Tolerance Test

Procedure for Lactose

* 3 hr GTT is performed the day before a lactose tolerance is performed. * 3 hr lactose tolerance is performed the same as GTT except lactose is given instead of glucose. * if patient lacks enzyme glucose levels will rise no more then 20mg/dl from fasting level. * if patient has the enzyme the curve should match the curve from the 3 hr GTT done the day before.

Procedure for GTT

* Patient should eat a well balanced meal with approx. 150g. Of carbohydrates 3 days prior to testing. * the day of the test patient should be fasting for 12 hours only water is allowed. * a fasting blood sugar is drawn and should be below 200mg/dl in order to continue. * patient then. given 75-100g of glucose solution to drink (must drink in 5 minutes) * then begin timing for blood draws. ~blood is drawn 30mins after finishing drink then 1 hour 2 hour and 3 hour. * no food may be eaten during the entire procedure. * some places collect urine every time they draw blood. * normal glucose metabolism peaks at an hour, being to fall and return to normal by 2 hours. * if patient is diabetic the glucose level ill remain high at 3 hours. * if patient is hypoglycemic the glucose level will drop below normal during the 5th and 6th hour.

Procedure for Epinephrine

* fasting glucose level drawn. * solution of epinephrine hydrochloride is given IV * glucose level is drawn 30 minutes later. * normal glycogen stores the blood glucose level increases at least 30mg/dl above fasting level.

Hyperglycemia

High glucose.

Insulin

Is a hormone produced by the pancreas and released in response to a high blood sugar. Responsible for regulating blood glucose levels.

Glycogen

Is stored in the liver and converted to glucose when needed. Epinephrine speeds up the conversion.

Glucose tolerance test (GTT)

Is used to diagnose problems of carbohydrate metabolism.

Hypoglycemia

Low glucose.

Epinephrine Tolerance Test

Used to evaluate the amount and availability of liver glycogen.

Glucagon Tolerance Test

Also tests for presence and availability of liver glycogen stores. The procedure is the same as epinephrine just substitute Glucagon for epinephrine.

Lactose Tolerance Test

Determines if patient lacks the enzyme that is necessary to convert milk sugar lactose into glucose and galactose. A person lacking the enzyme suffers from GI distress and diarrhea following ingestion of milk.

Oral glucose test (OGTT)

Evaluates the body's ability to metabolize glucose by monitoring the patients tolerance to high levels of glucose without adverse effects.

The GTT

Gives the patient a known amount of glucose and then monitors how well your body metabolizes it by drawing blood frequently to check level of glucose.

Diabetes mellitus

If not enough insulin is produced or the insulin does not work glucose levels remain high and can damage many organs.

Depletion

If there is no rise in glucose level it indicates depletion of glycogen stores or Von Gierek's disease.