An inconvenience, maybe, but not a disadvantage.
Remember Allie Reynolds, the great Yankee pitcher? He used to say he had the "classic Indian disease"; he was a diabetic, and this seems to be a problem with American Indians---could be genetic, I don't know, but it never interfered with him. He was also inclined to hypoglycemia, and one time his doctor told him to eat two to four oranges a day when he was pitching. It worked so well that next thing you know, the whole Yankee team had taken it up!
There are things you can do, and unless you have to keep on injecting that insulin every hour on the hour I see no reason you can't pitch. Ask your doctor. 8)