title: Determinants of salivary cotinine concentrations in Chinese male smokers.
abstract: BACKGROUND
  Identifying factors that affect cotinine levels in smokers may be useful for smoking cessation programs. Our aims were to characterize the distribution of salivary cotinine levels in Chinese smokers and to investigate factors that influence cotinine concentrations.
  
  
  METHODS
  In a cross-sectional study, 600 Chinese adult smokers answered a questionnaire on smoking habits and provided a saliva sample for cotinine analysis. Modification of the relation between number of cigarettes smoked and cotinine concentration by individual characteristics, smoking behavior, and type of tobacco was evaluated.
  
  
  RESULTS
  Quadratic model provided the best fit for the relation between number of cigarettes smoked in the previous 24 hours and salivary cotinine concentration. Among those smoking up to 20 cigarettes, the median cotinine concentration was higher among younger subjects, those smoking cigarettes without filter and regular rather than light cigarettes, and those inhaling frequently and deeply. Such trends were not observed among heavier smokers. The increase in cotinine per cigarette tended to be larger in those with lower median cotinine level.
  
  
  CONCLUSIONS
  Our findings show that smoking behavior-related factors modify the relation between number of cigarettes smoked and salivary cotinine concentration. This suggests that smokers may regulate their smoking behavior to achieve a certain optimum nicotine level.
authors.affiliation: Department of Epidemiology, Bloomberry School of Public Health, Johns Hopkins University, Baltimore, MD, USA. Maritta.Jaakkola@occuphealth.fi
authors.forename: Maritta S
authors.initials: MS
authors.lastname: Jaakkola
authors.forename: Jiemin
authors.initials: J
authors.lastname: Ma
authors.forename: Gonghuan
authors.initials: G
authors.lastname: Yang
authors.forename: Ming Feng
authors.initials: MF
authors.lastname: Chin
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
authors.forename: Marion
authors.initials: M
authors.lastname: Ceraso
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Samet
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D003367:Cotinine / Q000032:analysis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D012307:Risk Factors; D012463:Saliva / Q000737:chemistry*; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014505:Urban Population
chemical_list: D003367:Cotinine