podmog, i googled this:
Glucose Tolerance Test
How it is performed
After an overnight fast a sample of blood is taken. Then 75 g of glucose dissolved in 250 to 350 ml of water is drunk. Two hours later another blood sample is taken. The levels of glucose in the two samples are then carefully measured. Account is taken of the fact that the concentration of glucose measured in plasma is 10 per cent higher than in whole blood.
A diagnosis of diabetes is made if the level of glucose in the fasting blood sample is over 6.7 mmol/l or the level in plasma is over 7.8 mmol/l and/or the levels in the second sample are 10 mmol/l and 11.1 mmol/l. A mole is a basic unit of amount of substance. A millimole (mmol) is a thousandth of a mole. Glucose levels are measured in thousandths of a mole per litre (mmol/l).
In healthy people the glucose concentration rises to about twice the normal level within the first hour and returns to normal within two hours. In diabetes, the blood glucose rises to a much higher level than normal and the return to normal takes three hours or more. The urine test shows that a large amount of glucose is being excreted.
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