Academic studies? No, sorry, I can't find any either. Here's a a source of anecdotal evidence, FWIW. http://www.askapatient.com/viewrating.asp?drug=18612&name=NI...
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.