AIDSmeds.com - CS Test Popups : Chem-Screen Test Definitions

Chem-Screen Test Definitions, from AIDSmeds.com

Glucose

All foods take the form of either sugars (glucose), fats, or proteins once inside the bloodstream. A balance of each is necessary to fulfill the body's energy needs and to maintain adequate fat & muscle. Glucose is simply a measure of sugars in your blood. Glucose, triglyceride, and cholesterol levels are most reliably measured in the fasted state, that is in the morning before eating. Certain medications, such as protease inhibitors, are thought to increase cholesterol, triglyceride, and glucose levels in some persons, which may increase the risk of heart attack and stroke, and can be a sign of lipodystrophy (see our lesson on this). Normal levels should be between 65 and 125 milligrams per deciliter of blood (mg/dL).

Sodium

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Sodium levels should be between 136 and 144 millimoles per liter of blood (mmol/L).

Potassium

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Potassium levels should be between 3.6 and 5.1 millimoles per liter of blood (mmol/L).

Chloride

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Chloride levels should be between 99 and 109 millimoles per liter of blood (mmol/L).

Carbon Dioxide (Bicarbonate)

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Bicarbonate levels should be between 21 and 31 millimoles per liter of blood (mmol/L).

BUN (Blood Urea Nitrogen)

BUN, creatinine, and uric acid are all blood & urine waste products, and are primarily used to evaluate kidney function. Your kidneys excrete these waste products in your urine. Numerous drugs affect BUN by competing with it for excretion by the kidneys, including many taken by people with AIDS & HIV, so watch for higher than normal levels on these tests.

Creatinine

BUN, creatinine, and uric acid are all blood & urine waste products, and are primarily used to evaluate kidney function. Your kidneys excrete these waste products in your urine. Numerous drugs affect creatinine by competing with it for excretion by the kidneys, including many taken by people with AIDS & HIV, so watch for higher than normal levels on these tests.

BUN/Creatinine Ratio

Uric Acid

BUN, creatinine, and uric acid are all blood & urine waste products, and are primarily used to evaluate kidney function. Your kidneys excrete these waste products in your urine. Numerous drugs affect uric acid by competing with it for excretion by the kidneys, including many taken by people with AIDS & HIV, so watch for higher than normal levels on these tests.

Phosphate

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Phosphate levels should be between 2.3 and 4.5 milligrams per deciliter of blood (mg/dL).

Calcium

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Calcium levels should be between 8.8 and 10.3 milligrams per deciliter of blood (mg/dL).

Magnesium

Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all "electrolytes", the charged particles that make up salt. Electrolytes play a crucial role in the operation of cells and the electrical activity of the heart. Very often, an HIV-infected person who is experiencing a chronic illness associated with diarrhea or vomiting, or whose kidneys aren't functioning properly, will have abnormal electrolyte levels. Magnesium levels should be between 1.5 and 2.5 grams per deciliter of blood (g/dL).

Cholesterol

All foods take the form of either sugars (glucose), fats, or proteins once inside the bloodstream. A balance of each is necessary to fulfill the body's energy needs and to maintain adequate fat & muscle. The two major fats (lipids) in the blood are triglycerides and cholesterol. Glucose, triglyceride, and cholesterol levels are most reliably measured in the fasted state, that is in the morning before eating. Certain combinations of anti-HIV therapies are thought to increase cholesterol, triglyceride, and glucose levels in some persons, which may increase the risk of heart attack and stroke, and can be a sign of lipodystrophy (see our lesson on this). Normal levels of cholesterol should be between 120 and 199 milligrams per deciliter of blood (mg/dL).

HDL Cholesterol

Cholesterol can be broken down into two types: low-density lipoproteins (LDLs), known as the "bad" cholesterol, and high-density lipoproteins (HDLs), known as the "good" cholesterol. The higher the amount of HDL, the better (levels between 35 and 59 mg/dL are considered normal). This form of cholesterol helps clear LDL cholesterol from the arteries and helps purge it from the body through the liver. Even if someone has a high level of LDL, a high level of HDL greatly decreases the risk of heart disease. Some combinations of anti-HIV therapies are known to lower HDL, and can be a sign of lipodystrophy (see our lesson on this).

