Normal Regulation of Blood Glucose and The important roles of insulin and glucagon

 

Normal Regulation of Blood Glucose

The important roles of insulin and glucagon

 

Normal Response

A person is said to have a normal response when the 2-hour glucose level is less than or equal to 110 mg/dl. 

 

Why glucose test is done?

 

 Blood glucose tests are done to:

• Check for diabetes.

• Monitor treatment of diabetes.

• Check for diabetes that occurs during pregnancy (gestational diabetes).

• Determine if an abnormally low blood sugar level (hypoglycemia) is present. A test to measure blood levels of a protein called C-peptide may be done along with a blood glucose test to determine the cause of hypoglycemia. For more information, see the medical test C-Peptide.

 

 

 

How to Prepare?

Fasting blood sugar (FBS)

For a fasting blood sugar test, do not eat or drink anything other than water for at least 8 hours before the blood sample is taken.

If you have diabetes, you may be asked to wait until you have had your blood tested before taking your morning dose of insulin or diabetes medication.

 

2-hour postprandial blood sugar (2-hour PC)

 

For a 2-hour postprandial test, eat a meal exactly 2 hours before the blood sample is taken. A home blood sugar test is the most common way to check 2-hour postprandial blood sugar levels.

 

Random blood sugar (RBS)

 

No special preparation is required before having a random blood sugar test.

 

How It Is Done?

 

The health professional taking a sample of your blood will:

• Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.

• Clean the needle site with alcohol.

• Put the needle into the vein. More than one needle stick may be needed.

• Attach a tube to the needle to fill it with blood.

• Remove the band from your arm when enough blood is collected.

• Apply a gauze pad or cotton ball over the needle site as the needle is removed.

• Apply pressure to the site and then a bandage.

 

Fasting blood glucose :	70–99 milligrams per deciliter or less than 5.5 mmol/L
2 hours after eating (postprandial):	70–145 mg/dL (less than 7.9 mmol/L)
Random (casual):	70–125 mg/dL (less than 7.0 mmol/L)

 

Normal results may vary from lab to lab. Many conditions can change your blood glucose levels. 

 

Impaired Fasting Glucose

 

When a person has a fasting glucose equal to or greater than 110 and less than 126 mg/dl, they are said to have impaired fasting glucose. This is considered a risk factor for future diabetes, and will likely trigger another test in the future, but by itself, does not make the diagnosis of diabetes. 

 

Impaired Glucose Tolerance 

 

A person is said to have glucose tolerance when the 2-hour glucose results from the oral glucose tolerance test are greater than or equal to 140 but less than 200 mg/dl.  This is also considered a risk factor for future diabetes. There has recently been discussion about lowering the upper value to 180 mg/dl to diagnose more mild diabetes to allow earlier intervention and hopefully prevention of diabetic complications.

 

High values

• The American Diabetes Association (ADA) criteria for diagnosing diabetes are met when any of the following results have been repeated on at least two different days:

• A fasting blood glucose level is 126 mg/dL (7.0 mmol/L) or higher.

• A 2-hour oral glucose tolerance test result is 200 mg/dL (11.1 mmol/L) or higher. For more information, see the medical test Oral Glucose Tolerance Test.

• Symptoms of diabetes are present and a random blood glucose test is 200 mg/dL (11.1 mmol/L) or higher. Symptoms of diabetes include increased thirst and frequent urination (especially at night), unexplained increase in appetite, unexplained weight loss, fatigue, erection problems, blurred vision, and tingling or numbness in the hands or feet.

• If your fasting blood glucose level is between 100 mg/dL (5.5 mmol/L) and 126 mg/dL (7.0 mmol/L), you are considered to have prediabetes (impaired fasting glucose), and you have an increased chance of getting diabetes.

• Other conditions that can cause high  blood glucose levels include severe stress, heart attack, stroke, Cushing's syndrome, medications such as corticosteroids, cancers, or excess production of growth hormone (acromegaly).

 

Low values

 

A fasting glucose level below 40 mg/dL (2.2 mmol/L) in women or below 50 mg/dL (2.8 mmol/L) in men that is accompanied by symptoms of hypoglycemia may mean you have an insulinoma, a tumor that produces abnormally high amounts of insulin.

Low glucose levels also may be caused by:

• Addison's disease.

• Decreased thyroid hormone levels (hypothyroidism).

• A tumor in the pituitary gland.

• Liver disease, such as cirrhosis.

• Kidney failure.

• Malnutrition or an eating disorder, such as anorexia.

• Medications used to treat diabetes.