I go to the gym after I get back from work (between 5.30 and 6.30). I take 3 SR metformin only with meals (or last thing at night if I've forgotten).
I'll eat at lunch (12-1) and then I don't usually bother eating before the gym. My most strenuous exercise is a boxercise class which wipes me out, but it's never got to the point where I've felt faint or like my performance has suffered through not eating.
After I've cooled down i'll usually eat within an hour of finishing my workout. To be honest I don't always feel hungry that soon after a workout, but I don't like to eat too close to bed.
As Nicole said, you're not at risk from hypo so I suppose the biggest consideration is how it makes you feel. High intensity exercise sometimes isn't a good idea if your blood sugar is high to start with (it can raise it). So depending on what you're eating, that could be a factor.
My TLDR from this long, rambly post is that you don't need to eat prior to working out....