CHOL/HDL Ratio

Cholesterol can be broken down into two types: low-density lipoproteins (LDLs), known as the "bad" cholesterol, and high-density lipoproteins (HDLs), known as the "good" cholesterol. The higher the amount of HDL, the better (levels between 35 and 59 mg/dL are considered normal). This form of cholesterol helps clear LDL cholesterol from the arteries and helps purge it from the body through the liver. Even if someone has a high level of LDL, a high level of HDL greatly decreases the risk of heart disease. Thus, the lower the cholesterol/HDL ratio, the better. Some combinations of anti-HIV therapies are known to raise this ratio, and can be a sign of lipodystrophy (see our lesson on this).

LDL Cholesterol

Cholesterol can be broken down into two types: low-density lipoproteins (LDLs), known as the "bad" cholesterol, and high-density lipoproteins (HDLs), known as the "good" cholesterol. LDL levels above 130 mg/dL indicate that too much of it is in the arteries, possibly increasing the risk of heart disease. Some combinations of anti-HIV therapies are known to raise LDL, and can be a sign of lipodystrophy (see our lesson on this).

Triglycerides

All foods take the form of either sugars (glucose), fats, or proteins once inside the bloodstream. A balance of each is necessary to fulfill the body's energy needs and to maintain adequate fat & muscle. The two major fats (lipids) in the blood are triglycerides and cholesterol. Glucose, triglyceride, and cholesterol levels are most reliably measured in the fasted state, that is in the morning before eating. Certain medications, such as protease inhibitors, are thought to increase cholesterol, triglyceride, and glucose levels in some persons, which may increase the risk of heart attack and stroke, and can be a sign of lipodystrophy (see our lesson on this). Normal levels of triglycerides should be between 40 and 200 milligrams per deciliter of blood (mg/dL).

Total Protein

One of the most basic nutrients, protein is needed by virtually all cells in the body to function properly. Protein is necessary to build muscle mass and is also used by the immune system to produce new cells every day. Normal levels should be between 6.5 and 8.3 g/dL. Albumin and globulin (see below) are the two types of protein that are measured by Total Protein.

Albumin

Albumin and globulin are the two types of protein that are measured by Total Protein. Albumin is the most important type of protein with respect to the needs of cells in the body. Low albumin levels can occur in people who have dietary problems—including diarrhea, nausea, or decreased appetite—and can often be corrected easily.

Globulin

Albumin and globulin are the two types of protein that are measured by Total Protein. Globulin is the protein found in antibodies produced by the immune system to fight and ward off infections. Because antibodies are produced to fight HIV, people with the virus may have increased levels of globulin.

Albumin/Globulin Ratio

The albumin/globulin, or A/G ratio reflects the amount of albumin in relation to the amount of globulin in the blood. Many HIV-infected patients have lower-than-normal A/G ratios considering the relatively high number of anti-HIV antibodies in the blood. This usually isn't anything to worry about, as long as albumin levels are normal.

Bilirubin, alkaline phosphatase, GGT, AST (SGOT), and ALT (SGPT)

Bilirubin (total and direct), alkaline phosphatase, GGT, AST (SGOT), and ALT (SGPT) are all enzymes produced by the liver. High levels of these enzymes can indicate liver damage, which can be caused by anti-HIV/AIDS medications, alcohol, or hepatitis. With the exception of elevated bilirubin levels—which can cause the skin and eyes to take on a yellowish color—there are usually no symptoms of liver damage. Thus it is important to keep a watchful eye on these enzyme levels to ensure liver health.

Amylase

Amylase is a digestive enzyme produced by salivary glands and by the pancreas. A blood test for amylase is used to diagnose swelling of the pancreas (pancreatitis) and other pancreatic problems. Monitoring amylase levels is important, especially in people who are taking anti-HIV medications that can cause pancreatitis (for example, Videx/Videx EC).

LD (LDH)

LD or LDH stands for lactate (or lactic) dehydrogenase. It is a general indicator of acute or chronic tissue damage in the body. In the past, LD was used in combination with other tests, such as creatine phosphokinase (CPK), to help diagnose heart attacks. Today, LD is less frequently used for this purpose. An elevated LD level, combined with abnormal levels of other lab tests, is still valuable in diagnosing liver disease, pancreatitis, some cancers, intestinal and pulmonary problems, and muscular problems.

Iron

Iron is an important mineral that works with red blood cells to transport oxygen to all cells and tissues in the body. Low levels can be a sign of anemia and/or internal bleeding and should be followed up by a health-care provider.