My glucose levels are checked with my blood testing every three months. They were high within range at one time. If you are within range per a certified blood test, you are fine.
However, you can improve. Now I watch "fast" sugar intake - I think it is a killer! I try to get all my carbos from veggies and avoid products with high sugar content. This includes processed flour and even fruits. I read labels.
The results were dramatic for me, especially with improvements in all aspects of cholesterol control and blood pressure.. Body composition changed to the better with fat reduction. I did lose a lot of body weight, going from a blubbery 230 to a thin 175 over about 9 months. I urinated continually the first weeks.