A man had a glucose tolerance test to indicate if he had type 2 diabetes - Scottish Highers Human Biology - Question 9 - 2019

It is predicted that his blood glucose concentration will return to its original value in approximately 120 minutes.

At 60 minutes, if the blood glucose concentration is 250 mg/100 cm³, then the mass of glucose in the blood can be calculated using the formula:

$ext{Mass (mg)} = ext{Concentration (mg/100 cm}^3) imes ext{Volume (litres)}$

$= 250 imes 0.05 ext{ (since 5 litres = 5000 cm}^3) = 12,500 ext{ mg}$

The production of insulin did not lower the blood glucose concentration in the first hour because the cells in the man's body are less sensitive to insulin. This could be due to fewer insulin receptors or desensitization of these receptors. As a result, the cells cannot effectively convert or take up glucose.

One reason for the decrease in blood glucose concentration after 60 minutes is that the cells began to respond to the insulin production, allowing glucose to be taken up into the cells.

The evidence that suggests this man does not have type 1 diabetes is that he is still able to produce insulin, as indicated by the increasing insulin concentration shown in the graph, contrasting with the lack of insulin production seen in type 1 diabetes.

Apart from reducing sugar intake, this man could control his blood glucose levels by engaging in regular exercise, which helps improve insulin sensitivity.