blood glucose levels

I have been on topiramate for two months now; gradually increasing to 50 mg twice daily (and coming off sodium valporate) for treatment for migraine. The changeover made me really foggy and sleepy and I've been signed off work while I've been stabilising the dose. It's had a great affect on reducing my headaches and migraines and I'm beginning to feel to feel a bit a bit more with it since coming off the sodium valporate completely. My routine blood checks have shown that my blood glucose levels are raised though; I've got to have some further tests. I was wondering if anyone else had had this as a side effect and if it had settled down or if it became a problem and meant you had to change medication again?