I'm diabetic, and have no issues with it.
My blood sugar levels test higher on my home kit. I was concerned initially because they were testing high to the point where I would have felt the effects before I started vaping. But I noticed that I wasn't feeling anything at all. My A1C test came back fine, though.
Every diabetic has their own "normal" range on the home test kit. They may need to redefine what that range is after vaping, because it may change drastically. My normal range used to be between 80 and 100. Now it's closer to 150-200. But it's the A1C test that is the real indication of how you're doing. My results haven't changed since I started vaping.