Glucose tolerance test is one of the tests that used for diagnosis of diabetes mellitus. Diabetes mellitus is characterized by recurrent hyperglyaemia associated with glucosuria, polyuria and polydepsia. Their are two types of glucose tolerance test: Oral Glucose tolerance test and intravenous glucose tolerance test. For oral glucose tolerance test:
The patient must be fasted for 8-12 hours before the time of test. A blood sample is drawn to measure blood glucose level. A measured amount of glucose is given to the patient. Blood glucose level is measured at one and two hours. Normal glucose tolerance test:
Fasting blood glucose level is below 110 mg/dl blood glucose level at one hour must be less than 160 mg/dl. Blood glucose level at two hours must be less than 140 mg/dl. Impaired glucose tolerance test (pre-diaetic state of hyper glycaemia):
Fasting blood glucose level is higher than 110 mg/dl and less than 126 mg/dl blood glucose level at two hours is higher than 140 mg/dl and less than 200 mg/dl. Diabetes mellitus is confirmed when fasting blood glucose level is higher than 126mg/dl and when blood glucose at two hours is higher than 200 mg/dl.