Two individuals—a healthy volunteer and a volunteer diagnosed with Type 2 diabetes—were given a standard 75 g glucose drink at 0 minutes0\text{ minutes}0 minutes. Their blood glucose concentration was monitored over the next 180 minutes180\text{ minutes}180 minutes, and the results are shown in the graph below.
Explain why the blood glucose concentration of the individual with Type 2 diabetes remained significantly elevated between 60 and 150 minutes150\text{ minutes}150 minutes.