title: The relationship between the nicotine metabolite ratio and three self-report measures of nicotine dependence across sex and race.
abstract: BACKGROUND
  Variability in the rate of nicotine metabolism, measured by the nicotine metabolite ratio (NMR), is associated with smoking behavior. However, data linking the NMR with nicotine dependence measured by the Fagerström test for nicotine dependence (FTND) are mixed. Few past studies have examined alternative measures of nicotine dependence and how this relationship may vary by sex and race.
  
  
  OBJECTIVE
  Using data from smokers undergoing eligibility evaluation for a smoking cessation clinical trial (n = 833), this study examined variability in the relationship between NMR and nicotine dependence across sex and race and using three measures of nicotine dependence: FTND, time-to-first-cigarette (TTFC), and the heaviness of smoking index (HSI).
  
  
  RESULTS
  Controlling for sex and race, nicotine metabolism was associated with nicotine dependence only when using the HSI (p < 0.05). Male normal metabolizers of nicotine were more likely to have high nicotine dependence based on the FTND and HSI (p < 0.05), but NMR was not related to measures of nicotine dependence in women. For African Americans, the NMR was associated with nicotine dependence only for the TTFC (p < 0.05), but NMR was not associated with nicotine dependence among Caucasians. Post hoc analyses indicated that the NMR was associated with cigarettes per day, overall, and among men and Caucasians (p < 0.05).
  
  
  CONCLUSIONS
  While there was some variation in the relationship between nicotine metabolism and nicotine dependence across measures and sex and race, the results indicate that this relationship may be more attributable to the association between NMR and cigarettes per day.
authors.affiliation: Department of Psychiatry and Abramson Cancer Center, University of Pennsylvania, 3535 Market Street, 4th Floor, Philadelphia, PA, 19104, USA, Schnoll@mail.med.upenn.edu.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schnoll
authors.forename: Tony P
authors.initials: TP
authors.lastname: George
authors.forename: Larry
authors.initials: L
authors.lastname: Hawk
authors.forename: Paul
authors.initials: P
authors.lastname: Cinciripini
authors.forename: Paul
authors.initials: P
authors.lastname: Wileyto
authors.forename: Rachel F
authors.initials: RF
authors.lastname: Tyndale
mesh_terms: D001741:Black or African American; D003367:Cotinine / Q000031:analogs & derivatives* / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D057566:Self Report; D012720:Severity of Illness Index; D012727:Sex Characteristics; D014029:Tobacco Use Disorder / Q000503:physiopathology*; D014481:United States; D044465:White People
chemical_list: C001381:hydroxycotinine; D003367:Cotinine