Abstract
Smokeless tobacco has been proposed as a reduced risk substitute for smoking, but no large studies have investigated exposure to the powerful carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in smokeless tobacco users versus smokers. The purpose of this study was to carry out such a comparison. Levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL), a biomarker of NNK exposure, and cotinine, a biomarker of nicotine exposure, were quantified in the urine of 420 smokers and 182 smokeless tobacco users who were participants in studies designed to reduce their use of these products. The measurements were taken at baseline, before intervention. Levels of total NNAL per milliliter of urine were significantly higher in smokeless tobacco users than in smokers (P < 0.0001). When adjusted for age and gender, levels of total NNAL per milligram of creatinine were also significantly higher in smokeless tobacco users than in smokers (P < 0.001). Levels of cotinine per milliliter of urine and per milligram of creatinine were significantly higher in smokeless tobacco users than in smokers (P < 0.001). These results show similar exposures to the potent tobacco-specific carcinogen NNK in smokeless tobacco users and smokers. These findings do not support the use of smokeless tobacco as a safe substitute for smoking. (Cancer Epidemiol Biomarkers Prev 2007;16(8):1567–72)
- 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol
- smokeless tobacco users
- urine
- cigarette smokers
Footnotes
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Grant support: DA-13333 and CA-83451 from the NIH. S.S. Hecht is an American Cancer Society Research Professor (grant RP-00-138). National Institute on Drug Abuse grant K01-DA 19446 (M. Mooney).
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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Note: Present address for W.T. Riley: National Institute of Mental Health, Bethesda, Maryland.
- Accepted June 7, 2007.
- Received March 22, 2007.
- Revision received May 30, 2007.