title: Nicotine Metabolism in Young Adult Daily Menthol and Nonmenthol Smokers.
abstract: BACKGROUND
  Menthol cigarette smoking may increase the risk for tobacco smoke exposure and inhibit nicotine metabolism in the liver. Nicotine metabolism is primarily mediated by the enzyme CYP2A6 and the nicotine metabolite ratio (NMR = trans 3' hydroxycotinine/cotinine) is a phenotypic proxy for CYP2A6 activity. No studies have examined differences in this biomarker among young adult daily menthol and nonmenthol smokers. This study compares biomarkers of tobacco smoke exposure among young adult daily menthol and nonmenthol smokers.
  
  
  METHODS
  Saliva cotinine and carbon monoxide were measured in a multiethnic sample of daily smokers aged 18-35 (n = 186). Nicotine, cotinine, the cotinine/cigarette per day ratio, trans 3' hydroxycotinine, the NMR, and expired carbon monoxide were compared.
  
  
  RESULTS
  The geometric means for nicotine, cotinine, and the cotinine/cigarette per day ratio did not significantly differ between menthol and nonmenthol smokers. The NMR was significantly lower among menthol compared with nonmenthol smokers after adjusting for race/ethnicity, gender, body mass index, and cigarette smoked per day (0.19 vs. 0.24, P = .03). White menthol smokers had significantly higher cotinine/cigarettes per day ratio than white nonmenthol smokers in the adjusted model. White menthol smokers had a lower NMR in the unadjusted model (0.24 vs. 0.31, P = .05) and the differences remained marginally significant in the adjusted model (0.28 vs. 0.34, P = .06). We did not observe these differences in Native Hawaiians and Filipinos.
  
  
  CONCLUSIONS
  Young adult daily menthol smokers have slower rates of nicotine metabolism than nonmenthol smokers. Studies are needed to determine the utility of this biomarker for smoking cessation treatment assignments.
authors.affiliation: Cancer Prevention and Control Program, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI; pfagan@cc.hawaii.edu.
authors.forename: Pebbles
authors.initials: P
authors.lastname: Fagan
authors.affiliation: Cancer Prevention and Control Program, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI;
authors.forename: Pallav
authors.initials: P
authors.lastname: Pokhrel
authors.affiliation: Cancer Prevention and Control Program, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI;
authors.forename: Thaddeus A
authors.initials: TA
authors.lastname: Herzog
authors.affiliation: Cancer Prevention and Control Program, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI;
authors.forename: Ian S
authors.initials: IS
authors.lastname: Pagano
authors.affiliation: Cancer Prevention and Control Program, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI;
authors.forename: Adrian A
authors.initials: AA
authors.lastname: Franke
authors.affiliation: TMF Health Quality Institute, Austin, TX;
authors.forename: Mark S
authors.initials: MS
authors.lastname: Clanton
authors.affiliation: College of Public Health, University of Kentucky, Lexington, KY;
authors.forename: Linda A
authors.initials: LA
authors.lastname: Alexander
authors.affiliation: School of Community and Global Health, Claremont Graduate University, Claremont, CA;
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Trinidad
authors.affiliation: College of Public Health and Human Sciences, Oregon State University, Corvallis, OR;
authors.forename: Kari-Lyn K
authors.initials: KL
authors.lastname: Sakuma
authors.affiliation: School of Community and Global Health, Claremont Graduate University, Claremont, CA;
authors.forename: Carl A
authors.initials: CA
authors.lastname: Johnson
authors.affiliation: Cambridge, MA.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Moolchan
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002248:Carbon Monoxide / Q000032:analysis; D003367:Cotinine / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008610:Menthol / Q000032:analysis / Q000378:metabolism*; D009538:Nicotine / Q000032:analysis / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry; D012907:Smoking / Q000208:ethnology / Q000378:metabolism*; D062789:Tobacco Products / Q000032:analysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D008610:Menthol; C001381:hydroxycotinine; D009538:Nicotine; D002248:Carbon Monoxide; D003367:Cotinine