Thanks for your replies.
I exercise regularly but I guess I need to take a closer look at my eating. My sugar levels range from 4.8 to 12.0. The burning sensation is there whether the sugar levels are low or high and I guess it could be unrelated to diabetes. I've never felt anything like it before and it doesn't feel like normal heart burn in the center of the chest, rather it's over the breast area, and I don't feel it when I first wake up, but minutes after I get out of bed.