Blood sugar

Is it dangerous for me to go around with my bllod sugar over 300? My kidney Dr. gave me some (glipizide er 5mg) and I have been taking it 8 days. When I called him he said to keep that up for a couple of more weeks and we would see what happens.I got people telling me I need to be in the hospital with blood sugar 340-380.

The solution I am using is dianeal low calcium 1.5% and 4.25% dex peritoneal dialysis solution.

Again, is it dangerous for me to be walking around with blood sugar that high?