Inadequate insulin would inhibit muscle growth. Which the begs the question, why are your numbers high. Is it because of excessive carb consumption or because you aren't using enough insulin?
I would also suggest getting your BG into the target range before you try and build muscle. Exercise further destabilises poor control. You need to build on a solid platform. And it needs to be based on stable blood sugar.
I was only able to achieve this by cutting right back on the carbs. And I was pleasantly surprised that workouts don't affect my BG by anywhere nealy as much as they did when on a high-carb way of eating. Don't fall into the carbo-loading trap. For some debate on this, visit
Low Carb Muscle - LowCarbMuscle.com 
