If you use VG as opposed to PG juice and a non sweat flavour, i.e nicotine, then I really don't see how. It was the pharmaceuticals that were lobbying the EU fiercely to get e-cigs banned and GPs are getting sucked into their propaganda. I seriously doubt any juice will raise BG levels. In fact, the frustration I feel in writing this response has probably raised my BG level by a measurable amount more than a good vape session.the doctor told me it does increase b.g but not so much as one would notice, so I wouldn't worry. It hasn't made a difference to mine