title: Magnitudes of biomarker reductions in response to controlled reductions in cigarettes smoked per day: a one-week clinical confinement study.
abstract: Tobacco toxicant-related exposure reduction is an important tool in harm reduction. Cigarette per day reduction (CPDR) occurs as smokers migrate from smoking cigarettes to using alternative tobacco/nicotine products, or quit smoking. Few reports characterize the dose-response relationships between CPDR and effects on exposure biomarkers, especially at the low end of CPD exposure (e.g., 5 CPD). We present data on CPDR by characterizing magnitudes of biomarker reductions. We present data from a well-controlled, one-week clinical confinement study in healthy smokers who were switched from smoking 19-25 CPD to smoking 20, 10, 5 or 0 CPD. Biomarkers were measured in blood, plasma, urine, and breath, and included smoke-related toxicants, urine mutagenicity, smoked cigarette filter analyses (mouth level exposure), and vital signs. Many of the biomarkers (e.g., plasma nicotine) showed strong CPDR dose-response reductions, while others (e.g., plasma thiocyanate) showed weaker dose-response reductions. Factors that lead to lower biomarker reductions include non-CPD related contributors to the measured response (e.g., other exposure sources from environment, life style, occupation; inter-individual variability). This study confirms CPDR dose-responsive biomarkers and suggests that a one-week design is appropriate for characterizing exposure reductions when smokers switch from cigarettes to new tobacco products.
authors.affiliation: R.J. Reynolds Tobacco Co., 950 Reynolds Boulevard, Winston-Salem, NC 27105, United States. Electronic address: theophe@rjrt.com.
authors.forename: Eugenia H
authors.initials: EH
authors.lastname: Theophilus
authors.affiliation: Carson Watts Consulting, 1266 Carson Watts Road, King, NC 27021, United States.
authors.forename: Christopher R E
authors.initials: CR
authors.lastname: Coggins
authors.affiliation: R.J. Reynolds Tobacco Co., 950 Reynolds Boulevard, Winston-Salem, NC 27105, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Chen
authors.affiliation: R.J. Reynolds Tobacco Co., 950 Reynolds Boulevard, Winston-Salem, NC 27105, United States.
authors.forename: Eckhardt
authors.initials: E
authors.lastname: Schmidt
authors.affiliation: R.J. Reynolds Tobacco Co., 950 Reynolds Boulevard, Winston-Salem, NC 27105, United States.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Borgerding
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000453:epidemiology / Q000378:metabolism* / Q000639:trends*; D016540:Smoking Cessation / Q000379:methods*; D011795:Surveys and Questionnaires; D013997:Time Factors; D062789:Tobacco Products; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Biomarkers; Cessation; Cigarettes; Clinical confinement