Effects of Nicotine-Free Hookah Smoking on Blood Flow to the Heart, Muscle and Skin

This is a pilot study on the acute effects of nicotine-free hookah (herbal/steam stones) smoking on the sympathetic neural control of the human cardiovascular system. Hookah smoking is known to transiently increase blood pressure and heart rate while decreasing heart rate variability suggesting - but not proving - sympathetic mediation. The contribution of nicotine to these effects is unknown. Here the investigators will directly measure the acute effects of nicotine-free Hookah smoking on sympathetic nerve activity with microneurography (intraneural microelectrodes) and quantify associated regional changes in vasomotor tone.