title: Relationship of human toenail nicotine, cotinine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol to levels of these biomarkers in plasma and urine.
abstract: Recently, we developed sensitive and quantitative methods for analysis of the biomarkers of tobacco smoke exposure nicotine, cotinine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in human toenails. In this study, we further evaluated the newly developed toenail biomarkers by investigating their relationship to demographic factors, reported exposure, plasma nicotine, cotinine, and trans-3'-hydroxycotinine, and urinary NNAL. Toenails of 105 smokers, mean age 38.9 years (range, 19-68), were analyzed. Fifty-five (53.4%) were male, with approximately equal numbers of Whites and African-Americans. The average number of cigarettes smoked per day was 18 (range, 5-50). There was no effect of age or gender on the toenail biomarkers. Toenail NNAL was higher in White than in African-American participants (P = 0.019). Toenail nicotine and toenail cotinine correlated significantly with cigarettes smoked per day (r = 0.24; P = 0.015 and r = 0.26; P = 0.009, respectively). Toenail nicotine correlated with plasma nicotine (r = 0.39; P < 0.001); toenail cotinine correlated with plasma cotinine (r = 0.45; P < 0.001) and plasma trans-3'-hydroxycotinine (r = 0.30; P = 0.008); and toenail NNAL correlated with urine NNAL (r = 0.53; P = 0.005). The results of this study provide essential validation data for the use of toenail biomarkers in investigations of the role of chronic tobacco smoke exposure in human cancer.
authors.affiliation: The Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA. stepa011@umn.edu
authors.forename: Irina
authors.initials: I
authors.lastname: Stepanov
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Hecht
authors.forename: Bruce
authors.initials: B
authors.lastname: Lindgren
authors.forename: Peyton
authors.initials: P
authors.lastname: Jacob
authors.forename: Margaret
authors.initials: M
authors.lastname: Wilson
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis* / Q000097:blood / Q000652:urine; D003367:Cotinine / Q000032:analysis* / Q000097:blood / Q000652:urine; D023381:Endpoint Determination; D004781:Environmental Exposure; D005260:Female; D005731:Ganglionic Stimulants / Q000032:analysis / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007202:Indicators and Reagents / Q000032:analysis; D019570:Inhalation Exposure; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000737:chemistry*; D009538:Nicotine / Q000032:analysis* / Q000097:blood / Q000652:urine; D009602:Nitrosamines / Q000032:analysis* / Q000097:blood / Q000652:urine; D012680:Sensitivity and Specificity; D012907:Smoking
chemical_list: D015415:Biomarkers; D005731:Ganglionic Stimulants; D007202:Indicators and Reagents; D009602:Nitrosamines; D009538:Nicotine; C016583:4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone; D003367:Cotinine