Due tot he Pandemic we decided to terminate this project.

The purpose of this study is to assess the acute effects of Hookah (waterpipe) smoking on blood vessel function. Hookah smoking has been shown to immediately increase blood pressure and heart rate which could result in damage in the inner lining of the body's blood vessels.

The investigators will measure acute endothelial and vascular changes before and after a 30-minute Hookah smoking session in a controlled laboratory environment to: (1) Determine the acute effects of Hookah smoking on large-vessel endothelial vasodilator function measured by brachial artery flow mediated dilation; (2) Determine the acute effects of Hookah smoking on micro-vessel endothelial function as measured by reactive hyperemia peripheral arterial tonometry; (3) Determine the acute effects of Hookah smoking on pulse wave velocity and aortic pressure waveform measured by pulse tonometry.

Inclusion Criteria:

• 18 to 29 years of age
• Habitual Hookah smoker defined as having smoked Hookah >=12 times in the past 12 months
• Have not smoked cigarettes within the past 12 months

Exclusion Criteria:

• History of cardiopulmonary, diabetes, dyslipidemia or psychiatric disease
• Exhaled carbon monoxide level >10 ppm
• BP < 140/90 mmHg
• BMI <18.5 or > 30 kg•m2
• Resting heart rate > 100 beats/min
• Taking prescription medication
• History of illicit drug use
• Pregnant