I take issue with the remark about studies showing nicotine causes hypertension or atherosclerosis.
There are no long term, clinical studies showing that.
There is lab evidence that nicotine is a vasoconstrictor, but no evidence that vasoconstrictors cause hypertenstion (i.e. chronic, self perpetuating elevation in blood pressure) but rather transient, mild increases in blood pressure.
There is evidence from small experimental human studies with small numbers of subjects showing that in smokers, nicotine administration alters vascular reactivity (basically blood vessels constrict in an abnormal way), but one such study shows that in non-smokers nicotine does not have that effect.
There are the famous studies done retrospectively, that's true, on the Swedish Snus cohorts showing that use of tobacco alone (which we may consider reasonably worse than nicotine alone) does not significantly increase risk of hypertension, coronary disease, etc. It does show a moderate increase in the risk of diabetes. There is also a smaller increase in heart failure which, in my opinion, is confounded by the significantly higher proportion of alcohol abusers in the Snus users than in the non-Snus users.
There is recent data presented at the European cardiology meeting showing vaping causes no acute myocardial dysfunction. Just like the ones above, this does not prove vaping does not increase long-term risk of heart disease - a long term, clinical study is needed for that - but provides a workable hypothesis that this is the case.
There is a plethora of small experimental studies, these days, showing questionably relevant physiologic parameter changes with vaping or nicotine exposure. These are bad science from the get-go, but I won't get into that. These small studies do not really prove anything whatsoever. Nothing. Yet they are quoted amply both in the mass media and in policy making circles as "evidence" of "presumable harm".