title: Can urinary cotinine predict nicotine dependence level in smokers?
abstract: BACKGROUND
  Although nicotine dependence plays a role as a main barrier for smoking cessation, there is still a lack of solid evidence on the validity of biomarkers to determine nicotine dependence in clinical settings. This study aimed to investigate whether urinary cotinine levels could reflect the severity of nicotine dependence in active smokers.
  
  
  METHODS
  Data regarding general characteristics and smoking status was collected using a self-administered smoking questionnaire. The Fagerstrom test for nicotine dependence (FTND) was used to determine nicotine dependence of the participants, and a total of 381 participants were classified into 3 groups of nicotine dependence: low (n=205, 53.8%), moderate (n=127, 33.3%), and high dependence groups (n=49, 12.9%). Stepwise multiple linear regression model and receiver operating characteristic (ROC) curves analyses were used to determine the validity of urinary cotinine for high nicotine dependence.
  
  
  RESULTS
  In correlation analysis, urinary cotinine levels increased with FTND score (r=0.567, P<0.001). ROC curves analysis showed that urinary cotinine levels predicted the high-dependence group with reasonable accuracy (optimal cut-off value=1,000 ng/mL; AUC=0.82; P<0.001; sensitivity=71.4%; specificity=74.4%). In stepwise multiple regression analysis, the total smoking period (β=0.042, P=0.001) and urinary cotinine levels (β=0.234, P<0.001) were positively associated with nicotine dependence, whereas an inverse association was observed between highest education levels (>16 years) and nicotine dependence (β=-0.573, P=0.034).
  
  
  CONCLUSIONS
  The results of this study support the validity of using urinary cotinine levels for assessment of nicotine dependence in active smokers.
authors: Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University College of Medicine, Seoul, Korea.
authors: Hyun-Suk
authors: HS
authors: Jung
authors: Yeol
authors: Y
authors: Kim
authors: Jungsik
authors: J
authors: Son
authors: Young-Jee
authors: YJ
authors: Jeon
authors: Hong-Gwan
authors: HG
authors: Seo
authors: So-Hee
authors: SH
authors: Park
authors: Bong Ryul
authors: BR
authors: Huh
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine*; D003367:Cotinine / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea / Q000453:epidemiology; D012907:Smoking / Q000652:urine*; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000652:urine; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003367:Cotinine