My two youngest children are insulin-dependent diabetics. The risk of dehydration in diabetics is extremely high, especially during illness or when blood sugar readings are too high. Dehydration can lead to diabetic ketoacidosis, an extremely dangerous condition requiring hospitalization and IV fluids. Have to keep hydrated and keep those kidneys flushed out!
Gatorade or Poweraide have too many carbohydrates (sugars) for diabetics. We found a solution that works in our situation. My son (the 6 year old with diabetes) plays coaches pitch baseball and swims on a swim team. Needs the carbs/sugars to prevent him from going too low (but not TOO much sugar) and needs to stay hydrated when working out. We re-use the sports drinks containers with the 'sports bottle' top, but mix the powerade half and half with either Crystal Light or sugar-free Koolaid. It keeps him happy, and the kids on his team do not realize he is 'different'. Powerade used to make a "light" version, but I looked all over for it this summer without finding it. It had half of the carbs/sugars as regular and tasted pretty good. You may try searching in your area. If you find some, let me know!
Good luck to you!