Geriatric Diabetes Any Advice?

Does anyone know anything about this. Three weeks ago my 81 year old father told me he was getting his haircut a 10:30 am. We found him 90 miles away at 4:30 pm the next day. We are in Texas now and he was telling me he was on a business trip to Iowa among other things that never happened. Two days later he was bad also. We had him teasted. He does not have Alzheimers, dementia. Everything is great except his glucose was high. The man eats sweets 24/7. I buy low alcohol wine and I gave him a gl the two nights before. I have a glucose reader now. Has anyone else had this? I am afraid we are writing things off to old age that can be helped. We do have problems with potium in our family where it goes up and down. His potium was fine but the glucose level was high.