title: Is 24h nicotine equivalents a surrogate for smoke exposure based on its relationship with other biomarkers of exposure?
abstract: Nicotine and its 5 major metabolites (Nicotine equivalents, NE) may serve as a surrogate biomarker for smoke exposure.
  
  
  OBJECTIVE
  To investigate the relationship between nicotine equivalents (NE) and biomarkers of exposure (BOE) to cigarette smoke.
  
  
  METHODS
  Data from nine controlled studies in 916 adult smokers were used. BOEs to nicotine, NNK, pyrene, acrolein, benzene, 1,3-butadiene and CO were used.
  
  
  RESULTS
  Among all the factors investigated (NE, cigarette type, age, gender, BMI and study), NE was the most statistically significant factor for all biomarker relationships. Weak to moderate relationships (0.32 ≤ R(2)  ≤ 0.65) were found between NE and the BOEs.
  
  
  CONCLUSIONS
  Based on the relationships with BOEs, NE may be considered as a surrogate biomarker of total cigarette smoke exposure.
authors.affiliation: Altria Client Services, Center for Research and Technology, 601 E. Jackson Street, Richmond, VA 23219, USA.
authors.forename: Jingzhu
authors.initials: J
authors.lastname: Wang
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Liang
authors.forename: Paul
authors.initials: P
authors.lastname: Mendes
authors.forename: Mohamadi
authors.initials: M
authors.lastname: Sarkar
mesh_terms: D000171:Acrolein / Q000032:analysis; D000328:Adult; D001554:Benzene / Q000032:analysis; D015415:Biomarkers / Q000032:analysis*; D002070:Butadienes / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000032:analysis*; D009602:Nitrosamines / Q000032:analysis / Q000652:urine*; D011721:Pyrenes / Q000032:analysis; D011725:Pyridines / Q000652:urine*; D016032:Randomized Controlled Trials as Topic; D012906:Smoke / Q000032:analysis; D012907:Smoking / Q000378:metabolism; D013997:Time Factors; D014026:Nicotiana / Q000378:metabolism
chemical_list: D015415:Biomarkers; D002070:Butadienes; D009602:Nitrosamines; D011721:Pyrenes; D011725:Pyridines; D012906:Smoke; D009538:Nicotine; D000171:Acrolein; C016583:4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone; D002248:Carbon Monoxide; C030984:pyrene; C099565:4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol; D001554:Benzene; C031763:1,3-butadiene