I found the below on a forum, while I was googling about vaping and diabetes:
Hello Everyone, Another time to post here for i know in here i will get the answer i need. You see i am a smoker and we all know how smoking are bad for those who have diabetes. I am looking for
I found the answer below to the original poster’s question really interesting. I have been a little worried about vaping some of the sweeter liquids, but this put my mind somewhat at ease:
Propylene glycol is an organic compound which has ubiquitous applications in everything from food manufacturing to lubrication of industrial equipment. Oral toxicity for both acute and long-term exposure is very low. In humans, PG is metabolized into lactic, pyruvic (a ketone), and acetic (vinegar) acids, all three of which are already naturally found in the human body. The only complication I could see from this would be if you take metformin. Although rare, metformin has been known to potentiate lactic acidosis, a potentially life-threatening condition caused by a build-up of lactic acid. However, it’s doubtful that the amount of lactic acid the PG in your pseudo-cigarette would cause you to metabolize would be sufficient to induce lactic acidosis. The bottom line: propylene glycol is generally recognized as safe and should have a neutral effect on blood sugar concentration.
Vegetable glycerin, more commonly referred to as glycerol, is a polyol alcohol compound. Glycerol is a common food additive which works as a preservative, a sweetener, and thickening agent. Humans metabolize glycerol into a form of triglycerides, phospholipids, and possibly glucose. Since glycerol is an alcohol, it does metabolize like a carbohydrate, although it has a lower glycemic index than sucrose. Thus, it is likely to cause a small increase in your blood sugar, though the amount contained in your pseudo-cigarette is unlikely to make that increase significant (or perhaps even detectible). The bottom line: vegetable glycerin is generally recognized as safe and might produce a modest temporary elevation of blood sugar.
I had been avoiding PG 50/50 VG liquids in favour of PG 70/30 VG, but 50/50 provides more vapour and taste for me. My favourite vendors; Mrs Lord & Co and Triphammer both use 50/50, so it’s a relief to find I can still use them without worrying!