Wael K Al-Delaimy1, Walter C Willett. 1. Moores UCSD Cancer Center, Department of Family and Preventive Medicine, University of California-San Diego, La Jolla, CA 92093, USA. wael@ucsd.edu
Abstract
BACKGROUND: Accurate measurement tools of exposure for use in large epidemiologic studies are lacking. Biomarkers of tobacco exposure provide additional advantages to self-reports and there is a need to further develop and validate them. The objective is to compare toenail nicotine levels, a novel biomarker of tobacco exposure, with self-reports of tobacco exposure from a large cohort study. METHODS: In this cross-sectional analysis, toenail samples were collected from 2,485 women participating in the Nurses' Health Study in 1982. Detailed self-reports of smoking habits and reported exposure to secondhand smoke (SHS) were collected from these women near the time of toenail collection. The toenail samples were analyzed by a high-performance liquid chromatography method for measuring nicotine. RESULTS: The 5 to 95 percentile range of toenail nicotine was from 0.06 to 4.06 ng/mg toenail and the median level was 0.21 ng/mg. There was a significant difference in toenail nicotine levels according to reported smoking status (the median level for nonsmokers with no SHS was 0.10 ng/mg, the median level for nonsmokers with SHS was 0.14 ng/mg, and the median level for active smokers was 1.77 ng/mg). However there was considerable overlap in nicotine levels according to reported smoking status. Toenail nicotine level was strongly associated with reported smoking level (Spearman r = 0.63), but there was no complete concordance, suggesting that the two methods are measuring different aspects of the same exposure. CONCLUSION: Our findings show that toenail nicotine levels capture the overall burden of tobacco smoke exposure and provide additional information on exposure not captured by reported history.
BACKGROUND: Accurate measurement tools of exposure for use in large epidemiologic studies are lacking. Biomarkers of tobacco exposure provide additional advantages to self-reports and there is a need to further develop and validate them. The objective is to compare toenail nicotine levels, a novel biomarker of tobacco exposure, with self-reports of tobacco exposure from a large cohort study. METHODS: In this cross-sectional analysis, toenail samples were collected from 2,485 women participating in the Nurses' Health Study in 1982. Detailed self-reports of smoking habits and reported exposure to secondhand smoke (SHS) were collected from these women near the time of toenail collection. The toenail samples were analyzed by a high-performance liquid chromatography method for measuring nicotine. RESULTS: The 5 to 95 percentile range of toenail nicotine was from 0.06 to 4.06 ng/mg toenail and the median level was 0.21 ng/mg. There was a significant difference in toenail nicotine levels according to reported smoking status (the median level for nonsmokers with no SHS was 0.10 ng/mg, the median level for nonsmokers with SHS was 0.14 ng/mg, and the median level for active smokers was 1.77 ng/mg). However there was considerable overlap in nicotine levels according to reported smoking status. Toenail nicotine level was strongly associated with reported smoking level (Spearman r = 0.63), but there was no complete concordance, suggesting that the two methods are measuring different aspects of the same exposure. CONCLUSION: Our findings show that toenail nicotine levels capture the overall burden of tobacco smoke exposure and provide additional information on exposure not captured by reported history.
Authors: Jennifer M Wray; Julie C Gass; Eleanor I Miller; Diana G Wilkins; Douglas E Rollins; Stephen T Tiffany Journal: Psychol Assess Date: 2015-10-19
Authors: S Jean Hsieh; Lorraine B Ware; Mark D Eisner; Lisa Yu; Peyton Jacob; Christopher Havel; Maciej L Goniewicz; Michael A Matthay; Neal L Benowitz; Carolyn S Calfee Journal: Crit Care Med Date: 2011-01 Impact factor: 7.598
Authors: Erika Avila-Tang; Wael K Al-Delaimy; David L Ashley; Neal Benowitz; John T Bernert; Sungroul Kim; Jonathan M Samet; Stephen S Hecht Journal: Tob Control Date: 2012-09-02 Impact factor: 7.552