Your pancreas must secrete a large amount of insulin, to get all that glucose into your cells. If it just stays in your blood for hours and hours, it 'cooks' your kidneys and your eyes, among other internal organs, and they fail sooner than they should.
This is a description of Diabetes ... the production of not enough insulin (Type-2) or none at all (Type-1).
There's no cure. The treatment is:
-- be reasonable about the carbs you take in;
-- get regular exercise;
-- if you still have high levels of glucose in your blood, you'll have to start regular medication (pills) or insulin injections.