I was not diagnosed at the time I got the tattoos, though I got one of my tattoos around the same time my symptoms of hyperglycemia first started to develop. I remember I had to stop the artist three times so I could go to the bathroom. It was miserable.
Tattoos definitely have an effect on your blood sugar, but having diabetes will not prevent you from getting tattooed. You just have to make sure that your sugars are in a good range when you go in, and make sure that you’re checking it throughout your session in case anything happens to fluctuate one way or the other :) Also bring a lot of snacks and be sure your artist is aware of your diabetes so they can be as accommodating as possible during your session!