''
What the Breathalyzer Measures
Ignoring for the moment the inherent inaccuracy and unreliability of these machines, most suffer from a little-known design defect: they do not actually measure alcohol! Rather, they use infrared beams of light which are absorbed by any chemical compound (including ethyl alcohol) in the breath which contains the "methyl group" in its molecular structure; the more absorption, the higher the blood-alcohol reading. The machine is programmed to assume that the compound is "probably" alcohol.
Diabetes and the Breathalyzer
Unfortunately, thousands of compounds containing the methyl group can register as alcohol. One of these is "acetone". And a well-documented by-product of hyperglycemia is a state of DKA or "Diabetic Ketoacidosis", which causes the production of acetones in the breath. In other words, the Breathalyzer will read significant blood alcohol levels on the breath where there may be little or none. See, for example, Brick, "Diabetes, Breath Acetone and Breathalyzer Accuracy: A Case Study", 9(1) Alcohol, Drugs and Driving (1993). ''
https://www.avvo.com/legal-guides/ugc/diabetes-and-the-counterfeit-dui
This is assuming all breathalyzers work on the same principal Here and in the USA.