Nicotine exposure in daily waterpipe smokers and its relation to puff topography.

Waterpipe tobacco smoking is increasing in popularity worldwide and available evidence point to its addictive and harmful potential. This study is conducted to assess nicotine exposure in daily waterpipe smokers, and its correlation with puff topography parameters. Sixty-one waterpipe tobacco smokers (56 males; mean age±SD, 30.9±9.5years; mean number of weekly waterpipe smoking episodes 7.8±5.7) abstained from smoking for at least 24h, and then smoked tobacco from a waterpipe ad libitum in a laboratory setting. During the session puff topography parameters were monitored continuously, and pre- and post-smoking expired-air CO was measured. Before and after smoking, venous blood was sampled for the assessment of plasma nicotine using Gas Chromatography-Mass Spectrometry. The average pre- and post-smoking expired-air CO was 4±1.7 and 35.5±32.7ppm, respectively (i.e., a CO boost of 31.5ppm, p<.001). Mean plasma nicotine concentration increased from 3.07±3.05ng/ml pre-smoking to 15.7±8.7ng/ml post-smoking (p<.001). Plasma nicotine boost was correlated with total session time (Pearson correlation coefficient r=.31, p=.04), cumulative puff duration (r=.37, p=.01), mean puff duration (r=.34, p=.02), and total smoke inhaled in the session (r=.34, p=.02. These data show considerable nicotine exposure in daily waterpipe smokers, and that nicotine exposure is a function of waterpipe smoking patterns.