Sample: Serial sera
Range: Less thsan 200 mg/dL after 2hrs
Remarks: Glucose Tolerance Test (GTT) is done after a net 75g glucose load and serial serum glucose levels at 30, 60 and 120 min. If serum glucose after 2hrs lies below 140 mg/dL diabetes is excluded. Values between 145 and 200mg/dL indicate impaired GTT. In pregnants the test is indicated as gestational diabetes screening test after 50g glucose load and sample drawn after 1hr: gestational diabetes is suspected if the 1hr glucose concentration is > 140 mg/dL.
Type 1 Diabetes (Insulin dependent): The insulin-producing beta cells of the pancreas are almost completely demaged and do not produce insulin.
Type 2 Diabetes (Non-insulin dependent): The insulin-producing beta cells of the pancreas produce either not enough insulin or the body of the patients becames resistant to the effects of their own insulin.