It would be pretty hard to separate the effects of nicotine from the effects of a lifetime of smoking + potentially poor dental hygiene (gum disease is rampant https://www.perio.org/consumer/cdc-study.htm) + aging.
Per wikipedia (https://en.wikipedia.org/wiki/Nicotine) the general medical consensus is that nicotine poses few risks on its own for nonpregnant adults, besides vasoconstriction and dependence.