title: Comparison of puff topography, toxicant exposure, and subjective effects in low- and high-frequency waterpipe users: a double-blind, placebo-control study.
abstract: BACKGROUND
  Clinical laboratory work among intermittent and daily waterpipe tobacco smokers has revealed significant risks for tobacco dependence and disease associated with waterpipe tobacco smoking (WTS). No studies have compared these groups directly. This study examined whether WTS frequency was associated with differential puff topography, toxicant exposure, and subjective response using a placebo-control design.
  
  
  METHODS
  Eighty participants reporting WTS of 2-5 episodes (LOW; n = 63) or ≥20 episodes (HIGH; n = 17) per month for ≥6 months completed 2 double-blind, counterbalanced 2-hr sessions that were preceded by ≥12hr of tobacco abstinence. Sessions differed by product smoked ad libitum for 45+ min: preferred brand/flavor of waterpipe tobacco (active) or a flavor-matched tobacco-free waterpipe product (placebo). Outcomes included puff topography, plasma nicotine, carboxyhemoglobin (COHb), and subjective response.
  
  
  RESULTS
  HIGH users had more puffs, shorter inter-puff-intervals, and a higher total puff volume for placebo relative to active, as well as relative to LOW users during placebo. Plasma nicotine concentrations increased when smoking active (but not placebo) with no significant differences between groups at 25min post-product administration. COHb increased significantly during all conditions; the largest increase was for HIGH users when smoking placebo. There was some evidence of higher baseline scores for nicotine/tobacco nicotine abstinence symptomology.
  
  
  CONCLUSIONS
  Higher frequency waterpipe users may be more sensitive to the effects of waterpipe smoke nicotine content. Among HIGH users, higher baseline nicotine/tobacco abstinence symptoms may indicate greater nicotine dependence. These data support continued surveillance of WTS and development of dependence measures specific to this product.
authors.affiliation: Schroeder Institute for Tobacco Research and Policy Studies, Legacy, Washington, DC;
authors.forename: Caroline O
authors.initials: CO
authors.lastname: Cobb
authors.affiliation: Department of Psychology, West Virginia University, Morgantown, WV;
authors.forename: Melissa D
authors.initials: MD
authors.lastname: Blank
authors.affiliation: Department of Psychology, Virginia Commonwealth University, Richmond, VA;
authors.forename: Alejandra
authors.initials: A
authors.lastname: Morlett
authors.affiliation: Department of Mechanical Engineering, American University of Beirut, Beirut, Lebanon;
authors.forename: Alan
authors.initials: A
authors.lastname: Shihadeh
authors.affiliation: Department of Mechanical Engineering, American University of Beirut, Beirut, Lebanon; Currently at the Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada;
authors.forename: Ezzat
authors.initials: E
authors.lastname: Jaroudi
authors.affiliation: Department of Mechanical Engineering, American University of Beirut, Beirut, Lebanon;
authors.forename: Nareg
authors.initials: N
authors.lastname: Karaoghlanian
authors.affiliation: Department of Psychology, Virginia Commonwealth University, Richmond, VA;
authors.forename: Barbara
authors.initials: B
authors.lastname: Kilgalen
authors.affiliation: Department of Psychology, Virginia Commonwealth University, Richmond, VA;
authors.forename: Janet
authors.initials: J
authors.lastname: Austin
authors.affiliation: Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA; Currently at the Center for Neurobehavioral Research on Addiction, University of Texas Medical School, Houston, TX.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Weaver
authors.affiliation: Department of Psychology, Virginia Commonwealth University, Richmond, VA; teissenb@vcu.edu.
authors.forename: Thomas
authors.initials: T
authors.lastname: Eissenberg
mesh_terms: D000293:Adolescent; D062186:Arterial Pressure; D002248:Carbon Monoxide / Q000032:analysis; D002263:Carboxyhemoglobin / Q000378:metabolism*; D004311:Double-Blind Method; D005260:Female; D005421:Flavoring Agents; D015386:Hazardous Substances; D006339:Heart Rate; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000097:blood*; D012907:Smoking / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D062789:Tobacco Products / Q000706:statistics & numerical data*; D014029:Tobacco Use Disorder / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D005421:Flavoring Agents; D015386:Hazardous Substances; D009538:Nicotine; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin