A paraphrase from Peter Green and Rory Jones' book Celiac Disease: A Hidden Epidemic:
Celiacs show higher amounts of insulin antibodies, which tend to go down on a gluten free diet. Therefore, undiagnosed celiac disease can put you at risk for developing diabetes and many people end up with both. Those with both tend to get their celiac disease diagnosis second.
What I gather from the above is that if you haven't yet developed diabetes and stay off gluten successfully, there is a good chance that your pre-diabetes situation will resolve itself. Best of luck in that!