CO exposure and puff topography are associated with Lebanese waterpipe dependence scale score.

INTRODUCTION Waterpipe tobacco smoking involves self-administration of the dependence-producing drug nicotine. Few studies have examined if dependence in waterpipe smokers influences toxicant exposure and smoking behavior. METHOD Current waterpipe tobacco smokers were categorized based on Lebanese Waterpipe Dependence Scale-11 (LWDS-11) score (LWDS-11: LOW < 7; N = 59; HIGH > 13; N = 59). Participants abstained from smoking for 12 hr and then completed a single 30-min waterpipe tobacco smoking episode. Expired-air carbon monoxide (CO) was measured before and 5 min after smoking and puff topography was measured during smoking. RESULTS Total mean smoking time was 30.9 min (SD = 3.5) and did not differ significantly by LWDS-11 score. CO boost was greater for participants in the HIGH versus LOW groups (62.3 vs. 43.6 ppm, p < .01). Similarly, those in the HIGH versus LOW group took more puffs (198.6 vs. 157.1 puffs, p < .01), longer duration puffs (2.7 vs. 2.3 s, p < .05), puffs with lower flow rate (10.3 vs. 12.6 L/min, p < .01), and less time between puffs (8.0 vs. 12.4 s, p < .001). CONCLUSION The puff topography of waterpipe tobacco smokers can be predicted by LWDS-11 score, with those scoring higher taking longer duration and lower velocity puffs at a higher frequency. These behavioral differences may underlie the 40% greater CO exposure observed for those with higher LWDS-11 scores. To the extent that waterpipe dependence is associated with more smoke inhalation, more dependent smokers will be exposed to greater amounts of toxic smoke constituents.