title: Nicotine Dependence and Urinary Nicotine, Cotinine and Hydroxycotinine Levels in Daily Smokers.
abstract: Nicotine dependence and smoking frequency are critical factors for smoking cessation. The aims of this study are (1) to determine if nicotine dependence Fagerström Test for Nicotine Dependence (FTND) scores are associated with urinary levels of nicotine metabolites, (2) to assess the relationship of hydroxycotinine/cotinine ratio with FTND score and cigarettes smoked per day (CPD), and (3) to identify significant predictors of cigarettes per day among biomarker concentrations and individual FTND items.
  
  
  
  Urine samples and questionnaire data of 239 daily smokers were obtained. Nicotine, cotinine and hydroxycotinine urinary levels were determined by UPLC MS/MS.Multiple linear regression models were developed to explore the relationship between nicotine, cotinine, hydroxycotinine levels and separate FTND scores (for all six items).
  
  
  
  We found significant correlations between the different urinary biomarker concentrations, and the FTND score. The time before the first cigarette after waking (TTFC) was significantly associated with the nicotine, cotinine and hydroxycotinine concentrations. No association was found between the ratio of hydroxycotinine to cotinine and either the FTND or the CPD. A model including four FTND questions, sex, age, and the cotinine concentration, accounted for 45% of the variance of CPD.
  
  
  
  There are significant relationships between urinary levels of nicotine, cotinine, and hydroxycotinine and the FTND score. Especially the FTND question about TTFC is relevant for explaining the biomarker concentrations. CPD (below 15) was significantly explained by four FTND dependence items and urinary cotinine levels in a regression model.
  
  
  
  We investigated associations between urinary levels of nicotine, cotinine, and hydroxycotinine in daily smokers and the FTND scores for nicotine dependence. We did not find association between the hydroxycotinine/cotinine ratio and CPD. We developed a model that explains the cigarettes smoked daily (CPD) in a group of light smokers by combining FTND items, urinary cotinine levels, sex, and age. Our results might be of importance for clinical use or future studies on larger smoking populations.
authors.affiliation: Department of Food, Medicines and Consumer Protection, Scientific Institute of Public Health, Brussels, Belgium; ilse.vanovermeire@wiv-isp.be.
authors.forename: Ilse P I
authors.initials: IP
authors.lastname: Van Overmeire
authors.affiliation: Department of Food, Medicines and Consumer Protection, Scientific Institute of Public Health, Brussels, Belgium;
authors.forename: Tom
authors.initials: T
authors.lastname: De Smedt
authors.affiliation: Department of Cardiology, University of Hasselt and Jessa Hospital, Hasselt, Belgium;
authors.forename: Paul
authors.initials: P
authors.lastname: Dendale
authors.affiliation: University Hospitals, Department of Respiratory Diseases, KU Leuven, University of Leuven, Leuven, Belgium;
authors.forename: Kristiaan
authors.initials: K
authors.lastname: Nackaerts
authors.affiliation: IDEWE, External Service for Prevention and Protection at Work, Heverlee, Belgium;
authors.forename: Hilde
authors.initials: H
authors.lastname: Vanacker
authors.affiliation: Mensura Occupational Health Service Brussels, Brussels, Belgium;
authors.forename: Jan F A
authors.initials: JF
authors.lastname: Vanoeteren
authors.affiliation: General Hospital Oudenaarde, Oudenaarde, Belgium.
authors.forename: Danny M G
authors.initials: DM
authors.lastname: Van Laethem
authors.affiliation: Department of Food, Medicines and Consumer Protection, Scientific Institute of Public Health, Brussels, Belgium;
authors.forename: Joris
authors.initials: J
authors.lastname: Van Loco
authors.affiliation: Department of Food, Medicines and Consumer Protection, Scientific Institute of Public Health, Brussels, Belgium;
authors.forename: Koen A J
authors.initials: KA
authors.lastname: De Cremer
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000652:urine*; D003367:Cotinine / Q000031:analogs & derivatives / Q000652:urine; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009538:Nicotine / Q000652:urine; D012720:Severity of Illness Index; D012907:Smoking / Q000652:urine*; D016540:Smoking Cessation; D000074606:Smoking Prevention; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry; D014029:Tobacco Use Disorder / Q000175:diagnosis* / Q000517:prevention & control / Q000652:urine; D055815:Young Adult
chemical_list: D015415:Biomarkers; C001381:hydroxycotinine; D009538:Nicotine; D003367:Cotinine