The three-year study at the University of Wisconsin evaluated the physiological response in 395 people, 164 of who vaped for an average of 4.1 years compared with 117 people who smoked for around 23 years and 114 who had not used any nicotine products. “Immediately after vaping or smoking, there were worrisome changes in blood pressure, heart rate, heart rate variability and blood vessel tone (constriction),” said lead study author Matthew Tattersall, an assistant professor of medicine at the University of Wisconsin School of Medicine and Public Health.