I didn't know that.
Smoking is weird as regards BS levels.
I was smoking at least 20 a day when I decided to cut down by half, intending to stop completely eventually.
I restricted myself to a maximum of 10 a day (mostly less) and managed easily with no stress etc. However, my BS levels went up. Not by a lot, but by enough to notice. I did some reading on it and found this had happened to others.
If what
@JohnEGreen says is true, it could be because I was wearing nicotine patches.
It was temporary though. My BS levels did return to normal. I still smoke those 10.