Reading a Chemistry, Glucose

Glucose is commonly called blood sugar.  It can be tested with a Chem machine or with a handheld glucometer.  It should be noted, however, that due to various reasons, glucometer readings may vary greating from those found on a Chem test.  For monitoring purposes, a tech should choose one machine and use it exclusively to get consistent results; ideally the Chem machine may be used for accuracy or the owner's glucometer may be used for consistency.


Increased glucose or "hyperglycemia" may be caused by:
-Diabetes mellitus:  Glucose is often used to indirectly monitor insulin.  This is because cells cannot consume the glucose in the blood without the presence of insulin, often described as the "key" to allow glucose into the cell.  So, when the body stops producing insulin (diabetes melletus), glucose cannot be used by the cells and begins building up in the blood.  Hyperglycemia on a fasting blood test very likely indicates diabetes mellitus.
-Pancreatitis
-Drug-induced:  prolonged use of steroids or morphine may cause hyperglycemia.
-Stress: this means that more than one blood test may be needed to diagnose diabetes mellitus.

Decreased glucose or "hypoglycemia" may be caused by:
-Too much insulin given:  if the animal is being treated for diabetes the cause of low blood sugar is likely that the animal was given too much insulin relative to what it ate.  The short-term fix might be giving an extra meal in minor cases, giving sugar water, or in the case of dangerously low blood sugar IV administration of dextrose or in a home setting, rubbing karo syrup (corn syrup) on the gums and mucous membranes of the mouth.
-Starvation: the body runs out of fuel and cannot keep up with the demand for glucose.
-Artifact:  when blood is drawn it contains living cells.  If those cells are left to sit, even after spinning, before the test is run, they continue to use glucose.  So, if you want a good glucose reading the blood must be processed and the test run promptly or, if a delay is unavoidable, you can spin the blood, then draw off the serum and freeze it for later testing.
-Advanced liver disease: the liver produces and stores glycogen which can be quickly converted to glucose, and thus serves as a reserve for glucose.  If over 70% of the liver's function is lost it may not be able to produce or store this reserve and hypoglycemia may result.
-Insulinoma: an insulin-producing tumor that results in increased glucose use within the body.
-Sepsis: infection can cause increased glucose utilization.
-Pregnancy toxemia: especially in bovine, in late pregnancy, ketosis may occur due to the demands of the growing fetus.
-Addison's disease: results in decreased glucogenesis and increased glucose use by skeletal muscle.