancer but also with an enlarged prostate or a prostate that is inflamed (prostatitis). The American Cancer Society recommends that an annual screening digital rectal exam and PSA are performed on all males beginning at the age of 50 and for those males with a positive family history or other risk factors at the age of 40-45.
The OSU Lab Test cannot substitute for medical advice, diagnosis or treatment. Diagnosis and treatment of human illness should be based on your medical history, including your family’s medical history and a physical examination along with your doctor’s professional judgment and review of test results. It is therefore important for you to discuss your test results with your personal physician. Physician judgment must remain central to the selection of diagnostic test and therapy options of a specific patient’s medical condition. If any of your test results are abnormal, or if you are continuing to have symptoms that prompted you to request these tests, it is recommended that you see a physician. In the context of a physical exam and medical history, your physician may determine it necessary to repeat this test.
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